JP3227778B2 - Conductive connection structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive connection structure using an anisotropic conductive adhesive.

[0002]

2. Description of the Related Art For example, when conductively connecting a connection terminal of one wiring board and a connection terminal of another wiring board in a state where they are opposed to each other, conductive particles made of metal or the like are mixed with a thermoplastic resin or a thermosetting resin. An anisotropic conductive adhesive dispersed in an insulating adhesive such as a resin or a photocurable resin may be used. In that case, as shown in FIG. 7, the anisotropic conductive adhesive 1 is provided on the connection portion including the connection terminal 3 of the one wiring board 2,
The other wiring board 5 having the connection terminals 4 is disposed thereon in opposition, and then the other wiring board 5 is crimped on the one wiring board 2 as shown in FIG. Heat or expose. Then, since the extra insulating adhesive 6 of the anisotropic conductive adhesive 1 escapes in the lateral direction, a part of the conductive particles 7 in the anisotropic conductive adhesive 1 The terminals are sandwiched between the connection terminals 3 and 4, whereby the connection terminals 3 and 4 of the pair of wiring boards 2 and 5 are conductively connected. Further, the insulating adhesive 6 of the anisotropic conductive adhesive 1 is solidified or cured by heating or exposure, whereby the pair of wiring boards 2 and 5 are bonded. In this state, since the adjacent conductive particles 7 are separated from each other, insulation between adjacent connection terminals 3 and between adjacent connection terminals 4, that is, insulation in the horizontal direction is secured. Thus, according to the anisotropic conductive adhesive 1,
While the conductive terminals 7 can electrically connect the connection terminals 3 and 4 located in the thickness direction, the insulation can be ensured in the horizontal direction and the wiring substrates 2 and 5 can be bonded at the same time.

[0003]

However, in the conventional conductive connection structure as described above, the conductive particles 7 are uniformly dispersed in the insulating adhesive 6 of the anisotropic conductive adhesive 1 before the pressure bonding. Even in the state after crimping, as shown in FIG. 9, the conductive particles 7 adhere to the ends of the connection portions of the wiring boards 2 and 5 (the portions indicated by a in FIG. 9), and the adjacent connection terminals 3 and the connection terminal 4 were sometimes short-circuited. That is, when the wiring board 5 is press-bonded on the wiring board 2 with the anisotropic conductive adhesive 1 interposed therebetween, the extra insulating adhesive 6 of the anisotropic conductive adhesive 1 moves in the horizontal direction. The amount of the insulating adhesive 6 increases from the center to the end of the connection portion, and the conductive particles 7 also move with the increase. The distance that the conductive particles 7 move also from the center. It gets bigger toward the end. For this reason, the density of the conductive particles 7 increases at the end of the connection portion, and the adjacent connection terminals 3 and the connection terminals 4 are short-circuited.

An object of the present invention is to provide a conductive connection structure capable of uniformly dispersing conductive particles in an insulating adhesive of an anisotropic conductive adhesive even after pressure bonding.

[0005]

According to the first aspect of the present invention,
A first wiring board having an opening between the plurality of first connection terminals and the first connection terminal; and a second wiring board corresponding to each of the first connection terminals formed on the first wiring board. A second wiring board having connection terminals and not having an opening in a region corresponding to a connection portion of the first wiring board, between the first wiring board and the second wiring board; A connection part including a region corresponding to the opening between the first wiring board and the second wiring board, the connection part comprising an interposed anisotropic conductive adhesive. The first wiring board is entirely filled and enters the opening of the first wiring board. In the above, the width of the opening is
It can be smaller than the width of the continuation.

[0006]

According to the present invention, since an opening is provided in the wiring board, excess insulating adhesive at the time of crimping can be released into the opening of the wiring board. Will not move, and the conductive particles can be uniformly dispersed in the insulating adhesive of the anisotropic conductive adhesive even after the pressure bonding.

[0007]

1 to 3 show a first embodiment of a conductive connection structure according to the present invention in the order of manufacturing steps. The first embodiment of the conductive connection structure of the present invention will be described below in the order of manufacturing steps with reference to this drawing. First, FIG. 1 (a) is a sectional view,
(B) is a plan view), a first wiring substrate 11 is prepared. On the surface of the first wiring board 11, a plurality of strip-shaped connection terminals 12 are formed at predetermined intervals by a metal such as copper or silver. Further, the first wiring board 11
In a connection portion 13 with a second wiring board described later, two openings 14 are provided in the longitudinal direction of the connection terminal 12 at portions between the adjacent connection terminals 12. The opening 14 is formed by mechanical means such as drilling or etching or chemical means, and penetrates the back surface of the first wiring board 11.

[0010] Next, as shown in FIG. 2, conductive particles 16 made of a metal or the like are uniformly dispersed in an insulating adhesive 15 on a portion of the first wiring board 11 on the connection portion 13. An electrically conductive adhesive 17 is provided. Further above, a second wiring board 19 in which a plurality of connection terminals 18 are provided at predetermined intervals as in the case of the first wiring board 11 is opposed to each other. Thereafter, the second wiring board 19 is pressed on the first wiring board 11 with the anisotropic conductive adhesive 17 interposed therebetween as shown in FIG. At this time, when the insulating adhesive 15 of the anisotropic conductive adhesive 17 is a thermosetting resin or a thermoplastic resin, pressure bonding is performed while heating to cure or temporarily soften the resin. Pressure bonding while irradiating light. Then, the connection terminals 1 of the first wiring board 11 are
The conductive particles 16 of the anisotropic conductive adhesive 17 are sandwiched between the connection terminals 18 of the second wiring board 19 and the connection terminals 18 of the second wiring board 19.
The first and second wiring boards 11 and 19 are bonded together by the conductive adhesive 16 and the insulating adhesive 15 of the anisotropic conductive adhesive 17. At this time, the opening 1 is provided between the adjacent connection terminals 12.
According to the first wiring board 11 provided with 4, the extra insulating adhesive 15 of the anisotropic conductive adhesive 17 can escape to the opening 14. Therefore, in this case, the conductive particles 16 move together with the insulating adhesive 15 of the anisotropic conductive adhesive 17 from the center of the connection portion between the first and second wiring boards 11 and 19 toward the end. However, the conductive particles 16 can be uniformly dispersed in the insulating adhesive 15 of the anisotropic conductive adhesive 17 even after pressure bonding. Therefore,
The conductive particles 16 do not come into close contact with each other at the end of the connection portion, and do not short-circuit between the connection terminals 12 of the first wiring board 11 and between the connection terminals 18 of the second wiring board 19. Insulation between the terminals 12 and between the connection terminals 13 can be sufficiently ensured. In addition, extra insulating adhesive 15
Can be released into the opening 14 of the first wiring board 11, the pressing force at the time of crimping can be reduced and the unreasonable force applied to the first and second wiring boards 11 and 19 can be reduced. In addition, the amount of the anisotropic conductive adhesive 17 before the pressure bonding can be controlled more freely than before, and the manufacturing workability can be improved. In addition, as the first wiring board 11 and the second wiring board 19, any of a flexible board made of resin and a hard board made of glass epoxy or ceramic can be used.

FIG. 4 is a view for explaining a second embodiment of the present invention, and is a plan view of the first wiring board 11. FIG. In the second embodiment, the connection terminals 12 of the first wiring board 11
The openings 14 are provided in the portions between each other, and the openings 14 are also provided in the portions of the connection terminals 12 so as not to hinder the function of the terminals and the sandwiching of the conductive particles. By doing so, the anisotropic conductive adhesive 17 can be used at the time of pressure bonding.
The excess insulating adhesive 15 can be more easily released into the opening 14 of the first wiring board 11. In particular, as apparent from FIG. 3, the portion between the opposed connection terminals 12 and 18 becomes narrow and the excess insulating adhesive 15 becomes large, so that the opening 14 is provided in the portion of the connection terminal 12. That is very effective.

FIG. 5 is a sectional view showing a third embodiment of the present invention. In the third embodiment, the first wiring board 11
At the same time, the second wiring board 19 is also provided with the openings 14 at the portions between the connection terminals 18 and at the portions of the connection terminals 18. In this way, the excess insulating adhesive 15 of the anisotropic conductive adhesive 17 can be released into the opening 14 of the wiring board more easily than in the second embodiment during crimping.

FIG. 6 is a sectional view showing a fourth embodiment of the present invention. In this case, an opening 14 is provided in a portion between adjacent connection terminals 12 in the first embodiment. Electronic component 22 having connection terminal 21 on first wiring board 11
Are connected by an anisotropic conductive adhesive 17. In addition,
The electronic component 22 can be connected to the first wiring board 11 shown in the second embodiment in which the opening 14 is also provided in the connection terminal 12 portion. Further, a specific example of the electronic component 22 is an IC chip.

[0012]

As described above, according to the present invention, the opening is provided in the wiring board, and the excess insulating adhesive of the anisotropic conductive adhesive is allowed to escape into this opening at the time of pressure bonding. Therefore, the conductive particles do not move together with the insulating adhesive, and the conductive particles can be uniformly dispersed in the insulating adhesive of the anisotropic conductive adhesive even after the pressure bonding. Therefore, the conductive particles do not short-circuit between adjacent connection terminals, and sufficient insulation between adjacent connection terminals can be secured.

[Brief description of the drawings]

FIGS. 1A and 1B show a first wiring board according to a first embodiment of the present invention, wherein FIG. 1A is a sectional view and FIG.

FIG. 2 is a cross-sectional view showing the first embodiment of the present invention in a state in the course of manufacturing.

FIG. 3 is a cross-sectional view showing the first embodiment of the present invention in a state where manufacturing is completed.

FIG. 4 is a plan view showing a first wiring board according to a second embodiment of the present invention.

FIG. 5 is a sectional view showing a third embodiment of the present invention.

FIG. 6 is a sectional view showing a fourth embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a conventional conductive connection structure in a state of being manufactured.

FIG. 8 is a cross-sectional view showing a conventional conductive connection structure in a state where manufacturing is completed.

FIG. 9 is a cross-sectional view for explaining a drawback of a conventional conductive connection structure.

[Explanation of symbols]

 11, 19 First and second wiring boards 12, 18 Connection terminal 14 Opening 15 Insulating adhesive 16 Conductive particle 17 Anisotropic conductive adhesive 21 Connection terminal 22 Electronic component

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H05K 1/14 H01L 21/60 311 H01R 11/01 H01R 12/06

Claims (2)

(57) [Claims] A first wiring board having a plurality of first connection terminals and an opening between the first connection terminals;
A second wiring having a second connection terminal corresponding to each of the first connection terminals formed on the first wiring board and having no opening in a region corresponding to a connection portion of the first wiring board A substrate, and an anisotropic conductive adhesive interposed between the first wiring substrate and the second wiring substrate, wherein the anisotropic conductive adhesive is provided on the first wiring substrate. A conductive connection structure filled with the entire connection portion including a region corresponding to the opening between the first wiring substrate and the second wiring substrate, and penetrating into the opening of the first wiring substrate. Wherein the width of the opening, the conductive connection structure according to claim 1, wherein a is smaller than the width of the connecting portion.