JPH11354958A - Control unit for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect electronic components from the temperature rise in a casing by providing a gelled material expansion preventive wall for preventing the expansion of gel substance disposed on a printed board and a frame which, being in contact with the gelled material, fixes the printed board. SOLUTION: This unit is constituted of a gelled material expansion preventive wall 4 disposed on a printed board 1 so as to prevent the expansion of the gelled material 5 covering electronic components 2, 3 disposed on an upper face of the printed board 1 and a frame 6 which, being in contact with the material 5, fixes the printed board 1. Even if the temperature in the casing exceeds an operation guaranteeing range for an IC 2, the IC2 can be kept near the cooling water temperature and thereby can be protected from the temperature rise in the casing since the generated heat is transmitted to the cooling water 12 through a high heat transmission path from the gel 5, then to the frame 6, to the casing 10 and finally to the cooling water 12. The gelled material expansion preventive wall 4 also prevents the leakage of the gel out of the board caused by the vibration of the vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for electronic components in a control unit for a vehicle, and more particularly to a control unit for a vehicle disposed inside a high-temperature housing.

[0002]

2. Description of the Related Art Conventionally, a method of cooling an electronic component is a method of cooling using a fan or a method of diffusing heat by bringing a film containing a cooling material into contact with the electronic component as disclosed in Japanese Patent Laid-Open No. 5-102359. (Liquid heat sink).

[0003]

However, in the above prior art, in a vehicle control unit in which the unit body is constantly exposed to vibration, the liquid heat sink moves in the unit and applies stress to the electronic components, so that it can be applied. Did not.

[0004]

According to a first aspect of the present invention, there is provided a vehicle control unit comprising: a printed circuit board; electronic components disposed on upper and lower surfaces of the printed circuit board; A gel-like substance arranged to cover, and a gel-like substance diffusion preventing wall arranged on a printed circuit board to prevent the gel-like substance from diffusing,
The electronic component can be cooled without applying stress to the electronic component because the frame is configured to contact the gel-like substance and fix the printed circuit board.

Further, a vehicle control unit according to a second aspect of the present invention is a vehicle control unit comprising: a printed circuit board; electronic components disposed on upper and lower surfaces of the printed circuit board; and a gel-like substance disposed so as to cover the electronic component. In a control unit for a vehicle having a frame for preventing the gel substance from diffusing, a gel substance diffusion preventing wall disposed on a printed circuit board, and a frame for contacting the gel substance and fixing the printed circuit board, Since the frame has at least a fin-shaped portion in contact with the gel-like substance, the cooling efficiency is good and the gel-like substance can be suppressed to a small amount.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment according to the present invention will be described. FIG. 1 is a diagram illustrating the configuration of the first embodiment. In FIG. 1, 2 is an electronic component having a low operation guarantee temperature, 3 is an electronic component having a high operation guarantee temperature, 5 is a gel-like substance having a high thermal conductivity, and 4 is a gel-like substance that prevents leakage from the substrate 1. Is a frame that adheres to the gel and fixes the substrate 1, and 7 is a cover that blocks external noise and protects the circuit board. The vehicle control unit constituted by 1 to 7 is disposed inside 10 which is a housing of the motor control device.
The motor control device itself includes a power semiconductor module 20, a smoothing capacitor 21, a DC
It is composed of reactor 22, bus bar 23, etc.
The electric motor (not shown) is rotated by switching the power semiconductor module 20 with a signal from the control unit and controlling the current.

A control unit in a motor control device for a vehicle is exposed to a high temperature inside the motor control device due to heat generated from a power semiconductor module 20, a smoothing capacitor 21, a DC reactor 22, a bus bar 23, and the like. Therefore, a method of convection of the air inside the housing and a method of enlarging the housing have been adopted. As a method other than a fan, a liquid heat sink or the like is effective, but it cannot be applied due to a problem of vehicle vibration.

In the control unit according to the first embodiment of the present invention, the printed circuit board 1, the electronic components 2 and 3 disposed on the upper and lower surfaces of the printed circuit board 1, and the gel disposed so as to cover the electronic components 2 and 3. A gel-like substance 5, a gel-like substance diffusion preventing wall 4 disposed on the printed circuit board 1 to prevent the gel-like substance 5 from diffusing, and a frame 6 that contacts the gel-like substance 5 and fixes the printed circuit board 1. Due to the configuration, even if the temperature inside the housing exceeds the guaranteed operation range of the IC 2, the IC 2 is transferred to the gel 5, the frame 6, the housing 10, and the cooling water 12 as shown in FIG. Since it has a heat path, it can be kept close to the temperature of the cooling water, and can be protected from temperature rise inside the housing. Further, the gel diffusion preventing wall 4 can prevent the gel from leaking out of the substrate due to the vibration of the vehicle.

Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment is an improved version of the first embodiment. In order to increase the heat transfer area between the gel 5 and the frame 6, a portion of the frame 6 that contacts the gel 5 is processed into a fin shape. Therefore, the heat transfer area can be increased, and the heat generated by the electronic component can be efficiently released.

Next, a manufacturing method according to the present invention will be described with reference to FIG. First, solder paste is applied to the surface A of the printed circuit board 1 and the surface-mounted electronic components are placed thereon and passed through a reflow furnace.
Next, surface-mounted electronic components are attached to the B side with an adhesive,
A soldering furnace process is performed with the discrete component 25 inserted and the frame 6 attached to prevent deformation of the component substrate, and the gel-like substance 5 is finally injected through a hole provided in the frame 6 to complete the process. . In the above process, gel is injected from the hole of the frame at the end,
The discrete component 25 can also be brought into contact with the gel 5, so that the discrete component 25 having a low operation guarantee temperature can be used.

[0011]

As described in the above embodiment, the vehicle control unit according to the first aspect of the present invention covers the printed circuit board, the electronic components disposed on the upper and lower surfaces of the printed circuit board, and the electronic component. It is constituted by a placed gel-like substance, a gel-like substance diffusion preventing wall placed on a printed circuit board in order to prevent the gel-like substance from diffusing, and a frame that contacts the gel-like substance and fixes the printed board. Therefore, the loss of the electronic component can be efficiently transmitted to the frame by the gel, so that the loss of the electronic component can be protected from a rise in the temperature inside the housing. Further, the gel diffusion preventing wall can prevent the gel from leaking out of the substrate due to the vibration of the vehicle.

A vehicle control unit according to a second aspect of the present invention includes a printed circuit board, electronic components disposed on upper and lower surfaces of the printed circuit board, a gel-like substance disposed so as to cover the electronic component, A vehicle control unit comprising: a gel substance diffusion preventing wall disposed on a printed circuit board for preventing the gel substance from diffusing; and a frame that contacts the gel substance and fixes the printed circuit board. Since at least the portion in contact with the gel-like substance has a fin shape, the loss of the electronic component can be efficiently transmitted to the frame, and the cooling efficiency can be further increased.

According to a third aspect of the present invention, a reflow furnace and a soldering furnace process are performed in a state where the gel-like substance is removed, and the gel-like substance is finally injected through a hole provided in the frame.
Discrete components can also be brought into contact with the gel and efficient cooling can be performed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a vehicle control unit according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a flow of heat radiation according to the first embodiment.

FIG. 3 is a sectional view of an electronic component according to a second embodiment.

FIG. 4 is a cross-sectional view of the electronic component illustrating a manufacturing process.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Printed circuit board, 2 ... Electronic components (ICs), 3 ... Electronic components, 4 ... Gel diffusion prevention wall, 5 ... Gel-like substance, 6 ... Frame, 7 ... Lower cover, 10 ... Control device housing, 11 ... Control device lid, 12: cooling water channel, 20: power semiconductor module, 21: smoothing capacitor, 22: DC reactor,
23 busbar, 24 terminal block, 25 discrete components.

Claims (3)

[Claims] 1. A printed circuit board, electronic components disposed on the upper and lower surfaces of the printed circuit board, a gel-like material disposed to cover the electronic component, and a device for preventing the gel-like material from diffusing. A control unit for a vehicle, comprising: a gel substance diffusion preventing wall disposed on a printed circuit board; and a frame that contacts the gel substance and fixes the printed circuit board. 2. A printed circuit board, electronic components arranged on the upper and lower surfaces of the printed circuit board, a gel-like material arranged to cover the electronic component, and a device for preventing the gel-like material from diffusing. In a vehicle control unit having a gel-like substance diffusion preventing wall disposed on a printed circuit board and a frame that contacts the gel-like substance and fixes the printed circuit board, the frame is at least a portion that contacts the gel-like substance. Is a fin-shaped vehicle control unit. 3. The control unit for a vehicle according to claim 1, wherein the gel-like substance is removed from the reflow furnace,
A method for manufacturing a control unit for a vehicle, in which a solder furnace process is performed, and a gel-like substance is injected through a hole provided in a frame.