JPH09246682A - Printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a reliability by preventing occurrence of oxidation corrosion at an intercormection part between first and second printed wiring boards having anisotropic conductive materials integrally formed thereon in a simple manner. SOLUTION: A conductive pattern exposure part of a printed circuit board 3 is contact-compressed by means of a head part of a swaging device with a part of a printed circuit board 2 to be contact compressed. The swaging head 15 is provided in its swaging surface with a step which corresponds in its step height to a thickness of a base material 4, a conductive pattern 5, pattern protective film 7, etc., in such a manner that the swaging surface can be evenly contacted with the surface of a surface of the conductive pattern 2 to be swaged to achieve a stable conductive connection therebetween. The base material 4 of the printed circuit board 3 is extended onto a protective film 12 of the board 2 as overlapped therewith and as to cover a gap between the protective film 12 of the board 2 and the conductive pattern 5 of the board 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board, and more particularly to a printed circuit board which is provided inside an OA device, a camera, a telephone or the like, and which is characterized by a crimping portion structural portion for crimping connection from an anisotropic conductive material.

[0002]

2. Description of the Related Art Conventionally, a structure for crimping a printed wiring board integrally provided with an anisotropic conductive material and another printed wiring board is, for example, a sectional view taken along the line EE of FIGS. It is configured as shown in FIG.

That is, as shown in FIG. 10, a conventional printed wiring board 101 is a printed wiring board 102 to be pressure-bonded.
And a printed wiring board 103 for crimping and connecting the printed wiring board 102 to be crimped.
The conductive pattern 105 is provided on the base material 104, and the anisotropic conductive material 106 (see FIG. 11) is integrally formed on the entire surface of the base material 104 provided with the conductive pattern 105. The other surface of the material 106 has a structure in which a pattern protective film 107 is coated except the conductive pattern exposed portion 108 which is a pressure-bonded portion with the printed wiring board 102 to be pressure-bonded.

On the other hand, in the printed wiring board 102 to be pressure-bonded, the conductive material 113 is provided on the base material 111 (see FIG. 11), and the base material 1 provided with the conductive pattern 113 is provided.
The surface 11 has a structure in which a pattern protective film 112 is coated except for the pressure-bonded portion 114 with the exposed portion 108 of the conductive pattern of the printed wiring board 103 provided with the anisotropic conductive material.

Then, as shown in FIG. 11, the conductive pattern exposed portion 108 of the printed wiring board 103 provided with the anisotropic conductive material and the crimped portion 1 of the printed wiring board 102 to be pressure-bonded.
14 and 14 are pressure-bonded and connected by a head portion 115 of a pressure-bonding device (not shown).

When the printed wiring board 103 on which the crimped printed wiring board 102 and the anisotropic conductive material 106 are integrally provided is made conductive by crimp connection, the conductive pattern 105 to which the head portion 115 of the crimping device is crimped, Generally, a certain gap is provided between the pattern protection film 112 of the printed wiring board 102 to be crimped and the outer shape of the printed wiring board 103 so that the surface 113 is evenly contacted for stable conductive connection. In addition, the conductive pattern 105 of the printed wiring board 106 integrally provided with the anisotropic conductive material 106 generally extends to the end surface of the printed wiring board 103.

In addition, solder may be plated on the surface of the conductive pattern 113 of the printed wiring board 102 to be pressure-bonded, which is gold, tin, or an alloy of zinc and tin to protect copper.

[0008]

In the conventional crimping structure as shown in FIGS. 10 and 11, unless the printed wiring board 102 to be crimped is plated, the conductive pattern 113 made of copper is used as shown in FIG. The exposed portion 120 is generated. Since the exposed portion 120 is made of copper, it is oxidatively corroded by wet corrosion that occurs when it comes into contact with water vapor in the air, and the corrosion progresses to the crimp portion 108, and finally the conductive pattern 1 is formed.
There is a disadvantage that the conductive connection between 05 and 113 becomes poor and the conductive connection is no longer fulfilled.

This phenomenon is particularly severe in an atmosphere of high temperature and high humidity. For example, when a temperature cycle test of room temperature → high temperature / high humidity → low temperature → high temperature / high humidity → room temperature is performed after 10 cycles, the inside of the crimp is corroded. And the significant increase in electrical resistance between the patterns is observed.

Further, even when tin plating or solder plating which is generally carried out is performed, the presence of a portion where the surface is exposed to water vapor can be a target of corrosion, and it cannot serve as a conductive connection. There are many drawbacks. That is, even if the plating can be applied to delay the progress of corrosion to some extent, the printed wiring board 10 integrally provided with the anisotropic conductive material 106 is provided.
As long as the non-platable conductive pattern 105 of No. 3 exists on the outer end face, it is corroded from there.

[0011] This means that in a product having a connection portion crimped by the conventional crimping structure, if water drops or the like are attached to the connection portion due to some reason such as carelessness of the user or dew condensation, there is a potential failure of conduction. It leads to having a defect.

For example, when a conductive pattern of a printed wiring board to be pressure-bonded is plated with gold, corrosion on the conductive pattern can be avoided, but gold plating is expensive, and even if it is plated with gold. Even if the conductive pattern of the printed wiring board integrally provided with the anisotropic conductive material is present on the end face of the outer shape, it is corroded from there.

The present invention has been made in view of the above circumstances, and a printed wiring board integrally provided with an anisotropic conductive material and a printed wiring board conductively connected to the printed wiring board are manufactured by an inexpensive and simple method. It is an object of the present invention to provide a highly reliable printed circuit board by preventing the occurrence of oxidative corrosion at the connection part with.

[0014]

A printed circuit board according to claim 1 of the present invention is a first printed circuit board having a first conductive pattern printed thereon.
The printed wiring board and the second printed wiring board on which the second conductive pattern integrally provided with the anisotropic conductive material is printed by pressure bonding, to thereby form the first conductive pattern and the second conductive pattern. In a printed circuit board for conductively connecting and, the crimp portion of the second printed wiring board is provided so as to overlap with a pattern protective film for protecting the first conductive pattern of the first printed wiring board. Composed.

In the printed circuit board according to claim 1 of the present invention, the crimping portion of the second printed wiring board overlaps the pattern protective film for protecting the first conductive pattern of the first printed wiring board. By being provided, the first printed wiring board and the second printed wiring board are connected by crimping, so that the crimping portion of the second printed wiring board is overlaid on the pattern protective film, which is inexpensive and simple. By such a method, it is possible to prevent the occurrence of oxidative corrosion in the connection portion between the second printed wiring board and the first printed wiring board integrally provided with the anisotropic conductive material, and to improve the reliability. .

The printed circuit board according to claim 2 of the present invention is the first
The first printed wiring board on which the conductive pattern is printed and the second printed wiring board on which the second conductive pattern on which the anisotropic conductive material is integrally printed are pressure-bonded to each other to form the first printed wiring board. In the printed circuit board that electrically connects the conductive pattern and the second conductive pattern, the second conductive pattern is configured not to exist at the outer edge of the second printed wiring board.

In the printed circuit board according to claim 2 of the present invention, the second conductive pattern is formed so as not to exist on the outer edge of the second printed wiring board, and the first printed wiring board and the second printed wiring board are formed. Second printed wiring integrally provided with an anisotropic conductive material by an inexpensive and simple method such as performing crimp connection with the printed wiring board described above, that is, the second conductive pattern is not formed even on the outer edge portion. It is possible to prevent oxidative corrosion from occurring in the connection portion between the board and the first printed wiring board, and to enhance reliability.

The printed circuit board according to claim 3 of the present invention is the first
The first printed wiring board on which the conductive pattern is printed and the second printed wiring board on which the second conductive pattern on which the anisotropic conductive material is integrally printed are pressure-bonded to each other to form the first printed wiring board. In a printed circuit board for conductively connecting a conductive pattern and the second conductive pattern, a through hole is provided in a portion of the first printed wiring board where a pattern protective film for protecting the first conductive pattern does not exist. Configure.

In the printed circuit board according to claim 3 of the present invention, the through hole is formed in the first printed wiring board of the first printed wiring board.
Of the pattern protection film for protecting the conductive pattern, the pattern protection film protecting the through hole by performing pressure bonding connection between the first printed wiring board and the second printed wiring board. It is possible to prevent the occurrence of oxidative corrosion at the connection between the second printed wiring board and the first printed wiring board, which are integrally provided with the anisotropic conductive material, by an inexpensive and simple method such as providing them in a portion where no , It is possible to increase reliability.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 relate to a first embodiment of the present invention. FIG. 1 is a structural view showing the structure of a printed circuit board, and FIG. 2 is a sectional view showing a cross section taken along the line AA of FIG. .

As shown in FIG. 1, a printed circuit board 1 of the present embodiment comprises a crimped printed wiring board 2 (first printed wiring board) and a crimped printed wiring board 3 for crimping and connecting the crimped printed wiring board 2. (Second printed wiring board), and the crimped printed wiring board 3 has a conductive pattern 5 (second conductive pattern) provided on a base material 4, and the surface of the base material 4 provided with the conductive pattern 5 An anisotropic conductive material 6 (see FIG. 2) is integrally formed on the entire surface of the anisotropic conductive material 6, and a pattern protective film 7 is formed on the other surface of the anisotropic conductive material 6 in a pressure-bonded portion with the printed wiring board 2 to be pressure-bonded. Except for the exposed portion 8 of the conductive pattern, the structure is coated.

On the other hand, in the printed wiring board 2 to be pressure-bonded, the conductive pattern 13 (first conductive pattern) is provided on the base material 11 (see FIG. 2), and the surface of the base material 11 provided with the conductive pattern 13 is provided. Has a structure in which the pattern protective film 12 is coated except for the pressure-bonding portion 14 with the conductive pattern exposed portion 8 of the printed wiring board 3.

Then, as shown in FIG. 2, the conductive pattern exposed portion 8 of the crimping printed wiring board 3 provided with the anisotropic conductive material 6 and the crimping portion 14 of the crimped printed wiring board 2 are crimped (not shown). The head portion 15 of the device is adapted to be crimped and connected.

The pressure-bonding head 15 has a base material 4, a conductive pattern 5, a pattern protective film 7, etc. on the pressure-bonding surface so that the surface of the conductive pattern 13 to be pressure-bonded can be evenly contacted and stable conductive connection can be achieved during pressure-bonding. Step 1 according to the thickness of
7 are provided.

The base material 4 of the pressure-bonded printed wiring board 3 is also used.
Is extended so as to overlap with the upper portion of the protective film 12 of the printed wiring board 2 to be pressure-bonded, and is configured to cover a gap between the protective film 12 of the printed wiring board 2 to be pressure-bonded and the conductive pattern 5 of the printed wiring board 3. There is.

As described above, the printed circuit board 1 of the present embodiment
Then, the pattern exposed portion 8 without the pattern protective film 7 is filled with the anisotropic conductive material 6, and the base material 4 is extended so as to overlap with the upper portion of the protective film 12 of the printed wiring board 2 to be pressure-bonded. Therefore, the anisotropic conductive material 6 formed on the entire surface of the one surface of the base material 4 should completely cover the gap between the protective film 12 of the printed wiring board 2 to be pressure-bonded and the conductive pattern 5 of the pressure-bonded printed wiring board 3. Therefore, it is possible to prevent the invasion of water vapor or the like that causes corrosion from the outside.

3 and 4 relate to the second embodiment of the present invention, FIG. 3 is a structural view showing the structure of a printed circuit board, and FIG. 4 is a sectional view showing a cross section taken along the line BB of FIG. .

Since the second embodiment is almost the same as the first embodiment, only different points will be described, the same components will be denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 3, the printed circuit board 21 of the present embodiment includes a crimped printed wiring board 22 and a crimped printed wiring board 3 for crimping and connecting the crimped printed wiring board 22.
Since the pressure-bonded printed wiring board 3 has the same structure as that of the first embodiment, the description thereof will be omitted.

The printed wiring board 22 to be pressure-bonded is made of the base material 3
1 (see FIG. 4) and a conductive pattern 33 on the opposite surface are provided respectively, and the through holes 34 electrically connect the conductive patterns 32 and 33.

On the surface of the base material 31 provided with the conductive pattern 32, a pattern protective film 35 is coated except for the pressure-bonded portion 36 with the conductive pattern exposed portion 8 of the pressure-bonded printed wiring board 3, and the conductive pattern 33 is formed. Base material 31 provided
The surface is covered with a pattern protective film 37.

Then, as shown in FIG. 4, the conductive pattern exposed portion 8 of the crimping printed wiring board 3 and the crimping portion 36 of the crimped printed wiring board 22 are crimped and connected by a head portion of a crimping device (not shown). It has become.

In the printed circuit board 21 of the present embodiment, the conductive pattern 32 on the side of the pattern protection film 35 on the printed wiring board 22 to be pressure-bonded in FIG. 3 and FIG. To the conductive pattern 33, and again through the through hole 34 to the conductive pattern 32 provided in the pressure-bonding portion 36 without the pattern protective film 35.

Therefore, the crimped printed wiring board 3 and the crimped printed wiring board 22 are so arranged that the crimped portion 36 of the crimped printed wiring board 22 in this state is covered by the conductive pattern exposed portion 8 of the crimped printed wiring board 3. Crimping part 3
The anisotropic conductive material 6 can be filled up with 6 to prevent invasion of water vapor or the like from the outside that causes corrosion.

At this time, it is desirable that the conductive pattern 5 of the pressure-bonded printed wiring board 3 does not protrude from the end of the pressure-bonded printed wiring board 22. Of course, crimped printed wiring board 3
The conductive pattern 32 of No. 1 may have a structure to be wired to the conductive pattern exposed portion 8.

5 to 8 relate to a third embodiment of the present invention, and FIG. 5 is a structural diagram showing the structure of a printed circuit board,
6 is a cross-sectional view showing a cross section taken along line CC of FIG. 5, FIG. 7 is a configuration diagram showing a configuration of a modified example of the printed circuit board of FIG. 5, and FIG.
FIG. 6 is a cross-sectional view showing a cross section taken along line DD of FIG.

Since the third embodiment is almost the same as the first embodiment, only different points will be described, the same components will be denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 5, the printed circuit board 51 according to the present embodiment includes a crimped printed wiring board 52 and a crimped printed wiring board 5 for crimping and connecting the crimped printed wiring board 52.
3 and the pressure-bonded printed wiring board 53 is composed of the base material 5
4 is provided with a conductive pattern 55, and the conductive pattern 55
The anisotropic conductive material 5 is formed on the entire surface of the base material 54 provided with
6 (see FIG. 6) are integrally formed. Further, on the other surface of the anisotropic conductive material 56, a pattern protection film 57 is provided with a conductive pattern exposed portion 58 which is a pressure-bonded portion with the printed wiring board 52 to be pressure-bonded. Except for this, it has a coated structure.

On the other hand, the printed wiring board 52 to be pressure-bonded is provided with a conductive pattern 63 whose surface is plated with nickel and gold on a base material 61 (see FIG. 6).
3 is provided on the surface of the base material 61 on which the pattern protection film 62 is formed.
It has a coated structure except for the pressure-bonding portion 64 with 8.

In this embodiment, a gap G is formed between the pattern protection film 62 and the pressure-bonded printed wiring board 53,
The pressure is applied so that the plated conductive pattern 63 is exposed.

Further, in this case, if the tip of the conductive pattern 55 is located on the outer end surface of the crimping printed wiring board 53, corrosion starts from there, so that the conductive pattern 55 is configured to be crimped without extending to the outer end. There is. As a result, the tip end surface of the conductive pattern 55 is covered with the anisotropic conductive member 56, and it is possible to prevent invasion of water vapor or the like, which causes corrosion.

As shown in FIG. 7, the gap G may be sealed with a resin or the like to prevent invasion of water vapor or the like. In this case, as shown in FIG. 8, the conductive pattern 55 is formed.
Even if it extends to the outer edge, it is possible to prevent invasion of water vapor or the like which is a cause of corrosion.

The conductive pattern 63 provided on the base material 61 is vulnerable to corrosion if the end surface of the conductive pattern 63 is on the outer shape end surface of the base material 61. Therefore, it is better not to contact the outer shape end surface as shown in FIG. Good.

FIG. 9 is a configuration diagram showing the configuration of a printed circuit board according to the fourth embodiment of the present invention.

Since the fourth embodiment is almost the same as the first embodiment, only different points will be described, the same components will be denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 9, the printed circuit board 71 of the present embodiment comprises a crimped printed wiring board 2 and a crimped printed wiring board 73 for crimping and connecting the crimped printed wiring board 2. Since the plate 2 has the same structure as that of the first embodiment, its explanation is omitted.

Crimped printed wiring board 73 of the present embodiment
The base plate 74 has a different shape from that of the first embodiment. That is, the base plate 74 of the crimped printed wiring board 73 has the crimping portion 14 of the printed wiring board 2 to be crimped.
The tip portion is formed in a T shape so as to cover the portion arranged so as to overlap with the crimp portion 14 of the printed wiring board 2 to be crimped, which has no pattern protective film 13 from three directions, and the entire tip portion is formed. The anisotropic conductive material 75 is integrally configured.

The other structure is the same as that of the first embodiment.

Therefore, the printed circuit board 71 of the present embodiment.
In addition to the effects of the first embodiment, since the pressure-sensitive adhesive portion 14 is filled with the anisotropic conductive material 75 so as to cover it from three directions,
It is possible to more reliably prevent the invasion of water vapor or the like that causes corrosion from the outside.

The crimping in each of the above embodiments is
Either thermocompression bonding or room temperature bonding can be applied.

[0052]

As described above, according to the printed circuit board of the present invention, the crimp portion of the second printed wiring board overlaps the pattern protective film for protecting the first conductive pattern of the first printed wiring board. Since the first printed wiring board and the second printed wiring board are crimped and connected by such a configuration, the second printed wiring integrally provided with the anisotropic conductive material can be manufactured by an inexpensive and simple method. This has the effect of preventing the occurrence of oxidative corrosion at the connection between the board and the first printed wiring board and improving the reliability.

As described above, according to the printed circuit board of claim 1 of the present invention, the crimp portion of the second printed wiring board is on the pattern protective film for protecting the first conductive pattern of the first printed wiring board. Since the first printed wiring board and the second printed wiring board are crimped and connected by being provided so as to overlap with each other, the crimping portion of the second printed wiring board is overlaid on the pattern protective film, which is inexpensive and simple. According to the method, it is possible to prevent the occurrence of oxidative corrosion of the connection portion between the second printed wiring board and the first printed wiring board integrally provided with the anisotropic conductive material and to improve the reliability. is there.

Further, according to the printed circuit board of claim 2 of the present invention, since the second conductive pattern is not provided at the outer end portion of the second printed wiring board, the second printed circuit board and the second printed wiring board are provided.
Second printed wiring board integrally provided with an anisotropic conductive material by an inexpensive and simple method in which the second conductive pattern is not formed even on the outer edge portion, because crimp connection with the printed wiring board is performed. With this, it is possible to prevent the occurrence of oxidative corrosion at the connection portion between the first printed wiring board and the first printed wiring board and improve the reliability.

Further, according to the printed circuit board of claim 3 of the present invention, the through hole is formed in the first printed wiring board of the first printed wiring board.
Since the first printed wiring board and the second printed wiring board are pressure-bonded by being provided in a portion where the pattern protective film for protecting the conductive pattern does not exist, the pattern protective film for protecting the through hole does not exist. By using an inexpensive and simple method such as providing it on a part, the occurrence of oxidative corrosion at the connection between the second printed wiring board and the first printed wiring board integrally provided with the anisotropic conductive material is prevented, and reliability is improved. There is an effect that can increase.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a printed circuit board according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a section taken along the line AA of FIG.

FIG. 3 is a configuration diagram showing a configuration of a printed circuit board according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a cross section taken along the line BB of FIG.

FIG. 5 is a configuration diagram showing a configuration of a printed circuit board according to a third embodiment of the present invention.

6 is a cross-sectional view showing a cross section taken along line CC of FIG.

7 is a configuration diagram showing a configuration of a modified example of the printed circuit board of FIG.

8 is a cross-sectional view showing a cross section taken along line DD of FIG.

FIG. 9 is a configuration diagram showing a configuration of a printed circuit board according to a fourth embodiment of the present invention.

FIG. 10 is a configuration diagram showing a configuration of a conventional printed circuit board.

11 is a cross-sectional view showing a cross section taken along line EE of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Printed circuit board 2 ... Printed wiring board to be pressure-bonded 3 ... Pressure-bonded printed wiring board 4, 11 ... Base material 5, 12 ... Conductive pattern 6 ... Anisotropic conductive material 7, 13 ... Pattern protective film 8 ... Conductive pattern exposed part 14 … Crimping part 15… Head part

Claims (3)

[Claims] 1. A first printed wiring board having a first conductive pattern printed thereon, and a second printed wiring board having a second conductive pattern printed integrally with an anisotropic conductive material. In a printed circuit board for electrically connecting the first conductive pattern and the second conductive pattern by pressure bonding, the pressure bonding portion of the second printed wiring board is the first printed wiring board of the first printed wiring board. The first protective layer is provided so as to overlap the pattern protective film for protecting the conductive pattern.
The printed circuit board, wherein the printed circuit board and the second printed circuit board are crimped and connected. 2. A first printed wiring board having a first conductive pattern printed thereon and a second printed wiring board having a second conductive pattern printed integrally with an anisotropic conductive material. In a printed circuit board that electrically connects the first conductive pattern and the second conductive pattern by pressure bonding, the second conductive pattern may not be present at an outer end portion of the second printed wiring board. Characterized printed circuit board. 3. A first printed wiring board having a first conductive pattern printed thereon and a second printed wiring board having a second conductive pattern printed integrally with an anisotropic conductive material. In a printed circuit board that electrically connects the first conductive pattern and the second conductive pattern by pressure bonding, there is no pattern protective film for protecting the first conductive pattern of the first printed wiring board. A printed circuit board having a through hole in a portion thereof.