JP2005183647A - Printed wiring board and its connection method, and repairing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed wiring board provided with a connection structure for easing repair, and its connection method, a repairing method. <P>SOLUTION: When an electrode terminal is formed in the connection part of the printed wiring board, a conductor is exposed by a length necessary for connecting wiring boards plus the same length and an excessive length. When the electrode terminals are bonded with each other to connect the wiring boards, a joint part and a non-joint part are formed in the electrode terminals, and the non-joint part is made larger than a length necessary for connecting the wiring boards. Further, when the printed wiring board is repaired, it is cut to remove the bonded part, thereby obtaining the printed wiring board that is provided with an electrode terminal having at least a length enough to connect the wiring boards, and the wiring board provided with the electrode terminal having such the length is used to connect the printed wiring boards again. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a printed wiring board having a connection structure that can easily realize repair in a printed wiring board used for internal wiring of an electronic device, a connection method thereof, and a repair method.

Conventionally, when connecting a flexible printed wiring board (FPC) to each other or a flexible printed wiring board and another printed wiring board, a connector having a contact pitch suitable for the wiring board is mounted on one wiring board, and then the connector is connected. The other wiring board was inserted into the wiring board, ensuring electrical continuity between the wiring boards and maintaining the strength of the connecting portion. (For example, see Patent Document 1)
In recent years, methods for connecting printed wiring boards that do not use connectors have been proposed. (For example, see Patent Document 2)
FIG. 5 is a diagram for explaining the prior art of a method for connecting wiring boards without using a connector.
As shown in FIG. 5A, in the printed wiring board 100 in which the conductor 102 is formed on the insulating base material 101 and the surface of the conductor 102 is coated with the resist 103, the conductor is connected to the connecting portion (end portion). The electrode terminal part 104 which exposed is formed.
When connecting the printed wiring boards 100a and 100b having the electrode terminal portions, the electrode terminal portions 104a and 104b of the wiring boards face each other (see FIG. 5B), and the electrode terminal portions 104a, A conductive adhesive material such as solder or anisotropic conductive film (ACF) is interposed between 104b, and the electrode terminal portions 104a and 104b are directly bonded to each other via this adhesive material (see FIG. 5C). .
When forming the electrode terminal portion 104 in the connection portion of the printed circuit board, the conductor 102 having a length (part) necessary for connection between the wiring boards is exposed, thereby ensuring and connecting the electrical conductivity between the wiring boards. The strength of the part was maintained.
JP 2000-188487 A Japanese Patent Laid-Open No. 9-160064

However, in the printed wiring board in which the wiring boards are connected using the connector, the cost of the connector and the mounting cost are high, and it is difficult to reduce the price. Furthermore, it is difficult to reduce the size and size of the printed wiring board because of the space for mounting the connector and the bulk of the connector itself.
Further, even with a printed wiring board in which wiring boards are connected without using a connector, it is difficult to repair the printed wiring board when the connection method according to the prior art is used.
For example, when repairing a printed wiring board in which the electrode terminal portions are bonded together via solder, a soldering iron for remelting the solder interposed between the electrode terminal portions in order to peel off the connected wiring boards. In addition, a heating device such as a welder is required, and when the electrode terminal portions are joined again, flux coating must be applied to control the layer thickness of the solder.
In addition, for example, when repairing a printed wiring board in which the electrode terminal portions are bonded via an anisotropic conductive film, the bonding is performed using a special solvent for removing the anisotropic conductive film (resin). A special process such as peeling the electrode terminal parts from each other had to be performed. In recent years, product specifications for printed wiring boards have been particularly strict, and printed wiring boards with an anisotropic conductive film (thermosetting resin) have been used to reinforce connection, reflow resistance, and maintain insulation between adjacent terminals. In other words, it was almost impossible to remove and repair only the anisotropic conductive film interposed between the electrode terminal portions of the printed wiring boards using the solvent, and to peel off the wiring boards.

Therefore, in the present invention, in the printed wiring board in which the surface of the conductor formed on the insulating base material is coated with a resist, in forming the electrode terminal portion where the resist is removed and the conductor is exposed at the connection portion of the printed wiring board. Provided is a printed wiring board in which a conductor having a length obtained by adding a surplus portion longer than the length necessary for connecting the wiring boards to each other is exposed.
Further, when connecting the printed wiring boards by joining the electrode terminal parts, a joined part and a non-joined part are formed in the electrode terminal part at the connecting part of the printed wiring board, and the non-joined part connects the wiring boards to each other. Connect the printed wiring board so that it is longer than the length necessary for connection.
Further, when repairing the printed wiring board, the printed wiring board is cut to remove the joining portion, and at least a printed wiring board having an electrode terminal portion having a length necessary for connecting the wiring boards is obtained. At the same time, a printed wiring board having an electrode terminal portion having a length necessary for connecting at least the wiring boards is used, and the printed wiring boards are connected again.

According to the present invention, when repairing a printed wiring board, the printed wiring board can be cut to remove the joint, and the printed wiring board can be reused. There is no need for special solvents, and work is easy.
In addition, it is possible to easily repair a printed wiring board on which an anisotropic conductive film (thermosetting resin) is applied in order to reinforce a connection part, reflow resistance, and maintain insulation between adjacent terminals. .

A printed wiring board, a connection method thereof, and a repair method thereof according to the present invention will be described with reference to FIGS.
In the present invention, the printed wiring board means a flexible printed wiring board (FPC), a rigid board, a rigid flex board, a flexible flat cable (FFC), a membrane board, a ceramic board, a tape carrier package (TCP), etc. Defined to include various wiring boards and electrical components.

An embodiment of a printed wiring board according to the present invention is shown in FIG.
In this embodiment, in a printed wiring board 10 in which the surface of a conductor 2 formed on an insulating substrate 1 is coated with a resist 3, an electrode in which the conductor 3 is exposed at the connecting portion (end) thereof. It is a printed wiring board in which the terminal portion 4 is formed, and when the electrode terminal portion 4 is formed, the length required for connecting the wiring boards (the length necessary for joining the terminals) is The conductor of the length which added the extra length part more than this is exposed.
The surplus length part is an electronic terminal part 4 where the conductor 2 is exposed and has an exposed part longer than the length necessary for connecting the wiring boards (the length necessary for joining the terminals). Okay (see FIG. 1A), for example, a conductor exposed portion having a length obtained by adding 1 mm or more to a length necessary for connecting wiring boards (a length necessary for joining terminals). .
In other words, by exposing the conductor of the length including the extra length, 2 of the length necessary for connecting the wiring boards to the connection portion of the printed wiring board (the length necessary for joining the terminals) is 2 An electrode terminal portion 4 is formed in which a conductor having a length more than double is exposed.

FIG. 1A shows a first embodiment of a printed wiring board connecting portion structure.
In the connection part of the printed wiring board according to this embodiment, when forming the electrode terminal part 4 from which the resist 3 is removed and the conductor 2 is exposed, the length is required to connect the wiring boards. By removing the resist 3 having a length including the above extra length portion, the conductor 2 more than twice as long as necessary to connect the wiring boards was exposed.
The exposed portion of the conductor 2 is subjected to Au plating, Au / Ni plating, Sn plating, solder plating, rust prevention treatment, or the like as necessary.
The length of the electrode terminal portion 4 (including the extra length portion) is at least twice the length necessary for connecting the wiring boards when the printed wiring board 10 is repaired once. When the printed wiring board 10 is repaired N times, at least N + 1 times the length necessary for connecting the wiring boards to each other is set.

FIG. 1B shows a second embodiment of the printed wiring board connecting portion structure.
In the connection portion of the printed wiring board according to this embodiment, as in the first embodiment, the electrode terminal exposing the conductor 2 having a length obtained by adding the extra length portion to the length necessary for connecting the wiring boards to each other. In addition to forming the portion 4 and partially leaving the resist in the surplus length portion, the electrode terminal portion 4 is divided into a plurality of portions, and at least a plurality of exposed portions having a length necessary for connecting the wiring boards are formed. did.
In this example as well, Au plating, Au / Ni plating, Sn plating, solder plating, rust prevention treatment, etc. were performed on the exposed portion of the conductor 2 as necessary.

In the embodiment shown in FIG. 1B, in forming the electrode terminal portion 4 from which the conductor 3 is exposed by removing the resist 3 at the connection portion of the printed wiring board 10, the resist is partially left at three places. (The 1st-3rd remaining resists 31-33) and the electrode terminal part 4 were divided into four by these remaining resists (1st-4th exposed parts 41-44).
That is, by arranging the first to third remaining resists 31 to 33 at equal intervals, the first to fourth exposed portions 41 to 44 are formed, and at least a conductor having a length necessary for connecting the wiring boards is exposed. Four exposed portions were formed.
Then, the first exposed portion 41 where the resist is removed and the conductor is exposed is formed at the tip of the connecting portion, and the second exposed portion 42 is formed next to the first exposed portion 41 through the first remaining resist 31. A third exposed portion 43 was formed next to the second exposed portion 44 via the second remaining resist 32, and a fourth exposed portion 44 was formed next to the third exposed portion 43 via the third remaining resist 33.

  Next, a printed wiring board connection method and a repair method in which the electrode terminal portion 4 in which the conductor 2 is exposed at least twice the length necessary for connecting the wiring boards to the connection portion of the printed wiring board is formed. Will be described with reference to FIGS.

The printed wiring board connecting method shown in FIG. 2 uses the printed wiring board 10 in which the first to fourth exposed portions 44 to 44 are formed in the connecting portion of the printed wiring board 10 (FIG. 1B). See). That is, in forming the electrode terminal portion at the connection portion of the printed wiring board, the first printed wiring board 10a in which the first to third remaining resists 31a to 33a are provided to form the first to fourth exposed portions 41a to 44a is formed. Similarly, the second printed wiring board 10b provided with the first to third remaining resists 31b to 33b to form the first to fourth exposed portions 41b to 44b is used.
In each of the exposed portions, at least a conductor having a length necessary for connecting the wiring boards is exposed.

In this embodiment, when connecting the printed wiring boards 10a and 10b, the first exposed portions 41a and 41b formed at the tips of the connecting portions face each other (see FIG. 2A), and the first A conductive adhesive material such as solder or anisotropic conductive film (ACF) is interposed between the exposed portions, and the first exposed portions 41a and 41b are directly bonded to each other through the adhesive material (FIG. 2B). See).
When the printed wiring boards are connected to each other by joining the first exposed portions 41a and 41b, the first exposed portions 41 and 41b have a conductor having a length necessary to connect at least the wiring boards. Since it is exposed, the electrical continuity between the wiring boards can be ensured and the strength of the connecting portion can be maintained.

Next, a method for repairing a printed wiring board connected by the connection method shown in FIG. 2 will be described with reference to FIG.
The repair of the printed wiring board includes a peeling process for peeling the connected printed wiring boards and a reconnecting process for connecting the printed wiring boards again.

In this embodiment, when peeling the printed wiring boards formed by joining the first exposed portions 41a and 41b formed at the tips of the connecting portions, as shown in FIG. The first printed wiring board 10a and the second printed wiring board 10b were cut so as to remove 41b.
That is, by cutting the printed wiring board and removing the first exposed portions 41a and 41b, the joint portion is removed, and the printed wiring boards 10a and 10b connected to each other can be peeled off.
The printed wiring boards 10a and 10b are cut at the tips of the second exposed portions 41a and 42b formed on the printed wiring boards, so that the joint portions (first exposed portions) are removed and the printed wiring is provided. The first printed wiring board 10a in which the board is peeled off and the second exposed portion 42a is formed at the tip of the connecting portion, and the second printed wiring board 10b in which the second exposed portion 42b is also formed at the tip of the connecting portion. And can get.

  In this embodiment, the second exposed portions 42a and 42b formed at the front ends of the connecting portions are opposed to each other when the printed wiring boards 10a and 10b are connected again after the printed wiring boards are peeled off (FIG. 3 ( b)), a conductive adhesive material such as solder or anisotropic conductive film (ACF) is interposed between the second exposed portions, and the first exposed portions 41a and 41b are connected to each other through the adhesive material. It joined directly (refer Fig.3 (a)).

Furthermore, according to the printed wiring board according to the present invention, when a printed wiring board (for example, a flexible printed wiring board) using the insulating base material 1 having excellent flexibility is used, the printed wiring board can be folded and used. Yes (see FIG. 4).
For example, like the printed wiring board shown in FIG. 1B, the printed wiring board 10 provided with the first to fourth exposed portions 41 to 44 in the connecting portion is bent and used in the SZ method, and is attached to the tip of the connecting portion. When the printed wiring board is connected by joining the formed first exposed portion 41 and the printed wiring board is peeled off by removing the first exposed portion 41 to repair the printed wiring board, FIG. As shown in a), after the flexible printed wiring board 10 is cut at the tip of the second exposed portion 42 and the printed wiring boards are separated from each other, the folded shape is changed as shown in FIG. Then, the second exposed portion 42 of the flexible printed wiring board 10 is pulled out, and the flexible printed wiring board 10 having the second exposed portion 42 formed at the tip of the connection portion is used again. To connect the door wiring board.
When the flexible printed wiring board is used by being folded, the flexible printed wiring board may be folded in the Z system as shown in FIG.

As described above, in the printed wiring board connection method and the repair method shown in FIGS. 2 to 4, the first to fourth exposed portions 41 are formed on the electrode terminal portions 4 formed on the connection portions of the printed wiring board 10. When the printed wiring board formed with .about.44 is used and this printed wiring board is connected, the first exposed portions 41a and 41b formed at the tips of the connecting portions are joined. At this time, only the first exposed portion 41 is joined (joined portion), and the second to fourth exposed portions 42 to 44 are not joined (non-joined portion).
Then, when repairing the printed wiring board, the printed wiring board is cut at the tip of the second exposed portion 42 and the first exposed portion 41 is removed, so that the joint portion is removed, so that the printed wiring board is easily peeled off. be able to. Moreover, since the printed wiring board in which the second exposed portion 42 is formed at the tip of the joint portion of the printed wiring board can be obtained, the printed wiring board is connected again by joining the second exposed portion 42. Can do. At this time, since only the second exposed portion 42 is joined (joined portion) and the third to fourth exposed portions 43 to 44 are not joined (non-joined portion), it is possible to further repair.
That is, the exposed portion may be formed in accordance with the desired number of repairs. When the printed wiring board 10 is repaired once, at least two exposed portions having a length necessary for connecting the wiring boards to each other are provided. When forming and repairing the printed wiring board 10 N times, at least N + 1 exposed portions having a length necessary for connecting the wiring boards are formed.

  In addition, the electrode terminal part 4 which exposed the conductor of the length which added the extra length part more than the length to the connection part of a printed wiring board required for connecting wiring boards with each other is formed. In the case of using a printed wiring board in which the remaining resist is not provided and the electrode terminal portion 4 is not divided (see FIG. 1A), the electrode terminal portions are joined to each other to connect the printed wiring boards. By joining the electrode terminal portions to each other so that a joining portion and a non-joining portion are formed in the electrode terminal portion, and the non-joining portion is longer than a length necessary for connecting the wiring boards to each other, printing is performed. Connect the wiring board (not shown).

  In addition, when repairing a printed wiring board in which wiring boards are connected so that a joining part and a non-joining part are formed in the electrode terminal part (not shown), the joining part is removed by cutting the printed wiring board. And at least obtaining a printed wiring board having an electrode terminal part of a length necessary for connecting the wiring boards (printing wiring board peeling step), and connecting at least the wiring boards. A printed wiring board provided with an electrode terminal portion of an appropriate length is used, and the printed wiring boards are connected again (printed wiring board reconnection step).

It is a figure which shows the connection part structure of the printed wiring board by the Example of this invention. It is explanatory drawing of the connection method of printed wiring boards. It is explanatory drawing of the repair method of a printed wiring board. FIG. 4 is another embodiment of the printed wiring board repair method shown in FIG. 3. It is explanatory drawing of the connection method of the printed wiring board by a prior art.

Explanation of symbols

1, 1a, 1b Insulating substrate 2, 2a, 2b Conductor 3 Resist 4 Electrode terminal part 41, 42, 43, 41 Exposed part

Claims (7)

In the printed wiring board (10) in which the surface of the conductor (2) formed on the insulating substrate (1) is coated with the resist (3),
In forming the electrode terminal part (4) from which the resist is removed and the conductor is exposed at the connection part of the printed wiring board, an extra length part longer than that length is required to connect the wiring boards to each other. A printed wiring board in which a conductor having an added length is exposed.   The electrode terminal part (4) is divided into a plurality by partially leaving the resist, and at least a plurality of exposed parts (41 to 44) having a length necessary for connecting the wiring boards are formed. The printed wiring board according to claim 1.   The printed wiring board according to claim 1 or 2, wherein a flexible insulating substrate (1) is used. An electrode terminal portion (4) was formed by exposing a conductor having a length obtained by adding an extra length portion equal to or longer than the length necessary for connecting the wiring boards to the connection portion of the printed wiring board. A printed wiring board connection method,
In joining electrode terminal parts and connecting printed wiring boards,
Joining the electrode terminal portions so that a joining portion and a non-joining portion are formed in the terminal electrode portion (4), and the non-joining portion is longer than a length necessary for connecting the wiring boards. A method for connecting a printed wiring board. An electrode terminal portion (4) is formed by exposing a conductor having a length obtained by adding a surplus portion equal to or longer than the length necessary for connecting the wiring boards to the connection portion of the printed wiring board. In addition, the printed wiring in which a plurality of exposed portions (41 to 44) having a length necessary for connecting at least wiring boards are formed by partially leaving the resist to divide the electrode terminal portion (4) into a plurality of parts. A board connection method,
When connecting the printed wiring boards (10a, 10b) by joining the electrode terminal parts,
A method for connecting printed wiring boards, wherein only the first exposed portions (41a, 41b) arranged at the tips of the connecting portions are joined together. The method of repairing the printed wiring board which connected the printed wiring board by the connection method of Claim 4, and connected the wiring boards so that a junction part and a non-joining part may be formed in an electrode terminal part (4). Because
The step of removing the joint by cutting the printed wiring board, obtaining a printed wiring board having an electrode terminal portion (4) of a length necessary to connect at least the wiring boards;
Using the printed wiring board from which the joint portion has been removed, connecting the printed wiring boards again by joining at least the electrode terminal portions of a length necessary for connecting the wiring boards,
A method of repairing a printed wiring board, comprising: The printed wiring board is connected by the connection method according to claim 5, and the printed wiring board in which the wiring boards are connected by repairing the first exposed portions (41 a, 41 b) arranged at the tips of the connecting portions is repaired. A way to
Cutting the printed wiring board to remove the first exposed portions (41a, 41b) and obtaining a printed wiring board having the second exposed portions (42a, 42b) formed at the tips of the connecting portions;
A step of connecting the printed wiring boards again by joining the second exposed portions (42a, 42b) using the printed wiring board in which the second exposed portions (42a, 42b) are formed at the tips of the connecting portions. When,
A method of repairing a printed wiring board, comprising:

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