JP2573524Y2 - Circuit boards for automotive electrical components - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an automotive electronic device having an electronic component mounted thereon and an outer surface coated with a coating agent.
A new automobile with a stable mounting state of electronic components and a coated lead on the mounted electronic components so that no leakage occurs between the leads with respect to the circuit board of the component It is an object of the present invention to provide a circuit board for electrical components for use .

[0002]

2. Description of the Related Art Waterproofing and moistureproofing measures must be taken for electronic components used in situations where the environment changes remarkably, such as electrical components for automobiles.

FIG. 11 shows a circuit board a of a conventional electrical component for a vehicle which is provided with waterproofing and moistureproofing measures.

Are electronic components, and leads c, c,... Are inserted into land holes (not shown) formed in the printed circuit board d, and leads c, c are formed. ,
..Of printed circuit board d by soldering a portion protruding from the opposite mounting surface side of printed circuit board d to printed circuit board d
Is implemented.

Next, the electronic components b, b,... Are mounted on the printed circuit board d on which the electronic components b, b,.
... and coating agent e on the outer surface of printed circuit board d
To take waterproofing and moistureproofing measures for the circuit board a.

[0006]

However, in such a conventional circuit board a for automotive electrical components , the coated coating layer e 'is relatively thin only for waterproofing and moistureproofing. When the vibration is applied to the circuit board a, the electronic components b, b,... Move easily with respect to the printed circuit board d due to inertia, and therefore, the fixed parts of the electronic components b, b,. That is,
There is a problem in that the force due to vibration concentrates on the soldered portion f, and cracks occur in the soldered portion f.

The electronic components b, b,...
.. Move, the electronic components b, b,...

Further, a coating agent e is applied to the soldered portion f.
Are not easily placed on the soldered portion f, or when the leads c, c,... Protrude from the soldered portion f, the protruding portion is exposed, and the exposed portion has water droplets due to condensation or the like. There was a problem that g adhered and caused a leak (see FIG. 13).

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has an opening at an upper end surface which is slightly larger than a printed circuit board in a plane shape, and a depth at which the printed circuit board is sufficiently buried. Insert the printed circuit board into the sub case body with the anti-mounting surface of the printed circuit board facing downward, inject the coating agent into the sub case body, embed the printed circuit board in the coating agent, The outer surface of the case body is coated with a coating agent in a film form, and the sub case body integrated with the circuit board is
It is stored in the body .

[0010]

Therefore, according to the circuit board of the present invention, a sufficient coating layer can be formed on the mounting surface of the printed circuit board, and the periphery of the lower end of each electronic component is held by a thick coating layer. Each electronic component does not move even if vibration is applied to the circuit board,
Therefore, it is possible to prevent cracks from occurring in the soldered portions between the leads of the electronic component and the printed circuit board, and to prevent the electronic component from being damaged.

Also, since the soldered portion between the lead of the electronic component and the printed circuit board is embedded in the coating agent, the soldered portion or the portion of the lead projecting from the soldered portion is not exposed. Therefore, it is possible to prevent water droplets due to condensation or the like from adhering to the soldered portion and / or the leads protruding from the soldered portion and to prevent leakage.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the circuit board of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a circuit board of an electrical component for an automobile . A printed board 2 on which a predetermined circuit pattern is formed and electronic components 3, 3,.
Etc.

The leads 4, 4,... Of the electronic components 3, 3,... Are inserted through land holes (not shown) formed in the printed board 2, and the leads 4, 4,.・ ・
Of the printed circuit board 2 is soldered to the printed circuit board 2 and the electronic components 3, 3,.
.. Are mounted on the printed circuit board 2.

5 is a printed circuit board 2 having an open upper end surface.
This is a sub case body which is slightly larger in a planar shape and has a depth at which the printed board 2 is sufficiently buried.

The depth at which the printed board 2 is sufficiently buried is defined as the soldered portions 6, 6 between the leads 4, 4,... Formed on the opposite mounting surface of the printed board 2 and the circuit pattern of the printed board 2. , ... and the soldered portions 6, 6, ...
・ Leads 4, 4,... Of electronic components projecting downward from
Does not contact the bottom surface of the sub-case body 5, and the distance from the mounting surface of the printed circuit board 2 to the opening surface of the sub-case body 5 is larger than the thickness of a coating layer formed by a coating agent described later. This is the depth at which the lower part of 3, 3,... Can be buried.

Then, the printed circuit board 2 on which the electronic components 3, 3,... Are mounted is inserted into the sub case body 5 with the mounting surface facing downward, and the soldered portion of the printed circuit board 2 is mounted. , 6, and the soldered portion 6,
6, leads of electronic components projecting downward from
Are fixed to the sub-case body 5 so that the tips of 4,.

For fixing the printed circuit board 2 to the sub-case body 5, for example, a boss is protruded from the bottom surface of the sub-case body 5,
With the printed circuit board 2 placed on the boss portion, this is performed by means such as screwing.

Next, the surface of the printed circuit board 2 and the electronic components 3, 3,... Fixed to the sub case body 5 are coated with a coating agent 7.

The coating is performed, for example, in a bath (not shown) containing the molten coating agent 7, the sub-case 5, the printed circuit board 2, and the electronic components 3, 3, 3.
.. Are dipped, the coating agent 7 is adhered to these surfaces, and then taken out.

At this time, the sub-case body 5 is filled with the coating agent 7 so that the printed circuit board 2 and the lower parts of the electronic components 3, 3,... Are embedded in the coating agent 7. .

Thus, the coating layer 7'a is formed on the surface of the sub-case body 5, the printed circuit board 2, and the electronic components 3, 3,. .. Are embedded in the coating agent 7 to form a coating layer 7'b on the mounting surface of the printed circuit board 2, and the coating layer 7'b is 2 and the electronic component 3, 3,... Are formed thicker than the coating layer 7'a formed on the surface.

The surface of the sub-case 5, the printed circuit board 2, and the electronic components 3, 3,... Are coated beforehand with the coating agent 7 applied to the printed circuit board 2, the electronic components 3, 3,. After injecting the coating agent 7 into the fixed subcase body 5, the coating agent 7 may be applied or sprayed on these surfaces.

Also, the soldered portions 6, 6,... And the leads 4, 4,.
In order to reduce the amount of protrusion of the leads 4, 4,... Of the electronic components 3, 3,. ...
Out of the printed circuit board 2 may be bent along the printed circuit board 2 and then soldered.

FIGS. 5 to 7 show a modified example 1A of a circuit board of an electric component for an automobile .

A circuit board 1A according to this modification is obtained by attaching a heat sink to the circuit board 1 described above.

Numerals 8 and 8 denote heat radiating plates made of a slightly thicker aluminum plate or the like. The heat radiating plates 8 and 8 are erected so as to extend upward from the mounting surface of the printed circuit board 2 and are printed with screws or an adhesive. It is fixed to the substrate 2.

The upper end of the radiator plate 8, 8 fixed to the printed board 2 is higher than the upper end of the highest one of the electronic components 3, 3,... Mounted on the printed board 2. In addition, the upper end surface is masked (not shown).

The printed circuit board 2 on which the electronic components 3, 3,... And the heat radiating plates 8, 8 are mounted or fixed is coated with a coating agent on the surface thereof and in the sub-case body 5 in the same manner as the above-described coating process. 7 is coated or injected to form the circuit board 1A.

At this time, since the upper end surfaces of the heat radiating plates 8 and 8 are masked, after the coating of the coating agent 7 is completed, the masking is peeled off to expose the background of the heat radiating plates 8 and 8. .

The circuit board 1A thus formed is housed in, for example, a case body 9 and used.

FIG. 7 shows a state in which the circuit board 1A is housed in the case body 9.

The case body 9 is made of metal and has a size that can accommodate the circuit board 1A therein.

Reference numeral 10 is a lid of the case body 9.

The lid 1 is located between the upper end surfaces of the heat sinks 8 and 8.
And the radiator plates 8 and 8 are fixed to the lid 10 by screws or the like.
, Whereby the circuit board 1A is coupled to the lid 10.

The cover 1 to which the circuit board 1A is connected
The reference numeral 0 indicates that the circuit board 1A is inserted into the case body 9 so that the opening surface of the case body 9 is closed, and the circuit board 1A is connected to the case body 9 by an appropriate means.

At this time, since the coating layers 7 'are not formed on the contact surfaces of the heat radiating plates 8, 8 with the lid 10,
The background of the heat radiating plates 8 and 8 comes into direct contact with the lid 10 of the case body 9, and the case body 9 also performs a heat radiating action.

In the drawings, the radiating plates 8 and 8 and the electronic components 3 and
Are disposed apart from each other. However, in the case of the electronic component 3 having a large heat generation amount, the electronic component 3 may be directly attached to the heat radiating plate 8.

Further, the case body 9 is attached to the circuit board 1A.
In this case, the ground line of the circuit board 1A is connected to the heat radiating plates 8, 8 by connecting the ground line of the circuit board 1A to the case body 9 via the heat radiating plates 8, 8 and the lid 10. Is electrically conducted.

In the case where the electronic components 3, 3,... Mounted on the printed circuit board 2 have a space 11 between them and the mounting surface of the printed circuit board 2, as shown in FIG. There is.

In such a case, when the coating agent 7 is applied, the coating agent 7 hardly enters the space 11,
Therefore, the printed circuit board 2 and the electronic components 3, 3,... In a high-temperature atmosphere for curing the coating agent 7
When air is introduced, the air in the space 11 expands,
There is a problem that cracks occur in the coating agent 7 applied to the printed circuit board 2 and the electronic components 3, 3,.

Therefore, as shown in FIG. 9, the printed circuit board 2 of the electronic component 3 in which such a space 11 is likely to be formed in advance.
It is conceivable to form through holes 12, 12,.

In this way, the printed circuit board 2 and the electronic components 3, 3,.
When the coating material 7 is dipped, the coating agent 7 easily penetrates into the space 11 through the through holes 12, 12,..., So that no air remains in the space 11, and the printed circuit board 2 and the electronic components 3, 3. When the air conditioner is placed in a high temperature atmosphere, the air does not expand.
No cracks occur in the coating agent 7.

The printed circuit board 2 has through holes 12, 12,.
... was formed, but is not limited to this. For example,
For example, a slit penetrating the front and back of the printed circuit board 2 may be formed.

As another means for preventing the occurrence of cracks due to the air in the space 11, as shown in FIG. 10, when the electronic component 3 is mounted on the printed circuit board 2, a mat-shaped rubber 13 is used. It is also conceivable to intervene between them.

In this manner, the space 11 is
3 and no air remains. Therefore, when the printed circuit board 2 and the electronic components 3, 3,... Are dipped in the molten coating agent 7, air remains in the space 11. When the printed circuit board 2 and the electronic components 3, 3,... Are put in a high-temperature atmosphere, the air does not expand, so that the coating agent 7 does not crack.

[0047]

As is apparent from the above description , the circuit board of the present invention has a printed circuit board on which a predetermined circuit pattern is formed and an electronic component mounted on the printed board. A circuit board of an electrical component for automobiles , the upper end face of which is opened, is slightly larger in planar shape than the printed circuit board, and has a depth that allows the printed circuit board to be sufficiently buried. Insert the mounting surface in the downward direction, inject the coating agent into the sub case body, embed the printed circuit board in the coating agent, and also on the outer surface of the electronic component and the outer surface of the sub case body. The above sub-case body which is coated with a coating agent in the form of a film and integrated with the circuit board
It is characterized by being stored in the case body .

Therefore, according to the circuit board of the present invention, a sufficient coating layer can be formed on the mounting surface of the printed circuit board, and the periphery of the lower end of each electronic component is held by the thick coating layer. Because you can
Even if vibration is applied to the circuit board, each electronic component does not move, so that it is possible to prevent cracks from occurring in the soldered portion between the lead of the electronic component and the printed board,
Also, it is possible to prevent the electronic components from being damaged.

Further, since the soldered portion between the lead of the electronic component and the printed circuit board is embedded in the coating agent, the soldered portion or the portion of the lead protruding from the soldered portion is not exposed. Therefore, it is possible to prevent water droplets due to condensation or the like from adhering to the soldered portion and / or the leads protruding from the soldered portion and to prevent leakage.

It should be noted that the structures, shapes, numbers, and the like of the parts and members shown in the above-described embodiments are merely examples of the embodiment of the present invention, and the technical and technical features of the present invention will be described below. The scope should not be construed as limiting.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a procedure for coating a circuit board of an electrical component for a vehicle according to the present invention, in which a printed circuit board on which electronic components are mounted is inserted into a subcase body.

FIG. 2 is an enlarged sectional view showing a main part in FIG.

FIG. 3 is a cross-sectional view showing a processing procedure of coating subsequent to FIG. 1 and showing a state in which a printed board and a sub-case body on which electronic components are mounted are coated.

FIG. 4 is a cross-sectional view showing a main part in a state where a lead is bent along a printed board.

FIG. 5 shows a modified example of the circuit board of the electric component for the vehicle according to the present invention together with FIGS. FIG.

FIG. 6 is a cross-sectional view showing a printed circuit board on which electronic components are mounted, and a state where a coating is applied to a sub case body.

FIG. 7 is a cross-sectional view showing a state of being housed in a case body.

FIG. 8 is an enlarged cross-sectional view illustrating a problem related to mounting of an electronic component.

FIG. 9 is an enlarged sectional view of a main part showing a means for solving the problem relating to the mounting of the electronic component in FIG. 8;

FIG. 10 is an enlarged sectional view of a main part showing another means for solving the problem relating to the mounting of the electronic component in FIG. 8;

[11] Conventional electric automobile with FIGS. 12 and 13
FIG. 1 is a cross-sectional view showing an example of a circuit board of a product .

FIG. 12 is an enlarged sectional view showing a main part.

FIG. 13 is an enlarged sectional view showing a problem.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Circuit board 2 Printed board 3 Electronic component 5 Subcase body 7 Coating agent 8 Heat sink 9 Case body 1A Circuit board

Claims (2)

(57) [Scope of request for utility model registration] 1. A circuit board for an automotive electrical component comprising a printed circuit board on which a predetermined circuit pattern is formed and an electronic component mounted on the printed circuit board, wherein an upper end surface is opened and a planar shape is formed from the printed circuit board. In a subcase body that is slightly larger and deep enough for the printed circuit board to be buried,
The printed circuit board is inserted with the anti-mounting surface facing downward, a coating agent is injected into the sub case body to embed the printed circuit board in the coating agent, and the outer surface of the electronic component and the sub case body are inserted. On the outer surface of
The coating agent was coated on the film-like circuit board and one
A circuit board for electrical components for automobiles , characterized in that the sub-case is formed in a case body . 2. The method according to claim 1, wherein the mounting surface is set up from a mounting surface of the printed circuit board.
Characterized in that the heat radiating plate contacted to the case body
Item 2. A circuit board for an electrical component for an automobile according to item 1.