According to a fabricating method of the present invention, a cap shaped cover plate having a concaved portion on the inner surface is mounted on the rear surface of a semiconductor chip. After solder bumps are formed on a connecting pad of a wiring substrate, a fluid resin layer is formed on the bump formed surface. Thereafter, the semiconductor chip with the cover plate adhered is mounted with a face down on the resin layer formed surface of the wiring substrate. The solder bumps on the chip side and the solder bumps on the substrate side are contacted. At that time, the peripheral portion of the cover plate is contacted and adhered to the wiring substrate. Thereafter, while the bumps on the chip side and the bumps on the substrate side are being heated, melted, and connected, the fluid resin layer on the wiring substrate is hardened. Thus, the space between the semiconductor chip and the wiring substrate (namely, the height of the bumps) is controlled to a predetermined value. As a result, a semiconductor device having a flip-chip bonded portion with high reliability can be fabricated with simplified steps and high yield.

1. Field of the Invention
The present invention relates to a fabricating method of a semiconductor device for use with various electronic units.
2. Description of the Related Art
According to the demand of a smaller and thinner semiconductor device, a semiconductor element (chip) has been connected by use of flip-chip bonding. In the flip-chip bonding method, a semiconductor chip is mounted with a face down (with an electrode pad formed surface downward) on a wiring substrate. Protruded electrode composed of for example solder (hereinafter referred to as bumps) formed on an electrode pad of the semiconductor chip is pressed to a connecting pad of the wiring substrate and then heated. Thus, the solder is reflowed and thereby the electrode pad is connected to the connecting pad of the wiring substrate. Alternatively, solder bump may be formed on a connecting pad of a wiring substrate. The flip-chip bonding method is superior to the wire bonding method in the mount density.
In a flip-chip bonded semiconductor device, the thermal expansion coefficient of a semiconductor chip composed of silicon or the like is largely different from that of a wiring substrate (for example, a glass cloth-epoxy resin impregnated wiring substrate). The stress due to the difference of the thermal expansion coefficients between the semiconductor chip and the wiring substrate is applied to solder bumps that connect the semiconductor chip and the wiring substrate, the connected portion being deteriorated.
To prevent such a problem, after solder is reflowed, as shown in FIG. 8, liquid resin 22 such as epoxy resin is filled in a space (gap portion) between a semiconductor chip 20 an a wiring substrate 21 due to capillary phenomenon. Thus, a resin encapsulation layer (referred to as underfill) is formed. The resin encapsulation layer alleviates the thermal stress due to the difference of the thermal expansion coefficients between the wiring substrate and the semiconductor chip. In addition, the resin encapsulation layer reinforces and mechanically protects the flip-chip bonded portion. In FIG. 8, reference numeral 23 denotes solder bumps. Reference numeral 24 denotes a dispenser that dispenses drops of liquid resin.
However, in such a method of forming a resin encapsulation layer, it takes a long time to fill liquid resin. In addition, the dispersibility of a filler contained in the liquid resin deteriorates on the flow end side thereof. Thus, a flow mark will take place.
To fabricate a flip-chip bonded semiconductor device, a simultaneous connecting method is known. In the simultaneous connecting method, while-bumps are being heated and connected (solder is reflowed), the resin encapsulation layer is formed.
In the method, as shown in FIGS. 9 and 10, after fluid resin 25 that contains flux or a reductive material is coated on a wiring substrate 21 (FIG. 10A), at a flip-chip bonding step, the semiconductor chip 20 is mounted. Bumps 23 are heated and melted (reflowed). In addition, the height of the bumps 23 is controlled (FIG. 10B). Thereafter, the fluid resin 25 layer is heated and hardened. The height of the bumps 23 is controlled so as to keep the space between the semiconductor chip 20 and the wiring substrate 21 with a predetermined size.
Thereafter, when necessary, as shown in FIG. 10C, a cover plate 26 is placed on the upper surface (the opposite surface of the electrode pad formed surface) of the semiconductor chip 20. The cover plate 26 is adhered to the semiconductor chip 20 with adhesive agent 27.
However, in the simultaneous connecting method, since the fluid resin 25 is coated on the connecting pad of the wiring substrate 21, the fluid resin 25 resides at the connection interface of the bumps 23. Thus, a connection defect tends to take place. To prevent the connection defect due to adhesion and residue of such resin, an extra step is required along with the flip-chip bonding step. However, it is difficult to adjust each step. Thus, the steps become complicated.
In other words, when the semiconductor chip 20 is mounted, to force aside the fluid resin 25 coated on the bump 23a on the substrate side with the bump 23b on the chip side, the semiconductor chip 20 should be pressed downward. In addition, to prevent the fluid resin 25 from entering the contacted surface of the bumps 23a and 23b, while the semiconductor chip 20 is being pressed, the solder should be heated and melted.
As described above, to alleviate the stress due to the difference of the thermal expansion coefficients between the semiconductor chip 20 and the wiring substrate 21, it is necessary to keep the bumps 23 disposed therebetween with a predetermined height. Thus, while solder is being reflowed, the height of the bumps 23 should be controlled. Consequently, it is difficult to adjust such steps.
In addition, when there are many bumps 23, it is difficult to completely force aside the resin 25 at the connection interface of the bumps 23a on the substrate side and the bumps 23b on the chip side. Thus, a connection defect tends to take place due to the adhesion or residual of the resin 25 at the bumps connection interface.
Thus, in the simultaneous connecting method of which the flip-chip bonding step and resin filling step are simultaneously performed, it is difficult to accomplish a semiconductor device with high connection reliability that satisfies the requirements of small size and many pins.
In addition, when solder bumps are melted, they become round and thereby the connection height becomes lower. Thus, it is difficult to maintain the reliability of the semiconductor device. Further, since the bumps become round, it is difficult to decrease the pitch of the bumps.
The inventors of the present invention know that a fabricating method of a semiconductor device that prevents resin from adhering and residing between an electrode pad and bumps. In the method, a fluid thermosetting adhesive layer is formed on an electrode pad formed surface of a semiconductor chip or on a connecting pad of a wiring substrate. And the adhesive layer is forced aside by bumps.
However, in such a method, when the number of bumps becomes large, it is difficult to completely force aside the adhesive layer that resides at the bump interface with the bumps. Thus, since the adhesive agent layer resides at the bump interface, electric connections become insufficient. In other words, it is difficult to satisfy the requirements of smaller size and more pins of a semiconductor chip.
The present invention is made from the above-described point of view. An object of the present invention is to provide a method of fabricating a semiconductor device with high connection reliability of a flip-chip bonded portion with simplified steps and high yield.
A first aspect of the present invention is a fabricating method of a semiconductor device, comprising the steps of (a) forming a resin layer on a connecting terminal formed surface of a wiring substrate, the wiring substrate having a connecting terminal and a wiring layer on at least one main surface thereof, (b) adhering an inner surface of a cover member on the opposite surface of an electrode terminal formed surface of a semiconductor element, the semiconductor element having an electrode terminal on a main surface thereof, (c) mounting the semiconductor element with the cover member placed with a face down on a surface of which the resin layer of the wiring substrate is formed, contacting a peripheral portion of the inner surface of the cover member, and contacting the electrode terminal of the semiconductor element and the connecting terminal of the wiring substrate through bumps formed on at least one of the electrode terminal and the connecting terminal, and (d) heating and melting the bumps to connect the electrode terminal of the semiconductor element and the connecting terminal of the wiring substrate therewith.
As the bumps, bumps composed of low-melting metals such as solders can be used. In particular, it is preferable to use Pbxe2x80x94Sn solder bumps, Snxe2x80x94Ag solder bumps, or Snxe2x80x94Agxe2x80x94Cu solder bumps.
In the fabricating method of a semiconductor device according to the first aspect, at the bump connecting step, while bumps are being heated, melted, and connected, the resin layer formed on the wiring substrate can be cross-linked and hardened. When the bumps are connected and the resin layer is hardened at the same step, the number of steps can be reduced.
As an example of the cover member, a cap type cover member having a concaved portion in a semiconductor element attached portion can be used. The depth of the concaved portion is set to equal to or smaller than the sum of the height of the bumps being connected (hereinafter simply referred to as the height of bumps) and the thickness of the semiconductor element. The inner surface of the concaved portion is adhered with the opposite surface of the electrode terminal formed surface of the semiconductor element.
In such a structure, in the state that the semiconductor element is mounted on the wiring substrate, since the peripheral portion of the inner surface of the cover member directly contacts the wiring substrate, the bumps connection interface is stably pressed. Since the size of the space (gap portion) between the semiconductor element and the wiring substrate (namely, the height of the bumps) is controlled, it is not necessary to use an extra height controlling means.
As an example of the cover member, a plate member that does not have a concaved portion can be used. In this case, an adhesive layer with the thickness that is equal to or smaller than the sum of the height of the bumps and the thickness of the semiconductor element is formed at the peripheral portion of the inner surface of the cover member. At the semiconductor element mounting step, it is preferable to contact and adhere the adhesive layer and the wiring substrate.
Instead of disposing the adhesive layer on the cover member, a resin layer with the thickness that is equal to or smaller than the sum of the height of the bumps and the thickness of the semiconductor element may be formed in a peripheral area of a semiconductor element mounted portion of the wiring substrate. In the semiconductor element mounting step, the cover member may be contacted to the wiring substrate through the resin layer. As an example of the resin, resist such as solder resist is used. In such a method, the resin layer functions as a dam for an underfill resin layer formed on the connecting terminal formed surface of the wiring substrate. Thus, the resin layer is prevented from excessively spreading out. Consequently, an underfill having a fillet-shaped portion is formed.
According to the first aspect of the present invention, at the step of which a semiconductor element with a cover member is mounted to a wiring substrate, a peripheral portion of a inner surface of a cover member is contacted to the wiring substrate directly or through another layer (an adhesive layer or a resist layer). Thus, the connection interface of bumps between the semiconductor element and the wiring substrate is stably pressed. In such a stably pressing state, the bumps are heated and melted. Thus, the resin for underfill does not adhere, reside, or interpose at the connection interface of the bumps. Consequently, a connection defect will not take place. Thus, the yield will improve.
When a cover member is placed on a semiconductor element, at the bump connecting step, the size of the space between the semiconductor element and the wiring substrate is kept constant. Thus, the height of the bumps is controlled. Consequently, it is not necessary to use a high controlling means for preventing the semiconductor element from lowering. Thus, the process can be simplified. In addition, the number of fabrication steps can be decreased. Moreover, the yield will improve and high throughput can be accomplished.
A second aspect of the present invention is a fabricating method of a semiconductor device, comprising the steps of (a) forming a non-fluid resin layer with a predetermined thickness on a connecting terminal formed surface of a wiring substrate, the wiring substrate having a connecting terminal and a wiring layer on at least one of main surfaces thereof, the non-fluid resin layer being not formed on the connecting terminal, (b) mounting a semiconductor element with a face down on a surface of which the non-fluid resin layer of the wiring substrate is formed, the semiconductor element having an electrode terminal on a main surface thereof, and contacting the electrode terminal of the semiconductor element and the connecting terminal of the wiring substrate through bumps formed on at least one of the electrode terminal and the connecting terminal, and (c) heating, melting the bumps to connect the electrode terminal of the semiconductor element and the connecting terminal of the wiring substrate therewith, and contacting the semiconductor element to the non-fluid resin layer.
As the bumps, bumps composed of low-melting metals such as solders can be used. In particular, it is preferable to use Pbxe2x80x94Sn solder bumps, Snxe2x80x94Ag solder bumps, or Snxe2x80x94Agxe2x80x94Cu solder bumps.
In the fabricating method of a semiconductor device according to the second aspect, at the bump connecting step, while bumps are being heated, melted, and connected, the non-fluid resin layer formed on the wiring substrate can be hardened (for instance, cross-linked). When the bumps are connected and the non-fluid resin layer is hardened at the same step, the number of steps can be reduced.
As an example of the non-fluid resin, thermosetting resin or thermoplastic resin that contain 70 to 90% by weight of a filler such as silica can be used. The non-fluid resin layer can be formed as follows. The resin is formed in a sheet shape or a film shape. A resin sheet or film that has a through-hole corresponding to the connecting terminal of the wiring substrate is aligned with the wiring substrate and then adhered by adhesive agent.
When the content of the filler increases, the thermal expansion coefficient lowers. Thus, when a non-fluid resin layer of which the content of filler is large is formed between a semiconductor element and a wiring substrate, the stress due to the difference of the thermal expansion coefficients therebetween is effectively alleviated. Consequently, a semiconductor device with high connection reliability can be obtained.
In the case that a thermoplastic resin sheet containing high density of a filler is used, when bumps are thermally bonded, the thermoplastic resin layer swells out along the side peripheral surface of the semiconductor element. Thus, an underfill is formed in a good shape. In addition, the shape of the bumps can be controlled.
The non-fluid resin layer may be formed in the following method. In this method, photo-setting fluid resin is coated on a wiring substrate. The coated layer is exposed and developed with a mask having a predetermined pattern. Thus, a hardened resin layer having a pattern except for the connecting terminal can be formed.
According to the second aspect of the present invention, at the step of which bumps are heated, melted, and connected, with a support layer of a non-fluid resin layer formed on the connecting terminal formed surface of the wiring substrate, the height of the bumps (namely, the size of the space between the semiconductor element and the wiring substrate) is controlled. Thus, without a height controlling means for preventing the semiconductor element from lowering, the height of the bumps can be kept.
In addition, since a layer formed on a connecting terminal formed surface of a wiring substrate is a non-fluid resin layer, the resin does not adhere, reside, or interpose at the connection interface of the bumps. Thus, a connection defect does not take place. The thermal stress due to the difference of the thermal expansion coefficients between the semiconductor element and the wiring substrate is effectively alleviated with the bumps. Thus, a semiconductor device with high connection reliability can be accomplished.
In addition, when the thickness of the non-fluid resin layer is adjusted, the height of the bumps can be controlled. Thus, high and thin bumps (the height of the bumps is larger than the diameter thereof) can be accomplished. Consequently, the pitch of bumps can be narrowed corresponding to the pitch of the connecting pad.
These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of a best mode embodiment thereof, as illustrated in the accompanying drawings.

Fabricating method of semiconductor device


An optical scanning device includes a housing and a cover. An engaging hole is formed in the housing and an engaging piece is formed in the cover. The engaging piece has a first portion following a side wall portion of the housing and a second portion folded so as to face the first portion at an interval. When the engaging piece has been inserted into the engaging hole, the first portion is elastically deformed toward the side wall portion of the housing, and the second portion is elastically deformed toward the first portion and abuts a lower portion of an inner edge of the engaging hole, so that the engaging piece and the engaging hole are engaged with each other and the cover is pressed with respect to the housing by the restoring force of the engaging piece.

The technology of the present disclosure relates to an optical scanning device and an image forming apparatus including the same.
An optical scanning device (an exposure device) installed in an electrophotographic image forming apparatus includes a light source that emits light for exposure and a scanning optical system that deflects and scans the light from the light source onto a surface to be scanned. In addition, the scanning optical system is configured with lenses, mirrors and the like.
Such an optical scanning device has a casing for accommodating the scanning optical system in order to suppress dust from being attached to the lenses and the mirrors. For example, the casing includes a housing having an accommodation area where the scanning optical system is accommodated, and a cover that closes an opening of the accommodation area of the housing.
Herein, when the housing and the cover are firmly and closely adhered to each other, no rattling occurs in the cover and furthermore, there is almost no entrance of dust into the accommodation area of the housing. However, each dimension of the housing and the cover varies within a tolerance range. Consequently, actually, rattling occurs in the cover and dust enters into the accommodation area of the housing.
In this regard, in the aforementioned optical scanning device, there has been proposed to separately provide an elastic member for enhancing an anti-vibration property and a dustproof property in the housing. This elastic member is installed along a peripheral wall of the housing and is elastically engaged with a peripheral wall of the cover mounted to the housing. In the state in which the peripheral wall of the cover has been engaged with the elastic member, the cover is pressed with respect to the housing by elastic force (restoring force) of the elastic member. In this way, an upper end of the peripheral wall of the housing and the cover are closely adhered to each other.

Optical scanning device and image forming apparatus including the same


A fuel assembly, where crystallographic orientations of a channel box are brought into a random distribution; and cladding tubes, spacers and a channel box are made from highly corrosion-resistant, Fe--Ni, zirconium-based alloy, hardened in the (.alpha.+.beta.) phase or .beta.-phase temperature region, has an average discharge burnup level of 50 to 550 GWd/t.

The present invention relates to a fuel assembly for a light water reactor, and more particularly to a fuel assembly to be charged in a boiling water reactor.
Recent increasing interests are in longer operating cycles of light water reactors and higher burnup levels of uranium fuel, because of an increase in economical merits such as reduction in discharge of spent fuel, power generation cost, etc. Particularly in Japan, the atomic power generation is based on reprocessing of spent fuel as its premise, with keen requirements for higher burnup level, including reutilization of plutonium extracted by the reprocessing. The nuclear fuel is now discharged from the reaction at a burnup level (discharge burnup level) of about 30 GWd/t, and when a nuclear fuel can have a discharge burnup level of 60 GWd/t, the economical merit will be much improved. In order to attain a higher burnup level in light water reactors, it has been so far tried to improve the corrosion resistance of materials of members for a fuel assembly, prevent deformation of members of a fuel assembly in a neutron irradiation circumstance, optimize the enrichment and arrangement of uranium fuel, and improve the thermohydraulic characteristics of a fuel assembly.
A higher corrosion resistance is required for materials for a fuel assembly of high burnup level than for the conventional materials. As materials of members for the fuel assembly, a zircaloy (Zry: Zn--Sn--Fe--Cr--Ni alloy having the following composition: Sn: 1.2-1.7 wt. %, Fe: 0.07-0.24 wt. %, Cr: 0.05-0.15 wt. %, Ni: <0.08 wt. %, the balance being Zr and impurities) is now used. On the zircaloy members of a fuel assembly, local corrosion called "nodular corrosion" develops in the prevailing circumstance of the boiling water type, light water reactor (BWR). To prevent such a corrosion, processes of improving the corrosion resistance of zircaloy by heat treatment, for example, by heating it to an (.alpha.+.beta.) phase or .beta.-phase temperature region for a short time, followed by quenching, have been proposed (Japanese Patent Publications Nos. 61-45699 and 63-58223). Furthermore, a technique of improving the corrosion resistance by changing the alloy composition is known. For example, a zircaloy having higher Fe and Ni content is known [Japanese Patent Applications Kokai (Laid-open) Nos. 60-43450 and 62-228442].
The Zr alloy material is used in locations subjected t neutron irradiation and thus undergoes irradiation growth and deformation. Particularly, when a curving deformation or expansion deformation takes place at the channel box (FCB), clearances between FCB and control rod are decreased (e.g. to zero), resulting in nuclear reactor operation troubles. To prevent the deformations, a process for suppressing the irradiation growth by making the crystallographic orientation parameter, in the FCB longitudinal direction of (0002) face of hexagonal Zr crystal of 0.15 to 0.5, has been proposed in Japanese Patent Application Kokai (Laid-open) No. 59-229475.
In a boiling water type nuclear reactor, cooling water flows into clearances among fuel rods from the lower tie plate of a fuel assembly and is heated and boils, while passing through the clearances among the fuel rods from the bottom position upwards, to form a two-phase stream of steam voids and liquid water which flows out through through-holes of the upper tie plate. The void ratio is 0% at the bottom position of the fuel assembly and reaches about 70% at the top position. That is, a ratio of hydrogen atoms (H) to heavy metal atoms (U) (H/U ratio) differs between the bottom and the top of the fuel rods. At the bottom position of a fuel assembly, where the H/U ratio is high, the average neutron energy is lowered and the fission reaction of thermal neutrons with nuclear fuel substance is promoted, whereas at the top position of the fuel assembly where the H/U ratio is low, the fission reaction of neutrons with the nuclear fuel substance is suppressed. As a result, the linear heat rating is higher at the bottom position of the fuel assembly than at the top position of the fuel assembly, resulting in uneven power distribution in the axial direction of the fuel rods. Uneven power distribution occurs even in the radial direction of the fuel assembly. The outermost periphery of a square lattice arrangement of 8.times.8, 9.times.9 or 10.times.10 fuel rods is surrounded by an FCB to form a water gap between the outermost periphery of the fuel rods and the adjacent FCB. That is, the H/U ratio is higher at the outermost peripheral region of a fuel assembly than at the inner region thereof, and thus the linear heat rating will be higher. To attain a longer operating cycle and a higher burnup level of nuclear fuel, it is necessary to increase the uranium enrichment. In a fuel assembly having a higher uranium enrichment, such an uneven power distribution is more pronounced. In order to flatten the power distribution in the axial direction and the radial direction, optimization of shape and arrangement of water rods, optimization of uranium enrichment distribution, partial change of fuel rod length, prevention of local power peaking at the initial burnup period with burnable poisons such as Gd, B, etc., and the like have been carried out.
All the above-mentioned techniques relate to the so-called element techniques. Even if some element technique is distinguished, a fuel assembly of higher burnup level cannot be obtained when the fuel assembly partially has some inconvenience. For example, Japanese Patent Application Kokai (Laid-open) No. 59-229475 discloses that irradiation growth and curving deformation can be prevented by controlling an Fl value as a crystallographic orientation parameter of a channel box to 0.15-0.5; but among the crystallographic orientation parameters a crystallographic orientation parameter in the normal-to-plate direction (Fr value) is most important. Furthermore, the fuel rods undergo irradiation growth and are elongated more than the initial length. As a result, the following inconveniences appear. Since the bottom ends of the fuel rods are fixed to the lower tie plate, the elongated fuel rods push the upper tie plate upwards. Since the top end of the channel box is fixed to the upper tie plate and the bottom end of the channel box is inserted into the lower tie plate, the channel box is pushed upwards due to the irradiation growth of the fuel rods, and at the final burnup stage the length of fitting allowance between the lower tie plate and the channel box is considerably decreased. In the nuclear fuel for high burnup level, the irradiation growth of the fuel rods is so large that the channel box is pushed upwards beyond the length of fitting allowance between the lower tie plate and the channel box. This has been a problem.

Fuel assembly, components thereof and method of manufacture


An object of the present invention is to provide a positive active material for a nonaqueous electrolyte secondary battery which has a large discharge capacity and is superior in charge-discharge cycle performance, initial efficiency and high rate discharge performance, and a nonaqueous electrolyte secondary battery using the positive active material. The present invention pertains to a positive active material for a nonaqueous electrolyte secondary battery containing a lithium transition metal composite oxide which has a crystal structure of an α-NaFeO2 type, is represented by a compositional formula Li1+αMe1−αO2 (Me is a transition metal element including Co, Ni and Mn, α>0), and has a molar ratio Li/Me of Li to the transition metal element Me of 1.2 to 1.6, wherein a molar ratio Co/Me of Co in the transition metal element Me is 0.02 to 0.23, a molar ratio Mn/Me of Mn in the transition metal element Me is 0.62 to 0.72, and the lithium transition metal composite oxide is observed as a single phase attributed to a space group R3-m on an X-ray diffraction chart when it is electrochemically oxidized up to a potential of 5.0 V (vs. Li/Li+).

Conventionally, LiCoO2 is mainly used as a positive active material for a nonaqueous electrolyte secondary battery. However, the discharge capacity of LiCoO2 is about 120 to 130 mAh/g.
A solid solution of LiCoO2 and another compound is known as a material of a positive active material for a nonaqueous electrolyte secondary battery. Li[Co1−2xNixMnx]O2 (0<x≦½), which has a crystal structure of an α-NaFeO2 type and is a solid solution of three components, LiCoO2, LiNiO2 and LiMnO2, has been presented in 2001. LiNi1/2Mn1/2O2 or LiCo1/3Ni1/3Mn1/3O2 as an example of the solid solution has a discharge capacity of 150 to 180 mAh/g and is also superior in charge-discharge cycle performance.
For the above-mentioned so-called "LiMeO2 type" active material, the so-called "lithium excess type" active material, in which a compositional ratio Li/Me of lithium (Li) to a transition metal (Me) is more than 1 and for example Li/Me is 1.25 to 1.6, is known. A compositional formula of such a material can be denoted by Li1+αMe1−αO2 (α>0). Here, when the compositional ratio Li/Me of lithium (Li) to a transition metal (Me) is denoted by β, β=(1+α)/(1−α), and thus α=0.2 if Li/Me is 1.5, for example.
In Patent Document 1, an active material, which is a kind of such an active material and can be represented as a solid solution of three components of Li[Li1/3Mn2/3]O2, LiNi1/2Mn1/2O2 and LiCoO2, is described. Further, as a method of manufacturing a battery using the above-mentioned active material, it is described that by providing a production step in which charge at least reaching a region where a potential change is relatively flat, occurring within a positive electrode potential range of more than 4.3 V (vs. Li/Li+) and 4.8 V (vs. Li/Li+) or less, is performed, it is possible to manufacture a battery which can achieve a discharge capacity of 177 mAh/g or more even when employing a charge method in which a maximum achieved potential of a positive electrode at the time of charge is 4.3 V (vs. Li/Li+) or less.
Such a so-called "lithium-excess type" positive active material has a problem that charge-discharge cycle performance and high rate discharge performance are not sufficient. Further, as described above, when in at least the first charge, charge is performed up to a relatively high potential more than 4.3 V, particularly up to a potential of 4.4 V or more, there is a feature of achieving a high discharge capacity, but initial charge-discharge efficiency (hereinafter, referred to as initial efficiency) in this case is not adequately high. Moreover, in Patent Document 1, the stability of the crystal structure, the oxygen position parameter, the specific surface area, and the tapped density are not described.
In Patent Document 2, it is described that a lithium-containing metal composite oxide of a layered rock salt type, an oxygen position parameter and a distance between lithium and oxygen relate to an initial discharge capacity and charge-discharge cycle performance. However, it is not described how the oxygen position parameter affects the high rate discharge performance.
In Patent Documents 3 and 4, an active material for a lithium secondary battery of the general formula xLiMO2.(1−x)Li2M′O3 (0<x<1) is described, and it is also described that M is at least one selected from Mn, Co and Ni, and Mn is selected for M′, and it is shown that the active material containing enriched Li stabilizes a crystal structure, and by using the active material, a lithium secondary battery having a large discharge capacity is attained, but the stability of the crystal structure in being electrochemically oxidized to a high potential is not clear, and improvements in charge-discharge cycle performance, initial efficiency and high rate discharge performance are not described. Also, in these Patent Documents, an active material in which the content of Mn is large and the content of Co is small is not specifically described, and the oxygen position parameter, the specific surface area, and the tapped density are not also described.
In Patent Document 5, an active material for a lithium secondary battery of the general formula Li1+xNiαMnβAγO2 (x is 0 to 0.2, α is 0.1 to 0.5, β is 0.4 to 0.6, and γ is 0 to 0.1) is described, and it is also described that Co is selected for A, and it is shown that by using the active material having the above composition and containing enriched Li, which is produced by a specific method, a lithium secondary battery having a large discharge capacity is attained, but improvements in charge-discharge cycle performance, initial efficiency and high rate discharge performance are not described. Further, in Patent Document 5, the invention of an active material in which a molar ratio of Li to a transition metal element is 0.2 or more and the content of Mn in the transition metal element is more than 0.6 is not described, and the stability of the crystal structure, the oxygen position parameter, the specific surface area, and the tapped density are not also described.
In Patent Document 6, described is "A lithium battery, wherein when at least one transition metal selected from Groups 7A and 8A of the periodic table is denoted by Me, a transition metal different from the Me is denoted by Mt, and at least one element selected from the group consisting of Mt, Na, K, Rb, Cs, Al, Ga, In, Tl, B, Mg, Ca, Sr, Ba and Pb is denoted by A, the battery includes a positive active material comprising a composite oxide having the composition represented by LiXMeYA(1−Y)O(1+X) (1.3≦X≦2.5, 0.5≦Y≦0.999), and a hexagonal crystal structure" (claim 1), and it is shown that the positive active material containing enriched Li stabilizes a crystal structure, and by using the positive active material, a lithium secondary battery having a high energy density is attained, but the stability of the crystal structure in being electrochemically oxidized to a high potential is not clear, and improvements in charge-discharge cycle performance, initial efficiency and high rate discharge performance are not described. Further, in Patent Document 6, an active material in which x is 1.3, Me is Mn, A is Co, the content of Mn is large and the content of Co is small is described, but it is not specifically described that Co and Ni are selected as A, and the oxygen position parameter, the specific surface area, and the tapped density are not also described.
In Patent Document 7, described is the invention of "A positive electrode material for a nonaqueous electrolyte secondary battery using a lithium manganese nickel cobalt oxide comprising lithium, manganese, nickel, cobalt and oxygen, wherein the lithium manganese nickel cobalt oxide has a layered structure and is represented by Li[Li[(1−2x−y)/3]NixCoyMn[(2−x−2y)/3]]O2, and x and y satisfy 0.2<x<0.5, 0<y<0.2, and 1<2x+y" (claim 1), and it is shown that by using the positive electrode material, cycle characteristics are improved, but improvements in initial efficiency and high rate discharge performance are not described. Further, as an example, Li1.15Ni0.25Co0.05Mn0.55O2, a lithium manganese nickel cobalt oxide in which a molar ratio Li/Me of Li to all transition metal elements Me is 1.353, a molar ratio Co/Me is 0.059, and a molar ratio Mn/Me is 0.647, is described (Example 4), but the stability of the crystal structure of the positive electrode material, the oxygen position parameter, the specific surface area, and the tapped density are not described.
In Patent Document 8, described is "A positive active material containing a lithium composite oxide represented by the following chemical formula: [Chem. 1] Li1+a[MnbCocNi(1−b−c)](1−a)O(2-d), wherein a, b, c and d satisfy 0<a<0.25, 0.5≦b<0.7, 0≦c<(1−b), and −0.1≦d≦0.2" (claim 1), and it is shown that by using the positive active material, a large discharge capacity and good cycle characteristics can be realized, and charge-discharge efficiency is also shown, but the invention is not intended to improve the charge-discharge efficiency, and an improvement in high rate discharge performance is not described. Further, as an example, lithium composite oxides in which a molar ratio Li/Me of Li to all transition metal elements Me is 1.30 are described (Example 1-3, Examples 2-2 to 2-8, Examples 3-1 and 3-2), but these composite oxides are synthesized by using "a solid state method", and most of the composite oxides contain less Mn. As only one active material containing Mn in a large amount, Li1.13[Mn0.65Co0.20Ni0.15]0.87O2 is shown, but the stability of the crystal structure of the positive active material, the oxygen position parameter, the specific surface area, and the tapped density are not described.
On the other hand, with respect to lithium transition metal composite oxides composed of Li and transition metal elements (Co, Ni, Mn, etc.), active materials in which the specific surface area and the tapped density are increased are known (refer to e.g., Patent Documents 9 and 10).
In Patent Document 9, described is the invention of "A positive active material having a laminar crystal structure, wherein a sequence of a lithium element and an oxygen element composing an oxide composed of crystal particles of the oxide containing at least three transition metal elements is a cubic structure, and a specific surface area is 0.9 to 2.5 m2/g, and a tapped density is 1.8 to 2.5 g/cm3" (claim 1), and it is shown that in accordance with this invention, a lithium secondary battery having high initial charge-discharge efficiency (initial efficiency) and excellent durability of a charge-discharge cycle can be obtained. Further, in Patent Document 9, described is "A positive active material for a lithium secondary battery represented by the general formula Li[LiqCoxNiyMnz]O2, in which q satisfies −0.2≦q≦0.2, 0.8≦1+q≦1.2, X satisfies 0.1<X≦0.6, Y satisfies 0.1<Y≦0.6, Z satisfies 0.2<Z≦0.6, and X, Y and Z satisfy 0.7≦X+Y+Z≦1.2" (claim 2), but since a positive active material, in which a molar ratio of Li to the transition metal element is 1.2 or more and a molar ratio of Mn in the transition metal element is 0.625 or more, is not specifically described, the initial efficiency and the charge-discharge cycle performance of the positive active material having such composition cannot be predicted. Further, the stability of the crystal structure composing the positive active material and the oxygen position parameter are not described.
In Patent Document 10, described is the invention of "A lithium nickel manganese cobalt composite oxide for a lithium secondary battery positive active material represented by the following general formula (1):LixNi1−y−zMnyCozO2  (1)
in which x satisfies 0.9≦x≦1.3, y satisfies 0<y<1.0, z satisfies 0<z<1.0, and y and z satisfy y+z<1, wherein an average particle size is 5 to 40 μm, a BET specific surface area is 5 to 25 m2/g, and a tapped density is 1.70 g/ml or more" (claim 1), and it is shown that in accordance with this invention, a lithium secondary battery having high initial efficiency and excellent loading characteristics (high rate discharge performance) can be obtained. However, since a positive active material in which x is 1.2 or more and y is 0.625 or more is not specifically described in Patent Document 10, the initial efficiency and the high rate discharge performance of the positive active material having such composition cannot be predicted. Further, the stability of the crystal structure composing the positive active material and the oxygen position parameter are not described.
In improvement in high rate discharge performance of the lithium transition metal composite oxide in which lithium is enriched, partial fluorination of a part of oxygen (Non-patent Document 1) and a surface coating technology (Non-patent Document 2) are proposed. However, all of these are technologies expecting use at 4.5 V or more as a positive electrode charge potential corresponding to a potential region of decomposition of an electrolyte solution, and are not technologies intended to improve high rate discharge performance at the time when the positive electrode charge potential is changed to a potential lower than 4.5 V, for example, 4.3 V, after initial formation to use a battery.
Moreover, the so-called "lithium-excess type" positive active material has a problem that oxygen gas is generated during charge (refer to e.g., Patent Documents 11, 12, and Non-patent Documents 3, 4).
In Patent Document 11, described is the invention of "A method of manufacturing an electrochemical element comprising the step of charging an electrode active material having a plateau potential, at which gas is generated in a charge range, to the plateau potential or more; and the step of removing the gas" (claim 1), "The manufacturing method according to any one of claims 1 to 3, wherein the positive active material has a plateau potential of 4.4 to 4.8 V" (claim 4), "The manufacturing method according to claim 1, wherein the gas is oxygen (O2) gas" (claim 5), "An electrochemical element, wherein an electrode active material having a plateau potential at which gas is generated in a charge range is charged to the plateau potential or more, and then the gas is removed" (claim 6), "The electrochemical element according to claim 6, wherein the electrode active material has a plateau potential of 4.4 to 4.8 V" (claim 7), and "The electrochemical element according to claim 8, wherein after charging to the plateau potential or more and removing gas, a discharge capacity of the electrode active material ranges from 100 mAh/g to 280 mAh/g in a voltage range of 3.0 to 4.4 V" (claim 10).
Further, when as the above electrode active material, a chemical formula 1 "a solid solution of XLi(Li1/3M2/3)O2+YLiM′O2 in which M is one or more elements selected from metals having an oxidation number of 4+, M′ is one or more elements selected from transition metals, and X and Y satisfy 0<X<1, 0<Y<1, and X+Y=1" (claim 2, claim 8, and paragraph [0024]) is used, "When being charged to an oxidation-reduction potential of M′ or more, Li is extracted and simultaneously oxygen is also detached in order to have a balance between oxidation and reduction. Accordingly, the electrode active material has a plateau potential" (paragraph [0025]), "The compound of the chemical formula 1 is preferred since the electrode active material functions stably as an electrode active material in a charge-discharge cycle after the electrode active material is charged to a charge voltage (4.4 to 4.8 V) of a plateau potential or more and the gas removal step is performed" (paragraph [0026]), and "Preferably, M is one or more elements selected from Mn, Sn and Ti metals, and M′ is one or more elements selected from Ni, Mn, Co and Cr metals" (paragraph [0027]) are described.
Moreover, in Patent Document 11, "When a battery is configured by a method in which the active material is charged to a plateau potential or more once or more and then the gas removal step is performed according to the present invention, even though the active material is charged to a plateau potential or more continuously, a battery having a high capacity is configured, and a problem of a battery due to gas generation can also be solved. That is, After charging to a plateau potential or more, gas is not generated in charge in the subsequent cycles, and a plateau range disappears (refer to FIG. 4) (paragraph [0022]) is described, and as Example 4, it is shown that in the case where Li(Li0.2Ni0.2Mn0.6)O2(⅗[Li(Li1/3Mn2/3)O2]+⅖[LiNi1/2Mn1/2]O2) is used as a positive active material (paragraph [0048]), and "charged to 4.8 V in a first cycle, and charged to 4.4 V in a second cycle" (paragraph [0060]), a battery having a high capacity can be obtained (refer to FIG. 5). However, it is suggested that as described in Comparative Examples 5 and 6, oxygen gas is not generated when charging up to 4.25 V or 4.4 V that is a plateau potential or less, but only a battery having a low discharge capacity can be obtained (paragraph [0056], FIG. 1, paragraph [0057], and FIG. 2), and therefore it cannot be said that a positive active material, which does not generate oxygen gas even when charging up to a voltage higher than a plateau potential, is shown.
In Non-patent Documents 3 and 4, it is shown that when Li[NixLi(1/3−2x/3)Mn(2/3−x/3)]O2 is used as a positive active material, oxygen gas is generated at a charge voltage (4.5 V to 4.7 V) that is a plateau potential or more (left column line 4 to right column line 2 in page A818 in Non-patent Document 3, left column line 9 in page A785 to right column line 4 in page A788 in Non-patent Document 4), but it is not shown that oxygen gas is not generated when charging up to a high voltage that is a plateau potential or more.
In Patent Document 12, described is the invention of "A nonaqueous-type (lithium ion) secondary battery formed by winding or layer stacking a positive electrode plate, in which a current collector is provided with an active material layer capable of intercalation/deintercalation lithium ions thereon, and a negative electrode plate with a separator sandwiched between the electrode plates to form an electrode group, and housing the electrode group in a case hermetically together with a nonaqueous electrolyte, wherein an active material to be charged at 4.3 V or less on the Li/Li+ basis and a substance to generate oxygen gas at the time of overcharge exist on the positive electrode plate" (claim 1), and "The lithium ion secondary battery according to claim 1, wherein an active material represented by Li[(Ni0.5Mn0.5)xCoy(Li1/3Mn1/3)z]O2 (x+y+z=1, z>0) or LiαNiβMnγO2 (α is 1.1 or more, β:γ=1:1) is used as the substance to generate oxygen gas at the time of overcharge" (claim 2), and it is described that the lithium-excess transition metal composite oxides (Examples 1 to 3 and 7: Li1.2Ni0.4Mn0.4O2, Examples 4 to 6: Li[(Ni0.5Mn0.5)1/12Co1/4(Li1/3Mn2/3)1/3]O2 (x= 5/12, y=¼, z=⅓)) easily generate oxygen gas at the time of overcharge in comparison with the lithium transition metal composite oxide (not lithium-excess) (Comparative Examples 1: LiCoO2, Comparative Example 2: LiNi0.5Mn0.5O2, Comparative Example 3: Li(N1/3Mn1/3Co1/3)O2) (paragraph [0064]), and it is described that in the invention described in Patent Document 12, on the contrary, utilizing the above-mentioned property of the lithium-excess transition metal composite oxide, "By gas generation at the time of overcharge, since the positive active material layer is detached from the current collector, the positive electrode plate is detached from the separator, or positive electrode layer inside is split, it is possible to cut out charge and prevent decomposition of the electrolyte solution, decomposition of the positive active material and short-circuit due to deposit of Li to the negative electrode side" (paragraph [0010]).
Moreover, since it is described in Patent Document 12 that "In the lithium ion secondary battery of the present invention, as the positive active material generating oxygen gas at the time of overcharge, it is preferred to use a lithium-excess positive active material Li[(Ni0.5Mn0.5)xCoy(Li1/3Mn1/3)z]O2 (wherein x+y+z=1, z>0) or an active material represented by LiαNiβMnγO2 (α is 1.1 or more, β:γ=1:1). When the above active material is used, oxygen gas is generated at about 4.5 V on the Li/Li+ basis, and thereby, a distance between the positive electrode and the negative electrode can be increased", the positive active material not generating oxygen gas when charging up to 4.5 V or more is not shown.
On the other hand, since oxygen gas generated from the positive active material causes failures such as oxidation of a solvent constituting an electrolyte of a nonaqueous electrolyte secondary battery (lithium secondary battery) and heating of the battery, a positive electrode (positive active material) for a nonaqueous electrolyte secondary battery in which oxygen gas generation at the time of overcharge or high-temperature is suppressed is also developed (refer to e.g., Patent Documents 13 and 14).
With respect to the invention described in Patent Document 13, in claim 1, difficulty of generation of oxygen gas of a lithium-containing composite oxide (lithium transition metal composite oxide) is specified as "a local maximum value of oxygen generation peak in gas chromatography-mass spectrometry measurement of the composite oxide" and "a range of 330 to 370° C.", and it is described that "In GC/MS measurement, a temperature of a positive composite is raised at a rate of 10° C./min from room temperature to 500° C., and behavior of oxygen generation was observed. Here, the obtained oxygen generation spectrum (A) is shown in FIG. 3. As is apparent from FIG. 3, in the spectrum (A), a local maximal value of an oxygen generation peak is positioned at a side of temperature higher than 350° C. From this, it is evident that the positive active material of the present invention is hardly decomposed while generating oxygen, and is extremely superior in stability even when being exposed to high-temperature in overcharge region of a battery voltage of 4.7 V" (paragraph [0041]).
However, in Patent Document 13, only the positive active material "represented by the general formula: LizCo1−x−yMgxMyO2, wherein an element M in the general formula is at least one selected from the group consisting of Al, Ti, Sr, Mn, Ni and Ca, and x, y and z in the general formula satisfy 0≦z≦1.03, 0.005≦x≦0.1, and 0.001≦y≦0.03" is specifically described (claims 2 and 3), and the "lithium-excess type" positive active material not generating oxygen gas in an overcharge region is not shown.
In Patent Document 14, it is shown that release of oxygen from a positive electrode at the time of high-temperature is suppressed by mixing an oxygen-storing material with a positive active material or attaching the oxygen-storing material to the positive active material (claim 1, paragraphs [0005], [0056]), and it is described that "Peak temperatures of oxygen detachment of the positive electrodes (samples 1 to 4) having a Ce oxide or a Ce—Zr oxide as an oxygen-storing material are all 300° C. or higher, and the peak temperatures were significantly increased relative to that in the sample 5 not having an oxygen-storing material. This shows that in the samples 1 to 4, a phenomenon of releasing oxygen from the positive electrode is suppressed better (to higher temperature) than the phenomenon in the sample 5" (paragraph [0057]), but the positive active material (lithium transition metal composite oxide) not generating oxygen gas at a high-temperature is not shown.

Positive active material for nonaqueous electrolyte secondary battery, method of manufacturing the positive active material, electrode for nonaqueous electrolyte secondary battery, nonaqueous electrolyte secondary battery and method of manufacturing the secondary battery


A substrate cassette contains two physically spaced and parallel reels. A relatively long web of flexible substrate material is wound about one reel and the exposed end of the web is connected to the other reel, to thus expose a relatively short length of the substrate material at a deposition-plane that lies between the two reels. A first idler roller is associated with the first reel, a second idler roller is associated with the second reel, and the web is guided by the two idler rollers as the web moves between the two reels. The two idler rollers are mounted at fixed positions in order to accurately establish a fixed-position deposition-plane. The substrate cassette is placed within one or more vacuum deposition chambers, the web is advanced between the two reels, and one or more semiconductor layers are deposited on substantially the entire length of the web. A protective layer is provided as part of the web in order to protect the semiconductor layer(s) when the web is wound unto a take-up reel. A constant tension is maintained in the web as the web advances from one reel to the other. The two opposite ends of the web are clamped to the two reels by the operation of an axially-split cylindrical cover that covers each reel and is compressed down onto each web end.

1. Field of the Invention
This invention relates to the field of material deposition, and more specifically, to the deposition of one or more semiconductor layers/films onto a substrate member.
2. Description of the Related Art
It is known in the field of semiconductor manufacturing that semiconductor material be selectively deposited onto a substrate member. In so doing, it is known that an in-line horizontal, and in-line vertical, or a circular assembly of vacuum deposition chambers may be used wherein the substrate member is sequentially moved from one chamber to another as is needed to achieve a desired sequence of semiconductor layers on the substrate member.
It is usual that the limited internal volume of a vacuum deposition chamber limits the physical size of a substrate member that can be inserted into the chamber(s), and upon which semiconductor material may be deposited.
It would be desirable to provide a means whereby a substrate holder would enable a larger area of substrate to be operated upon by a deposition chamber(s).
This invention provides a substrate cassette for use in a single chamber deposition system for use in an in-line multiple chamber deposition system, and for use in a circular multiple chamber or cluster tool deposition system.
A substrate cassette in accordance with this invention contains two physically spaced and parallel reels, either of which can be designated as the supply reel, whereupon the other reel becomes the take-up reel. A relatively long and linear web of flexible substrate material (for example, a stainless steel or plastic substrate material that is about 0.003-inches thick), about 1-foot wide and about 100-feet long, is wound about the supply reel, and the 1-foot wide exposed end of the web is connected to the take-up reel. In this way, a relatively short length (for example, 1-foot by 1-foot square) of the substrate material is supported in a deposition plane, usually either vertical or a horizontal plane, that lies between the supply reel and the take-up reel.
In an embodiment of the invention, a protective backing web is provided adjacent to the back side of the substrate web, this protective web operating to protect a deposition layer(s) that is carried by the deposition side of the substrate web.
In an embodiment of the invention wherein a single layer of a semiconductor material is to be deposited on substantially the entire 100-foot length of the substrate web, the substrate cassette of the invention is placed in a deposition chamber, and a relatively short 1-foot length of the substrate is exposed to the deposition volume of the deposition chamber. A reel-to-reel servo system then operates to advance the substrate from the supply reel to the take-up reel at a relatively slow but constant speed, while maintaining a constant tension in the web, as substantially the entire 100-foot length of the substrate web receives a deposited layer; for example, a semiconductor layer, onto one side surface of the web. The end result is a take-up reel having about 100 feet of substrate material that contains a single deposition layer.
Embodiments of the invention provide for the deposition of multiple layers onto the long substrate web.
In a first embodiment wherein multiple layers are produced, a first layer is deposited on the entire 100 foot length of the substrate web as above described. The substrate web is then rewound from the take-up reel back onto the supply reel, and the above-described process is repeated in order to deposit a second and usually different layer onto the first layer. Of course, this process can be repeated N times in order to deposit N layers onto the 100 foot length of the substrate web. While it may be preferred to rewind the substrate web between use of the cassette in another deposition chamber, it is within the spirit of the invention to eliminate this rewind step, and to rewind the substrate web from the take-up reel to the supply reel as deposition of a second layer is taking place in the second deposition chamber.
In a second embodiment wherein multiple layer structures are produced, the substrate cassette of the invention is placed in a first deposition chamber, and a relatively short length of the substrate is exposed to the deposition volume of the first deposition chamber. A first layer is then deposited on this first length of the substrate web. The cassette is then moved to a second deposition chamber, and a second layer is deposited on the substrate""s first length of the substrate web. In this manner, the cassette is moved between a number of deposition chambers as a like number of layers are deposited on the first length of the substrate web. Once all layers have been deposited on the first length of the substrate web, a reel-to-reel servo system operates to step advance the substrate web to expose a second length of the substrate at the deposition operative position between the two reels. The cassette is then recycled through the deposition chambers to produce a second multiple layer structure on the substrate second length. In this embodiment of the invention, when the substrate has been completely wound from the supply reel to the take-up reel, the take-up reel contains a number of individual substrate areas, each individual substrate area containing one multiple layer structure. For example, when the substrate web is about 100-feet long and about 1 foot wide, and when each individual substrate deposition length is about 1 foot long, the finished web contains as many as 100 individual multiple layer structures, each measuring about 1 foot by 1 foot.
In a preferred embodiment of the invention, a number of vacuum deposition chambers are mounted in a generally circular configuration so as to occupy a generally common horizontal plane, and a centrally-located vacuum chamber contains a robotic arm that is mounted at a central location relative to the deposition chambers. This robotic arm periodically rotates in the common plane to thereby step transport the substrate cassette from one deposition chamber to another deposition chamber, as multiple layers are vacuum deposited on the substrate member. In another embodiment of the invention, the multiple vacuum deposition chambers are arranged in a generally linear or in-line fashion, either horizontal or vertical, and a transport means operates to step transport the substrate cassette through the deposition chambers.
A non-limiting use of a single vacuum chamber deposition system is in the manufacture of a thin semiconductor, such as an amorphous silicon layer, a thin film amorphous silicon alloy layer, a micro-crystalline silicon, or a poly-crystalline silicon layer on a relatively long/narrow and inert substrate web.
A non-limiting example of the use of such a linear or circular vacuum deposition chamber configuration is in the manufacture of n-i-p semiconductor structures, such as amorphous silicon, micro-crystalline silicon or poly-crystalline type semiconductor on a relatively long/narrow and inert substrate web. In this use, a first vacuum chamber is used to deposit a n-type layer on the substrate member, a second vacuum chamber is used thereafter to deposit an intrinsic layer on the n-type layer, and a third vacuum chamber is used thereafter to deposit a p-type layer on the intrinsic layer, or three such vacuum chambers can be used in the opposite sequence to produce p-i-n semiconductor structures.
As will be appreciated, deposition chambers other than those above described can be used, as desired, in order to manufacture virtually any type of semiconductor structure. For example, a deposition chamber can be used to deposit a first metal contact layer on the substrate web prior to deposition of the above described first semiconductor layer, and yet another vacuum deposition chamber can be used to deposit a second metal contact layer on the last semiconductor layer; for example, by using techniques such as, but not limited to, metal vapor deposition and metal evaporation.
The present invention provides a new and unusual substrate cassette or substrate magazine physical format that contains a relatively long, narrow and flexible substrate web that is length advanced through a single station deposition system, or through the various stations of a multiple station deposition system.
While the substrate cassette of this invention finds utility in both single station vacuum deposition systems and multiple station vacuum deposition systems, the spirit and scope of this invention is not to be limited thereto, since substrate cassettes of this invention are useful in virtually any deposition system wherein a layer is deposited on the substrate web as the substrate web moves from a first reel, through a deposition area, and then onto a second reel.
As a feature of the present invention, the substrate cassette of the invention includes a first idler roller that is associated with the first reel, and a second idler roller that is associated with the second reel. While the effective diameters of the two reels change as the substrate web moves from one reel to the other, the substrate web is guided by the two idler rollers as it moves between the two reels, and the two idler rollers are structurally mounted to accurately establish a deposition plane whereat deposition takes place along substantially the entire length of the substrate web.
As another feature of the present invention, each of the two reels within the substrate cassette is driven by its own electrical motor, and these two motors are servo-controlled so as to maintain a constant tension within the relatively short length of the substrate web that extends between the two idler rollers, thus ensuring that this short length of the substrate web is always maintained in one, non-varying, deposition plane.
As a feature of the invention the two ends of the substrate web are clamped to the respective two reels by the operation of an axially split cylindrical cover that is radially compressed to capture an end of the substrate web against the underlying cylindrical surface of a reel.
These and other features and advantages of the invention will be apparent to those of skill in the art upon reference to the following detailed description, which description makes reference to the drawing.

Semiconductor vacuum deposition system and method having a reel-to-reel substrate cassette


An image formation apparatus for forming a color image, having an image combining member for overlapping a plurality of different mono-color images formed by an electrophotographic process with a plurality of respective different colorants to form the color image thereon and a density measuring unit for measuring a reflective density at a desired portion of the color image, the density measuring unit having light emitting portion, such as a light emitting diodes, for emitting light toward the image combining member and a photoelectric conversion element, such as a phototransistor, for receiving and photoelectrically-converting the light reflected at the image combining member to a density signal, the plurality of colorants being divided into first and second groups, the first group of the plurality of different colorants having a higher reflectivity than the image combining member with respect to the light, a second group of the plurality of different colorants having a lower reflectivity than the image combining member comprises: a switching circuit for causing the light emitting portion to change an intensity of the light in response to an intensity control signal.

1. Field of the Invention
This invention relates to image formation apparatus for forming a color image, having a combining member for overlapping a plurality of different mono-color half tone or continuous tone images formed by an electrophotography process with a plurality of different colorants such as yellow, magenta, cyan, and black to form the color image thereon.
2. Description of the Prior Art
A color copy apparatus is known as a color image formation apparatus for forming a color image, having a combining member for overlapping a plurality of different mono-color half tone or continuous tone images formed by an electrophotography process with a plurality of different colorants such as yellow, magenta, cyan, and black to form the color image thereon. Such a prior art color copy apparatus comprises a photosensitive member, a charger for charging the photosensitive member, an optical system for consecutively forming and exposure each of primary color images and an achromatic color (black) image of half tone or continuous tone onto the charged photosensitive member to obtain electrostatic latent images, a developing system for consecutively developing the primary color images and the achromatic color image on the photosensitive member from the electrostatic latent images, and image combining member for receiving, overlapping, and combining each of primary colors and achromatic color images developed on the photosensitive member consecutively and a transfer unit for transferring the combined primary color and achromatic color images onto a paper for recording.
FIG. 4 is a side view of the prior art color image formation apparatus for showing a general structure which is common to the embodiment of this invention. FIG. 5 is a graph showing a general relation between an input image density and an output image density, that is a .gamma. characteristic, which is common to the embodiment of this invention. FIG. 6 is a block diagram of a prior art density measuring unit for measuring a reflective density of a portion of image formed on the combining member 6. FIG. 7 is a schematic circuit diagram of the prior art density measuring unit shown in FIG. 6. FIG. 8 is a graph showing relations between densities of input images of the primary colors and the achromatic color (black) image and output voltages of the prior art measuring unit 43 shown in FIG. 6.
In FIG. 4, a photosensitive member 1 formed in an endless belt is supported between rollers 2 and 3 with a suitable tension and rotated in the direction shown by an arrow A. An optical system 4 forms consecutively forming primary color images, such as yellow, magenta, and cyan, and an achromatic image, such as a black onto the photosensitive member 1 through electrophotographic process. During formation of the images, the photosensitive member 1 circulates and the optical system 4 scans a surface of the photosensitive member 1 with a laser beam to form a color image by forming each of primary color images and the black image on the photosensitive member 1 in phase with circulation of the photosensitive member 1. A charger 42 charges the photosensitive member 1 prior to exposure of each of primary color and black images. A developing system 5, having yellow, magenta, cyan, and black developers 5y, 5m, 5c and 5b, consecutively develops primary color images of yellow, magenta, cyan, and black image using colorants, such as toners, with correspondence to exposure of respective primary color images by the optical system 4. An image combining member 6 formed in an endless belt supported by roller 8, 9, and 10 with a suitable tension receives, overlapping and combining each of consecutively developed primary and achromatic color images. The image combining member 6 is circulated in the direction shown by an arrow B and its portion is contacted with a portion of the photosensitive member 1 to receive each of primary color and black images from the photosensitive member 6. The image combining member 6 combines primary color and black images by consecutively receiving the developed primary color and black images and transfer the combined color image to a paper 13 by the transferring unit 14.
It is possible to form a color image by combining primary color images, such as yellow, magenta, and cyan. However, generally, in order to improve a picture quality of color image, a black image of an achromatic color is added to the color image which has been formed by combining primary color images.
A density sensor 7 measures a density of a portion of a color image formed on the image combining member 6 by emitting a light and receiving a reflected light from the image combining member 6. The image combining member 6 has a intermediate reflectivity between those of colorants of primary colors and the achromatic color, i.e., black with respect to the emitted light. A position sensor 11 detects a reference marker, for example a hole provided to the image combining member 6 for generating position signals of the image combining member 6. The image combining member 6 combines primary color images and black image with reference to the position signals to match positions of primary color images and black image to reduce positional deviation. A paper 13 for recording is transported in the direction shown by an arrow C from a paper retainer 12 to a contacting portion between the roller 9 and a transferring unit 14 through a paper path 15. In operation, the charger 42 charges the photosensitive member 1 and then, the optical system 4 expose one of primary color and achromatic color images, for example yellow, with rotation of the photosensitive member 1. One of developers 5y, 5m, 5c, and 5b, develops the electrostatic latent image. For example the developer 5y develops a yellow image. Then the yellow image is transferred to the image combining member 6 from the photosensitive member 1. Then, the charger 42 charges the photosensitive member 1 again after cleaning and the optical system 4 exposes the next image onto the photosensitive member, for example a magenta image is exposed. The magenta image is developed as similar to the yellow image and then transferred to the image combining member 6 where the yellow image has been formed. A cyan image and black image are consecutively formed and combined on the image combining member 6. The combined color image is transferred to the paper 3 by the transferring unit 14. The order of formations of primary colors and achromatic color, i.e., black is predetermined in accordance with the quality of the formed color image or the like.
A density measuring unit 43 including the density sensor 7 measures a portion of each of primary color and black images formed on the image combining member 6.
Generally, the electrophotographic, or zerography processing is subjected to the various variations of the circumstances, such as the ambient temperature, humidity, or the like, so that difference in density or hue is developed in the resultant output image though the same picture image is formed. The graph shown in FIG. 5 represents a general relation between an input image density and an output image density. This relation is referred to as a .gamma. characteristic. Each of primary color images and the achromatic image has each .gamma. characteristic, so that the difference in density or hue is developed by the variation of the circumstance.
Therefore, it is possible to obtain a more stable output picture images by compensating the .gamma. characteristics of respective primary color and achromatic color images against the variation of the circumstance. The density measuring unit 43 is provided for detecting the density of a portion of the image combining member 6 in order to obtain the .gamma. characteristics and to compensate the quality of the resultant output picture image.
A control unit (not shown) including a microprocessor generates mono color and achromatic gray scale signals in response to position signals from the position sensor 11 and expose the photosensitive member 1 to an scanning light beam 44 to form gray scales of primary colors and achromatic color on the image combining member 6 and detects or samples a density signal of the density measuring unit 43 to measuring the density of the formed gray scales in response to the position signals from the position sensor 11.
As shown in FIG. 6, the density measuring unit 43 comprises a reference voltage generator 16 for generating a reference voltage Vr, a voltage-to-current converter 17 for converting the reference voltage to a reference current If, a light emitting portion 71 of the density sensor 7 for emitting an illumination light 7a to a portion of the combining member 6, a photosensitive portion 72 of the density sensor 7 for receiving a light 7b reflected at the image combining member 6 and producing a current signal Is in accordance with an intensity of the received light, a current-to-voltage converter 18 for converting the current signal Is to a voltage signal Vs, and an amplifier 19 for outputting a density signal Vo.
The reference voltage generator 16 generates the reference voltage Vr which determines the intensity of the reference current If for controlling a brightness of the illumination light 7a. The voltage-to-current converter 17 converts the reference voltage to a reference current If. The density sensor 7 has the light emitting portion 71 and the photo-sensitive portion 72 in one. The light emitting portion 71 emits the illumination light 7a to a desired portion of the image combining member 6. The image combining member 6 moves in the direction shown by an arrow D, so that when the illumination light 7a hits a shadow portion 6a of a gray scale, the photosensitive portion 72 receives the light reflected by the shadow portion 6a of the gray scale. When the illumination light 7a hits a bare portion of the combining member 6, the photosensitive portion 72 receives the light reflected at the image combining member 6. When the other intermediate density portion of the gray scale is illuminated, a portion of the illumination light is reflected by the colorant and the other portion of the illumination light is reflected by the surface of the image combining member 6. Therefore, the photosensitive portion 72 of the density sensor 7 detects the reflective density at the image combining member 6 by representing the current signal Is. The current-to-voltage converter 18 converts the current signal Is to a voltage signal Vs. The amplifier 19 outputs a density signal Vo to the control unit (not shown) to detect the .gamma. characteristics.
FIG. 7 shows the schematic diagram of the prior art density measuring unit 43. The reference voltage generator 16 comprises resistors 20 and 21 for dividing the supply voltage Vd to generate the reference voltage Vr. The voltage-to-current converter 17 comprises resistors 22, 23, 25, and 27, an operational amplifier 24, and a transistor 26 and determines the current signal If which is given by If=Vr/resistance of resistor 27. The current signal If determines the intensity of the illumination light 7a.
The current-to-voltage converter 18 comprises resistors 28 and 29 outputs the voltage signal Vs given by Vs=Is.times.a resistance of the resistor 28. The amplifier 19 comprises resistors 30 and 31, and an operational amplifier 32 and outputs the density signal given by Vo=(1+resistance of the resistor 31/resistance of the resistor 30).times.Vs.
The reference voltage Vr and the reflectivity of the image combining member 6 is determined as follows:
FIG. 8 shows the relation of a prior art between the density of input image signal (data) and the voltage of the density signal Vo. The colorants of primary color images shows a characteristic curve 8a increasing from a reference point Vor with the density of input image signal, on the other hand the colorant of achromatic color shows a characteristic curve 8b decreasing from the reference point Vor with the density of input image signal. The reference point Vor represents the reflectivity of the boar portion of the image combining member 6. That is, the colorants of the primary colors show higher reflectivities than the combining member 6 with respective to the wavelength of the illumination light 7a. On the other hand, the colorants of the achromatic color shows a lower reflectivity than the image combining member 6. Therefore, the reference voltage Vr is determined such that the reference point Vor is positioned middle of the range of the characteristic curves 8a and 8b. That is, the intensity of the illumination light 7a is determined by the reference voltage Vr in consider of the ranges of the characteristic curves 8a and 8b.
However, in the prior art image formation apparatus mentioned above, there is a problem that dynamic ranges of the characteristic curves 8a of the primary colors and a dynamic rage of the achromatic color is smaller than the case that densities of primary colors and the density of achromatic color would be detected by different circuits. Therefore, the a resolution of density is low, so that fine density control was impossible and the picture quality was not suitably improved.

Color image formation apparatus with density measurement

Matsushita Electric Industrial Co., Ltd.


A HEMT cell includes two or more gallium nitride (“GaN”) high-electron-mobility transistor (“HEMT”) devices electrically connected in series with each other. The HEMT cell includes a HEMT cell drain, a HEMT cell source, and a HEMT cell gate. The HEMT cell drain connects with the drain of a first GaN HEMT device in the series. The HEMT cell source connects with the source of a last GaN HEMT device in the series. The HEMT cell gate connects to a first two-dimensional electron gas (“2DEG”) gate bias resistor that connects with the gate of the first GaN HEMT device. The HEMT cell gate connects to a second 2DEG gate bias resistor that connects with the gate of the second GaN HEMT device. The first and second 2DEG gate bias resistors are located in a 2DEG layer of the HEMT cell. A multi-throw RF switch is also disclosed.

The present disclosure generally relates to active solid-state devices, and more specifically to gallium nitride, high-electron-mobility transistors used as switches.
A gallium nitride (hereinafter "GaN") high-electron-mobility transistor (hereinafter "HEMT") is a depletion mode device (normally ON) that may be used as a switch. To turn the switch OFF, a gate needs to be biased at a negative voltage. Most applications do not have a negative voltage available on an application platform, thus the negative voltage needs to be generated from a smaller positive supply voltage. Generation of a negative voltage requires many stages of charge pump circuits. Each stage of a charge pump requires a capacitor. A size of the capacitor is dependent on a load current that the charge pump circuit has to source. The load current is a gate current of the HEMT device that the charge pump circuit is driving.
Modern applications demand that an RF switch handle high speed switching of high power RF signals, with high broadband isolation and low noise when the switch is OFF, and with low broadband insertion loss when the switch is ON. Every switch can have parasitic inductance, capacitance, conductance, and resistance. These parasitic components combine to attenuate and degrade the signal that the switch is being use to route. The power loss and voltage attenuation caused by these components varies with frequency of the input signal and can be affected by the insertion Joss of the switch at that frequency. It is important that the insertion loss of a switch is acceptable at the bandwidth requirement of the application.
Many RF switches, such as PIN diode switches, suffer from high current drain. This can result in undesirable wasted power and generation of heat in certain applications.


A distributed computing system is provided. The system includes a first node, a second node in communication with the first node, and a device coupled to the first node and second nodes. The first node and the second node include component specific modules. The first and second nodes access the device via a selected component specific module defined in the first and second nodes, respectively. The selected component specific module corresponds with the device. An apparatus for using a device having quorum device functionality as a quorum device in a clustering environment, a method and computer program embodied on a computer readable medium for using a device as a quorum device in a cluster environment, and a method and a computer program embodiment on a computer readable medium for interfacing with a quorum device coupled to a node in a cluster environment, are also provided.

Highly available distributed computer systems can provide businesses with round-the-clock uninterrupted access to reliable data. One way to achieve high availability is by implementing computer clustering. A computer system cluster (herein also referred to as cluster) includes a group of two or more nodes wherein each node has the capability to communicate and exchange data with every other node in the cluster. One or more storage devices coupled to one or more cluster nodes can also be included. Maintaining the integrity of data and resources in a cluster, and minimizing the negative effects of split-brain and amnesia can be achieved by using a quorum algorithm and establishing a quorum. In certain scenarios, however, an external vote provided by a quorum device is needed to establish a quorum (e.g., a two-node cluster wherein the majority of votes cannot be gained by a single node).
Currently, very few device types can be used as quorum devices. Furthermore, the current cluster computer program code is a rather long monolithic, and significantly intermeshed code. The cluster code includes quorum algorithm code as well as pieces of computer code written specifically to deal with the few available quorum device types. As a result, adding a new type of quorum device to a cluster can require significant modifications to the cluster code. Of course, such substantial modifications can be a rather time consuming and magnanimous task. Yet further, the cluster code has to be modified repeatedly as new device types are to be used as quorum devices. Still further, the monolithic and intermeshed nature of the code requires that pieces of code associated with every type of quorum device to be loaded into the operating system kernel. In most scenarios, however, the node may only be coupled to a single type of quorum device.

Pluggable device specific components and interfaces supported by cluster devices and systems and methods for implementing the same


A method of preparing insoluble transition metal compound particles is described, comprising: providing a transition metal salt solution having the formula (TM)(S) wherein TM is one or more of Mn, Ni, Co, Mg, Zn, Ca, Sr, Cu, Zr, P, Fe, Al, Ga, In, Cr Ge or Sn; providing a source of a carbonate-, hydroxide-, phosphate-, oxyhydroxide- or oxide-based anionic compound wherein the anionic component, represented by S′, is reactive with TM to form the particles; adding the transition metal salt solution and anionic compound to a reaction chamber; and subjecting the chamber to sonication at an intensity of about 0.1 to about 50 W/mL. In an exemplary embodiment, MnCO3 particles are formed from: MnSO4; and Na2CO3 and/or NH4HCO3, wherein the ratio of MnSO4 to Na2CO3 and/or NH4HCO3 is from about 1:1.5 to 1.5:1. The particles may have narrow size distribution and a tap density of about 1.7-2.3 g/mL.

The control of particle size, morphology or both is important in some circumstances. Particles size can be affected after production of the particles using processes such as milling, but such processes may have a detrimental effect on the material properties. During precipitation or crystallization from solution, particle size, morphology or other properties may be controlled.
Crystallization or precipitation is achieved by mixing a solvent containing an active principal to be crystallized with an anti-solvent, so that after mixing the solution is supersaturated and crystallization occurs. Precipitation can also be achieved by the reaction of two or more reagents that form a product which has reduced solubility in the solvents being used. The resulting insoluble reaction product precipitates or crystallizes from the solution. In such a situation, the solvents being used in the reaction would be considered to be anti-solvents with respect to the reaction product. The term "anti-solvent" means a fluid which promotes precipitation of the active principal from the solvent. The anti-solvent can be the same liquid as the solvent but at a different temperature, it may be a different liquid from the solvent, or (in the case of two reagents reacting to form a new product) it may be the solvent used in the reaction.
Ultrasonic irradiation (or sonication) has been used while precipitating or crystallizing particles. For example, Hussein OUBANI and others, in the Asia-Pacific Journal of Chemical Engineering 5 (2010) 599-608, describe the precipitation of NaCl microparticles from a NaCl—Ethanol—Water antisolvent system; L. BOELS and others, in the Journal of Crystal Growth 312 (2010) 961-966, describe the crystallization of a supersaturated calcite suspension under ultrasonic irradiation; and I. NISHIDA, in Ultrasonics Sonochemistry 11 (2004) 423-428, describes the ultrasonic irradiation of a supersaturated solution of calcium carbonate.
Hielscher Ultrasonics produces ultrasonic devices and describes an ultrasonic precipitation process at <http://www.hielscher.com/ultrasonics/precipitation—01.htm>.
A poster presentation by B. POHL, N. ÖZYLIMAZ, G. BRENNER, and U. PEUKER, entitled "Untersuchungen zur Optimierung von kontinuierlichen Ultraschalldurchflussreaktoren", publically available at least as early as Dec. 20, 2010, describes how flow chamber size and geometry of ultrasonic reactors affect the formation of I3− and BaSO4.
A poster presentation by B. POHL, G. BRENNER, and U. PEUKER, entitled "Optimierung von Ultraschallfällungsreaktoren—kontrollierte Nanopartikelherstellung", publically available at least as early as Dec. 20, 2010, teaches that ultrasonic precipitation reactors can be used to form agglomerations of Fe3O4 particles, where the agglomerates are between 20 nm and 300 nm (cavitation field reactor) or between 20 nm and 1 μm (conical reactor).
A review article discussing the chemical effects of ultrasonic irradiation was authored by Kenneth SUSLICK in Science 247:4949 (1990) 1439-1445. Another review article, by G. RUECROFT and others in Organic Process Research & Development, discusses the application of ultrasound to crystallization of organic molecules, and discusses equipment that could be used in industrial environments, such as parallel plate transducer systems.
Chunling LU and Jinglin ZHANG, in The Journal of the Chinese Ceramic Society 35:3 (2007) 377-380, describe subjecting a reaction of manganese sulfate (MnSO4) and ammonium bicarbonate (NH4HCO3) to ultrasonic irradiation, using an ultrasonic bath having an intensity of about 1 W/cm2, to form cubical manganese carbonate (MnCO3) particles from 400 to 500 nm.
Ting-Feng YI and Xin-Guo HU, in the Journal of Power Sources 167 (2007) 185-191, disclose preparing sub-micro spinel LiNi0.5−xMn1.5+xO4 (x<0.1) cathode materials with homogeneous particle size using an ultrasonic-assisted co-precipitation of LiNO3, Mn(NO3)2, and Ni(NO3)2.6H2O. The precipitation was sonicated at 80° C. for 5 h in an ultrasonic cleaner at 50 W and 28 kHz.
Peizhi SHEN and others, in the Journal of Solid State Electrochemistry (2005) 10:929-933, describe preparing a LiCrxMn2−xO4 (x=0, 0.02, 0.05, 0.08, 0.10) compound with spinel crystal structure using an ultrasonic co-precipitation method. Lithium acetate, manganese acetate, chromic nitrate and citric acid were dissolved in water and treated in an ultrasonic bath.
U.S. Patent App. No. 2010/0018853 describes the control of crystal and precipitate particle size of pharmaceutical drugs or other medicaments using ultrasonic irradiation.
Ultrasonic irradiation is also used in other processes for preparing particles. Tingfeng Y I, Xinguo H U and Kun G A O, in the Journal of Power Sources 162 (2006) 636-643, prepare Al-doped LiAl0.05Mn1.95O4 powders using an ultrasonic assisted sol-gel method, using adipic acid as a chelating agent. A sol-gel process is a wet-chemical technique used primarily for the fabrication of materials (typically a metal oxide) starting from a chemical solution (or sol) that acts as the precursor for an integrated network (or gel) of either discrete particles or network polymers. Stoichiometric amounts of reactants Li(CH3COO).2H2O, Al(NO3)3.9H2O and Mn(CH3COO)2.6H2O were used to prepare the LiAl0.05Mn1.95O4 powders.
S. H. PARK and others, in the Journal of Applied Electrochemistry (2003) 33: 1169-1173, describe the preparation of Li[Ni1/2Mn1/2]O2 using an ultrasonic spray pyrolysis method. In spray pyrolysis, the dissolved reagents are atomized using an ultrasonic nebulizer and the resulting aerosol stream is introduced into a heated reactor. They teach that stoichiometric amounts of Ni and Mn nitrate salts (cationic ratio of Ni:Mn—1:1) were dissolved in water and that the dissolved solution was added to a continuously agitated aqueous citric acid solution, which was used as a polymeric agent for the reaction. The starting solution was atomized using an ultrasonic nebulizer with a resonant frequency of 1.7 MHz and the aerosol stream was introduced into a reactor heated at 500° C.
In a similar process, S. H. PARK and others, in Electrochimica Acta 49 (2004) 557-563, teach the preparation of Li[Ni1/3Co1/3Mn1/3]O2 materials using a spray pyrolysis method, where citric acid is again used as a polymeric agent for the reaction.
Spherical particles can be used in the preparation of battery materials, as discussed by SUN and others in Process of Precipitation for Spherical Manganese Carbonate and Their Products Produced Thereby (WO 2006/109940), as well as in the pharmaceutical industry. Weijun TONG and Changyou G A O, in Colloids and Surfaces A: Physiochem Eng. Aspects 295 (2007) 233-238, describe the preparation of hollow spherical manganese carbonate capsules by the reaction of manganese sulfate and ammonium bicarbonate solutions to form manganese carbonate particles and then acid dissolution of the particle cores. Similarly, Alexei ANTIPOV and others, in Colloids and Surfaces A: Physiochem Eng. Aspects 224 (2003) 175-183, describe the formation of hollow capsules made using cadmium carbonate particles, manganese carbonate particles and calcium carbonate particles as core templates for adsorption of oppositely charged polyelectrolytes and subsequent core removal.
Although ultrasonic irradiation has been used during precipitation of metal compound particles, as described above, it is desirable to provide an ultrasonic irradiation-based method that allows for the production of particles with desired morphologies, desired size distribution and/or desired particle sizes.

Transition metal compound particles and methods of production


A damper includes a pressure tube and a piston defining a rebound chamber and a compression chamber within the pressure tube. The damper further includes an adapter attached to the pressure tube. The damper includes a retainer slidably disposed within the pressure tube. The retainer and the adapter define an end chamber therebetween within the pressure tube. The damper also includes a cup movably disposed within the pressure tube between the retainer and the adapter. The damper further includes a tubular member disposed adjacent to the cup and attached to the adapter. The tubular member includes at least one through aperture. The damper includes a base valve attached to the adapter. The damper also includes a first spring disposed between the retainer and the cup and a second spring disposed between cup and the adapter.

Shock absorbers/dampers are generally installed on different types of equipment, such as vehicles, to damp vibrations during operation. For example, dampers are generally connected between a body and the suspension system of the vehicle in order to absorb the vibrations. Conventional dampers typically include a pressure tube, a reserve tube, a piston, a piston rod, and one or more valves. During a compression stroke and a rebound stroke of the damper, the piston may limit a flow of damping fluid between working chambers defined within a body of the damper due to which the damper produces a damping force for counteracting the vibrations. By further restricting the flow of damping fluid within the working chambers of the damper, greater damping forces may be generated by the damper.
Typically, a damper is provided with a hydraulic compression end stop (HCS) member. The HCS member is configured to operate during the compression stroke of the damper. In conventional HCS members, a secondary piston is attached to a primary piston though an extension rod. However, such an arrangement may increase an overall cost of the shock absorber.

Tenneco Automotive Operating Company Inc.