WEET Analyze Point Contact Diode Structure and The Internals of the Lead Frame SMD Diode Design

The WEET point contact diode is formed by pressing a metal pin on a single crystal of germanium or silicon and then current method.
Its PN junction has small electrostatic capacity and is suitable for high frequency circuits.
Because of its simple structure, it is cheap.
For small signal detection, rectification, modulation, mixing, limiting and other general purposes,
it is a wide range of applications. Compared with the lead frame type, the forward and
reverse characteristics of the point contact diode are poor, so it can‘t be used in high current and rectification.
Manufacturing process: one end of the thin aluminum wire is connected to the anode lead,
and the other end is pressed on the doped N-type semiconductor.
When the voltage is applied, the fine aluminum wire melts at the contact point and penetrates into the melted part.
In this way, the contact point is actually a p-type semiconductor and is attached to the N-type semiconductor to form a PN junction.
The WEET lead frame type is applied in the field of chip diode packaging.
Its function is to gather single chip diode together so as to facilitate subsequent processing. 

The existing SMA chip type diode structure usually adopts the mode that the independent connecting piece is
placed on the lead frame and then connected by welding, or the two lead frames are stacked and welded.
On the one hand, it needs to use two copper strips for the early stamping,
which not only causes waste of copper strips, but also leads to low production efficiency;
on the other hand, the unit density of the existing lead frame products is low, the utilization rate of copper strips is low,
and the labor efficiency is not high. So the cost for SMD type diode is high.

WEET DO-27 SF51G THRU SF58G (SF51G, SF52G, SF53G, SF54G, SF55G, SF56G, SF58G) Ultra-Fast Recovery Rectifiers


WEET DO-27 SF51 THRU SF58 (SF51, SF52, SF53, SF54, SF55, SF56, SF58) Ultra-Fast Recovery Rectifiers



WEE Technology Company Limited
Manufacturer of Surface Mount (SMD) and Through Hole (DIP) Diodes & Rectifiers

Website: www.weetcl.com, www.weediode.com, www.smddip.com, www.wdiode.com
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