JP3622695B2 - Electrical connection structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrical connection structure.
[0002]
[Prior art]
For example, a connector for electrically connecting wiring boards generally requires a mechanism / member for mechanically fixing the connector and the wiring board together with a member responsible for electrical connection in order to maintain the connected state. The conventional connector having such a mechanical coupling means has a complicated structure and is difficult to reduce in size and thickness.
In order to deal with this problem, the present applicant previously formed a metal thin film on a metal mold having a concavo-convex pattern in Japanese Patent Application No. 2000-243950, and the metal thin film on the convex part was interfaced from the mold. A method has been proposed in which an electrode (wiring pattern) is formed on the pressure-sensitive adhesive by peeling and transferring the pressure-sensitive adhesive onto the pressure-sensitive adhesive.
[0003]
According to the electrical connection member formed by using this method, the adhesive is adhered to the plate surface of the counterpart wiring board to be connected, whereby mechanical coupling is performed, that is, the adhesive is used as a mechanical coupling means. Therefore, simplification of the structure of the electrical connection member (connector) and further reduction in size and thickness can be realized.
FIG. 4 shows a state of connection between the electrical connection member having this adhesive and the wiring board. In the figure, 11 indicates the electrical connection member, 12 indicates the base material, and 13 indicates the base material 12. A pressure-sensitive adhesive disposed on one surface, 14 indicates an electrode formed by transfer. On the other hand, the wiring board 15 has electrodes 16 on its plate surface.
[0004]
The electrodes 14 and 16 to be connected are opposed to each other, and the electrical connection member 11 is pressed against the wiring board 15 so that the electrodes 14 and 16 are in contact with each other and connected to each other, and between the electrodes 14 of the electrical connection member 11. adhesive 13 is exposed by adhesive to the plate surfaces of the wiring board 15 as shown in FIG. 4C and electric connection member 11 and the wiring board 15 is fixed to.
The pressure-sensitive adhesive 13 is elastically deformed by pressing and adheres to the plate surface of the wiring board 15, and its elastic restoring force contributes as a load in the direction in which the electrodes 14 and 16 are pressed against each other. Can do.
[0005]
[Problems to be solved by the invention]
4 does not have a structure for mechanically positioning (matching) the positions of both electrodes 14 and 16 to be connected, the positions of these electrodes 14 and 16 are shown in FIG. As you can see, it sticks easily even in a deviated state.
On the other hand, in order to align the electrodes 14 and 16, for example, a visual marker is provided in a region different from the electrodes 14 and 16 on both the electrical connection member 11 and the wiring board 15 to perform optical alignment. Although there is a method of performing the connection, there is a problem that the connection by such alignment is troublesome and the connection process becomes complicated.
[0006]
In view of this problem, the object of the present invention is to mechanically position both electrodes in the connection between the electrical connection member having the above-mentioned adhesive and the counterpart wiring board, and thus the connection process can be simplified. An object of the present invention is to provide an electrical connection structure.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, the connection of the electrical connection member to the counterpart wiring board, which comprises a base material provided with an adhesive on one side and an electrode transferred onto the adhesive and protrudingly formed on the adhesive. An electrical connection having a structure in which the adhesive is adhered to the plate surface of the wiring board so that the electrical connection member is fixed to the wiring board, and the electrode is connected to and connected to the electrode of the wiring board. In the structure, the electrode of the wiring board is positioned in the recess formed in the plate surface, and the thickness of the electrode of the electrical connection member is larger than the recess amount of the upper surface of the electrode of the wiring board with respect to the plate surface. The electrode of the electrical connection member is engaged.
[0008]
In the invention of claim 2, in the invention of claim 1, the base material and the pressure-sensitive adhesive are transparent.
According to a third aspect of the present invention, in the first aspect of the present invention, the electrodes of the electrical connection member have a multilayer structure of different metals and a structure including a barrier metal layer.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an embodiment of the present invention, and parts corresponding to those in FIG.
[0010]
In this example, the electrodes 16 of the wiring board 15 are positioned in the recesses 21 formed on the plate surface of the wiring board 15, and the upper surface of these electrodes 16 is recessed from the plate surface of the wiring board 15. .
[0011]
The width of the recess 21 is substantially equal to the width of the corresponding electrode 14 of the counterpart electrical connection member 11 so that the electrode 14 can be engaged with the recess 21. Note that the amount of depression d _{1 of the} upper surface of the electrode 16 with respect to the plate surface of the wiring board 15 is set to be smaller than the thickness d ₂ of the electrode 14 of the electrical connecting member 11.
The wiring board 15 having such an electrode structure is manufactured as follows, for example.
That is, the required electrode 16 is first formed on the substrate 22, and a planarizing agent is applied over the entire surface of the substrate 22 to form the insulating layer 23. For example, an acrylic resin is used as the leveling agent.
[0012]
Next, the insulating layer 23 is patterned to remove a portion located on the electrode 16 by etching. As a result, the electrode 16 is exposed and the structure is located on the bottom surface of the recess 21.
By configuring the wiring board 15 as described above, in connecting the wiring board 15 and the electrical connection member 11, the electrodes 14 of the electrical connection member 11 are fitted into the corresponding recesses 21, whereby both the electrodes 14. , 16 can be mechanically positioned.
[0013]
That is, according to this example, the electrodes 14 and 16 are positioned relative to each other by the unevenness of the electrodes 14 and 16 themselves, and the connection process can be simplified. FIG. 1C shows a state in which the electrical connection member 11 and the wiring board 15 are connected.
In order to facilitate the fitting of the electrode 14 into the recess 21, as shown in FIG. 2, the cross-sectional shape of the electrode 14 may be trapezoidal or semicircular to form an invitation. .
[0014]
The cross-sectional trapezoidal shape or semicircular shape of the electrode 14 corresponds to the trapezoidal shape or semicircular shape of the convex surface of the transfer source mold on which the metal thin film to be adhesively transferred is formed, for example, by etching. It can be formed by processing into a shape.
By the way, in the case of the conventional connection structure between the electrical connection member 11 and the wiring board 15, there is a problem that the thickness of the electrode 14 on the electrical connection member 11 side cannot be increased too much.
[0015]
As shown in FIG. 6, when the electrode 14 is thickened, the distance between the surface of the pressure-sensitive adhesive 13 and the plate surface of the wiring board 15 increases, and in order to bring the adhesive 13 portion into contact with the wiring board 15, electrical connection is required. This is because the member 11 has to be greatly deformed and does not adhere sufficiently, or even if it is attached, the member 11 peels off due to a change with time due to elastic deformation of the base material 12 or the adhesive 13.
In this respect, in this example, as shown in FIG. 1, the electrode 16 of the wiring board 15 is located in the recess 21, so that even if the thickness of the electrode 14 of the electrical connection member 11 is increased, the recess 21 By increasing the depth accordingly, the distance between the surface of the pressure-sensitive adhesive 13 and the plate surface of the wiring board 15 can be set small, can be sufficiently attached (adhered), and peels off due to changes over time. Can be reduced.
[0016]
That is, according to this example, the thickness of the electrode 14 of the electrical connecting member 11 can be set thicker than in the prior art, and the conductor resistance value of the electrode can be reduced at that point. It becomes possible to improve the rigidity.
The electrode 14 of the electrical connection member 11 formed by adhesive transfer has, for example, three layers of Au / Ni / Au in order to prevent disconnection by providing releasability from a mold, symmetry as a film structure, and rigidity. A structure is conceivable.
However, Ni for securing rigidity has a problem that the film formation rate is slow, and when the thickness of the electrode 14 is increased, it becomes a factor that hinders productivity. On the other hand, Cu 3 has a high film formation rate and is inexpensive, but if it has a three-layer structure such as Au 2 / Cu 2 / Au 2, reliability is impaired due to mutual diffusion between Au 2 and Cu 2.
[0017]
Therefore, in this example, the electrode 14 has a five-layer structure of Au / Ni / Cu / Ni / Au, and the cost is reduced by using Cu, and Ni is used as a barrier metal to prevent mutual diffusion between Au and Cu. Intervene layers.
Thus, by making the electrode 14 have a multilayer structure of different metals and a structure including a barrier metal layer, it is possible to obtain the electrode 14 which is excellent in reliability and can be reduced in price.
In the above multilayer film structure, for example, if Au on the surface side of the electrode 14 is a multilayer film of Au / Sn, that is, gold-tin solder is formed so that electrical connection can be performed by soldering, the reliability of the connection Can be improved.
[0018]
On the other hand, if the base material 12 and the adhesive 13 of the electrical connection member 11 are made of a transparent material, the electrode 14 and the recess 21 (electrode 15) can be visually recognized in the connection with the wiring board 15 described above, and the connection work Can be performed more easily.
As such a transparent material, for example, polyimide is used for the substrate 12, and a silicon-based adhesive is used for the adhesive 13.
In addition to the transparent base material 12 and the pressure-sensitive adhesive 13, if the electrode 14 is made of a transparent conductive material such as ITO or tin oxide, it can be applied to an electrode of a liquid crystal display element, for example.
[0019]
FIG. 3 shows an application example of the present invention in which an alignment marker 31 is provided on the adhesive 13 of the electrical connection member 11 in the same manner as the electrode 14 and with the same material, while the marker 31 is provided on the wiring board 15 side. And the recesses 32 corresponding to the above are provided by applying a flattening agent and patterning as described above, and by fitting the markers 31 and the recesses 32, the electrodes 14 and 16 can be positioned and connected to each other. It is shown.
[0020]
【The invention's effect】
As described above, according to the electrical connection structure of the present invention, since both electrodes to be connected are mechanically positioned by the unevenness of the electrodes themselves, the connection process can be simplified.
In addition, since the thickness of the electrode can be increased as compared with the conventional case, the conductor resistance value of the electrode (wiring pattern) can be reduced, and the rigidity can be improved.
Moreover, according to the invention of claim 2, the connection work can be performed more easily.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining an embodiment of the present invention.
FIG. 2 is a view showing an example in which an invitation shape is provided on the electrode of the electrical connection member in FIG. 1;
FIG. 3 is a view for explaining positioning by convex markers and concave portions as an application example of the present invention.
FIG. 4 is a view for explaining a conventional connection structure between an electrical connection member having an electrode on an adhesive and a counterpart wiring board.
5 is a diagram for explaining a problem in the connection structure of FIG. 4;
FIG. 6 is a diagram for explaining a problem when the electrode thickness is increased.

Claims (3)

A connection structure with a counterpart wiring board of an electrical connection member comprising a base material provided with an adhesive on one side and an electrode formed on the adhesive and protruding on the adhesive ,
An electrical connection structure in which the adhesive is adhered to the plate surface of the wiring board, whereby the electrical connection member is fixed to the wiring board, and the electrode is connected to and connected to the electrode of the wiring board. In
The electrode of the wiring board is located in a recess formed in the plate surface ,
The thickness of the electrode of the electrical connection member is larger than the amount of depression of the upper surface of the electrode of the wiring board with respect to the plate surface,
An electrical connection structure, wherein the electrode of the electrical connection member is engaged with the recess. The electrical connection structure according to claim 1,
An electrical connection structure, wherein the substrate and the pressure-sensitive adhesive are transparent. The electrical connection structure according to claim 1,
An electrical connection structure characterized in that the electrode of the electrical connection member has a multilayer structure of different metals and includes a barrier metal layer.

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