JPH07202390A - Construction of bump - Google Patents

Abstract

PURPOSE:To obtain construction of a bump which can be used again after the detachment of the electrode of a counterpart by a method wherein a recess is formed in each electrode and a metal supporting piece whose one end is linked with the electrode is formed in the recess so as to be approximately parallel with the electrode and a spherical contact is formed to protrude on the supporting piece. CONSTITUTION:Respective spherical contacts 24 are supported by respective supporting pieces 22 and the gang connection between a plurality of electrodes 12 on which the spherical contacts 24 are formed and the electrodes 12 of a counterpart is achieved by utilizing the warping of the supporting pieces 22. The spherical contact 24 itself is not deformed and the support piece 22 is elastically recovered when the pressure given by the counterpart electrode 12 is released. Therefore, even if the electrodes 12 are mated with the counterpart electrodes 12 and unmated and then mated again with other electrodes 12, the connection quality is not deteriorated at all, so that the significantly useful bump construction 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 bump structure in which spherical contacts are 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 contacted with a plurality of electrodes formed on another printed circuit board, a terminal board, a connector or the like so as to be connected thereto. In this case, in order to obtain a good contact state between the electrodes, it has been conventionally practiced to form a spherical contact on each electrode on the substrate.

FIG. 3 shows an example of a conventional bump structure in which this type of spherical contact is formed on an electrode. Board 1
A plurality of electrodes 12 are arrayed on one surface of 1.
Spherical contacts 13 are formed so as to project at the portions of these electrodes 12 that are connected to the counterpart electrodes (in this example, the portions that are close to one end of the substrate 11). The spherical contact 13 is made of the same material as the electrode 12, for example, and is formed integrally therewith.

When the spherical contacts 13 are formed on each electrode 12 as described above, when the opposing electrodes are pressed against the electrodes 12 and the pressure is applied, the applied pressure is concentrated on the spherical contacts 13 and a large contact is made. When pressure is obtained, for example spherical contact 1
When the top of 3 is crushed by the pressing force, it is possible to absorb the warp or waviness of the electrode forming surface or the variation in the height of each spherical contact 13 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 contacts by applying pressure. The spherical contact having a high height is likely to be greatly deformed. After connecting multiple electrodes with spherical contacts and multiple electrodes of the other party, maintain that state without desorption, that is, in the case of permanent connection, there is no problem even if the spherical contacts are deformed. Although it does not occur, connect multiple electrodes with spherical contacts to each other after detachment, such as when replacing a printed circuit board or the like on which the other electrode is formed with another one. If it is necessary, a good contact state cannot be obtained with the already deformed spherical contact, that is, the conventional bump structure is basically not reusable.

An object of the present invention is to eliminate the drawbacks of the prior art and to provide a bump structure which can be reused after attachment / detachment.

[0007]

According to the present invention, in a bump structure in which a plurality of electrodes are provided on substantially the same surface and a spherical contact is formed on each electrode, a recess is formed in each electrode and each recess is formed. A support piece made of a metal material, one end of which is connected to the electrode, is provided substantially parallel to the electrode surface, and the spherical contacts are formed on the support piece in a protruding manner.

[0008]

In the present invention constructed as described above, the spherical contact is made movable by the bending of the support piece, so that the spherical contact is not deformed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIG. A plurality of electrodes 12 arrayed on one surface of the substrate 11
A circular concave portion 21 is formed in each of the portions connected to the counter electrode. In this example, each recess 21 is formed on the substrate 11
Are arranged near the one end surface 11a along the one end surface 11a.

Within each recess 21, a support piece 22 having one end connected to the electrode 12 around the recess 21 is provided with a plate surface 22.
a is provided substantially parallel to the electrode surface 12a. The support piece 22 is made of a metal material such as Cu, and in this example, is connected to the electrode 12 on the side of the recess 21 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 spherical contacts 24 are formed on the circular portion 23 of the support piece 22 so as to project therefrom. Therefore, each spherical contact point 24 is formed on the concave portion 21,
It is arranged in a state of being supported by the support piece 22.

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

In this example, electrode 12 comprises electrodes 12-1 and 1
2-2, and a part of the electrode 12-2 constitutes the support piece 22. In addition,
The electrodes 12-1, 12-2 and the spherical contact 24 are made of Cu, for example.
Etc., the same material may be used, or different materials may be used. In the bump structure according to the present invention, when the spherical contact 24 is brought into contact with the opposite electrode and is pressed, 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 recess 21 side. Since each spherical contact point 24 is individually movable in this way, when the opposing electrodes are collectively brought into contact with these spherical contact points 24, for example, even if the height of each spherical contact point 24 varies. By displacing each spherical contact point 24 in accordance with its height, all the spherical contact points 24 are brought into contact with the counterpart electrodes. Then, due to the elastic restoring force of the support piece 22, each spherical contact point 24 is elastically contacted with the counter electrode and is well connected.

[0013]

As described above, according to the present invention, each spherical contact point is supported by a supporting piece, and the deflection of the supporting piece is used to form a plurality of electrodes having the spherical contact point and a counter electrode. This is for making a good batch connection, and the spherical contact itself is not deformed, and the supporting piece is elastically restored when the pressure applied by the counter electrode is released.

Therefore, even if the opposite electrode is detached and then re-connected to another electrode after the connection, the connection quality is not deteriorated at all, so that the bump structure can be reused and an extremely useful bump structure is provided. You can

[Brief description of drawings]

1A is a plan view showing an embodiment of a bump structure according to the present invention, and B is an enlarged view of a CC cross section thereof.

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

FIG. 3A is a plan view showing a conventional bump structure, and B is an enlarged view of a CC cross section thereof.

[Explanation of symbols]

 11 substrate 12 electrode 21 concave portion 22 supporting piece 24 spherical contact

Claims (1)

[Claims] 1. A plurality of electrodes are provided on substantially the same plane,
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 in each of the recesses, a metal support piece whose one end is connected to the electrode is substantially parallel to the electrode surface. A bump structure in which the above-mentioned spherical contacts are formed to project on the supporting pieces.