Axial diode device

Abstract

The utility model discloses an axial diode device, which comprises a vertically arranged chip, a first pin electrically connected with the positive electrode surface of the chip, a second pin electrically connected with the negative electrode surface of the chip, and an epoxy packaging body coated on the outer side of the chip, one end of the first pin and one end of the second pin which extend horizontally are respectively provided with a welding disc, and the other end of the first pin and the other end of the second pin extend horizontally. The welding disc parallel to the chip is connected with the positive electrode face or the negative electrode face of the chip in a welding mode through a soldering tin layer, the welding disc is located in the epoxy packaging body, and the other end of the first pin and the other end of the second pin extend outwards from the interior of the epoxy packaging body. The area of the surface of one side, facing the chip, of each bonding pad is smaller than the area of the surface, facing the bonding pad, of the chip, and the surface of one side, welded with the chip, of each bonding pad is provided with a plurality of wire slots which are arranged at intervals. According to the utility model, the stability of the connection structure and the contact resistor between the chip and the bonding pad and the stability of the performance in the long-term use process can be ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor power devices, in particular to an axial diode device. Background Art

[0002] The diode is one of the earliest semiconductor devices and is widely used. In particular, in various electronic circuits, diodes are reasonably connected with components such as resistors, capacitors, and inductors to form circuits with different functions, which can realize multiple functions such as rectification of AC power, detection of modulated signals, limiting and clamping, and stabilization of power supply voltage. The axial diode is installed on the electronic circuit board through its leads to play a rectifying role. During the processing of the current axial diode, it is often difficult to accurately control the amount of solder paste in the solder layer, which easily leads to poor chip welding stability and affects the performance of the device. Utility Model Content

[0003] The utility model aims to provide an axial diode device, which can ensure the stability of the connection structure and contact resistance between a chip and a welding pad and the stability of the performance during long-term use.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: an axial diode device, comprising: a vertically arranged chip, a first pin electrically connected to the positive electrode surface of the chip, a second pin electrically connected to the negative electrode surface of the chip, and an epoxy package body coated on the outside of the chip, the first pin and the second pin extending horizontally each have a welding pad at one end, the welding pad arranged parallel to the chip is welded to the positive electrode surface or the negative electrode surface of the chip through a solder layer, the welding pad is located in the epoxy package body, the other end of the first pin and the second pin each extends outward from the epoxy package body, the area of ​​the surface of the welding pad facing the chip is smaller than the area of ​​the surface of the chip facing the welding pad, and a plurality of spaced wire grooves are provided on the surface of each welding pad on the side where it is welded to the chip.

[0005] The further improved scheme in the above technical scheme is as follows:

[0006] 1. In the above solution, the surface of the welding pad on the side where the chip is welded is a circular surface.

[0007] 2. In the above solution, each of the three wire grooves extends in the radial direction of the surface of the welding disk and is evenly spaced in the circumferential direction.

[0008] 3. In the above solution, the welding pad is integrally formed with the main body of the first pin and the second pin.

[0009] 4. In the above solution, a plurality of protrusions and / or depressions are arranged at intervals on the outer surface of the welding pad.

[0010] Due to the application of the above technical solution, the utility model has the following advantages and effects compared with the prior art:

[0011] The utility model axial diode device has a first pin and a second pin extending horizontally, each of which has a welding pad at one end. The welding pad arranged in parallel with the chip is welded to the positive electrode surface or the negative electrode surface of the chip through a solder layer. The welding pad is located in the epoxy package body. The other end of the first pin and the second pin extends outward from the epoxy package body. The area of ​​the surface of the welding pad facing the chip is smaller than the area of ​​the surface of the chip facing the welding pad. A plurality of wire grooves arranged at intervals are provided on the surface of the side where each welding pad is welded to the chip, which can avoid direct contact between the chip and the welding pad due to the thin solder layer. It can also prevent the chip from being deflected due to the excessive thickness of the solder layer between the chip and the welding pad, and prevent the solder layer from overflowing after melting and affecting the tightness of the chip, the welding pad and the epoxy package, thereby ensuring the stability of the connection structure and contact resistance between the chip and the welding pad and the stability of the performance during long-term use; in addition, a number of convex points and / or concave points are arranged on the outer surface of the welding pad at intervals, which further enhances the bonding and covering force between the welding pad and the epoxy package, avoids delamination, and ensures the stability of the overall performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Attached Figure 1 This is a schematic diagram of the structure of the axial diode device of the utility model;

[0013] Attached Figure 2 It is a front view of the welding plate in the utility model.

[0014] In the above figures: 1, chip; 21, first pin; 22, second pin; 3, epoxy package; 4, welding pad; 5, solder layer; 6, wire groove; 71, bump; 72, pit. DETAILED DESCRIPTION

[0015] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0016] Embodiment 1: An axial diode device comprises: a vertically arranged chip 1, a first pin 21 electrically connected to the positive surface of the chip 1, a second pin 22 electrically connected to the negative surface of the chip 1, and an epoxy package 3 wrapped around the outside of the chip 1, wherein the first pin 21 and the second pin 22 extending horizontally each have a welding pad 4 at one end, and the welding pad 4 arranged parallel to the chip 1 is welded to the positive surface or the negative surface of the chip 1 through a solder layer 5, the welding pad 4 is located in the epoxy package 3, and the other end of the first pin 21 and the second pin 22 respectively extends outward from the epoxy package 3, the area of ​​the surface of the welding pad 4 facing the chip 1 is smaller than the area of ​​the surface of the chip 1 facing the welding pad 4, and a plurality of spaced wire grooves 6 are provided on the surface of each welding pad 4 on the side where the chip 1 is welded, and the wire grooves can provide overflow and material leveling space for the molten solder paste during the welding process, thereby achieving good welding while avoiding chip skewness caused by uneven solder layer thickness.

[0017] The surface of the welding pad 4 on the side where the chip 1 is welded is a circular surface; the three wire grooves 6 each extend in the radial direction of the surface of the welding pad 4 and are evenly spaced in the circumferential direction;

[0018] A plurality of protrusions 71 are arranged at intervals on the outer surface of the welding pad 4 .

[0019] Embodiment 2: A biaxial diode device comprises: a vertically arranged chip 1, a first pin 21 electrically connected to the positive surface of the chip 1, a second pin 22 electrically connected to the negative surface of the chip 1, and an epoxy package 3 wrapped around the outside of the chip 1, wherein the first pin 21 and the second pin 22 extending horizontally each have a welding pad 4 at one end, and the welding pad 4 arranged parallel to the chip 1 is welded to the positive surface or the negative surface of the chip 1 through a solder layer 5, the welding pad 4 is located in the epoxy package 3, and the other end of the first pin 21 and the second pin 22 each extends outward from the epoxy package 3, the area of ​​the surface of the welding pad 4 facing the chip 1 is smaller than the area of ​​the surface of the chip 1 facing the welding pad 4, and a plurality of spaced wire grooves 6 are provided on the surface of each welding pad 4 on the side where it is welded to the chip 1.

[0020] The welding pad 4 is integrally formed with the main body of the first pin 21 and the second pin 22;

[0021] The outer surface of the welding pad 4 is provided with a plurality of protrusions 71 and depressions 72 at intervals, and the protrusions 71 and depressions 72 are arranged alternately, so as to further enhance the bonding and covering force between the welding pad and the epoxy package, avoid delamination, and ensure the stability of the overall performance.

[0022] When using the above-mentioned axial diode device, it can avoid the situation where the chip and the welding pad are directly partially welded or holes are formed due to the solder layer being too thin, and the chip is deflected due to the local excessive thickness between the chip and the welding pad caused by the solder layer being too thick. It can also avoid the overflow of the solder layer after melting to affect the tightness of the chip, the welding pad and the epoxy package, thereby ensuring the stability of the connection structure and contact resistance between the chip and the welding pad and the stability of the performance during long-term use; and further improve the bonding coating force between the welding pad and the epoxy package to avoid stratification and other situations, thereby ensuring the stability of the overall performance.

[0023] The above embodiments are only for illustrating the technical concept and features of the utility model, and their purpose is to enable people familiar with the technology to understand the content of the utility model and implement it accordingly, and they cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. An axial diode device, comprising: A vertically arranged chip (1), a first pin (21) electrically connected to the positive electrode surface of the chip (1), a second pin (22) electrically connected to the negative electrode surface of the chip (1), and an epoxy package (3) covering the outer side of the chip (1), characterized in that: one end of each of the first pin (21) and the second pin (22) extending horizontally is provided with a welding pad (4), the welding pad (4) arranged parallel to the chip (1) is welded to the positive electrode surface or the negative electrode surface of the chip (1) through a solder layer (5), the welding pad (4) is located in the epoxy package (3), the other end of each of the first pin (21) and the second pin (22) protrudes outward from the epoxy package (3), the area of ​​the surface of the welding pad (4) facing the chip (1) is smaller than the area of ​​the surface of the chip (1) facing the welding pad (4), and a plurality of wire grooves (6) arranged at intervals are provided on the surface of each welding pad (4) on the side where it is welded to the chip (1).

2. The axial diode device according to claim 1, characterized in that: The surface of the welding pad (4) on the side where it is welded to the chip (1) is a circular surface.

3. The axial diode device according to claim 2, characterized in that: The three wire grooves (6) each extend in a radial direction of the surface of the welding plate (4) and are evenly spaced in the circumferential direction.

4. The axial diode device according to claim 1, characterized in that: The welding pad (4) is integrally formed with the main body of the first pin (21) and the second pin (22).

5. The axial diode device according to claim 1, characterized in that: A plurality of convex points (71) and / or concave points (72) are arranged at intervals on the outer surface of the welding plate (4).

Images