CN202196774U - Plastic packaged power diode with welded metal pad - Google Patents

Abstract

The utility model discloses a plastic-encapsulated power diode welded with a metal gasket, which relates to the technical field of semiconductor separators. It is composed of copper wire with dry prefix, lead-tin-silver solder, ferroalloy gasket, silicon chip and non-cavity plastic package. Iron alloy gasket is welded on the copper wire with dry prefix, and the wire with metal gasket is connected to the silicon chip to lead out the diode. positive and negative poles. The utility model has the advantages of strong thermal stress impact resistance, good high temperature characteristics, high reliability, simple and easy process and suitable for large-scale production.

Description

Plastic encapsulated power diodes with metal gasket soldering

technical field

The utility model relates to the technical field of semiconductor discrete devices, in particular to a plastic-encapsulated power diode. the

Background technique

At present, plastic-encapsulated power diodes are widely used in televisions, computers, energy-saving lamps, and electronic instrumentation circuits. The packaging forms can be divided into: epoxy resin plastic packaging, glass packaging, metal packaging, ceramic packaging, etc. Epoxy resin plastic packaged power diodes are easy to mass-produce and low in cost, and are the mainstream of packaged diodes today. the

There are many ways to manufacture plastic-encapsulated power diodes. Most power diodes with high reverse voltage resistance are manufactured by mesa-type technology. Mainly adopt glass passivation (GPP) silicon chip and acid-etched silicon chip. The former silicon chip can be packaged by injection molding after welding the wire, while the latter is after the chip is welded to the wire, and then cleaned by acid corrosion and high-purity water. Silicone rubber After protection, it can be injection molded and packaged. the

Traditional plastic-encapsulated power diodes are soldered with copper wires, lead-tin-silver solder, and silicon chips, and then encapsulated in epoxy resin plastics. When the temperature is high, the thermal stress applied to the silicon chip will cause the reverse leakage current of the diode to increase or even fail early, and the high temperature characteristics of the diode will deteriorate. the

Utility model content

The purpose of the utility model is to overcome the deficiencies of the prior art and provide a plastic-encapsulated power diode welded with a metal gasket.

The utility model is composed of a copper wire with a dry prefix, a lead-tin-silver soldering piece, an iron alloy pad, a silicon chip and a non-cavity plastic package, the copper wire with a dry prefix is welded with an iron alloy pad, and the wire with a metal pad is connected to the silicon chip Lead out the positive and negative poles of the diode. the

The shape of the ferroalloy spacer is preferably circular, and its diameter is equal to the diameter of the top surface of the dry lead wire. the

The length of the dry prefix copper wire is shorter than that of the existing copper wire, and the shape of the diode is preferably a non-cavity plastic package. the

The substrate of the diode chip is semiconductor silicon, which is relatively brittle and has a small thermal expansion coefficient. When the silicon chip is subjected to thermal stress and mechanical external force, it is easy to cause microcracks, especially in high temperature environments, copper wires, Materials such as plastic packages have a large thermal expansion coefficient, and the thermal stress applied to the silicon chip is very large, which easily leads to early failure of the diode and reduces reliability. the

The utility model has the advantage that the circular copper-plated or nickel-plated iron alloy pads formed by welding and cold stamping are used, and the thermal stress acts on the two metal pads and the silicon chip, and the metal pads share the effect of the thermal stress, which greatly alleviates the stress. The impact of thermal stress on the silicon chip, the high temperature characteristics of the diode are good, and the dry-shaped copper wire material is shortened compared with the traditional diode, saving copper. the

The plastic-encapsulated diode disclosed by the utility model has strong resistance to thermal stress impact, good high-temperature characteristics, high reliability, simple and easy process, and is suitable for large-scale production. the

Description of drawings

Fig. 1 is a structural schematic diagram of a wire with a metal gasket;

Fig. 2 is a schematic diagram of the internal structure of a plastic-encapsulated power diode welded with metal gaskets of the present invention;

FIG. 3 is a schematic diagram of the shape and structure of the plastic-encapsulated power diode with metal pad welding shown in FIG. 2 .

Detailed ways

The utility model is described in detail below in conjunction with accompanying drawing:

In the figure: 1. Copper wire with dry prefix, 2. Solder lug, 3. Ferroalloy spacer, 4. Solder lug for welding silicon chip, 5. Silicon chip, 6. Non-cavity plastic-encapsulated cylinder, 7. Color ring mark .

It is composed of copper wire with dry prefix, lead-tin-silver solder, ferroalloy gasket, silicon chip and non-cavity plastic package. The copper wire with dry prefix is welded with ferroalloy gasket, and the wire with metal gasket is connected to the silicon chip to lead out the diode. positive and negative poles. The shape of the ferroalloy spacer is circular, and its diameter is equal to the diameter of the top surface of the dry lead wire; the length of the dry lead copper wire is shorter than that of the existing copper lead, and the shape of the diode is a non-cavity plastic package. the

Claims (2)

1. A plastic-encapsulated power diode welded with a metal gasket, characterized in that: it is composed of a dry prefix copper wire, a lead-tin-silver solder sheet, an iron alloy gasket, a silicon chip and a non-cavity plastic package, and the dry prefix copper Iron alloy gaskets are welded on the wires, and the wires with metal gaskets are connected to the positive and negative poles of the diodes drawn from the silicon chip. 2. The plastic-encapsulated power diode welded with a metal gasket according to claim 1, wherein the shape of the ferroalloy gasket is circular, and its diameter is equal to the diameter of the upper surface of the stem wire.

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