JP2835376B2 - Bump 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 bump structure having spherical contacts formed on electrodes.

[0002]

2. Description of the Related Art For example, a plurality of electrodes formed on a substrate such as a printed circuit board are connected to corresponding plurality of electrodes formed on another printed circuit board, a terminal plate, a connector, or the like. In such a case, a spherical contact is conventionally formed on each electrode on the substrate in order to obtain a good contact state between the electrodes.

FIG. 3 shows an example of a conventional bump structure in which a spherical contact of this kind is formed on an electrode. Substrate 1
A plurality of electrodes 12 are arranged and formed on one surface of one.
Spherical contacts 13 are protruded from portions of the electrodes 12 connected to the counter electrode (in this example, portions close to one end of the substrate 11). The spherical contact 13 is formed integrally with, for example, the same material as the electrode 12 using the same material.

When the spherical contacts 13 are formed on each of the electrodes 12 as described above, when a counter electrode is brought into contact with these electrodes 12 and pressurized, the pressing force concentrates on the spherical contacts 13 and a large contact Pressure is obtained and, for example, spherical contacts 1
When the top of 3 is crushed by the pressing force, the warpage or undulation of the electrode forming surface or the variation in the height of each spherical contact 13 can be absorbed by the deformation of the spherical contact 13, and the collective connection of a large number of electrodes 12 is good. Can be done.

[0005]

As described above, the conventional bump structure enables good collective connection of a plurality of electrodes by deforming the spherical contact by applying pressure. The tall spherical contact point is likely to be greatly deformed. After connecting a plurality of electrodes having a spherical contact and a plurality of electrodes of the other party, without desorption, maintain that state, that is, in the case of permanent connection, there is no problem even if the spherical contact is deformed This does not occur, but, for example, when replacing the printed circuit board or the like on which the counter electrode is formed with another, after desorption, connect the plurality of electrodes having the spherical contacts to a plurality of electrodes different from the previous one When it is necessary to make the connection, it is impossible to obtain a good connection state with the deformed spherical contact, that is, the conventional bump structure cannot be basically reused.

SUMMARY OF THE INVENTION An object of the present invention is to provide a bump structure which eliminates the conventional drawbacks and can be reused after being detached.

[0007]

SUMMARY OF THE INVENTION The present invention provides a bump structure in which a plurality of electrodes are provided on substantially the same surface and a spherical contact is formed on each of the electrodes. Inside, a support piece of a metal material, one end of which is connected to an electrode, is provided substantially parallel to the electrode surface, and the spherical contacts are formed on the support piece to protrude.

[0008]

According to the present invention having the above-described structure, the spherical contact is made movable by the bending of the supporting piece, so that the spherical contact is not deformed.

[0009]

An embodiment of the present invention will be described with reference to FIG. A plurality of electrodes 12 arranged and formed on one surface of a substrate 11
The circular concave portions 21 are respectively formed in portions connected to the counter electrode. In this example, each recess 21 is
Are arranged along the one end face 11a near the one end face 11a.

In each recess 21, a support piece 22 having one end connected to the electrode 12 around the recess 21 has a plate surface 22.
a is provided substantially parallel to the electrode surface 12a. The support piece 22 is made of, for example, a metal material such as Cu. In this example, the concave portion 21 is connected to the electrode 12 on the side opposite to the one end surface 11a of the substrate 11. The other end of each support piece 22 is enlarged, for example, in a circular shape, and a spherical contact 24 is formed on the circular portion 23 of the support piece 22 so as to protrude. Therefore, each spherical contact 24 is located on the recess 21 respectively.
It is arranged while being supported by the support piece 22.

Next, an example of a method for forming a bump structure having the above-described configuration will be described in the order of steps with reference to FIG. FIG. 2 shows one of the plurality of electrodes. An electrode 12-1 is formed on a substrate 11 (A), and the electrode 12-1 is etched, for example, to form a recess 21 (B). The recess 21 is filled with a filler 25 made of a metal or resin different from the electrode 12-1 (C), and the electrode 12-2 is placed on the electrode 12-1 and the filler 25.
(D). A C-shaped region 26 (see FIG. 1A) of the electrode 12-2, which is later surrounded by the contour of the support piece 22 and the contour of the recess 21, is etched away (E) and surrounded by the C-shaped region 26. Contact 2 on the electrode 12-2
4 is formed (F). Then, the filler 25 is removed by etching through the void-shaped C-shaped region 26 (G). Thus, a bump structure in which the spherical contact 24 is supported by the support piece 22 is completed.

In this example, the electrode 12 is connected to the electrodes 12-1 and 1-1.
2-2, and a part of the electrode 12-2 constitutes the support piece 22. In addition,
The electrodes 12-1 and 12-2 and the spherical contact 24 are made of, for example, Cu.
And the like, and may be formed of the same material or different materials. In the bump structure according to the present invention, when the spherical contact 24 is pressed against the counter electrode, the supporting piece 22 supporting the spherical contact 24 is bent by the applied pressure, and the spherical contact 24 is deformed. Instead, it is displaced toward the concave portion 21 side. Since the spherical contacts 24 are individually movable as described above, when the electrodes of the other party are collectively brought into contact with the spherical contacts 24, for example, even if the heights of the spherical contacts 24 vary. Each of the spherical contacts 24 is displaced in accordance with its height, so that all the spherical contacts 24 come into contact with the counter electrode. Then, each spherical contact 24 is elastically contacted with the counter electrode by the elastic restoring force of the support piece 22, and is connected well.

[0013]

As described above, according to the present invention, each spherical contact is supported by a supporting piece, and the bending of the supporting piece is used to make a connection between a plurality of electrodes having the spherical contacts and a counter electrode. In this configuration, the spherical contacts themselves are not deformed, and the support piece is elastically restored when the pressure applied by the counter electrode is released.

Therefore, even if the mating electrode is detached and then reconnected to another electrode after the connection, the connection quality is not deteriorated at all, and the connection can be reused and an extremely useful bump structure is provided. Can be.

[Brief description of the drawings]

FIG. 1A is a plan view showing one embodiment of a bump structure according to the present invention, and FIG.

FIG. 2 is a diagram for explaining an example of a method for forming a bump structure according to the present invention.

FIG. 3A is a plan view showing a conventional bump structure, and FIG.

[Description of Signs] 11 Substrate 12 Electrode 21 Concave portion 22 Support piece 24 Spherical contact

Claims (1)

(57) [Claims] 1. A plurality of electrodes are provided on substantially the same surface,
In a bump structure in which a spherical contact is formed on each of the electrodes, a recess is formed in each of the electrodes, and a support piece of a metal material having one end connected to the electrode is substantially parallel to the electrode surface in each of the recesses. And a bump structure in which the spherical contacts are formed on the support pieces.