JP2003124662A - On-vehicle electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle electronic device having excellent heat dispersibility, vibration-proofness, water-proofness and mass productivity. SOLUTION: The on-vehicle electronic device comprises a housing for housing a printed board 11 and having an annular frame 24, a base 1 having a high heat conductivity, and a cover 31 in such a manner that the respective connecting parts are connected by using an adhesive sealing material 52 having adhesive properties and the water-proofness, a screw clamping part of the frame 24 and the base 1 via the board 1, and an engaging and locking part of the frame 24 to the cover 31. A heating electronic component 12 to be mounted on the board 11 is soldered by using a folding lead wire 12a, an elastic component 53 is used at a heat transfer protrusion 6 provided in a protruding shape from the base 1, and press fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle-mounted electronic device having a structure in which a printed board is housed in a housing.

[0002]

2. Description of the Related Art Electronic devices for vehicles are required to have a structure having excellent vibration resistance to withstand vehicle vibrations, waterproofness that can be installed outside the vehicle cabin, and mass productivity, and are mounted on a printed circuit board. It is important to improve heat dissipation to efficiently dissipate heat generated from heat-generating electronic components.

As a structure of a housing for a printed circuit board in a conventional vehicle-mounted electronic device, a two-piece structure composed of a case for housing the printed circuit board and a cover is the simplest structure, and a known example thereof is Japanese Patent Laid-Open No. Hei 8 No. 148842 and Japanese Patent Application Laid-Open No. 11-346418, and in Japanese Patent Application Laid-Open No. 8-148842, a heat-generating electronic component is molded with a resin having electrical insulation, and the component is formed into a housing. There has been proposed a method for preventing electrical short-circuiting by contacting a constituent cover and improving the heat dissipation effect. Further, Japanese Patent Laid-Open No. 11-346418 discloses a method in which a connector housing and a cover are integrated and a printed circuit board is adhesively fixed to the cover to improve vibration resistance and waterproofness.

Further, as a structure of a housing for a printed circuit board, there is a three-piece structure composed of an intermediate frame portion for fixing the printed circuit board and an upper and lower cover portions. Known examples thereof are Japanese Patent Laid-Open No. 6-318790. JP-A-8-18
Japanese Patent Laid-Open No. 6-318.
Japanese Patent No. 790 discloses a method of improving waterproofness and mass productivity by adhesively fixing an intermediate frame and upper and lower covers using an adhesive resin. In addition, JP-A-8
JP-A-181471 discloses a method of utilizing the elastic force of a printed circuit board to press a heat-generating electronic component against an intermediate frame portion to efficiently radiate heat.

On the other hand, in Japanese Unexamined Patent Publication No. 8-204072, the heat generated by the heat-generating electronic component mounted on the surface of the circuit board having the through-hole in the mounting portion of the heat-generating electronic component is generated on both sides of the through-hole penetration portion and the circuit board. Heat is transferred to the back side of the circuit board via a heat conducting piece that has a heat conducting surface integrally formed,
A method has been proposed in which the circuit board is fixed to a heat conductive casing via a heat conductive sheet mounted on the back surface side to efficiently radiate heat.

[0006]

As described above, in the in-vehicle electronic device having the structure in which the printed circuit board is housed in the housing, various structures have been conventionally proposed, but none of them are effective. For example, the one disclosed in JP-A-8-148842 has a problem that sufficient heat conduction cannot be obtained because a heat-generating electronic component molded with a resin having poor heat conductivity is brought into contact with the housing. In addition, JP-A-8-
According to the method disclosed in Japanese Patent No. 181471, the heat-generating electronic component is pressed against the housing depending on the elastic force of the substrate. Therefore, it is necessary to reduce the stress at the soldering portion of the heat-generating electronic component, and sufficient heat conduction is achieved. There was a problem that could not be obtained.
In addition, JP-A Nos. 11-346418 and 6-
The one disclosed in Japanese Patent No. 318790 does not discuss improvement of heat dissipation in the heat-generating electronic component.

Further, in the device disclosed in Japanese Patent Laid-Open No. 8-204072, when a large number of through holes are provided, the contact area with the heat-generating electronic component is reduced, and problems such as inflow of solder into the through holes occur. There was a problem.

The present invention has been made to solve the above problems, and an object thereof is to provide an in-vehicle electronic device having a structure excellent in heat dissipation, vibration resistance, waterproofness, and mass productivity. And

[0009]

An on-vehicle electronic device according to the present invention has an annular frame integrally formed with a connector housing in which a large number of connection pins are press-fitted, and a lower end of the annular frame has adhesiveness and waterproofness. A case having a base having a high thermal conductivity which is mounted using an adhesive sealing material and a cover which is mounted using an adhesive sealing material having adhesiveness and waterproofness on the upper end of the annular frame, and is housed in a housing. , A printed circuit board sandwiched and fixed between the annular frame and the base, and the heat generating electronic components mounted on the printed circuit board generate heat from the heat transfer protrusions provided in a protruding shape from the base to the inside of the housing. Is configured to transfer heat to the base,
The housing is assembled by mounting the cover in a state where the printed circuit board is sandwiched and fixed between the annular frame and the base.

The housing is mounted on the vehicle by using the mounting feet provided on the base. Further, the printed circuit board is configured to be temporarily fixed to the annular frame by press-fitting a protrusion provided on the annular frame into a mounting hole provided in the printed circuit board. Further, the joining of the annular frame and the base is performed by sandwiching the printed circuit board and fixing the peripheral parts of the annular frame, the printed circuit board and the base with screws, and the annular frame in the first annular groove provided in the outer peripheral part of the base. A hermetically sealed structure is obtained by fitting a first annular projection portion provided at the lower end of the frame, filling the fitting portion with an adhesive sealing material having adhesiveness and waterproofness, and curing the sealing material.

Further, the cover has a bent portion which fits into a second annular groove provided at the upper end of the annular frame on the outer peripheral portion thereof, and the bent portion has an opening inclination whose front end is opened like a funnel. Portion and the opening sloped portion have notches formed at a predetermined interval, and the joining of the annular frame and the cover is performed by inserting the bent portion of the cover into the second annular groove provided at the upper end of the annular frame. Then, the fitting structure is filled with an adhesive sealing material having adhesiveness and waterproofness and cured to obtain a closed structure. In addition, the annular frame and the cover are fitted and locked with a protrusion provided on the outside of the side surface of the annular frame and a hole formed partially continuously from the bent portion provided on the outer periphery of the cover. It is fixed by fitting the parts together.

Further, the connector housing has an annular wall portion that divides the connection pin into a plurality of groups, and the annular wall portion is provided on a mating connector having a female pin electrically connected to the connection pin press-fitted into the connector housing. It is mounted by interposing the annular groove portion and the elastic packing. Further, the heat-generating electronic component is soldered to the printed board via the lead wire including the bent portion. Further, the heat-generating electronic component is a component that is vertically elongated and is vertically fixed to the printed circuit board, and is pressed and fixed to the wall surface of the heat transfer protrusion that is provided in a protruding shape from the base by using an elastic component. Further, the heat-generating electronic component is closely fixed to the upper surface of the heat transfer protrusion provided in a protruding shape from the base in a state where the vertically elongated component is laid horizontally on the printed circuit board.

Further, the heat-generating electronic component is a chip component,
The chip part has heat dissipation electrodes on almost the entire surface, and the printed circuit board has copper foil patterns on both sides, a first plating layer including through hole plating, resin for filling the through holes, and a filling material for the through holes. Has a second plating layer for encapsulating the chip component and a solder layer for joining the chip component, and the back surface side of the region where the chip component is mounted is provided on the upper surface of the heat transfer protrusion portion protruding from the base. The heat generated by the chip component is generated by the heat dissipation electrode from the solder layer, the second plating layer, and the through-hole plating on the printed circuit board. The heat is transferred to the heat transfer protrusion through the second plated layer formed on the back surface side of the printed circuit board and the insulating material that is soft and has thermal conductivity.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. An on-vehicle electronic device according to an embodiment of the present invention will be described below with reference to the drawings. 1 is a top view of a vehicle-mounted electronic device according to Embodiment 1 of the present invention, FIG. 2 is a top view showing a state in which the cover of FIG. 1 is removed, and FIG. 3 is a cross-sectional view taken along the line AA of FIG. 3A is a side view seen in the direction, FIG. 3A is an overall view, and FIG. 3B is an enlarged view of a portion indicated by reference symbol B in FIG.

In the drawing, reference numeral 1 is a die cast aluminum, for example, and a rectangular high heat conductive base (hereinafter, simply referred to as a base) which constitutes a lower surface of a housing for accommodating a printed circuit board 11 described later, 2 is a base 1 The mounting feet are provided in a protruding shape on the outer side of the square, and each have mounting holes 3.
Reference numeral 4 denotes screw holes provided inside the four corners of the base 1 for fixing the base 1 and an annular frame 24 described later by sandwiching a printed circuit board 11 described later. The screw hole 4 provided in the base 1 has a bag shape to prevent outside air from entering the housing. Reference numeral 5 is a first annular groove provided on the upper surface of the outer peripheral portion of the base 1, and reference numeral 6 is a heat transfer protrusion provided in a protruding shape from the base 1 to the inside of the housing.

Reference numeral 11 is a printed circuit board on which a plurality of electronic components including a heat-generating electronic component 12 are mounted. Small holes 13a are provided at the four corners of the printed circuit board 11, and are located at positions corresponding to the screw holes 4 provided in the base 1, respectively. Reference numeral 13b is a small hole provided in the center of the printed board 11 for fixing the printed board 11 to the base 1 at the center.

Reference numeral 21 is a connector housing formed by molding using, for example, PBT (polybutylene terephthalate) resin, and 22 is a large number of bent type (right angle type) connection pins 2 press-fitted into the connector housing 21.
An annular wall portion for grouping 3 and fitting with a mating connector described later. The other end of the connection pin 23 is connected to the printed board 11. Reference numeral 24 denotes an annular frame which is formed integrally with the connector housing 21 and constitutes the wall portion of the housing, and 25 is provided on the lower surface of the annular frame 24 and fits into the first annular groove 5 provided on the base 1. The first annular protrusion portion 26 is a second annular groove provided on the upper surface of the annular frame 24. Reference numerals 27 are small holes provided at the four corners of the annular frame 24, respectively, at positions corresponding to the screw holes 4 provided in the base 1.

Reference numeral 31 is a cover made of sheet metal or the like and constitutes the upper surface of the housing. Reference numeral 32 is a bent portion provided on the outer peripheral portion of the cover 31, and is configured to be fitted into the second annular groove 26 provided on the upper surface portion of the annular frame 24.

Reference numeral 51 denotes a small hole 27 provided in the annular frame 24 and a small hole 13a provided in the printed circuit board 11.
The printed circuit board 11 is sandwiched between the annular frame 2 and the screw which is inserted into the screw hole 4 provided in the base 1.
4 and the printed circuit board 11 are fixed to the base 1. Reference numeral 52 designates, for example, a silicon-based adhesive sealing material which is hardened when left at room temperature, and seals the adhesive portion in a waterproof manner. 53 is a heat-generating electronic component 1
2 is an elastic component for pressing the heat transfer protrusion 6 of the base 1.

FIG. 4 is a side view of the cross section taken along the line C--C of FIG. 2 as seen in the direction of the arrow. 28 is provided in a part of the annular frame 24 and is provided on the printed circuit board 11. The annular frame 2 is a protrusion that is press-fitted into the mounting hole 14.
The printed circuit board 11 is temporarily fixed to 4.

FIG. 5 is a side view of the housing of the on-vehicle electronic device according to the first embodiment, and FIG. 6 is a side view of the section taken along the line D--D of FIG. 29 is a plurality of fitting protrusions provided outside the annular frame 24, 33
Is a fitting locking portion having a hole portion 33a formed partially continuous from a bent portion 32 provided on the outer peripheral portion of the cover 31, and a fitting protrusion provided on the annular frame 24 with the hole portion 33a. The cover 31 is fixed to the annular frame 24 by fitting with the portion 29.

FIG. 7 is a sectional view of the connector portion of the housing of the vehicle-mounted electronic device according to the first embodiment, where 41 is a mating connector that fits with the annular wall portion 22 of the connector housing 21, and 42 is a mating connector. An annular groove portion into which the annular wall portion 22 provided in the mating connector 41 is fitted, and 43 is an annular groove portion 42.
The elastic packing is made of a rubber material or the like provided inside. A female pin (not shown) electrically connected to the connection pin 23 provided on the connector housing 21 is provided inside the mating connector 41.

Further, FIG. 8 is an enlarged view of a portion indicated by reference symbol E in FIG. 7, showing the details of the fitting portion between the cover 31 and the annular frame 24. The bent portion 32 provided on the outer peripheral portion of the cover 31 fitted into the second annular groove 26 provided on the annular frame 24 has an opening inclined portion 34 having a funnel-shaped opening at its tip. The tip of the opening inclined portion 34 is substantially parallel to the wall surface 26a of the second annular groove 26 and the wall surface 26a.
And a peripheral edge cut portion 35 having a gap G and punched and cut by press working. Further, the opening sloped portion 34 is provided with a notch portion 36 at a predetermined interval. This is because the adhesive seal material 52 filled in the second annular groove 26 after the bent portion 32 provided on the outer peripheral portion of the cover 31 is fitted into the second annular groove 26 is the second annular groove 2.
6 flows through the gap G and the notch 36 inside,
This is to ensure that the openings are evenly distributed around the inclined portion 34.

FIG. 9 is an enlarged cross-sectional view showing details of the mounting portion of the heat-generating electronic component in the vehicle-mounted electronic device according to the first embodiment. Reference numeral 15 is a cutout portion provided on the printed circuit board, and the cutout portion 15 is shown. The heat transfer protrusion 6 provided in a protruding shape from the base 1 protrudes onto the printed circuit board 11 through
The heat-generating electronic component 12 such as a transistor soldered to the printed circuit board 11 is pressed and fixed by the elastic component 53 to the heat transfer surface formed by the wall surface of the heat transfer protrusion 6. The heat-generating electronic component 12 is soldered to the printed circuit board 11 via the bent lead wire 12a.

Next, a method of assembling the vehicle-mounted electronic device according to this embodiment will be described. First, after mounting a large number of electronic components including the heat-generating electronic component 12 on the printed circuit board 11,
By press-fitting the protrusion 28 provided on the annular frame 24 into the mounting hole 14 provided on the printed circuit board 11,
With the printed circuit board 11 temporarily fixed to the annular frame 24, the other end of the connection pin 23 press-fitted into the connector housing 21 formed integrally with the annular frame 24 is printed by using a jet soldering device or the like. Solder to.

Next, after the adhesive sealing material 52 which is cured by being left at room temperature is injected into the first annular groove 5 of the base 1, the annular frame 24 fixed to the printed circuit board 11 is placed on the base 1 and bonded. The first annular protrusion 26 of the annular frame 24 is fitted into the first annular groove 5 filled with the sealing material 52, and the screw 51 is provided in the small hole 27 provided in the annular frame 24 and the printed circuit board 11. The printed circuit board 11 is sandwiched and the annular frame 24 is fixed to the base 1 by inserting the printed circuit board 11 into the small hole 13a and screwing it into the screw hole 4 provided in the base 1. Next, the heat-generating electronic component 12 soldered to the printed circuit board 11 is provided on the base 1 in a protruding shape, and the heat transfer protrusion is projected on the printed circuit board 11 via the cutout portion 15 provided on the printed circuit board 11. The elastic component 53 is pressed against the wall surface of the portion 6 and fixed.

Next, the second annular groove 2 of the annular frame 24.
After injecting the adhesive sealing material 52 into 6, the cover 31 is placed on the annular frame 24, and the second annular groove 26 filled with the adhesive sealing material 52 is bent at the outer peripheral portion of the cover 31. The fitting locking portion 3 formed by fitting the portion 32 into the fitting projection portion 29 provided on the annular frame 24 and partially continuing from the bent portion 32 provided on the cover 31.
The cover 31 is fixed to the annular frame 24 by fitting the three hole portions 33a. Integrated base 1,
The annular frame, the printed circuit board 11 and the cover 31 are
It is fixed to the vehicle body through the mounting feet 2 provided on the base 1 having high mechanical strength and heavy weight, and then the mating connector 4
1 is inserted into the annular wall portion 22 of the connector housing 21, and wiring work is performed.

In FIG. 3B, the printed circuit board 21
Although a method of sandwiching between the base 1 and the annular frame 24 and fixing them by using the screw 51 is shown, a rivet is press-fitted into the base 1 instead of the screw, and the annular frame 2 is pressed by the head of the rivet.
Alternatively, the pin 4 integrally formed with the base 1 may be fixed to the annular frame 24 by a method of pressing the pin 4 or by caulking. Also,
Although the method of fixing the printed circuit board 11 to the annular frame 24 by press-fitting the protrusions 28 provided on the annular frame 24 into the mounting holes 14 provided on the printed circuit board 11 in FIG. You may fix 24 and the printed circuit board 11. Further, although the cover 31 and the annular frame 24 have been described as being bonded and fixed using the adhesive sealing material 52, by fixing them with packing and screws, maintenance and inspection can be facilitated.

According to the present embodiment, the annular frame 24
When the mounting hole 14 provided in the printed circuit board 11 is press-fitted into the protrusion 28 provided on the printed circuit board 11,
Is temporarily fixed to the annular frame, which facilitates handling. Further, since the printed circuit board 11 is sandwiched and the annular frame 24 is fixed to the base 1 using the screws 51, an adhesive seal material for joining the annular frame 24 and the base 1 together. Workability can be improved, for example, by performing work such as transfer between steps before curing 52.

At the joint between the annular frame 24 and the cover 31, the tip of the bent portion 32 provided on the outer peripheral portion of the cover 31 is opened like a funnel, and the opening inclined portion 3 is formed.
4 is provided with the notch 36 at a predetermined interval, the adhesive sealing material 52 can be easily flowed through the notch 36 and the cover 31 from the second annular groove 26 of the annular frame 24 is provided. Can be prevented from falling off. Furthermore, the annular frame 24 and the cover 31 are
The fitting projection 29 provided on the outer side surface of the cover 4 has a cover 31.
Since it is fixed by fitting the fitting locking portion 33 having the hole portion 33a provided in the annular frame 24 before hardening, the adhesive sealing material 52 joining the annular frame 24 and the cover 31 to the annular frame 24 before curing. It is possible to prevent a phenomenon such as displacement of the joint portion of the cover 31.

Further, the heat-generating electronic component 12 has the printed circuit board 11 via the bent lead wire 12a including the bent shape portion.
Since the soldering is performed on the heat generating electronic component 12, it is possible to reduce the stress of the soldering portion due to the expansion and contraction of the lead wire due to the generated heat. Since the elastic component 53 is pressed and fixed to the wall surface of the protruding portion 6, the generated heat can be efficiently radiated to the base 1.

Further, since the connector housing 21 is divided into a plurality of groups, the connector can be easily attached and detached, and it is possible to prevent an unreasonable force from being applied to the periphery. Further, the elastic packing 43 is interposed so that the mating connector 41 is Since it is attached, the waterproofness of the connector can be improved. In addition, before mounting the cover 31, the connector housing 2
Since the annular frame 24 having 1 and the base 1 and the printed circuit board 11 are in an assembled state, the product check as an electronic device can be performed in this state. Further, since the electronic device is mounted on the vehicle by using the mounting feet 2 provided on the base 1 which is a heavy body in the vehicle-mounted electronic device, the load applied by the vehicle vibration to the printed circuit board 11 and the adhesive seal portion is reduced. It is possible to improve the vibration resistance of the vehicle-mounted electronic device.

Embodiment 2. FIG. 10 is a view for explaining the heat dissipation mechanism of the heat-generating electronic component in the vehicle-mounted electronic device according to the second embodiment of the present invention, and is an enlarged cross-sectional view showing the details of the mounting portion of the heat-generating electronic component. In the figure, 7 is a base 1
A heat transfer protrusion provided inside the housing in a protruding shape,
Is a notch provided in the printed circuit board 11, and 54 is a fixing screw. The rest of the configuration is the same as that of the first embodiment, so the description thereof is omitted.

In the present embodiment, the heat transfer protrusion 7 provided in a protruding shape on the base 1 protrudes onto the printed circuit board 11 through the notch 15 provided on the printed circuit board 11, and the bent lead wire 12a is formed. The heat-generating electronic component 12 soldered to the printed circuit board 11 is closely fixed to the upper surface of the heat transfer protrusion 7 with the screw 54. Instead of fixing the heat-generating electronic component 12 to the heat transfer protrusion 7 using the fixing screw 54, the heat-generating electronic component 1 is made using a rivet or a caulking method.
2 may be fixed to the heat transfer protrusion 7.

According to the present embodiment, the same effect as in the first embodiment can be obtained, and the heat-generating electronic component 12 is fixed to the heat transfer protrusion 7 provided on the base 1 by the fixing screw 54. It is possible to improve the vibration resistance of the vehicle-mounted electronic device.

Embodiment 3. 11A and 11B are views for explaining a heat dissipation mechanism of a heat-generating electronic component in a vehicle-mounted electronic device according to Embodiment 3 of the present invention. FIG. 11A is an enlarged cross-sectional view showing details of a mounting portion of the heat-generating electronic component, and FIG. Is a plan view.

In the figure, reference numeral 8 denotes a heat transfer protrusion portion provided in a protruding shape on the inner surface side of the housing of the base 1, and 9 denotes an insulating sheet provided in close contact with the upper surface of the heat transfer protrusion portion 8 of the base 1. , A soft and thermally conductive sheet such as a silicon material. Instead of the insulating sheet 9, an insulating adhesive having thermal conductivity may be applied to the heat transfer protrusion 8. 16
Is a heat-generating electronic component (chip component) such as a power transistor having a planar structure.
a, a second electrode (emitter terminal) 16c, and a third electrode (base terminal) 16d. The heat dissipation electrode (collector terminal) 16 a is formed on substantially the entire surface of the heat-generating electronic component 16.

Reference numeral 11a is a through hole provided in the printed board 11, 11b is a filling material made of epoxy resin or the like filling the through hole 11a, 17, 17a, 17
b, 17c and 17d are copper foil patterns formed by patterning copper foils formed on both surfaces of the printed board 11, and 18a, 18a, 18c and 18d are first platings including plating in the through holes 11a. In layers, the copper foil patterns 17 formed on both surfaces of the printed circuit board 11 are electrically connected via through hole plating. 19,
19a, 19b, 19c and 19d are through holes 11a.
Second plating layer 20, 20, 20a, 20c, 20d, such as copper plating, for enclosing the filling material 11b filled in
Is a solder layer and 55 is a solder resist layer.

The heat dissipation electrode 16a has copper foil patterns 17a, 17 via the solder layer 20a, the second plating layers 19a, 19b, and the first plating layer 18a including through-hole plating.
b is electrically connected to the second electrode 16c, the third electrode 16
d is the solder layers 20c and 20d and the second plating layer 19 respectively.
c, 19d, and the first plating layers 18c, 18d are electrically connected to the copper foil patterns 17c, 17d.
The solder layers 20c and 20d, the second plating layer 19c,
19d, the first plated layers 18c and 18d, and the copper foil patterns 17c and 17d are the heat dissipation electrodes 16a and 16d.
a, a solder layer 20a electrically connected to a, a second plating layer 19a, a first plating layer 18a, a copper foil pattern 17
It is configured to be electrically separated from a and 17b.

In the present embodiment, the heat transfer protrusion 8 provided in a protruding shape on the base 1 is configured to contact the back side of the printed circuit board 1 via the insulating sheet 9, and the chip-shaped heat generating electronic component 16 is formed. The heat generated from the printed circuit board 1 is generated from the heat dissipation electrode 16a through the solder layer 20a, the second plating layer 19a, and the first plating layer 18a including through-hole plating.
Of the second plating layer 19b to the heat transfer protrusions 8 provided on the base 1 through the insulating sheet 8 to radiate heat.

According to the present embodiment, the heat generated from the chip-shaped heat-generating electronic component 16 is passed through the through-hole 11a, which is provided in the printed-circuit board 11 and is filled with resin or the like, to the printed-circuit board. 11 to the heat transfer protrusions 8 provided on the high heat conductive base 1 via the soft and thermally conductive insulating sheet 9 arranged in contact with the back surface of the printed circuit board 1. By transferring heat, the heat generated from the chip-shaped heat generating electronic component 16 can be efficiently radiated. Further, by filling the through hole 11a with resin or the like and forming the second plating layer 19 so as to enclose the filling material 11b, it is possible to prevent the inflow of solder into the through hole 11a and to make contact for heat transfer. A flat surface can be secured.

[0042]

As described above, according to the vehicle-mounted electronic device of the present invention, since the printed circuit board and the annular frame are fixed to the base, the warp and strain occurring in the printed circuit board and the annular frame are limited to the respective elastic deformations. It is corrected by the deformation and the load is prevented from being applied to the adhesive seal portion and the like, and the assembly stability can be secured. Further, the heat-generating electronic component mounted on the printed board is closely fixed to the heat transfer surface of the base having high thermal conductivity, so that the generated heat can be efficiently radiated. Further, since the annular frame having the connector housing, the base and the printed circuit board are in an assembled state before the cover is attached, it is possible to check the product as an electronic device.

Further, since the electronic equipment is mounted on the vehicle by using the mounting feet provided on the base which is a heavy body in the on-vehicle electronic equipment, the load applied by the vibration of the vehicle on the printed circuit board and the adhesive seal portion is reduced. It is possible to improve the vibration resistance of the vehicle-mounted electronic device.

Further, since the printed circuit board is temporarily fixed to the annular frame by a simple method, the handling up to the main fixing becomes easy and the workability can be improved.

Further, the annular frame and the base are joined by sandwiching the printed circuit board and fixing the peripheral parts of the annular frame and the printed circuit board to the base with screws, and annularly in the annular groove provided on the outer peripheral part of the base. Since the annular protrusion provided at the lower end of the frame is fitted and joined by using the adhesive sealing material having adhesiveness and waterproofness, the joining portion between the annular frame and the base is displaced before the adhesive sealing material is cured. The phenomenon does not occur, the joining work is easy, and a highly waterproof joint can be obtained.

In addition, for joining the annular frame and the cover, a bent portion provided on the outer peripheral portion of the cover is fitted in an annular groove provided at the upper end of the annular frame, and an adhesive sealing material having adhesiveness and waterproofness is used. In addition to joining with each other, at the tip of the bent portion of the cover fitted in the second annular groove of the annular frame, a funnel-shaped opening inclined portion and notched portions at predetermined intervals in the opening inclined portion are formed. Since it is provided, it is possible to prevent the cover from falling off from the annular groove of the annular frame,
Since the adhesive seal material easily flows due to the cutout portion, the joining work is facilitated and the joining strength can be enhanced.

Further, since the annular frame and the cover are fixed by fitting the fitting locking portion having the hole provided in the cover and the projection provided on the outer side surface of the annular frame, the annular frame and the cover are fixed. Before the adhesive sealing material that joins the frame and the cover is cured, a phenomenon such as the joining portion between the annular frame and the cover being displaced does not occur, and a joining portion having high waterproofness can be obtained.

Further, since the connector housing is divided into a plurality of groups, it is easy to attach and detach the connector, and it is possible to prevent an unreasonable force from being applied to the periphery. Also, since the connector is mounted with the elastic packing interposed. The waterproof property of the connector part can be improved.

Further, since the heat-generating electronic component is soldered to the printed circuit board via the lead wire including the bent shape portion, it is possible to reduce stress on the soldering portion due to expansion and contraction of the lead wire due to generated heat.

Further, the vertically elongated heat generating electronic component is erected vertically on the printed circuit board, and is pressed and fixed to the wall surface of the heat transfer protrusion provided in the protruding shape from the base by using the elastic component, whereby the heat generating electronic component is fixed. It is possible to efficiently dissipate the generated heat and to reduce the mounting area of the heat-generating electronic component.

Further, the vertically elongated heat-generating electronic component is laid horizontally on the heat transfer protrusion provided in a protruding shape from the base and tightly fixed by screwing or the like to efficiently generate heat of the heat-generating electronic component. The heat can be dissipated and the height of the heat-generating electronic components mounted on the printed circuit board can be reduced, so that the housing can be made thin and the vibration resistance can be improved.

Further, the heat generated from the chip-shaped heat-generating electronic component is transferred to the back surface side of the printed circuit board through the through hole which is provided in the printed circuit board and is filled with resin or the like, so that the printed circuit board is backed. The heat transfer from the chip-shaped heat-generating electronic components by transferring heat to the heat transfer protrusions provided on the base having high heat conductivity through the soft and thermally conductive insulating sheet arranged in contact with the back side of The generated heat can be efficiently dissipated. Further, by filling the through hole with resin or the like and forming the second plating layer in a form of encapsulating the filling material, it is possible to prevent the inflow of solder into the through hole and to secure a contact plane for heat transfer. be able to.

[Brief description of drawings]

FIG. 1 is a top view showing a vehicle-mounted electronic device according to a first embodiment of the present invention.

FIG. 2 is a top view showing the inside of the housing of the vehicle-mounted electronic device according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing an in-vehicle electronic device according to the first embodiment of the present invention.

FIG. 4 is a partial cross-sectional view showing an annular frame of a vehicle-mounted electronic device and a temporary fixing portion of a printed circuit board according to Embodiment 1 of the present invention.

FIG. 5 is a side view showing the vehicle-mounted electronic device according to the first embodiment of the present invention.

FIG. 6 is a partial cross-sectional view showing details of a fitting portion between the annular frame and the cover of the vehicle-mounted electronic device according to the first embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a connector portion of the vehicle-mounted electronic device according to the first embodiment of the present invention.

FIG. 8 is a partial cross-sectional view showing details of the seal portion of the vehicle-mounted electronic device annular frame and the cover according to the first embodiment of the present invention.

FIG. 9 is a partial cross-sectional view for explaining the heat dissipation mechanism of the heat-generating electronic component of the vehicle-mounted electronic device according to the first embodiment of the present invention.

FIG. 10 is a partial cross-sectional view for explaining a heat dissipation mechanism of the heat-generating electronic component of the vehicle-mounted electronic device according to the second embodiment of the present invention.

FIG. 11 is a diagram for explaining a heat dissipation mechanism for heat generating electronic components of an in-vehicle electronic device according to Embodiment 3 of the present invention.

[Explanation of symbols]

1 high thermal conductivity base, 2 mounting feet, 3 mounting holes, 4
Screw hole, 5 first annular groove, 6 heat transfer protrusion, 7 heat transfer protrusion, 8 heat transfer protrusion, 9 insulating sheet 11 printed circuit board, 11a through hole, 11b filler, 12
Heat-generating electronic parts, 12a Bent lead wires, 13a, 13
b small hole, 14 mounting hole 15 notch, 16 heat-generating electronic component (chip component) 16a heat dissipation electrode (collector terminal), 16c second electrode (emitter terminal) 16d third electrode (base terminal), 17, 17a, 17
b, 17c, 17d Copper foil pattern, 18, 18a, 1
8c, 18d First plating layer, 19, 19a, 19
b, 19c, 19d Second plating layer, 20, 20a,
20c, 20d solder layer, 21 connector housing,
22 annular wall part, 23 connecting pin, 24 annular frame, 25 1st annular protrusion part, 26 2nd annular groove, 2
7 Small Holes, 28 Protrusions, 29 Fitting Protrusions 31 Covers, 32 Bends, 33 Fitting Locks, 33
a hole portion, 34 opening inclined portion, 35 peripheral edge cutting portion, 36
Notch part, 41 Counterpart connector, 42 Annular groove part, 43 Elastic packing, 51 Screw, 52 Adhesive sealing material, 53, Elastic component, 54 Fixing screw, 55 Solder resist layer.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 1/02 H05K 1/18 B 5E348 1/18 5/00 A 5F036 5/00 5/02 L 5 / 02 5/06 A 5/06 7/14 B 7/14 C F H01L 23/36 D F term (reference) 4E360 AB13 AB33 CA02 CA05 EA03 EA24 EA27 EC16 ED02 ED03 ED07 ED08 ED14 ED23 ED28 ED29 GA08 GA24 GA28 GA29 GA53 GB97 GC04 GC08 5E087 EE02 EE14 HH01 HH02 LL04 LL12 MM04 MM08 QQ04 RR12 5E322 AA03 AB04 AB08 EA10 FA04 5E336 AA01 AA16 BB02 BC04 CC03 CC55 CC56 EE01 EE15 EE17 GG03 5E338 AA02 BB02 BB05 BB13 BB75 CC01 CC08 EE02 EE51 5E348 AA03 AA08 AA31 AA32 5F036 AA01 BB21 BC09 BC33 BC35

Claims (11)

[Claims] 1. An annular frame integrally formed with a connector housing in which a large number of connection pins are press-fitted, and a high thermal conductivity attached to the lower end of the annular frame by using an adhesive sealing material having adhesiveness and waterproofness. A casing having a base having a base and a cover attached to the upper end of the annular frame by using an adhesive sealing material having adhesiveness and waterproofness, housed in the casing, and between the annular frame and the base. The heat-generating electronic component mounted on the printed circuit board is sandwiched and fixed, and the generated heat is transferred to the base from the base through the heat transfer protrusions provided in a protruding shape inside the housing. The housing is configured to be heated, and is assembled by mounting the cover in a state where the printed circuit board is sandwiched and fixed between the annular frame and the base. An in-vehicle electronic device characterized by the above. 2. The housing is mounted on a vehicle by using mounting feet provided on the base.
In-vehicle electronic device described. 3. The printed circuit board is configured to be temporarily fixed to the annular frame by press-fitting a protrusion provided on the annular frame into a mounting hole provided in the printed circuit board. The vehicle-mounted electronic device according to claim 1 or 2. 4. The joining of the annular frame and the base is carried out by sandwiching the printed circuit board, fixing the annular frame, the printed circuit board and the peripheral portion of the base with screws, and at the outer peripheral portion of the base. By inserting the first annular protrusion provided at the lower end of the annular frame into the provided first annular groove, and filling and curing the adhesive sealing material having adhesiveness and waterproofness in the fitted portion. The vehicle-mounted electronic device according to any one of claims 1 to 3, wherein a closed structure is obtained. 5. The cover has a bent portion that fits into a second annular groove provided at an upper end of the annular frame on an outer peripheral portion of the cover, and the bent portion has a tip end that opens like a funnel. The opening sloped portion and the opening sloped portion have cutouts formed at a predetermined interval, and the joint between the annular frame and the cover is formed in the second annular groove provided at the upper end of the annular frame. 5. A hermetically sealed structure is obtained by fitting a bent portion of a cover, filling the fitting portion with an adhesive sealing material having adhesiveness and waterproofness, and curing the adhesive sealing material. The in-vehicle electronic device according to the above 1. 6. The hole formed in the annular frame and the cover, which is partially continuous with a protrusion provided on the outer side surface of the annular frame and a bent portion provided on the outer peripheral portion of the cover. 6. The vehicle-mounted electronic device according to claim 5, wherein the vehicle-mounted electronic device is fixed by fitting a fitting locking portion having a portion. 7. The connector housing has an annular wall portion that divides the connection pin into a plurality of groups, and the annular wall portion has a mating side that is electrically connected to the connection pin press-fitted into the connector housing. The in-vehicle electronic device according to claim 1, wherein the in-vehicle electronic device is mounted via an annular groove provided in the connector and an elastic packing. 8. The vehicle-mounted electronic device according to claim 1, wherein the heat-generating electronic component is soldered to the printed circuit board via a lead wire including a bent portion. 9. The heat-generating electronic component is press-fixed to a wall surface of a heat transfer protrusion provided on the base in a state where a vertically elongated component is erected vertically on the printed circuit board by using an elastic component. The vehicle-mounted electronic device according to claim 8. 10. The heat generating electronic component is closely fixed to an upper surface of a heat transfer protrusion provided on the base in a state in which a vertically elongated component is laid horizontally on the printed circuit board. 8. The vehicle-mounted electronic device according to item 8. 11. The heat-generating electronic component is a chip component, the chip component has a heat-dissipating electrode on almost the entire surface, and the printed circuit board has a copper foil pattern on both sides thereof and a first plating including through-hole plating. A layer, a resin or the like for filling the through hole, a second plating layer for enclosing the filling material for the through hole, and a solder layer for joining the chip component, and the chip component is mounted. The back surface side of the region to be contacted with the upper surface of the heat transfer protrusion provided in a protruding shape from the base via an insulating material having soft and thermal conductivity, the heat generated by the chip component, The second plating layer formed on the back surface side of the printed board from the heat dissipation electrode through the solder layer on the printed board, the second plating layer, and the through-hole plating. And the in-vehicle electronic device according to any one of claims 1 to 7, characterized in that via an insulating material having the soft and thermal conductivity are constructed as heat is transferred to the heat transfer protrusions.