JPH0846311A - Electrode pad for connecting electric signal - Google Patents

Abstract

PURPOSE:To stabilize the repeated contact characteristics by a method wherein one or more trenches are formed on the electrode pad connected to a probe pin or conductive elastomer connector by pressurization. CONSTITUTION:A trench 4 is formed by chemical etching or mechanical processing, etc., on the surface of an electrode pad 2 ranging over an inner layer connecting land 5 forming a through hole 3 of a multilayer printed board 1. In such a case, any number of trenches may be formed. After the formation of the trench 4, plating process for contact e.g. Au plating step, etc., is performed for improving the electric contact property. Through these procedures, the chamfering of a probing pin or conductive elastomer conductor, etc., in contact with the electrode pad 2 can be improved thereby enabling the contact characteristics to be enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode pad for electrical signal connection formed on a surface of a printed wiring board or the like.

[0002]

2. Description of the Related Art For example, when it is desired to measure the electrical characteristics of a surface mounting LSI or a high density printed wiring board,
The object to be measured and the measuring section of the measuring device must be connected by some means so that the necessary electric signals can be input and output. According to the conventional technique, as shown in FIGS. 2-2A to 2C, for example, an electrode pad 2 for electrical signal connection is provided on the surface of the multilayer printed circuit board 1, and one side of the electrode pad 2 is connected to the measuring instrument side. Usually, the probe pin 6 or the conductive elastomer connector (conductive rubber connector) 7 having conductivity and elasticity is pressed to make a contact.

However, the electrode pad 2 and the probe pin 6
Alternatively, the contact surface to which the conductive elastomer connector 7 is pressed and connected is simply a smooth surface, so that it is apt to be "point contact", and it is not possible to obtain stable contact characteristics repeatedly.

[0004]

Recently, due to, for example, higher density and higher speed of semiconductor devices, etc., to be measured, connection terminals for inputting / outputting electric signals are being formed. It is becoming smaller and the arrangement density is higher.
Therefore, the structure of the measurement unit, which requires electrical connection for performing measurement, must be miniaturized and densified. Therefore, the area of the electrode pad to be the contact surface and the area of the contact surface of the probe pin and the conductive elastomer connector to be contacted therewith cannot be made large. Even if the instability of the contact characteristics is increased for a certain number of times, it has a problem that it cannot be eliminated.

In view of the above, the present invention provides an electrode pad that can be used for miniaturizing and increasing the density of a probe pin, a conductive elastomer connector or the like to be brought into contact and can stabilize repeated contact characteristics. It was intended.

[0006]

In order to achieve the above object, in the electrode pad for electrical signal connection of the present invention,
The surface with which the probe pin, the conductive elastomer connector, or the like contacts is not a smooth surface, but a groove is formed on the surface of the electrode pad to form irregularities. As a result, the contact with the probe pin or the conductive elastomer connector is improved at the time of contact, and so-called multi-point contact in which contact is made at a plurality of points is performed.

The concave and convex grooves on the surface of the electrode pad may be circular or rectangular, and the height, width and length of the steps are not particularly limited. good.

[0008]

[Action]

(1) Grooves that make the surface of the electrode pad uneven are also obtained by chemical etching or mechanical processing, and the surface to be the contact surface is plated with gold for contact, for example. (2) When the contact is made by the conductive elastomer connector, since the connector has elasticity, it is easy to fit on the uneven surface of the surface of the electrode pad, and the multipoint contact is more easily obtained.

[0009]

1A to 1D are conceptual views showing an embodiment according to the present invention. (1) As shown in FIG. 1A, an uneven groove 4 is formed on the surface of the electrode pad 2 which is continuous with the inner layer connecting land 5 which forms the through hole 3 of the multilayer printed board 1. The uneven grooves 4 are formed by chemical etching, mechanical processing, or the like. There is no limit to the number of grooves. (2) The outer shape of the electrode pad 2 may be a rectangular shape as shown in FIG. 1B, or may be another outer shape. (3) After forming the concave-convex groove 4, in order to improve the electrical contactability, a plating process for contacts such as Au plating is usually performed. (4) In FIG. 1C, similarly to FIG. 1A, the shape of the electrode pad 2 is circular, and the concave and convex grooves 4 are provided on concentric circles, and the inner layer connection land 5 is provided at the center thereof. Is. In this case, the through hole 3 of the land 5 for connecting the inner layer also constitutes a part of the formation of the uneven groove 4.

(5) FIG. 1D shows a situation in which the elastic conductive elastomer connector 7 is in contact with the electrode pad 2 in the case of the shape shown in FIG. 1C. A state is shown in which the surface is pressed against the concave and convex grooves 4 including the inner layer connecting lands 5 forming the through holes 3 and fits well to the surface. (6) The number of concave and convex grooves 4 and the height, width, and length of the steps are the same as the shapes of the probe pins 6 and the conductive elastomer connector 7.
It is determined from the shape and size of the electrode pad 2. (7) In this embodiment, the electrode pad 2 on the multilayer printed circuit board has been described, but there is no restriction on the portion which will be the base on which the electrode pad 2 is formed. (8) Further, by making the probe pin 6 on one side in contact with the probe pin 6 uneven, it is possible to further improve the stability of the contact characteristics.

[0011]

Since the present invention is configured as described above, it has the following effects. (1) By forming the concave and convex grooves on the electrode pad for electrical signal connection, the biting of the probe pin, the conductive elastomer connector or the like contacting the electrode pad is improved, so that the contact characteristics are significantly improved. (2) By including the inner layer connection lands as a part of the configuration of the concave and convex grooves of the electrode pad, the required area of the electrode pad and the inner layer connection lands is reduced,
Therefore, the arrangement of the electrode pads can be increased in density.
In addition, the electrode pad can be made larger by the reduction of the area of the inner layer connection land.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a configuration of an electrode pad for electrical signal connection according to a conventional technique.

[Explanation of symbols]

 1 Multilayer Printed Circuit Board 2 Electrode Pad 3 Through Hole 4 Uneven Groove 5 Inner Layer Connection Land 6 Probe Pin 7 Conductive Elastomer Connector

Claims (2)

[Claims] 1. An electrode pad (2) on a substrate which is electrically connected to a probe pin (6) or a conductive elastomer connector (7) by pressing, wherein one or a plurality of concave and convex grooves (4) are formed. An electrode pad for electrical signal connection, which is the electrode pad (2). 2. The electrode pad for electrical signal connection according to claim 1, wherein the electrode pad (2) and the inner layer connection land (5) forming the through hole (3) of the substrate are integrated.