JPH0548226A - Flexible printed-circuit board - Google Patents

Abstract

(57) [Summary] (Correction) [Structure] The flexible printed circuit board 1 is provided with a slit 11, a copper foil pattern 13 is formed around the slit, and a cover coat removing portion 14 is provided around the copper foil pattern. The copper foil pattern was formed and exposed to form an electrical connection portion. Further, in a flexible printed circuit board having an electrical connection portion formed by protruding an exposed portion of the copper foil, by forming a tongue portion in the peripheral portion of the electrical connection portion, when the tongue portion is folded back, The electrical connection was covered and protected. [Effect] A flexible printed circuit board having good solderability and high reliability, capable of dealing with a narrow pitch metal contact piece, and having good mounting workability can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible printed circuit board having an electrical connection part.

[0002]

2. Description of the Related Art Conventionally, in an electric device, a metal contact for receiving power from a built-in battery and supplying it to a flexible printed circuit board on which an electric circuit is formed, or
An electrical connecting portion between the flexible printed board and the metal contact piece for electrically connecting the flexible printed board and another board is configured as shown in FIG. In the figure, 5 is a flexible printed circuit board, 57 is solder, 5
8 is a metal contact piece.

An opening 51 is formed in the flexible printed circuit board 5 corresponding to the metal contact piece 58.
A copper foil pattern 53 is formed around the opening 51, and the cover coat removing portion 5 is formed around the copper foil pattern 53.
4 is provided and the copper foil pattern 53 is exposed to form an electrical connection portion.

Further, conventionally, an electrical connection portion between a switch composed of a plurality of metal contact pieces and a flexible printed circuit board is constructed as shown in FIG. In the figure, 6 is a flexible printed circuit board, 67 is solder, 6
8 is a switch.

The flexible printed board 6 has an opening 6 corresponding to a metal contact piece 68a constituting a switch 68.
1 is formed. A copper foil pattern 63 is formed around the opening 61, and a cover coat removing portion 64 is provided around the copper foil pattern 63.
The electrical connection portion is formed by exposing the.

[0006] As electric equipment becomes more sophisticated and smaller, the size and complexity of electric circuits have become more and more remarkable. This immediately requires the contradictory conditions of a larger mounting scale and a mounting space constraint. In order to effectively use the limited space for electrical mounting under such a circumstance, it is necessary to divide and house the circuit boards into a plurality of parts and then to electrically connect the circuit boards.

Conventionally, in order to efficiently make an electrical connection between circuit boards, a plurality of exposed copper foil portions are arranged at equal intervals to form an electrical connection, as shown in FIG.

[0008]

However, the former conventional example described above has the following drawbacks. (1) Since the size of the opening formed in the flexible printed board is larger than the thickness of the metal contact piece electrically connected to the flexible printed board, the metal contact piece and the soldering land portion are provided with a large size. A gap is generated, and when soldering, the solder escapes from this gap to the opposite surface, deteriorating the solderability and causing the solder that has flowed out to adhere to another component and cause an electrical short circuit. (2) If the gap between the plurality of metal contacts electrically connected to the flexible printed circuit board is narrow, the openings formed in the flexible printed circuit board come close to each other, so that the opening cannot be formed on the mold structure, and therefore the electrical connection is made. Part cannot be formed. (3) In the case of the component having the contact piece structure as shown in FIG. 6, when the opening is formed in the flexible printed circuit board so as to be aligned with the regular mounting position, the distance between the contact pieces of the metal contact piece is flexible at the tip. Since the distance becomes larger than the distance between the openings of the printed circuit board, not only the workability of mounting is extremely deteriorated, but also the tip of the metal contact piece may damage the electrical connection part of the flexible printed circuit board.

Further, in order to realize high-density electrical mounting in a limited space today, the circuit board must be laid out through an extremely narrow space. In the latter conventional example, for example, FIG. As shown in FIG.
Flexible printed board 7 having 41 at the tip
7 is laid out through the member 72 in which the through hole portion 91 is formed, the flexible printed board 77 is formed in the narrow through hole portion 9 so as not to damage the electrical connection portion 141.
It is necessary to be very careful in passing through the wire 1, and should the electrical connection part 141 be caught in the hole inside 92, problems such as bending or tearing of the electrical connection part 141 or peeling of the copper foil may occur. There was a drawback that occurred.

[0010]

According to the present invention, a slit is provided in a flexible printed circuit board, a copper foil pattern is formed in the peripheral portion of the slit, and a cover coat removal portion is formed in the peripheral portion of the copper foil pattern. By exposing the copper foil pattern to form the electrical connection portion, (1) good solderability and high reliability (2) compatible with narrow-pitch metal contact pieces (3) mounting workability Good It is to provide an excellent flexible printed circuit board as described above.

Further, according to the present invention, in a flexible printed circuit board having an electrical connection portion formed by projecting an exposed portion of a copper foil, a tongue-shaped portion is formed in the peripheral portion of the electrical connection portion. The tongue portion covers and protects the electrical connection portion when folded back.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram best representing the features of the first embodiment of the present invention. In the figure, 1 is a flexible printed circuit board, 11 is a slit, 12 is a hole, 13 is a copper foil pattern, and 14 is a cutout part where a cover coat as an insulating coating layer is partially removed. Next, the configuration of this embodiment will be described.

A slit 11 is formed in the flexible printed board 1. Holes 12 are formed at both ends of the slit 11 to prevent tearing. A copper foil pattern 13 is formed on the periphery of the slit 11, and a cover coat removing portion 14 is provided on the periphery of the copper foil pattern 13 to expose the copper foil pattern 13 to form an electrical connection portion. ing.

FIG. 2 shows a state of the flexible printed circuit board and the metal contact piece in this embodiment. 2 is a flexible printed circuit board, 21 is a slit, 22 is a hole, 23 is a copper foil pattern, 24 is a cover coat removal part,
Reference numeral 27 is solder, and 28 is a metal contact piece.

According to the figure, the slit 21 and the metal contact piece 28 are
Since it is in close contact, the solder does not flow out to the opposite side of the soldering land, eliminating the risk of electrical short-circuiting with another component, and also the area of the soldering land can be widened to ensure an electrical connection. The reliability of is greatly improved.

Further, because of the slit structure, an electrical connection portion can be formed even if the metal contact pieces are formed with a narrow pitch, and high-density and compact electrical mounting can be achieved.

FIG. 3 is a diagram best representing the features of the second embodiment of the present invention. In the figure, 3 is a flexible printed circuit board, 31 is a slit, 32 is a hole, 33 is a copper foil pattern, and 34 is a cover coat removal part. Next, the configuration of this embodiment will be described.

The flexible printed board 3 is formed with a slit 31 reaching the outer shape. The slit 3
A hole 32 for preventing tearing is formed at one end.
A copper foil pattern 33 is formed in the peripheral portion of the slit 31, and a cover coat removing portion 34 is further provided in the peripheral portion of the copper foil pattern 33 to expose the copper foil pattern 33 to form an electrical connection portion. is doing.

FIG. 4 shows a state of the flexible printed circuit board and the metal contact piece in this embodiment. 4 is a flexible printed circuit board, 41 is a slit, 42 is a hole portion, 43 is a copper foil pattern, 44 is a cover coat removal portion,
47 is solder and 48 is a switch.

According to the figure, the slit 41 and the switch 48
Since the metal contact piece 48a of No. 1 is in a close contact state, the solder does not flow out to the opposite surface of the soldering land, and not only the risk of electrical short circuit with another component disappears but also the area of the soldering land can be widened. Therefore, the reliability of electrical connection is significantly improved.

Further, because of the slit structure, the electrical connection portions can be formed even if the metal contact pieces are formed with a narrow pitch.

Further, if a slit is formed in the flexible printed circuit board in accordance with the regular mounting position, the flexible printed circuit board can be mounted simply by sliding it from the side surface of the metal contact piece 48a of the switch 48 at the time of mounting. This makes it possible to carry out extremely reliable mounting work without damaging the electrical connection part.

FIGS. 7 to 8 show a third embodiment of the present invention, and FIG. 7 is a drawing which best shows the third embodiment.
In the figure, 71 is a flexible printed circuit board, 81 is an electrical connection part, 82 is a tongue-shaped part, 83 is a copper foil pattern, 8
4 is a cover film and 85 is a through hole.

Next, details of the present invention will be described with reference to FIG. On the flexible printed circuit board 71, a plurality of base materials (not shown) and copper foil patterns 83b are projected and the cover film 84 at the protruding portions is removed to expose the copper foil patterns 83b to form a plurality of them at equal intervals. The contact portion 81 is formed. On the opposite side of the electrical connection portion 81, a tongue portion 8 made of a base material and a cover film is formed.
2 is formed. As shown in FIG. 7B, the tongue-shaped portion 82 is formed so as to cover at least the electrical connection portion 81 when folded back near the root of the tongue-shaped portion 82.

FIG. 8 is a diagram showing an actual use state of the present invention. In the figure, 72 is a member, 91 is a through hole, and 92 is a through hole.
Is the inner wall of the hole. Next, details will be described with reference to FIG.
Through holes 91 are formed in the member 72 for layout through the flexible printed circuit board 71. The flexible printed circuit board 71 can pass through the through hole 91 of the member 72 in a state where the tongue-shaped portion 82 is folded back from the vicinity of the root and covers the electrical connection portion 81. At this time, since the tip of the folded-back tongue-shaped portion 82 serves as a guide, it is easy to pass through the through hole portion 91 and the workability is good. Further, even if the flexible printed circuit board 71 is roughly inserted into and removed from the through hole portion 91, the tongue-shaped portion 82 that comes into contact with the hole inner wall 92 is the folded back tongue portion 82.
Therefore, problems such as bending, tearing, and peeling of copper foil do not occur.

FIG. 9 is a diagram best representing the features of the fourth embodiment of the present invention. In the figure, 73 is a flexible printed circuit board, 101 is an electrical connection part, 102 is a tongue-shaped part, 103 is a copper foil pattern, 104 is a cover film,
Reference numeral 105 is a through hole.

Next, details of the embodiment will be described with reference to FIG. On the flexible printed circuit board 73, a base material (not shown) and a copper foil pattern 103b are projected and the cover film 104 at the projecting portion is removed to remove the copper foil pattern 103.
An electrical connection portion 101 is formed by arranging a plurality of exposed b's at equal intervals. The electrical connection 1
A tongue-shaped portion 102 made of a base material and a cover film is formed on the front end side of 01. As shown in FIG. 9B, when the tongue-shaped portion 102 is folded back near the root of the tongue-shaped portion 102, at least the electrical connection portion 101 is formed.
Is formed so that it can be covered.

In this embodiment, since the folded-back portion of the tongue-shaped portion 102 is located at the tip of the electrical connection portion 101, the tip of the tongue-shaped portion is curled, which makes it difficult to insert it into the hole. Further, even if the flexible printed circuit board 73 is roughly inserted into and removed from the hole, the folded tongue 102 contacts the inner wall of the hole, so that the electrical connection portion does not catch on the inner wall of the hole and therefore bends or tears. Problems such as disconnection and peeling of copper foil do not occur. Furthermore, since there is no protrusion of the tongue-shaped portion in the insertion / removal direction of the flexible printed circuit board, the material collecting property of the flexible printed circuit board is improved and the cost can be reduced.

FIG. 10 is a diagram best representing the features of the fifth embodiment of the present invention. In the figure, 74 is a flexible printed circuit board, 111 is an electrical connection part, 112 is a tongue-shaped part, 113 is a copper foil pattern, 114 is a cover film,
Reference numeral 115 is a through hole, and 116 is a positioning hole.

Next, details of this embodiment will be described with reference to FIG. On the flexible printed board 74, a base material (not shown) and a copper foil pattern 113b are projected and the cover film 114 at the protruding portion is removed to remove the copper foil pattern 11 from the copper foil pattern 11.
An electrical connection portion 111 is formed by arranging a plurality of exposed portions of 3b at equal intervals. A tongue-shaped portion 112 made of a base material and a cover film is formed on the opposite side of the electrical connection portion 111. The tongue 112
It is formed so as to cover at least the electrical connection portion 111 when folded back near the root of the.

Further, the flexible printed board 7
4, the flexible printed circuit board 74 is fixed to a structural member, and the electrical connection portion 111 is provided.
A common positioning hole portion 116 for performing alignment with an electrical connection portion of another substrate electrically connected to the positioning hole is formed in the positioning dowel provided in the structural member. By inserting the portion 116, the substrate can be fixed and the electric connection portion can be aligned.

As described above, in the present embodiment, since the positioning hole is formed in the tongue-shaped portion for protecting the electrical connection portion, the flexible printed circuit board can be securely fixed and the electrical connection can be ensured. The workability of the connecting portion is improved, and a compact board that does not require a dedicated space for the positioning hole can be realized.

FIG. 11 best shows the characteristics of the sixth embodiment of the present invention. In the figure, 75 is a flexible printed circuit board, 121 is an electrical connection part, 122 is a tongue-like part, 123 is a copper foil pattern, 124 is a cover film,
125 is a through hole, 126 is a positioning hole, 12
Reference numeral 7 is a protrusion, and 128 is a hole.

Details of this embodiment will be described below with reference to FIG. On the flexible printed circuit board 75, a base material (not shown) and a copper foil pattern 123b are projected and the cover film 124 at the projecting portion is removed to remove the copper foil pattern 12 from the copper foil pattern 12.
An electrical connection portion 121 is formed by arranging a plurality of exposed portions 3b at equal intervals. A tongue portion 122 made of a base material and a cover film is formed on the tip side of the electrical connection portion 121. The tongue 122
When folded back near the base of the tongue 122 as shown in FIG. 10 (b), at least the electrical connecting portion 1
21 is formed so that it can be covered.

Further, the flexible printed board 7
5, a protrusion 127 and a hole 128 for hooking the protrusion 127 are formed so that the tongue 122 does not return due to tension when the tongue 122 is folded back.

In this embodiment, since the projection and the hole are provided so that the folded-back tongue-shaped portion does not open as described above, the workability in inserting / removing the through-hole can be further improved. There are advantages.

[0037]

As described above, since the electrical connection portion with the metal contact piece is formed around the slit formed in the flexible printed board, (1) good solderability and high reliability (2) ) Capable of handling narrow pitch metal contact pieces (3) Good mounting workability It is possible to provide an excellent flexible printed circuit board as described above, and achieve highly reliable, high-density and compact electrical mounting at low cost. ..

Further, according to the present invention, in a flexible printed circuit board having an electric connection portion formed by protruding an exposed portion of a copper foil, when a tongue-shaped portion formed around the electric connection portion is folded back. Since it is configured to cover at least the electric connection portion, the tip of the folded tongue portion serves as a guide when laying out through the narrow hole portion, and thus the workability is good, and the electric connection portion has a hole portion. Since it does not come into contact with the inner wall of the, there is an advantage that problems such as bending and tearing or peeling of copper foil do not occur.

Further, since the positioning hole is provided in the tongue-like portion, there is an advantage that the flexible printed circuit board can be securely fixed and the workability of the electrical connecting portion is improved.

Further, since the folded tongue portion is constructed so as not to be opened by the tension, workability at the time of inserting / removing into / from the through hole portion is further improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a mounting state of the first embodiment of the present invention.

FIG. 3 is a diagram showing a second embodiment of the present invention.

FIG. 4 is a diagram showing a mounting state of a second embodiment of the present invention.

FIG. 5 is a diagram showing a conventional implementation.

FIG. 6 is a diagram showing a conventional implementation.

FIG. 7 is a diagram showing a third embodiment of the present invention.

FIG. 8 is a diagram showing a usage state of a third embodiment of the present invention.

FIG. 9 is a diagram showing a fourth embodiment of the present invention.

FIG. 10 is a diagram showing a fifth embodiment of the present invention.

FIG. 11 is a diagram showing a sixth embodiment of the present invention.

FIG. 12 is a diagram showing a conventional implementation.

FIG. 13 is a diagram showing a usage state of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible printed circuit board 11 Slit 12 Hole part 13 Copper foil pattern 14 Cover coat removal part 71 Flexible printed circuit board 81 Electrical connection part 82 Tongue part 83 Copper foil pattern 84 Cover film 85 Through hole

Claims (3)

[Claims] 1. A flexible printed circuit board is provided with a slit, a copper foil pattern is formed in the peripheral portion of the slit, and a cover coat removal portion is formed in the peripheral portion of the copper foil pattern to expose the copper foil pattern. A flexible printed circuit board having an electrical connection portion. 2. A flexible printed circuit board having an electrical connection portion formed by protruding an exposed portion of a copper foil, wherein a tongue-shaped portion is formed around the electrical connection portion, and the tongue-shaped portion is folded back. A flexible printed board, characterized in that it covers at least the electrical connection portion. 3. The flexible printed board according to claim 2, wherein a hole for positioning is formed in the tongue-shaped portion of the flexible printed board.