WO2020006794A1

WO2020006794A1 - Mounting structure and mounting method for switching transistors

Info

Publication number: WO2020006794A1
Application number: PCT/CN2018/097571
Authority: WO
Inventors: 罗耀文; 冯颖盈
Original assignee: 深圳威迈斯电源有限公司
Priority date: 2018-07-03
Filing date: 2018-07-27
Publication date: 2020-01-09
Also published as: CN108684183A; CN108684183B

Abstract

Disclosed in the present invention are a mounting structure and mounting method for switching transistors. The mounting structure comprises: a plastic support connected to one sides of switching transistors and having fixing pins, a PCB fixed to the fixing pins and the pins of the switching transistors, a housing for accommodating the PCB, and an elastic member for fixing and tightly pressing the switching transistors. The present invention can protect the pins of the switching transistors well, and achieve better heat dissipation performance.

Description

Installation structure and installation method of switch tube

Technical field

The invention relates to the field of charging technology and voltage conversion of pure electric vehicles and hybrid vehicles, and in particular relates to a mounting structure of an on-board charger OBC, a voltage converter DCDC, and a switch MOSFET of a related integrated product.

Background technique

With the need for energy saving and emission reduction, and the need to control air pollution, new energy vehicles are gradually commercialized in the market, and electric vehicles are the main force of new energy vehicles. Electric vehicles are divided into pure electric vehicles and hybrid vehicles. The on-board charger OBC and voltage converter DCDC are important components of the electric vehicle, and the switch MOSFET is an important component of the on-board charger OBC and voltage converter DCDC. section. However, in the current welding and fixing solutions of switch MOSFETs, a solder-first solution is used (welding the switch MOSFETs before fixing the switch MOSFETs). This solution will lead to the pin and welding of the switch MOSFETs. The point is subject to great stress, which causes the function to fail, and also causes the switch MOSFET to not fit well on the heat sink, resulting in poor heat dissipation.

Summary of the invention

In order to solve the above-mentioned problems in the prior art, the present invention proposes a mounting structure of a switching tube, which includes: a plastic bracket with a fixed leg fixed to one side of the switching tube, and fixed to the fixed leg and the prong of the switching tube. The PCB board is used to receive the shell of the PCB board, and is used to fix the elastic piece that presses the switch tube.

Preferably, it further comprises a cooling device fixed on the opposite side of the switch tube from the casing, a thermally conductive insulating sheet attached to the cooling device, and fixed to the casing to place the plastic bracket toward the thermal insulation The sheet is compressed by an elastic piece.

In one embodiment, the plastic bracket is fixed to the switch tube by a double-sided tape. The shape of the plastic bracket is adapted to the side of the switch tube, and a groove for positioning the pin of the switch tube is provided, which can accurately locate the pin and the heat dissipation surface of the switch tube, and has a design for independently pressing the switch tube.

The cooling device is a water-cooling device, and the heat-conducting insulating sheet is affixed to the outer wall of the water channel of the water-cooling device; or the cooling device is an air-cooling device, and the outer wall of the air-channel of the air-cooling device is affixed to the cooling device. Thermally conductive insulating sheet.

The elastic member includes a fixing plate fixed to the casing, and an elastic piece with a circular arc angle at a connection point with the fixing plate.

In specific applications, the casing is a casing of a car charger, or a casing of a voltage converter, or other related products.

The invention also provides a method for installing a switching tube, which includes:

Step 1: Stick double-sided adhesive on a plastic bracket that matches the shape of the side of the switch tube;

Step 2: Install the switch tube on a plastic bracket and fix it;

Step 3: Assemble the plastic bracket and the switch tube on the PCB board, so that the fixing feet of the plastic bracket and the PCB board are fixed to form a PCBA;

Step 4. Fix the PCBA to the housing;

Step 5, the plastic bracket and the switch tube and the casing are relatively fixed by pressing the elastic sheet;

Step 6. Solder the switch tube to the PCB.

Preferably, in the step 2, the switch tube is adhered to a plastic bracket and fixed by double-sided adhesive;

In step 5, the plastic bracket is pressed by the elastic member, so that the switch tube is closely attached to the cooling device fixed in the casing through the thermally conductive insulating sheet.

The invention uses a plastic bracket to fix the switch tube assembly, and at the same time adopts the method of first installing and then welding, so that the pins of the switch tube assembly are not easy to loose, and it is also convenient to install elastic parts, so that the switch tube can be closely attached to the cooling device, and the heat dissipation effect is better , Longer life.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram of a plastic bracket of the present invention;

2 is a schematic diagram of fixing the plastic bracket and the switch tube assembly according to the present invention;

3 is a schematic diagram of the installation of the plastic bracket and the PCB board of the present invention;

4 is a schematic diagram of fixing the PABA and the shell of the present invention;

FIG. 5 is a detailed enlarged view of an elastic member according to the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be described in detail and completely in combination with the drawings in the embodiments of the present invention.

The installation structure and installation method of the switch tube according to a specific embodiment of the present invention are to apply the switch tube to the on-board charger OBC, the voltage converter DCDC, and integrated products related to them. They usually have a casing with a cooling device. The cooling device can be a water cooling device or an air cooling device. The water cooling device has a water channel and the air cooling device has an air channel.

As shown in FIG. 1, the switch tube 2 is first fixed to it by a plastic bracket 1. The plastic bracket is shown in FIG. 1. It is an integrally formed plastic piece that matches the shape of one side of the switch tube assembly. Corresponding receiving grooves 12 are provided on the side of each to accommodate each switching tube one by one, and a limiting block is located in the slot to locate the precise position of the switching tube, including a circular protrusion 13 that matches a circular hole on the switching tube, and Positioning blocks 14 on both sides of the switch tube allow the switch tube to be accurately positioned relative to the mounting position on the PCB, and the plastic bracket is also provided with a groove 11 that can fix the switch tube pin 21 to assist in positioning the switch tube. The pin 21 and the plastic support 1 are affixed with a high-temperature-resistant double-sided adhesive, and the switch tube component is pasted on the double-sided adhesive. Figure 2 shows the plastic bracket with the switch tube assembly attached. In addition to double-sided adhesive, it can also be fixed with glue or buckle.

As shown in Figure 3, then the plastic bracket 1 and the switch tube assembly are mounted on the PCB 3, and the fixing feet on the plastic bracket are fixed on the PCB by welding or other fixing methods, but the switch pin is not welded.

As shown in FIG. 4, a PCBA 4 with a plastic bracket and a switch tube assembly is mounted on the casing 5.

As shown in FIG. 5, the plastic bracket is pressed with an elastic member, so that the switch tube is closely attached to the thermally conductive insulation sheet, and the thermally conductive insulation sheet is adhered to the side of the water channel or air duct of the cabinet.

In this embodiment, the elastic member includes a fixing plate 61, an elastic piece 62 forming an arc angle at the connection point with the fixing plate 61, the fixing plate 61 is fixed to the housing by screws 63, one end of the elastic piece 62 is connected to the fixing plate, and the other end is The elastic movable end has a circular arc angle at the end connected to the elastic plate. Under normal circumstances, the clamping piece of the elastic piece is closely attached to the side wall of the water channel or the air duct of the cooling device in the casing. When the plastic bracket installed with the switch tube is inserted therein, the clamp piece can press the switch tube in the water channel or It is on the air duct and provides a better heat dissipation environment for the switch tube. In this process, the plastic bracket plays a good role in protecting the switch tube from being damaged or loosened due to the force exerted by the elastic member.

It should be understood that the foregoing description of the specific embodiments is more detailed and should not be considered as limiting the scope of patent protection of the present invention. The scope of patent protection of the present invention shall prevail.

Claims

An installation structure of a switch tube, comprising: a plastic bracket with a fixed foot fixed to one side of the switch tube, and a PCB board fixed with the fixed foot and a pin of the switch tube, for accommodating the switch tube. The shell of the PCB board.
The mounting structure according to claim 1, further comprising a cooling device fixed on the opposite side of the switch tube from the casing, a thermally conductive insulating sheet attached to the cooling device, and the casing An elastic member that fixes the plastic bracket toward the thermally conductive insulating sheet is fixed.
The mounting structure according to claim 1, wherein the plastic bracket is fixed to the switch tube by a double-sided tape.
The mounting structure according to claim 1, wherein the shape of the plastic bracket is adapted to the side of the switch tube, and a groove for positioning the pin of the switch tube is provided.
The installation structure according to claim 2, wherein the cooling device is a water cooling device, and the outer side wall of the water channel of the water cooling device is pasted with the thermally conductive insulating sheet; or the cooling device is an air cooling device. The outer side wall of the air duct of the air cooling device is pasted with the thermally conductive insulating sheet.
The mounting structure according to claim 2, wherein the elastic member comprises an elastic piece that forms an arc angle with the fixing plate of the housing and a connection point with the fixing plate.
The mounting structure according to claim 1, wherein the casing is a casing of a vehicle-mounted charger or a casing of a voltage converter.
A method for installing a switching tube, comprising:

Step 1: Stick double-sided adhesive on a plastic bracket that matches the shape of the side of the switch tube;

Step 2: Install the switch tube on a plastic bracket and fix it;

Step 3: Assemble the plastic bracket and the switch tube on the PCB board, so that the fixing feet of the plastic bracket and the PCB board are fixed to form a PCBA;

Step 4. Fix the PCBA to the housing;

Step 5: relatively fix the plastic bracket and the switch tube with the casing;

Step 6. Solder the switch tube to the PCB.
The method for installing a switch tube according to claim 8, wherein in the step 2, the switch tube is adhered to a plastic bracket and fixed by double-sided adhesive;
The method for installing a switch tube according to claim 8, wherein in the step 5, the plastic support is pressed by an elastic member, so that the switch tube is closely attached to the cooling device fixed in the casing through the thermally conductive insulating sheet.