Provided is an electronic material composition which is capable of forming a cured film exhibiting a desired glass transition temperature, a desired stiffness modulus in a rubbery state and a desired extensibility at low temperatures. Also provided is an electronic component comprising a molded body, a packed body, a covering body, an electrode or a joining body, all being formed of the aforementioned electronic material composition. Also provided is a method of using the aforementioned electronic material composition, which is featured in that the electronic material composition is applied in a semi-cured state, and after the application thereof, completely cured.

The present invention relates to an electronic material composition comprising a specific resin component, to electronic components to be manufactured from the employment of such an electronic material composition, and to the using method of such an electronic material composition.
Curable resins such as epoxy resin are employed as an important component in an electronic material composition which may or may not be mixed with a powdery electronic material such as ferrite powder or metallic powder in the employment thereof. Such electronic materials comprising a curable resin or a powdery electronic material are extensively employed mainly as a material for the manufacture of electronic components, e.g. as a molding material, a coating material, an electrode material, a bonding material, etc.
More specifically, the electronic materials can be employed as an electronic material for the following end-uses (1) to (5).
(1) As for the usage as a molding material of the electronic materials, they can be employed as a material on the occasion of manufacturing the core of wound chip coil for instance. In this case, ferrite powder is granulated together with a resin component and other components as required to obtain granules, which are then dry-molded into a rod like configuration and subjected to a curing treatment. The cured body thus obtained is then subjected to a cutting work to obtain a core whose both ends are provided with a flange. The same procedure can be also applied to the manufacture of the spool of air-core coil though the procedure involves no cutting work in this case. There is also known a so-called working-less manufacturing method wherein ferrite powder is wet-mixed with a resin component and a solvent to obtain a composition which is then molded by means of injection molding for instance to form a molded body, the molded body being subsequently cured.
(2) As for the usage of the electronic material as a coating material, there are four cases (a) to (d) as set forth below.
(a) The electronic material can be employed as an outer packaging material in such a manner that after a winding is applied to the aforementioned core, the resultant coil is coated with the electronic material.
(b) The electronic material can be employed as an electromagnetic shielding material covering the surface of a casing housing an electronic component. In this case, magnetic material powder is mixed with a resin component to obtain a mixture which is then molded into a sheet, a plurality of which are then simply adhered to each other so as to cover the surface of the casing. There is also known a case wherein the casing itself is constituted by a molded body molded from a mixture comprising metallic powder and a resin component.
(c) The electronic material can be employed as a covering material for a connecting cable of a digital video camera, a personal computer, a printer, etc. In this case, a resin component is turned into a molten state and then, extruded together with the cable.
(d) The electronic material can be employed as a covering material for covering the entire surface, including an electronic component, of a printed wiring board having an electronic component mounted thereon.
(3) As for the usage as an electrode material of the electronic materials, they can be employed as a conductive paste containing a glass frit and silver powder for instance, the paste being coated and then, baked to form an external terminal electrode of a chip component. There is also known a case wherein a conductive paste obtained through the mixing of conductive powder with a resin component and a solvent is coated on a chip component and then, baked to form an external terminal electrode likewise.
(4) As for the usage of the electronic material as a bonding material, there are two cases (a) and (b) as set forth below.
(a) The electronic material can be employed as a solder for soldering a chip component for example onto the soldering land of a printed wiring board.
(b) As in the case of manufacturing an LC laminated composite electronic component for instance, the electronic material can be employed as an adhesive material, i.e. as an interconnecting sheet in bonding different kinds of sheets with each other, for instance in a process wherein a green sheet laminate consisting of the same kind of material is laminated with another green sheet laminate consisting of the same kind of another material differing from the first mentioned material to form a composite laminate body, which is then baked to form an LC element. Namely, in this case, these green sheets can be formed of an electronic material composition wherein ferrite powder or dielectric material powder is wet-mixed with a resin and a solvent.
(5) As for the usage as a filler of the electronic materials, they can be employed for filling a joint portion in a situation wherein the wall of building is to be formed by joining electromagnetic shielding boards, panels or tiles to each other.
In relative to the aforementioned end-use (1), there is an increasing demand for the miniaturization of core in accordance with the recent trend to further miniaturize an electronic component. However, as the core becomes smaller, the rigid and fragile nature of the ferrite material becomes more prominent, thus making it difficult to exercise a fine working of the core. As a result, an off-specification product tends to generate, thus deteriorating the yield of the core. In the case of the core which is injection-molded using an electronic material composition prepared through a wet-mixing also, the toughness of core is insufficient. From a reflow soldering test wherein these worked or molded products are subjected to a thermal stress in the soldering step, these worked product as well as molded product are found accompanied with a problem in terms of strength.
In relative to the aforementioned end-use (2)(a), the conventional outer packaging material is accompanied with a problem in the mounting operation of so-called bulk component wherein individual component is picked up by means of an adsorption nozzle from an aggregate consisting of a large number of chips of the same kind and transferred so as to mount it at a predetermined region of a printed wiring board, because the outer packaging material is so rigid and hardly deformable that a gap tends to be generated between the adsorption nozzle and the surface portion of the outer packaging material being adsorbed, thus making it difficult for the adsorption nozzle to pick up the individual component due to slipping between them. Namely, a problem of mis-mount tends to be raised in picking up individual chip component from a large number of chips of the same kind. With a view to minimize this mis-mount, there has been conventionally proposed to improve the accuracy in configuration of the component. However, such a countermeasure is limited in terms of yield.
In relative to the aforementioned end-use (2)(b), when the configuration of casing includes a complicatedly deformed portion such as a complicatedly bent portion or a fine recessed and projected portion, it is difficult to closely adhere electromagnetic shielding sheets onto the wall of the casing. As a result, a sufficient electromagnetic shielding effect may not be ensured.
In relative to the aforementioned end-use (2)(a) and (2)(b), due to a thermal stress resulting from a difference in linear expansion coefficient between the coating material and the surface to be coated, the adhesion plane may be peeled off or a damage such as cracking may be generated in the coating material.
In relative to the aforementioned end-use (2)(c), since the coating material is formed of a resin material, the electromagnetic wave generated from the current flowing through the conductive wire of cable is allowed to radiate into the ambient atmosphere. As a result, the electronic instruments disposed around the cable would be badly affected by the electromagnetic wave, so that it is impossible to suppress so-called radiant noise which may become a cause for the malfunction of the electronic instruments. With a view to overcome this problem, there has been conventionally proposed a cable which is covered with a coating material formed of a magnetic material composition containing, as a resin component, acrylic-modified polyester resin. However, as for the cable which is an ordinary covered conductor not having such a countermeasure, there is no other way but to use as it is, so that such an ordinary cable, including the cable which has been already wired, is still accompanied with a problem that it is impossible to suppress the aforementioned radiant noise.
In relative to the aforementioned end-use (3), the electrode which is formed through the baking of a mixture comprising powdery silver and glass frit is employed on the occasion of soldering an electronic component to the soldering land of a printed wiring board. However, since the linear expansion coefficient of the electrode differs from that of the soldering land, a stress tends to generate between them due to changes in temperature. As a result, the electronic component is badly affected by such a stress, thereby deteriorating the durability of the electronic component in terms of keeping a predetermined performance thereof. The same problem as mentioned above is also applicable to the electrode which is formed through the baking of a mixture comprising powdery conductive material and a resin component. Because, since epoxy resin is employed as the resin component, the aforementioned thermal stress cannot be alleviated.
In relative to the aforementioned end-use (4)(a), since the solder to be employed for bonding the external terminal electrode of electronic component to the soldering land is so rigid and hardly deformable that it is impossible to alleviate the stress to be generated, due to changes in temperature, between the electrode and the soldering land as in the case of the aforementioned end-use (3), the electronic component would be badly affected by the stress, thereby deteriorating the durability of the electronic component. Therefore, if the problem pointed out in the aforementioned end-use (3) happens to occur simultaneously with this phenomenon, the durability of the electronic component would be further deteriorated.
In relative to the aforementioned end-use (4)(b), since, for example, a ferrite green sheet laminate constituting a composite laminate body differs in shrinkage factor from a dielectric material green sheet laminate also constituting the composite laminate body, cracks may be more likely to be generated on the occasion of baking the composite laminate body. Even if a baked body which is free from cracks can be obtained, since the composite laminate body is constituted by different kinds of green sheet laminates differing in linear expansion coefficient, cracks may be more likely to be generated in the baked body when the baked body is left under the conditions where the temperature thereof is caused to change, especially when the baked body is repeatedly left under such conditions.
In relative to the aforementioned end-use (5), although a silicone resin is generally employed as a filler, it is impossible to prevent an electromagnetic wave from entering into a building from the outside thereof through the filler containing the silicon resin, and at the same time, an electromagnetic wave generated form electronic instruments such as a personal computer employed inside the building is allowed to leak to the outside of the building through the resin-filled portions between electromagnetic shielding boards, panels or tiles, thereby raising a problem of the leakage of information via this leaked electromagnetic wave.
Therefore, a fist object of this invention is to provide an electronic material composition which enables to obtain a molded body having a sufficient strength even if the molded body is miniaturized, being suited for improving the yield, and being resistive to a sharp change of temperature, to provide an electronic component formed of such an electronic material composition, and to provide the use of such an electronic material composition.
A second object of this invention is to provide an electronic material composition to be employed for manufacturing an external packaging material which is capable of withstanding a stress that may be generated under a thermal load on the occasion of reflow soldering or on the occasion of heat cycle test, to provide an electronic component formed of such an electronic material composition, and to provide the use of such an electronic material composition.
A third object of this invention is to provide an electronic material composition to be employed for manufacturing an external packaging material having a sufficient flexibility enabling to obtain a bulk component which can be easily adsorbed by an adsorption nozzle of a mounter, and exhibiting an excellent resistivity to a thermal stress that may be generated due to a difference in linear expansion coefficient between the external packaging material and a body to be packaged, to provide an electronic component formed of such an electronic material composition, and to provide the use of such an electronic material composition.
A fourth object of this invention is to provide an electronic material composition to be employed for manufacturing a covering material having a sufficient flexibility enabling to cover a casing having a complicated surface configuration in conformity with the complicated surface configuration so as to ensure a sufficient electromagnetic shielding, and exhibiting an excellent resistivity to a thermal stress that may be generated due to a difference in linear expansion coefficient between the covering material and a body to be covered, to provide an electronic component formed of such an electronic material composition, and to provide the use of such an electronic material composition.
A fifth object of this invention is to provide an electronic material composition to be employed for manufacturing a covering material or a casing material, which is capable of preventing the generation of radiant noise, to provide an electronic component formed of such an electronic material composition, and to provide the use of such an electronic material composition.
A sixth object of this invention is to provide an electronic material composition to be employed for forming an external electrode for electronic component, which is capable of alleviating a stress resulting from changes in temperature of the electronic component even if the stress is generated in an electronic component mounted on a printed wiring board, to provide an electronic component formed of such an electronic material composition, and to provide the use of such an electronic material composition.
A seventh object of this invention is to provide an electronic material composition to be employed for bonding an electronic component to a printed wiring board, which is capable of alleviating a stress even if the stress is generated in the electronic component from changes in temperature thereof, to provide an electronic component formed of such an electronic material composition, and to provide the use of such an electronic material composition.
An eighth object of this invention is to provide an electronic material composition to be employed for manufacturing a bonding material which enables to obtain a bonded body of a couple of members, which is capable of absorbing a difference, if any, in irreversible expansion coefficient or shrinkage factor between these member due to the heat-treatment, thereby making it possible to prevent the generation of cracks in the bonded body, to provide an electronic component formed of such an electronic material composition, and to provide the use of such an electronic material composition.
A ninth object of this invention is to provide an electronic material composition which is capable of withstanding a thermal stress under a condition where temperature is differentiated, even if the electronic material composition is employed as a bonding material for bonding a plurality of members each having a different linear expansion coefficient from each other, or as a covering material for covering a plurality of members each having a different linear expansion coefficient, to provide an electronic component formed of such an electronic material composition, and to provide the use of such an electronic material composition.
A tenth object of this invention is to provide an electronic material composition which enables to obtain a filler to be employed for manufacturing an electromagnetic shielding wall which is capable of preventing an electromagnetic wave from entering or leaking through a gap between the electromagnetic shielding boards, panels or tiles of building, to provide an electronic component formed of such an electronic material composition, and to provide the use of such an electronic material composition.
A eleventh object of this invention is to provide the use of an electronic material composition which enables to prevent an object from being damaged which may be caused due to the heating for curing, and to provide an electronic component to be obtained from the use of such an electronic material composition.
With a view to solve the aforementioned problems, this invention provides (1) an electronic material composition comprising at least a curable polymer and exhibiting the following physical properties (a) and (b) after being cured to form a cured body;
(a) temperature characteristic in relative to stiffness modulus, which is featured in that a glass transition temperature in a process of shifting the cured body from a glassy state to a rubbery state due to the change of stiffness modulus in relative to temperature is in the range of xe2x88x9250 to 50xc2x0 C.; and
(b) stiffness modulus in said rubbery state which is in the range of 105 Pa to 107 Pa.
This invention further provides (2) an electronic material composition comprising at least a curable polymer and exhibiting the following physical properties (a), (b) and (c) after being cured to form a cured body;
(a) temperature characteristic in relative to stiffness modulus, which is featured in that a glass transition temperature in a process of shifting the cured body from a glassy state to a rubbery state due to the change of stiffness modulus in relative to temperature is in the range of xe2x88x9250 to 50xc2x0 C.;
(b) stiffness modulus in said rubbery state which is in the range of 105 Pa to 107 Pa; and
(c) extensibility which cannot be destroyed even if said cured body is subjected to a shear deformation of 5% at a temperature of xe2x88x9250xc2x0 C.
This invention further provides (3) an electronic material composition comprising at least powdery electronic material and a curable polymer, and exhibiting the following physical properties (d) and (e) after being cured to form a cured body;
(d) temperature characteristic in relative to stiffness modulus, which is featured in that a glass transition temperature in a process of shifting the cured body from a glassy state to a rubbery state due to the change of stiffness modulus in relative to temperature is in the range of xe2x88x9250 to 50xc2x0 C.; and
(e) stiffness modulus in said rubbery state which is in the range of 106 Pa to 108 Pa.
This invention further provides (4) an electronic material composition comprising at least powdery electronic material and a curable polymer, and exhibiting the following physical properties (d), (e) and (f) after being cured to form a cured body;
(d) temperature characteristic in relative to stiffness modulus, which is featured in that a glass transition temperature in a process of shifting the cured body from a glassy state to a rubbery state due to the change of stiffness modulus in relative to temperature is in the range of xe2x88x9250 to 50xc2x0 C.;
(e) stiffness modulus in said rubbery state which is in the range of 106 Pa to 108 Pa; and
(f) extensibility which cannot be destroyed even if said cured body is subjected to a shear deformation of 2% at a temperature of xe2x88x9250xc2x0 C.
This invention further provides (5) an electronic material composition according to any one of the aforementioned items (1) to (4), wherein the curable polymer comprises polysulfide-based polymer containing therein polysulfide rubber skeleton (xe2x80x94Sxe2x80x94Sxe2x80x94).
This invention further provides (6) an electronic material composition according to the aforementioned item (5), wherein the polysulfide-based polymer is polysulfide.
This invention further provides (7) an electronic material composition according to the aforementioned item (5), wherein the polysulfide-based polymer is polysulfide-modified epoxy polymer which is a reaction product between polysulfide and an epoxy compound.
This invention further provides (8) an electronic material composition according to any one of the aforementioned items (1) to (4), wherein the electronic material composition is adapted for use for forming an electronic component and formulated into a raw material for forming a body selected from the group consisting of a molded body, a packed body, a covering body, an electrode and a joining body.
This invention further provides (9) an electronic material composition according to any one of the aforementioned item (5), wherein the electronic material composition is adapted for use for forming an electronic component and formulated into a raw material for forming a body selected from the group consisting of a molded body, a packed body, a covering body, an electrode and a joining body.
This invention further provides (10) an electronic material composition according to any one of the aforementioned item (6), wherein the electronic material composition is adapted for use for forming an electronic component and formulated into a raw material for forming a body selected from the group consisting of a molded body, a packed body, a covering body, an electrode and a joining body.
This invention further provides (11) an electronic material composition according to any one of the aforementioned item (7), wherein the electronic material composition is adapted for use for forming an electronic component and formulated into a raw material for forming a body selected from the group consisting of a molded body, a packed body, a covering body, an electrode and a joining body.
This invention further provides (12) an electronic component comprising a body selected from the group consisting of a molded body, a packed body, a covering body, an electrode and a joining body as set forth in the aforementioned item (8).
This invention further provides (13) an electronic component according to the aforementioned item (12), wherein the molded body is a core of wound chip coil which can be obtained by means of molding, and the electronic component is a wound chip coil having said core.
This invention further provides (14) an electronic component according to the aforementioned item (12), wherein the covering body is an external packaging covering the winding of wound chip coil, and the electronic component is a wound chip coil having said external packaging.
This invention further provides (15) an electronic component according to the aforementioned item (12), wherein the covering body is an electromagnetic shielding covering body for a casing, and the electronic component is a casing for an electromagnetic component having said electromagnetic shielding covering body.
This invention further provides (16) an electronic component according to the aforementioned item (12), wherein the covering body is a cable sheath for preventing radiant noise, and the electronic component is a radiant noise-free cable having said cable sheath for preventing radiant noise.
This invention further provides (17) an electronic component according to the aforementioned item (12), wherein the covering body is an external packaging body for packaging mounted components on a printed wiring board, and the electronic component is a printed wiring board having said external packaging.
This invention further provides (18) an electronic component according to the aforementioned item (12), wherein the packed body is obtained by making use of an electromagnetic shielding caulking material as a filler for filling a gap between the electromagnetic shielding boards, panels or tiles, which are designed to form an electromagnetic shielding wall, and the electronic component is an electromagnetic shielding wall having said packed body.
This invention further provides (19) an electronic component according to the aforementioned item (12), wherein the electrode is an external electrode of a chip type electronic component, and the electronic component is a chip type electronic component having said electrode.
This invention further provides (20) an electronic component according to the aforementioned item (12), wherein the joining body is a conductive connecting body for connecting an external electrode of chip component with a soldering land of a printed wiring board, and the electronic component is a printed wiring board having said conductive connecting body.
This invention further provides (21) an electronic component according to the aforementioned item (12), wherein the joining body is an interface connecting body for connecting a pair of members with each other through the interface thereof, each member exhibiting a different irreversible expansion coefficient or shrinkage factor from the other as they are heat-treated, and the electronic component is a composite electronic component wherein said members are connected with each other via said interface connecting body and heat-treated.
This invention further provides (22) an electronic component according to the aforementioned item (12), wherein the joining body is designed to connect a plurality of members, each member exhibiting a different linear expansion coefficient from one another, and the electronic component is an electronic component having said plurality of members which are connected through said joining body.
This invention further provides (23) an electronic component comprising a body selected from the group consisting of a molded body, a packed body, a covering body, an electrode and a joining body as set forth in the aforementioned item (10).
This invention further provides (24) an electronic component according to the aforementioned item (23), wherein the molded body is a core of wound chip coil which can be obtained by means of molding, and the electronic component is a wound chip coil having said core.
This invention further provides (25) an electronic component according to the aforementioned item (23), wherein the covering body is an external packaging covering the winding of wound chip coil, and the electronic component is a wound chip coil having said external packaging.
This invention further provides (26) an electronic component according to the aforementioned item (23), wherein the covering body is an electromagnetic shielding covering body for a casing, and the electronic component is a casing for an electromagnetic component having said electromagnetic shielding covering body.
This invention further provides (27) an electronic component according to the aforementioned item (23), wherein the covering body is a cable sheath for preventing radiant noise, and the electronic component is a radiant noise-free cable having said cable sheath for preventing radiant noise.
This invention further provides (28) an electronic component according to the aforementioned item (23), wherein the covering body is an external packaging body for packaging mounted components on a printed wiring board, and the electronic component is a printed wiring board having said external packaging.
This invention further provides (29) an electronic component according to the aforementioned item (23), wherein the packed body is obtained by making use of an electromagnetic shielding caulking material as a filler for filling a gap between the electromagnetic shielding boards, panels or tiles, which are designed to form an electromagnetic shielding wall, and the electronic component is an electromagnetic shielding wall having said packed body.
This invention further provides (30) an electronic component according to the aforementioned item (23), wherein the electrode is an external electrode of a chip type electronic component, and the electronic component is a chip type electronic component having said electrode.
This invention further provides (31) an electronic component according to the aforementioned item (23), wherein the joining body is a conductive connecting body for connecting an external electrode of chip component with a soldering land of a printed wiring board, and the electronic component is a printed wiring board having said conductive connecting body.
This invention further provides (32) an electronic component according to the aforementioned item (23), wherein the joining body is an interface connecting body for connecting a pair of members with each other through the interface thereof, each member exhibiting a different irreversible expansion coefficient or shrinkage factor from the other as they are heat-treated, and the electronic component is a composite electronic component wherein said members are connected with each other via said interface connecting body and heat-treated.
This invention further provides (33) an electronic component according to the aforementioned item (23), wherein the joining body is designed to connect a plurality of members, each member exhibiting a different linear expansion coefficient from one another, and the electronic component is an electronic component having said plurality of members which are connected through said joining body.
This invention further provides (34) an electronic component comprising a body selected from the group consisting of a molded body, a packed body, a covering body, an electrode and a joining body as set forth in the aforementioned item (11).
This invention further provides (35) an electronic component according to the aforementioned item (34), wherein the molded body is a core of wound chip coil which can be obtained by means of molding, and the electronic component is a wound chip coil having said core.
This invention further provides (36) an electronic component according to the aforementioned item (34), wherein the covering body is an external packaging covering the winding of wound chip coil, and the electronic component is a wound chip coil having said external packaging.
This invention further provides (37) an electronic component according to the aforementioned item (34), wherein the covering body is an electromagnetic shielding covering body for a casing, and the electronic component is a casing for an electromagnetic component having said electromagnetic shielding covering body.
This invention further provides (38) an electronic component according to the aforementioned item (34), wherein the covering body is a cable sheath for preventing radiant noise, and the electronic component is a radiant noise-free cable having said cable sheath for preventing radiant noise.
This invention further provides (39) an electronic component according to the aforementioned item (34), wherein the covering body is an external packaging body for packaging mounted components on a printed wiring board, and the electronic component is a printed wiring board having said external packaging.
This invention further provides (40) an electronic component according to the aforementioned item (34), wherein the packed body is obtained by making use of an electromagnetic shielding caulking material as a filler for filling a gap between the electromagnetic shielding boards, panels or tiles, which are designed to form an electromagnetic shielding wall, and the electronic component is an electromagnetic shielding wall having said packed body.
This invention further provides (41) an electronic component according to the aforementioned item (34), wherein the electrode is an external electrode of a chip type electronic component, and the electronic component is a chip type electronic component having said electrode.
This invention further provides (42) an electronic component according to the aforementioned item (34), wherein the joining body is a conductive connecting body for connecting an external electrode of chip component with a soldering land of a printed wiring board, and the electronic component is a printed wiring board having said conductive connecting body.
This invention further provides (43) an electronic component according to the aforementioned item (34), wherein the joining body is an interface connecting body for connecting a pair of members with each other through the interface thereof, each member exhibiting a different irreversible expansion coefficient or shrinkage factor from the other as they are heat-treated, and the electronic component is a composite electronic component wherein said members are connected with each other via said interface connecting body and heat-treated.
This invention further provides (44) an electronic component according to the aforementioned item (34), wherein the joining body is designed to connect a plurality of members, each member exhibiting a different linear expansion coefficient from one another, and the electronic component is an electronic component having said plurality of members which are connected through said joining body.
This invention further provides (45) a method of using an electronic material composition, which comprises the steps of; forming an electronic component having a semi-cured state of a molded body, a packed body, a covering body, an electrode or a joining body by making use of the electronic material composition of any one of the aforementioned items (1) to (4); and completely curing the molded body, the packed body, the covering body, the electrode or the joining body to obtain the electronic component having a cured state of the molded body, the packed body, the covering body, the electrode or the joining body.
This invention further provides (46) a method of using an electronic material composition, which comprises the steps of; forming an electronic component having a semi-cured state of a molded body, a packed body, a covering body, an electrode or a joining body by making use of the electronic material composition of the aforementioned item (6); and completely curing the molded body, the packed body, the covering body, the electrode or the joining body to obtain the electronic component having a cured state of the molded body, the packed body, the covering body, the electrode or the joining body.
This invention further provides (47) a method of using an electronic material composition, which comprises the steps of; forming an electronic component having a semi-cured state of a molded body, a packed body, a covering body, an electrode or a joining body by making use of the electronic material composition of the aforementioned item (7): and completely curing the molded body, the packed body, the covering body, the electrode or the joining body to obtain the electronic component having a cured state of the molded body, the packed body, the covering body, the electrode or the joining body.
The electronic material composition according to this invention may be either a mixture comprising a resin component, to which powdery electronic materials such as powdery ferrite, powdery electric conductor and a functional filler such as a powdery filler are mixed together, or a mixture comprising a resin component, to which such powdery electronic materials are not mixed together. The former mixture can be employed, by optionally selecting a suitable kind of powdery electronic materials, as a coating material, a molding material, an electrode material, a joining material or a filler. Even in the case of the latter mixture, it may be employed as any of the aforementioned materials, for example as a packaging material for a wound chip coil. In any case, it is desirable that these resinous material compositions have the following physical properties.
First of all, in the case of the resinous material composition containing no powdery electronic material, the cured product thereof should desirably be provided with the following features (a) and (b).
(a) Temperature characteristic in relative to stiffness modulus, which is featured in that a glass transition temperature in a process of shifting the cured body from a glassy state to a rubbery state due to the change of stiffness modulus in relative to temperature is in the range of xe2x88x9250 to 50xc2x0 C.; and
(b) stiffness modulus in said rubbery state which is in the range of 105 Pa to 107 Pa.
With respect to the stiffness modulus in relative to temperature, the rate of change thereof is relatively large especially in the process of being shifted from a glassy state to a rubbery state. Therefore, due to this large rate of change, it can be distinguished from the glassy state or the rubbery state where the rate of change is relatively small. The glass transition temperature is located within the range of temperature which corresponds to the variation curve exhibiting a large rate of change and can be represented by Tg.
In terms of dynamic viscoelasticity, the storage elastic modulus (Gxe2x80x2) representing the magnitude of the elasticity characteristics of polymer generally decreases as the temperature increases. In the case, while the Gxe2x80x2 of thermoplastic resin continues to decrease even in the rubber region thereof, the Gxe2x80x2 of cross-linking type polymer keeps to remain the same level or increases in the rubber region thereof without further decreasing. On the other hand, the relationship between temperature and the dynamic loss modulus (Gxe2x80x3) representing the magnitude of viscosity characteristics of polymer can be shown by a curve having a maximal point. Further, dynamic loss (loss tangent) tan xcex4 (xcex4 is a phase angle (a phase difference between stress and strain vector)) can be measured from a phase difference between stress and the simple harmonic oscillation of strain, thereby making it possible to assume the dynamic loss as a scale indicating the degree of loss, due to the generation of heat, of dynamic energy received by the system. However, the temperature indicating the peak value of tan xcex4 in the curve Gxe2x80x3 would become Tg (glass transition temperature) of dynamic measurement, this peak value may be assumed as the aforementioned glass transition temperature Tg. This Tg value can be made higher by increasing the crosslinking density or by designing a polymer which is high in nuclear structural concentration such as phenyl nucleus. This Tg value can be also made lower by loosening the crosslinking density, by introducing an alkyl chain of fatty acid into the polymer, or by mixing a plasticizer into the polymer. The details on these matters can be found in a document xe2x80x9cThe Latest Pigment Dispersion Technologyxe2x80x9d, 1993, Technological Information Association, pp 53-54, para 2.1, which is incorporated herein for reference.
With regard to the aforementioned features (a) and (b), in the case of the cured product of epoxy resin that has been conventionally employed in the fields of electronic material, the Tg thereof is generally higher than 50xc2x0 C. and the stiffness modulus in the rubbery state is also higher than 108Pa. On the other hand, the ordinary crosslinked rubber exhibiting a large elasticity is generally extremely low in Tg, i.e. not less than twice lower than xe2x88x9250xc2x0 C. Whereas this invention is featured in the employment of an electronic material having the aforementioned features of not only (a) but also (b), which features are not found in the conventional electronic material. As a result, it is possible according to this invention to provide an electronic material excellent in flexibility, toughness and resistivity to thermal stress. By the way, the resin component to be employed in this invention is curable and hence can be distinguished from thermoplastic resin. If the value of Tg is too large, the toughness of the electronic material as it is placed under a condition where there is a prominent difference in temperature as in the case of the aforementioned reflow soldering test would be badly deteriorated. On the other hand, if the value of Tg is too small, the density of crosslinking would become low and hence become poor in heat resistance. Further, if the stiffness modulus is too large, the relaxation of thermal stress or mechanical stress would be badly deteriorated, while if the stiffness modulus is too small, the shape retention would be deteriorated.
As explained above, the resinous material composition to be employed in this invention can be distinguished from other conventional resinous material compositions in the respect that it is provided with the aforementioned features (a) and (b). It is also possible to further distinguish the resinous material composition of this invention from the conventional ones by further providing it with the following feature (c).
(c) Extensibility which cannot be destroyed even if a cured body is subjected to a shear deformation of 5% at a temperature of xe2x88x9250xc2x0 C.
This feature (c) illustrates the absorbency of external force, which enables to absorb an external force without giving rise to the fracture of cured product. In the case of the cured product of epoxy resin that has been conventionally employed in the fields of electronic material, a fracture is caused to occur as the cured product is subjected to a shear deformation of 5% at a temperature of xe2x88x9250xc2x0 C. Therefore, the conventional cured product of epoxy resin can be much more distinguished from the resinous material composition of this invention in this feature (c) rather than the aforementioned feature (b).
As for the resinous material composition which meets the aforementioned various characteristics, a resinous material composition comprising, as a main component, polysulfide-based polymer can be exemplified. It is of course possible to employ other kinds of resinous material composition.
This polysulfide-based polymer may be a polymer having a polysulfide rubber skeleton (xe2x80x94Sxe2x80x94Sxe2x80x94) in its molecule, a polymer comprising, as a main component, polysulfide having a large number of sulfide groups, or a polysulfide polymer itself. This polysulfide can be represented by the general formula, HSxe2x80x94( . . . xe2x80x94SS)n . . . xe2x80x94SH (wherein xe2x80x9c. . .xe2x80x9d is an organic group having a skeleton comprising a sulfide bond, a carbon-carbon bond, an ether bond, etc.; and n is an integer including zero), and is capable of bringing about a dehydration reaction in the presence of oxygen as shown below, the dehydration reaction taking place at the terminal portion of each polysulfide molecule for instance. Further, in the presence of oxidizer, the polysulfide may be formulated into a cold-setting polymer.
. . . xe2x80x94SH+HSxe2x80x94. . . +0xe2x86x92. . . xe2x80x94SSxe2x80x94. . .
As for the molecule of polysulfide, the following molecule can be exemplified specifically.
HSxe2x80x94C2H4OCH2OC2H4xe2x80x94SSxe2x80x94C2H4OCH2OC2H4xe2x80x94SH
This specific compound is known and employed as a component for a caulking material for building, and some kinds of this compound is placed on the market.
This polysulfide-based polymer may be a reaction product between polysulfide and a component of other kind of polymer or compound, or may be made curable by introducing epoxy group or other kinds of reactive functional group.
As for polysulfide modified epoxy resin consisting of a polysulfide modified epoxy polymer which is a reaction product between the aforementioned polysulfide and an epoxy compound, a resin consisting of a polymer to be obtained through a reaction between thiol group (xe2x80x94SH) and epoxy group can be exemplified. For example, a resin consisting of a straight-chain high-molecular weight compound to be obtained from the reaction shown in the following general formula (1) for instance and having a weight average molecular weight of 1000 to 22000 can be exemplified. It is also possible to exemplify a resin consisting of a straight-chain high-molecular weight compound comprising, as a fundamental skeleton, a reaction product to be obtained from the reaction shown in the following general formula (1), polysulfide polymer attached to epoxy groups formed respectively at both ends of the skeleton, and epoxy polymer attached to the terminal thiol group of the polysulfide polymer, said straight-chain high-molecular weight compound having a weight average molecular weight of 1000 to 22000, wherein the equivalent ratio formulated of the polymer components is adjusted such that the terminal group of said straight-chain high-molecular weight compound to be ultimately formed through the repetition of the polymerization thereof is constituted by epoxy group.
(wherein R represents a residual group to be derived by removing both terminal groups from polysulfide polymer, i.e. xe2x80x94(C2H4xe2x80x94Oxe2x80x94CH2xe2x80x94Oxe2x80x94C2H4xe2x80x94Sxe2x80x94S)nxe2x80x94C2H4xe2x80x94Oxe2x80x94CH2xe2x80x94Oxe2x80x94C2H4xe2x80x94; and Rxe2x80x2 is C6H4xe2x80x94CH2xe2x80x94C6H4xe2x80x94 (wherein C6H4is benzene ring)
The reaction components and the extensibility of product are schematically shown in FIG. 1 (R and Rxe2x80x2 of the general formula 1 are also shown therein).
Specific examples of epoxy compound useful in this case are bisphenol type epoxy resins such as bisphenol A-type epoxy resin, bisphenol F-type epoxy resin (both, Dai-Nippon Ink Chemical Industries Co., Ltd.), Eposet (BPA328) and Eposet (BPF307) (both, Nihon Shokubai Co., Ltd.).
Not only the aforementioned reaction product having epoxy group on both ends, but also a resin consisting of polysulfide-modified epoxy polymer having epoxy group at one end of the polymer as well as other portion of polymer can be cured by using them together with a curing agent. Whereas when a latent curing agent (a curing agent which is hardly capable of functioning as a curing agent at ordinary temperature but is capable of functioning as a curing agent upon heating) is employed together with these polymers, a molded product or coated film consisting of a cured resin can be obtained while maintaining the same workability as the ordinary coating material.
Polysulfides such as polysulfide polymer, epoxy compounds, the aforementioned polysulfide-modified epoxy polymer and other polysulfide-modified curable polymer where a reactive compound other than epoxy compound is employed can be formed, singly or in combination of two or more kinds, into a curable resin composition for electronic materials together with, if required, at least one kind of additive selected from the group consisting of other kinds of curable polymer, non-curable polymers including rubber, curing agents such as latent curing agents, fillers and coupling agents. The curable resin composition thus formulated can be employed for obtaining a cured molded product or coated film. It is possible, in this case also, to combine a greatly extensible skeleton with a slightly extensible skeleton as shown in FIG. 1.
As for the curing agent, it is possible to employ imidazole type amine adducts, straight chain type dicarbohydrazide, etc. Specific examples of the curing agent include PNxe2x80x94H and MYxe2x80x94H (trademark, Ajinomoto Co., Ltd.).
The cured film containing as a main component the aforementioned polysulfide-based polymer exhibits a Tg value which is the same with or lower than that of the cured film of silicone resin which is known as being excellent in flexibility, and also exhibits the same degree or a lower degree of relaxation to thermal stress when it is employed as a joining material or as an electrode material as compared with the known cured film of silicone resin. Even in the comparison with the cured film of epoxy resin, the cured film containing as a main component the aforementioned polysulfide-based polymer is comparable thereto or more excellent in terms of solvent resistance, chemical resistance and heat resistance of the adhesive power thereof to a metal, etc. For instance, the cured film containing as a main component the aforementioned polysulfide-based polymer is allowed to be barely oxidized when it is heated to a temperature higher than 230xc2x0 C.
As compared with silicone resin, the curing of the resinous material composition containing the aforementioned polysulfide can be more easily controlled by adjusting the quantity of oxygen to be supplied. Further, the degree of curing of polysulfide-based polymer having epoxy group introduced therein can be also easily controlled, so that the polymer in the B-stage thereof, i.e. in a semi-cured state thereof (irrespective of whether or not the quantity of curing is larger or smaller than a half thereof) can be employed for covering or filling an object in conformity with the specific configuration of the object. Thus, even if the object has an odd-shaped portion, the polymer can be applied and then completely cured so as to conform with the shape of the object.
As explained above, the resinous material composition containing the aforementioned polysulfide is provided with features which are comparable to those of the silicone resin and epoxy resin, and is also excellent in adaptability in the use thereof. Further, this resinous material composition can be employed together with these silicone resin and epoxy resin, thereby allowing the polysulfide or other kinds of polysulfide-based polymer to be reacted with the polymers of these resins. Alternatively, in addition to the co-use thereof together with silicone resin and/or epoxy resin, this resinous material composition can be employed together with other components so as to obtain a material satisfying the aforementioned physical features (a) and (b), or (a) to (c).
The aforementioned polysulfide-based polymer or a mixture thereof with other kinds of polymer component may be formulated together with a solvent including an epoxy-containing reactive diluent or other non-reactive solvent, thereby enabling the resinous material composition per set to be used as an electronic material composition. Alternatively, the resinous material composition may be mixed with a powdery electronic material, the examples of which include a magnetic material such as powdery ferrite; a conductive powder such as metallic powder (such as silver powder and copper powder) and carbon powder; and a functional filler such as a packing material, thereby obtaining an electronic material composition such as a conductive material composition or a magnetic material composition.
If the aforementioned polysulfide-based polymer or a mixture thereof with other kinds of polymer component is to be employed as a mixture thereof with a powdery magnetic material, 0 to 60% by volume of the powdery magnetic material can be mixed with 40 to 100% by volume of the polysulfide-based polymer or a mixture thereof with other kinds of polymer component to obtain a magnetic material composition which may further contain, if required, other kinds of resin, a solvent or other kinds of additive. As for the powdery magnetic material, various kinds of ferrite power can be employed. On the other hand, if the aforementioned polysulfide-based polymer or a mixture thereof with other kinds of polymer component is to be employed as a mixture thereof with a powdery conductive material, 0 to 60% by volume of the powdery conductive material can be mixed with 40 to 100% by volume of the polysulfide-based polymer or a mixture thereof with other kinds of polymer component to obtain a conductive material composition which may further contain, if required, other kinds of resin, a solvent or other kinds of additive. As for the powdery conductive material, a metallic powder composed of silver, copper, aluminum, etc. or carbon black can be employed. It is also possible in this case to employ fullerene (C60 or C70 type carbon). By the way, the aforementioned expression of: xe2x80x9c0 to 60% by volumexe2x80x9d may be replaced by the expression of: xe2x80x9cnot more than 60% by volumexe2x80x9d. The same substitution of expression can be also applied to where the expression of xe2x80x9c0 to - - -xe2x80x9d is referred to hereinafter.
The physical properties of cured products of an electronic material composition including the aforementioned magnetic material composition, conductive material composition and other kinds of material compositions to be obtained in the same manner as those of the aforementioned magnetic or conductive material composition are required to have the following features.
(d) Temperature characteristic in relative to stiffness modulus, which is featured in that a glass transition temperature in a process of shifting the cured body from a glassy state to a rubbery state due to the change of stiffness modulus in relative to temperature is in the range of xe2x88x9250 to 50xc2x0 C.; and
(e) stiffness modulus in said rubbery state which is in the range of 106Pa to 108Pa.
As explained above, the resinous components to be employed in this invention can be distinguished from the conventional resinous material compositions employing other resinous components in the respect that it is provided with the aforementioned features (d) and (e). It is also possible to further distinguish the resinous material composition of this invention from the conventional ones by further providing it with the following feature (f).
(f) Extensibility which cannot be destroyed even if a cured body is subjected to a shear deformation of 2% at a temperature of xe2x88x9250xc2x0 C.
The meanings of terms as well as the functions of features related to these features (d) to (f) are the same as described with reference to the aforementioned features (a) to (c).
It is possible, through the employment of such an electronic material composition, to provide a material for electronic parts or electronic products, which is capable of exhibiting an excellent effect which the conventional materials have failed to provide.
For example, by adjusting the quantity of a curing agent to be employed so as to reduce the inter-crosslinking point density representing one of the physical properties of cured product, or by increasing the ratio of polysulfide rubber skeleton occupying the skeleton of polymer so as to adjust the entanglement of rubber molecule chain, the glass transition temperature can be lowered and at the same time, excellent breaking extension property can be ensured while retaining a low stiffness modulus. As a result, it is now possible to simultaneously realize not only the reduction of residual stress at the moment of curing a resin, but also the relaxation of stress that has been generated by heat load.
Specifically, if the aforementioned magnetic material composition is to be employed as a packaging material to be applied to the winding of a wound chip coil, it is possible to reduce the quantity of volatilization of solvent or to make solvent-free thereby making it possible to reconsider the drying step as a curing condition of resin and at the same time, the glass transition temperature representing one of the physical properties of curable resin can be lowered, or the residual stress to be generated prominently at a temperature of not higher than the glass transition temperature can be minimized, thereby making it possible to reduce the residual stress at the moment of initial curing as well as at the moment of cooling. Further, owing to the lowering of glass transition temperature, the reduction of stiffness modulus (the reduction of stress generated) and the improvement of elastic limit elongation percentage (the absorption of stress generated at a temperature of not higher than the glass transition temperature), it is now possible to reduce or absorb the stress generated at the moment of the repetition of heat load. As a result, the generation of peel-off of packing material from the core or of cracking of packing material can be inhibited.
The aforementioned solvent-free can be realized by making use of a reactive diluent such as an epoxy-containing solvent for instance. The lowering of glass transition temperature can be realized by reducing the crosslinking density and by increasing the entanglement of molecule by long molecular chains. For the purpose of lowering the stiffness modulus of the cured product in a state of glass, a modified silicone oil for instance may be co-used as a flexibilizer. By making use of these additives, the glass transition temperature can be lowered to not higher than the normal temperature (25xc2x0 C.), the breaking extension percentage can be increased to 5% or more (even if a powdery electronic material such as ferrite powder for instance is added at a ratio of 50% by volume), the composition can be made solvent-free, and the Young""s modulus of the cured product in a state of glass can be reduced to about a half of the current volume products.
As for the method of increasing the breaking extension percentage, the modification of physical properties of cured product may be performed making use of a main component. Specifically, it is preferable, for this purpose, to employ polysulfide-modified epoxy polymer that can be derived from a reaction between the aforementioned epoxy resin and polysulfide polymer.
When the core of wound chip coil is molded by means of injection molding by making use of the aforementioned magnetic material composition, it is possible to obtain the core which is excellent in reflow solderability and in toughness to shock, and to increase, in conformity with the flexibility of polymer, the filling quantity of ferrite which influences the electric property of the core. Therefore, it is possible to obtain the core without necessitating the cutting work or with so-called work-less, while enabling the degree of freedom in configuration to be realized, enabling the miniaturization of the core to be realized, and enabling the high-functionalization of the core to be realized without necessitating high precision and with high yield. As a result, it is possible to obtain a wound chip coil of high performance at low cost, which the prior art has failed to realize.
The absorption of stress due to a difference in thermal expansion coefficient of the resin for packaging as well as the improvement in shock resistance in conformity with an increase in fineness of chip can be realized as mentioned above by decreasing the elastic modulus of resin, by lowering the glass transition temperature, by increasing the elongation percentage, thereby lowering the residual stress and relaxing the stress thus generated.
Further, when the aforementioned magnetic material composition or resin material composition is employed as a packaging material for covering the winding wound around the core of wound chip coil, a portion of the packaging material of the wound chip coil, on which the adsorption nozzle of a mounter is designed to be adsorbed, is constituted by a flexible polymer component exhibiting a low elastic modulus, so that the packaging material is enabled to be deformed in conformity with the configuration of the contacting surface of adsorption nozzle, thereby scarcely allowing a gap to be formed therebetween. As a result, no slipage can be caused to generate between the nozzle and the packaging material, thus making it possible to minimize the failure of mounting. After the mounting of the chip coil, the packaging material is allowed to restore to the original configuration without inviting no disadvantage as far as the external configuration of the chip coil is concerned.
Further, when the aforementioned magnetic material composition or resin material composition is employed for covering the walls of casing, an electromagnetic shielding layer which is capable of shielding electromagnetic waves from outside which may give an influence to electronic parts mounted inside the casing and hence capable of preventing the generation of noise can be formed. In this case, when the magnetic material composition is formed into a gel-like or putty-like state by making use of a semi-cured polymer component as it is employed for coating the casing and subsequently cured, the workability thereof can be greatly improved as compared with the case where completely uncured polymer is made use of. Irrespective of whether a semi-cured polymer is employed or a completely uncured polymer is employed, the magnetic material composition is formed at first into a sheet by casting it on a releasable film or by extrusion-molding it, and the resultant sheet is then adhered onto the casing (body to be covered with) under heating. In either cases, a troublesome operation of injection-molding an electromagnetic shielding sheet as in the case of the prior art can be omitted, and at the same time, since the polymer employed herein is low in elastic modulus and flexible, the magnetic material composition employing this Polymer can be employed to form an electromagnetic shielding sheet layer for the casing, which is capable of suitably conforming to an odd-shaped surface, of closely adhering to the casing, and of resisting repeated exposures to a difference in temperature of cold and hot.
Irrespective of whether this magnetic material composition is employed as a packaging material or as a covering material, this magnetic material composition is capable of exhibiting an excellent stress relaxation property against the thermal stress to be generated when these materials are placed under a condition where temperature is differentiated.
In the employment of the magnetic material composition as a covering material for the lead wire of cable, the magnetic material composition may be extrusion-molded together with the lead wire, or may be coated on the covering layer of the conventional cable or extrusion-molded together with the covering layer of the conventional cable. It is also possible in this case to provide a cable having a covering layer where the polymer component is low in elastic modulus and flexible, and which is capable preventing radiation noise.
In the employment of the magnetic material composition as an outer electrode material for electronic parts, a conductive material paste consisting of the magnetic material composition is coated on the electronic parts, and then the resultant film is baked. The outer electrode thus formed is then applied on the surface thereof with a copper plating or a nickel plating, after which the resultant electronic parts can be mounted on a printed wiring board by means of soldering. Since the polymer component is flexible, and the skeleton thereof is provided with rubber elasticity in this case also, the outer electrode material is excellent in stress relaxation and in reflow solderability, thereby making it possible to improve the durability of the electronic parts mounted on the printed wiring board. It is preferable that the outer electrode material is provided with the same properties as those of the aforementioned packaging material for wound coil.
In this case, instead of soldering the outer electrode, the aforementioned conductive material paste may be coated either on the aforementioned outer electrode or an outer electrode consisting of the conventional material, or on the soldering land of the printed wiring board, and then heated to form a cementing material for electronic parts. Heating condition in this case may be such that heating may be performed in the range of ordinary temperature to 160xc2x0 C. for several minutes to 20 minutes. Namely, the curing of this conductive material paste can be performed at a lower temperature as compared with the conventional soldering paste using a rosin-based material, thereby making it possible to minimize the damage to the other mounted parts on the printed wiring board, that might be caused due to the heating temperature.
Furthermore, when a cementing material to be obtained from an electronic composition comprising a resin material composition having the aforementioned features (a) and (b), or (a) to (c), or a powdery filler having the aforementioned features (d) and (e), or (d) to (f) is interposed between a green sheet laminate corresponding to an inductor portion and a green sheet laminate corresponding to a condenser portion of LC laminate composite electronic parts, it is possible, owing mainly to the low elastic modulus or flexibility of the polymer component, to relieve a stress that may be generated due to a difference in shrinkage factor between these green sheet laminates on the occasion of baking, thereby making it possible to prevent cracks from generating in the resultant baked body.
Further, when a green sheet laminate corresponding to an inductor portion and a green sheet laminate corresponding to a condenser portion are prepared in advance, and then bodies to be cemented and differing in expansion coefficient are bonded together by making use of an electronic material composition as in the case of the LC element which has been bonded by making use of an electronic material composition having the aforementioned features (d) and (e), or (d) to (f), it is possible to obtain electronic parts exhibiting relaxativity to a thermal stress even if the electronic parts are placed under a condition where temperature is differentiated.
Additionally, when the aforementioned magnetic material composition is employed as a caulking material for filling a joint portion of electromagnetic shielding board or tile constituting the external wall of building, it is possible to improve the heat resistance, weatheability and electromagnetic shielding effect of the joint portion without generating cracks owing to the low elastic modulus or flexibility of the polymer component even if the joint portion is exposed to a repeated difference in temperature of cold and hot. On this occasion, since the caulking material can be cured at the ordinary temperature, it is also convenient in this respect.
As explained above, the electronic material composition of this invention can be used for various end-use. For example, as mentioned above, the polymer component can be employed in a semi-cured state as in the cases of applying it for extrusion-molding the electromagnetic shielding layer of casing or for extrusion-molding the cover or skin of cable. However, in addition to these end-uses, the polymer component can be employed in a semi-cured state for other end-uses in the same manner as mentioned above. Namely, by controlling the heating temperature or heating time, it is possible to prevent electronic parts of electronic products from being damaged due to heating and to obtain other advantages.

Electronic material composition, electronic parts and use of electronic material composition


The present invention provides a new methodology and test composition for determining the presence of theophylline in test samples. The methodology employs enzymes that utilize or recognize theophylline as a substrate to measure the concentration thereof in samples, including body fluids. This new approach utilizes enzymes as opposed to traditional methods which use antibodies for the recognition of theophylline. The enzymatic approach to theophylline determination is quick, simple and convenient and allows test systems to be made in liquid as well as in dry-chemistry formats. Various protocols, systems or methodologies may be used for assaying and relating the results to the amount of theophylline present. Methods for obtaining theophylline utilizing or recognizing enzymes are also described.

The present invention relates to a method for determining theophylline in a sample. More particularly, the present invention relates to a method for determining theophylline which uses a theophylline utilizing enzyme.
Theophylline is a bronchodilator and respiratory stimulant used in the treatment of patients with asthmatic and allergic conditions. It is also used in the treatment of congestive heart failure and acute pulmonary edema. Benefits, as well as risks, from using this drug directly relate to its serum concentration. In order for the drug to be effective, a concentration of theophylline of about 10-20 mg/L level needs to be maintained in the blood. Theophylline levels of less than 10 mg/L are therapeutically ineffective and levels of more than 20 mg/L may be toxic to the patient. This toxicity may result in brain damage and death. Because the therapeutic advantage of the drug lies only within a narrow range of concentrations and because there is a large interpatient difference in drug elimination due to physiological differences, as well as diet or other prescribed drugs, it is important to monitor patients using this drug.
Theophylline has been measured by gas chromatography by Shah, J. Pharm. Sci., 63(8), 1283 (1974) and by a combination of gas chromatography and mass-selective detector by Desage, et al., J. Chromat., 336(2), 285 (1984). It has been measured by high-pressure liquid chromatography by Thompson, et al., J. Lab. Clin. Med., 84(4), 584 (1974) and by Naish, et al., Ann. Clin. Biochem., 16(5), 254 (1979). Schack, et al., J. Pharm., 97, 283 (1949) used an ultraviolet spectrophotometric method for the determination of theophylline. However, because these methods need cumbersome extractions, most clinical approaches today for the determination of theophylline use immunological methods which depend on antibodies for recognizing theophylline in the sample being tested. Such systems involve competitive protein binding where the antibody is the specific binding protein. After the reaction with antibodies takes place, the determination of theophylline varies depending on the particular assay, that is, the assay readout may be turbidimetric, nephelometric, radioactive or colorimetric depending on whether turbidity, radioactivity or color is produced. Examples of these systems are reported by Painter, et al., J. Clin. Lab. Autom., 3(3), 179 (1983), Samoszuk, et al., Ther. Drug Mon., 5(1), 113 (1983), Opheim, et al., Clin. Chem., 30(11), 1870 (1984), Boeckx and Munson, Ther. Drug Mon., 7(1), 95 (1985), Cook, et al., Res. Comm. in Chem. Path. & Pharm., 13(3), 497 (1976), and Landesman, et al., Clin. Chem., 29, 1238 (1983).
Immunological systems have also been reported by Li et al., Clin. Chem., 27(1), 22 (1981), Davis and Marks, Ther. Drug Mon., 5(4), 479 (1983), Chang, et al., Clin Chem 28(2), 361 (1982), Hinds, et al., Clin. Chem., 30(7), 1174 (1984), Jolley, et al., Clin. Chem., 27, 1575 (1983), Morris, et al., Anal. Chem., 53, 658 (1981), and Tyhach, et al., Clin. Chem., 27, 1499 (1981).
In addition, enzymes have been used in an enzyme amplification assay, U.S. Pat. No. 3,817,837. In this disclosure, enzymes are chemically bound to ligands and these enzyme-bound-ligands combine with receptors. The ligand may be a drug. The specific reaction of the ligand with the receptors gives the specificity to the reaction while the enzyme activity is utilized as a marker for the reaction. Therefore, the enzymes used have no enzymatic recognition of the drug. The use of these approaches are totally different to the presently described methodology which uses enzymes instead of antibodies or ligands for the recognition of theophylline.
It has been also reported in European Patent Application Number EP86300226.7, Jan. 15, 1986, as well as in Clin. Chem., 25, 1370 (1979), that the activity of alkaline phosphatase, which acts by cleaving phosphate groups from a substrate, can be inhibited by theophylline. In this approach, the enzymatic reaction of alkaline phosphatase continues to be that of cleaving the phosphate bonds but this action is interfered with by the presence of theophylline. Again, in this disclosure, the theophylline test produced is one in which theophylline is not enzymatically utilized or changed by the enzymatic reaction. By contrast, the present invention teaches that test systems can be produced, using enzymes which utilize or recognize theophylline and use it as a substrate for the quantitation of theophylline in samples.
Since theophylline is a xanthine derivative, commercially available xanthine oxidases and xanthine dehydrogenases and related enzymes were tried for their ability to utilize theophylline and to develop a test system. These attempts were unsuccessful. Although in humans, theophylline is known to be metabolized primarily to 1,3 dimethyluric acid and also to 1 methyluric acid and 3-methylxanthine (Cornish, H. H. and Christman, A. A., J. Biol. Chem., 228, 315 (1957), no theophylline utilizing enzyme has previously been isolated nor its use shown in a test system to quantitate theophylline in a sample.
Here, the present invention contemplates the measurement or quantitation of theophylline concentration using these theophylline utilizing or recognizing enzymes. Examples of these enzymes, namely, theophylline dehydrogenase, theophylline oxidase, and theophylline demethylase are used to demonstrate the efficacy of the method, test composition and test device of the present invention for the measurement of theophylline in samples such as body fluids, food extracts, and medicinal compounds and compositions. The tests that resulted from this enzymatic approach are rapid and convenient to perform. The advantages of the enzymatic approaches are 1) unitized reagent or test composition capability, 2) one step addition of sample to reagent or test composition, 3) a liquid system can be made to perform with instrument readout devices, and 4) the reagent or test composition can easily be incorporated into a solid-phase matrix. The present invention also contemplates a process of obtaining theophylline utilizing or recognizing enzymes from microbial sources which react with theophylline as a substrate and produce a product.


A terminal device includes a reception unit configured to receive first and second electromagnetic waves and first and second sound waves; and a processor configured to determine first and second frequencies respectively indicating transmission frequencies of the first and second sound waves based on the first and second electromagnetic waves, and determine first and second beacons from which the first and second sound waves are transmitted, based on the determined first and second frequencies, wherein the processor determines a location of the terminal device based on the determined first and second beacons.

As a method of determining a location of a terminal device, there is a method utilizing electromagnetic waves and sound waves, for example. FIG. 20 is a view illustrating this method utilizing electromagnetic waves and sound waves.
Beacons 200-1 to 200-3 periodically transmit electromagnetic waves and sound waves at the same time. A terminal device 100 receives an electromagnetic wave (EM1) transmitted from the beacon 200-1, for example, and obtains location information of the beacon 200-1 from information included in the electromagnetic wave (EM1). Then, the terminal device 100 receives a sound wave (S1) and calculates a distance to the beacon 200-1 based on a difference in arrival time between the electromagnetic wave (EM1) and the sound wave (S1). The distance to the beacon 200-1 may be determined, for example, by multiplying a speed difference between an electromagnetic wave and a sound wave by the arrival time difference. In the same way, the terminal device 100 obtains location information of the beacons 200-2, 200-3, and calculates distances to the beacons 200-2, 200-3. Having obtained the location information and the distances of the three beacons, the terminal device 100 calculates the location information of the terminal device 100 by trilateration.
In a method utilizing GPS, for example, a terminal device within doors is incapable of a location determination since radio waves from a GPS satellite do not reach indoors. In contrast, in the method utilizing electromagnetic waves and sound waves, a terminal device within doors is capable of a location determination since beacons configured to transmit the electromagnetic waves and the sound waves are installed within doors.
Moreover, in the method utilizing electromagnetic waves and sound waves, installation cost of equipment may be reduced since the method uses no location server or no synchronization server. In addition, this method utilizing arrival time differences of electromagnetic waves and sound waves is capable of calculating the distances to beacons without using received power strengths of the electromagnetic waves and the sound waves, and therefore achieves improvements in the accuracy of calculation of distances between a terminal device and beacons, and also in the accuracy of location information determination of the terminal device. Meanwhile, this method utilizing arrival time differences of electromagnetic waves and sound waves is under a restriction on the number of installable beacons such that the maximum number of installable beacons is 22, for example.
The followings are examples of techniques for the method utilizing electromagnetic waves and sound waves.
Specifically, one of the techniques is for an autonomous ultrasonic indoor positioning system in which a structured ultrasonic transmitter including a single RF transmitter and multiple ultrasonic transmitters transmits ultrasonic waves at regular intervals, and a reception device calculates the location of the reception device based on differences between reception times of the ultrasonic waves at the reception device.
This technique is considered to enable provision of a highly-accurate low-cost indoor positioning system.
Another technique is for a distance measurement method in which two sound sources placed at two locations at different heights transmit electromagnetic waves and sound waves at the same time, and a terminal device calculates the distances to the two sound sources from the received waves, and calculates the horizontal distance to the sound sources in accordance with the Pythagorean theorem.
This technique is considered to enable measurement of the horizontal distance to sound sources even in a location with a large difference in height and poor visibility.
The related techniques are disclosed in, for example, Japanese Laid-open Patent Publication Nos. 2009-288245 and 10-48309.

Location information determination system


A method includes determining a standard set of activities to perform an assessment and certification process, and identifying cost elements and cost drivers for each activity of the standard set of activities. Additionally, the method includes determining requirements for a particular assessment and certification project, and determining a cost estimation based upon at least one of the standard set of activities, the cost elements, the cost drivers, and the requirements.

1. Field of the Invention
The present invention relates to a method and system for determining and optimizing a cost estimation for performing an assessment and certification project.
2. Background of the Invention
The marketplace requires or encourages entities, e.g., corporations, companies, organizations, etc., to assess and certify their processes and procedures against industry standard quality models, such as eSCM, ISO/9000®, CMMI®, ITIL®, COBIT®, etc. Additionally, with some quality models, the entity may be required to perform the assessment and certification process on a regular basis, e.g., every 2-3 years. ISO is a registered trademark of International Organization for Standardization in the United States, other countries, or both. CMMI is a registered trademark of Carnegie Mellon University in the United States, other countries, or both. ITIL is a registered trademark, and a registered community trademark of the Office of Government Commerce, and is registered in the U.S. Patent and Trademark Office. COBIT is a registered trademark of the IT Governance Institute in the United States, other countries, or both.
An expert, or small teams, from a single location may be required to perform an assessment and certification project; however, these assessment and certification projects have grown more complex and involved, which requires large teams. Moreover, these teams can be from a variety of different countries, with different team members involved with different elements of the assessment and certification project. For example, an entity seeking certification may be located in, e.g., India, but may have additional offices in, e.g., Singapore. Moreover, the entity performing the assessment and certification may be located in, e.g., the United States.
Performing these assessment and certification audits may be very expensive, depending on, e.g., the quality model used and the particulars of the entity seeking certification. Accordingly, an entity seeking certification may desire an assessment and certification project cost estimation prior to granting approval to perform the assessment and certification project. However, with each new assessment and certification project and/or with the cost estimation for each new assessment and certification project, an auditor must start anew and size the audit based upon the quality model used and the particulars of the entity seeking certification.
Additionally, the assessment and certification cost estimation is based off of a non-standardized, custom sized analysis for that particular project. Thus, with each new assessment and certification project cost estimation, reviewers may be unfamiliar with the information presentation. Consequently, a review and approval process may require more time and increase costs.
Additionally, as assessment and certification projects have grown more complex and involved, utilizing people or teams from different countries, costs may be incurred in different currencies. As such, a cost estimate for performing an assessment and certification may include estimated costs in a plurality of currencies. Thus, preparing and reviewing a cost estimation for an assessment and certification project may require the preparers and reviewers to work with and analyze data in a plurality of currencies, which may complicate and slow the preparation and approval processes, and increase the costs.
Accordingly, there exists a need in the art to overcome the deficiencies and limitations described hereinabove.

Quality model certification assessment cost estimation and optimization

International Business Machines Corporation


In order, in an electric motor having a housing including a housing sleeve and a housing cover disposed at the end of the housing sleeve, a rotor mounted rotatably about a rotor axis in the housing, a stator disposed in the housing and having a least one motor winding and having an electrical connection unit disposed on the housing, to lead a feed line to the motor winding in the most favorable way possible in terms of assembly, it is proposed that at least one feed line leading from the electrical connection unit to the motor winding runs within the housing sleeve.

The invention relates to an electric motor, in particular a micro-motor, comprising a housing including a housing sleeve and a housing cover disposed at the end of the housing sleeve, comprising a rotor mounted rotatably about a rotor axis in the housing, comprising a stator disposed in the housing with a least one motor winding and with an electrical connection unit disposed on the housing.
Such electric motors are known in the prior art. The problem here is to lead a feed line to the motor winding in the most favorable way possible in terms of assembly.


Described are embodiments that include methods and devices for separating composite liquids into components. Embodiments involve the use of a flexible membrane for separating a composite liquid into components. The composite liquid may include, in embodiments, a cellular containing liquid, such as whole blood or components of whole blood. In one specific embodiment, the composite liquid is a buffy coat.

Apheresis blood processing plays an important role in a large number of therapeutic procedures. In these procedures, blood is withdrawn from a patient undergoing therapy, separated, and a selected fraction is collected while the remainder is returned to the patient. For example, a patient may undergo leukapheresis prior to radiation therapy, whereby the white blood cell component of his blood is separated, collected and stored to avoid exposure to radiation.
Both conventional blood collection and apheresis systems typically employ differential centrifugation methods for separating blood into its various blood components. In differential centrifugation, blood is circulated through a sterile blood processing vessel which is rotated at high rotational speeds about a central rotation axis. Rotation of the blood processing vessel creates a centrifugal force directed along rotating axes of separation, oriented perpendicular to the central rotation axis of the centrifuge. The centrifugal force generated upon rotation separates particles suspended in the blood sample into discrete fractions having different densities. Specifically, a blood sample separates into discrete phases corresponding to a higher density fraction comprising red blood cells and a lower density fraction comprising plasma. In addition, an intermediate density fraction comprising platelets and leukocytes forms an interface layer between the red blood cells and the plasma. A number of complementary separation techniques based on filtration, elutriation in a cell separation chamber and affinity-based techniques have been developed to achieve higher purities needed for use of blood components as therapeutic agents.
Embodiments of the present invention have been made in light of these and other considerations. However, the relatively specific problems discussed above do not limit the applicability of the embodiments of the present invention.


The present disclosure pertains to a system and method for managing a sleep session of a subject. Managing the sleep session is based on cardiac activity in the subject during the sleep session. Cardiac activity, as monitored via one or more sensors worn on an extremity of the subject and/or placed at a distance from the subject, is used to determine periods of slow wave sleep. Sensory stimulation is delivered to the subject during the periods of slow wave sleep to enhance slow wave activity. Wearing a sensor on an extremity, and/or placing a sensor at a distance from the subject during sleep, as opposed to the subject wearing an EEG cap, is more comfortable for the subject.

1. Field
The present disclosure pertains to a system and method for managing a current sleep session of a subject based on output signals generated by one or more sensors that convey information related to a pulse rate and/or a blood volume of the subject during the current sleep session.
2. Description of the Related Art
Systems for monitoring sleep are known. Typical systems for monitoring sleep include an electroencephalogram (EEG) cap worn on the head of a user during sleep. The EEG cap decreases the comfort level of the user which may interrupt sleep. Sensory stimulation during sleep is known. Sensory stimulation during sleep is often applied continuously and/or at intervals that do not correspond to sleeping patterns of a subject. The present disclosure overcomes deficiencies in prior art systems.

System and method for enhancing sleep slow wave activity based on cardiac activity


Automobile accident claims initiation systems and methods are described. An insured driver may initiate a claim by operating a mobile device. The system provides automated inquiries to the driver through the mobile device. The driver provides responses to the inquiries using the mobile device. The driver may provide images and audio data, as well as personal information and information on the parties and vehicles involved in the accident. The system may automatically arrange for services such as a rental car or a tow truck. The system may provide claim information, such as a claim number to the driver by transmitting information to the mobile device.

An automobile accident can be a very stressful situation. Even if no one is hurt, being in an accident can be very disconcerting for the people involved. However, if someone involved in an accident needs to file an insurance claim, it is best to quickly collect as much information as possible in order to properly submit the claim. If a claimant does not gather at least some information at the scene of the accident, information may later be unavailable or forgotten. Thus, a claimant often attempts to quickly and accurately collect information for an insurance claim at the scene of an accident while they are still under the stress of the accident. A claimant may also desire that such information be provided to an insurer as quickly as possible so that the claim process can be expedited. This may especially be the case when a claimant's vehicle may not be drivable due to the accident. Such a claimant may need a rental car or tow truck as soon as possible, and may wish to begin the claim process so that the claimant's vehicle is returned to service as soon as possible.

Systems and methods for automobile accident claims initiation

United Services Automobile Association (USAA)