JPH05203670A - Contact probe - Google Patents

Abstract

PURPOSE:To stabilize contact and conduction in a conducting passage in a contact probe used for performing the performance inspection of a circuit system on a circuit pattern formed in a substrate. CONSTITUTION:A head pin 13 which is a conductive member is provided at one end of a tubular sleeve 12 formed by an insulating member and a contact pin 15 is provided at the other end with a spring 14 interposed between the pin 15 and a head pin 13. Conductive connecting members 16 such as solder or liquid metal are interposed in portions where the head pin 13, the spring 14 and the contact pin 15 make contact with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact probe for performing an operation inspection of a circuit system on a circuit pattern formed on a substrate.

In recent years, external terminals have to be connected on a circuit pattern formed on a substrate for the purpose of confirming normal operation of a circuit system such as a semiconductor device and adjusting the operation. In this case, for that purpose, the external terminal cannot be brazed onto the circuit pattern, and the contact probe is brought into contact with the external terminal. Therefore, it is necessary to stabilize the contact between the probe and the circuit pattern and inside the probe.

[0003]

2. Description of the Related Art A contact probe conventionally used, though not shown, is provided with a contact pin slidable with a spring interposed in a sleeve formed of a good conductor metal having a cylindrical shape with one end open. Be done. In this case, the tip of the contact pin extends from the open portion of the sleeve and is brought into contact with the pad of the circuit pattern for measurement.

Generally, the contact between solid metal and solid metal is limited to a very small area under low load and no load due to the surface roughness of a good conductor. When an electric current flows through here, the electric current is narrowed, so that a resistance component called a lumped resistance is generated. Moreover, the connection is unstable.

In order to avoid this, a load is applied to the contact between the solid metal and the solid metal, and the contact area is increased by increasing the number of contact points and the area of the contact points.

That is, the contact pin of the contact probe is pressed against the pad of the circuit pattern, and the contact area is increased by the biasing force of the spring.

On the other hand, since the spring for applying the load and the sleeve for accommodating the spring are made of metal, unintended contact points are generated in the respective parts, and the conduction path at the time of energization becomes complicated. Therefore, the passage, which minimizes the conduction resistance, is set by arranging the sleeve, the spring, and the contact pin so that all contact points are generated in the load direction.

[0008]

However, the contact effect differs depending on the material. That is, since the pressing force and the contact effect are different depending on the materials of the pad and the contact pin, the contact pin and the spring, and the spring and the sleeve, there is a problem that stable contact conduction cannot always be obtained.

Further, even if the passage having the minimum conduction resistance is set, a contact point with the sleeve is inadvertently generated, and the behavior when an ultrahigh-speed switching signal is applied is complicated even when the DC resistance shows a low value. Therefore, there is a problem that stable contact conduction cannot be obtained.

Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a contact probe which stabilizes contact conduction in a conduction path in the probe.

[0011]

SUMMARY OF THE INVENTION In order to inspect the operation of a circuit system, a contact probe which is pressed against a circuit pattern formed on a substrate to bring it into contact and conduct is formed so that at least the inner surface is formed in an insulating state. And a head sleeve which is formed of a conductive member and is provided at one end of the sleeve, and an elastic member which is interposed between the head terminal and the sleeve inside the sleeve, and the tip of which is slidable. A contact terminal for contacting with a circuit pattern for electrical continuity, and a conductive connecting member interposed at a contact portion between the head terminal and the elastic member and a contact portion between the elastic member and the contact terminal. Will be solved by.

[0012]

As described above, in the contact probe of the present invention, at least the inner surface of the sleeve is formed in an insulating state, so that the contact terminal and the elastic member sliding in the sleeve are in a non-conductive state. As a result, the contact terminal has only one conduction path in the sliding direction, and it is possible to avoid the occurrence of unstable contacts other than the contact portion.

Further, the conductive connecting member is interposed at the contact portion between the head terminal and the elastic member, and the conductive connecting member is interposed at the contact portion between the elastic member and the contact terminal. As a result, the respective contact points are electrically connected to each other, and it is possible to avoid the generation of the direct current resistance due to the contact conduction and to make a reliable electric connection.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a block diagram of an embodiment of the present invention.
In the contact probe 11 of FIG. 1, a head pin 13 which is a head terminal is provided at one end of a cylindrical sleeve 12, and a contact pin which is a contact terminal with a head pin 13 and a spring 14 which is an elastic member interposed in the sleeve 12. 1
5 is slidably positioned. Pin tip 1 of contact pin 15
5a extends outward from the sleeve 12 and
The position is regulated by the caulking portion 12a at the other end of the.

The sleeve 12 is an insulating member, for example, a resin, and is formed in a cylindrical shape from an organic material such as polyethylene or polycarbonate. The head pin 13 is made of, for example, rhodium or phosphor bronze plated with Au (gold), and is fixed to one end of the sleeve 12.

The spring 14 is made of Au-plated beryllium (bronze) copper or piano hard wire.

The contact pin 15 is formed of Au-plated phosphor bronze, and the pin tip portion 15a has a sleeve 1.
2 is extended outward from the crimped portion 12a and the sliding portion 15
b is located in the sleeve 12 and slides.

In this case, the contact portion between the head pin 13 and the spring 14 or the sliding portion 15b between the spring 14 and the contact pin 15
A conductive connection member 16 made of solder (e.g., Au-Sn (tin) eutectic solder) or liquid metal is interposed at a contact point with the. The liquid metal is a metal that is liquid at a use temperature, and is, for example, Ga (gallium) -12% Sn eutectic alloy or Ga.
A 24.5% In (indium) eutectic alloy is used. For example, the pin diameter of the tip 15a of the contact pin 15 is 0.5 mm.
Liquid contact with 5 mg of the above liquid metal.

That is, the materials of the head pin 13, the spring 14 and the contact pin 15 are selected as described above to reduce the interfacial force with the solder or the liquid alloy and improve the solderability or the liquid metal holding force. This is because.

Next, FIG. 2 shows a diagram for explaining the use state of FIG. In FIG. 2, the contact probe 1
1 is attached to the test board 21 in a predetermined number (one in the drawing), and the test wire 22 is attached to the head pin 13 by Au-Sn.
It is brazed by the eutectic solder 23 or connected by the liquid metal (23).

On the other hand, the pin tip portion 15 of the contact probe 11 is placed on the counter contact circuit pattern (pad) 24 formed on the substrate 23 on which the object to be measured (not shown) is mounted.
a is pressed. In order to make a reliable connection, for example, a load of about 30 gf is applied. At this time, the contact pin 15 (sliding portion 15b) slides inside the sleeve 12, and the pin tip portion 15a is pressed against the circuit pattern 24 by the urging force of the spring 14.

As described above, the contact probe 11 is
Since the sleeve 12 is formed of an insulating member, the conduction path when energized does not become complicated, and only the conduction path is formed in the sliding direction of the contact pin 15 to avoid the occurrence of unstable contacts. can do. In addition, since the head pin 13 and the spring 14 and the spring 14 and the contact pin 15 are electrically connected by brazing or liquid metal, the electric connection can be surely made and the generation of the DC resistance can be prevented. Accurate measurement can be performed even if an ultrafast switching element is applied.

Next, FIG. 3 shows a block diagram of another embodiment of the present invention. FIG. 3A shows a case where a cylindrical sleeve 12a is formed of alumina as an insulating member.
Alumina is a brittle material, and the caulked portion 12a as shown in FIG. 1 cannot be formed by caulking. Therefore, the ring 32 having a smaller inner diameter than the sliding portion 15b of the contact pin 15 and a larger inner diameter than the pin tip portion 15a is provided with Sn-P.
It is brazed with b (lead) solder 32.

The ring 32 is made of, for example, a copper metal plated with Au or a metallized film (for example, an Au film made of Ni.
It is formed of alumina having a (nickel) film formed thereon. In addition, the brazing is performed with a low melting point such that the Au-Sn conductive connecting member 16 does not melt again.
It uses Pb solder.

Further, FIG. 3B shows the metal tube 3 of the conducting member.
3 shows a case where the sleeve 12b is formed on the inner surface of 3 by a ceramic coating (for example, an alumina film) by sputtering or the like, or an insulating coating 34 of resin coating such as polyimide by coating or the like. In this case, the ring 31 is brazed with the Sn—Pb solder 32 as in the case of FIG.

The insulating coating 34 may be formed not only on the inner surface but also on the outer surface. This is because, for example, when the contact probe 11 is put in a metal cylinder and used, the contact probe 11 is insulated from the cylinder.

[0027]

As described above, according to the present invention, at least the inner surface of the sleeve is insulated, and the conductive connecting member is interposed at the contact portion between the head terminal, the elastic member, and the contact terminal. The contact conduction can be stabilized with, and the circuit system can be tested easily and stably.

[Brief description of drawings]

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

FIG. 2 is a diagram for explaining a use state of FIG.

FIG. 3 is a configuration diagram of another embodiment of the present invention.

[Explanation of symbols]

 11 Contact Probe 12 Sleeve 12a Caulking Section 13 Head Pin 14 Spring 15 Contact Pin 15a Pin Tip 15b Sliding Section 16 Conductive Connection Member

Claims (4)

[Claims] 1. To test the operation of a circuit system,
A contact probe, which is pressed against a circuit pattern (24) formed on a substrate (23) to bring it into contact and conduct, at least an inner surface of which is formed of a tubular sleeve (12) and a conducting member. A head terminal (13) provided at one end of the sleeve (12) and an elastic member (14) interposed between the head terminal (13) in the sleeve (12) are slidable, and the tip end is slidable. A contact probe (15), which is in contact with the circuit pattern (24) for electrical conduction, and a contact terminal (15). 2. A conductive connecting member (16) at a contact point between the head terminal (13) and the elastic member (14) and at a contact point between the elastic member (14) and the contact terminal (15). The contact probe according to claim 1, wherein the contact probe is interposed. 3. The contact probe according to claim 1, wherein the sleeve (12, 12a) is formed of an insulating member. 4. The sleeve (12b) is connected to a conducting member (3).
The contact probe according to claim 1 or 2, wherein the contact probe is formed by 3) and an insulating coating (34) is applied to at least the inner surface.