JPH0829475A - Contact probe of mounted substrate inspection device - Google Patents

Abstract

PURPOSE:To enable the inspection of loose feet using four-terminal method to be carried out by use of two contact probes. CONSTITUTION:Each contact probe 30 has first 31 and second 35 plungers integrated therewith via an insulating material 32. One of the contact probes 30 is erected on a lead 20 and the other contact probe 30 is erected on a land 21, and thereby four terminals can be secured by the plungers 31, 35 on the lead 20 and by the plungers 31, 31 on the land 21, and an ammeter 22 is connected between the plungers 31, 31, and a stabilizing power supply 23 is connected between the plungers 35, 35, thereby the state of soldering between the lead 20 and the land 21 can be inspected.

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 a mounting board inspection apparatus, and it is possible to carry out a foot floating inspection of an IC or a connector for all leads by using a small number of contact probes for a high density mounting board. It was made possible.

[0002]

2. Description of the Related Art An in-circuit test or a function test is carried out after mounting on a mounting board in which an electronic component such as an IC is mounted on a printed board. The in-circuit test is a test to check whether or not each electronic component has a required characteristic, for example, resistance, inductance, or capacitance, and the function test is an electrical circuit formed on the mounting board to obtain a required input / output characteristic. It is a test to check whether or not it has.

To perform an in-circuit test or a function test, a fixture type inspection device is used. As shown in FIG. 4, this type of inspection apparatus includes an upper fixture 1 and a lower fixture 2. The upper fixture 1 has the positioning holes 3 at the four corners and many on the lower surface (about 1000 to 2000).
The contact probe 4 of FIG. The lower fixture 2 has positioning pins 5 at the four corners, and a large number (100
It has 0 to 2000 contact probes 6 and two substrate positioning pins 7, and is fixed to the base 8 of the apparatus.

FIG. 5 shows an inspection state. As shown in FIG. 5, the mounting substrate 10 is one in which an electronic component (IC or the like) 12 is mounted on the substrate 11 using cream solder or a solder bath, and the substrate 11 has two reference holes 13. Has been formed. Therefore, first, the board positioning pin 7
And the position of the mounting substrate 10 is determined. Next, the upper fixture 1 is lowered while performing positioning so that the positioning pin 5 fits into the positioning hole 3. By doing so, the tip (lower end) of the contact probe 4 contacts the inspection point on the upper surface of the mounting substrate 10, and the tip (upper end) of the contact probe 6 contacts the inspection point on the lower surface of the mounting substrate 10. Conversely, the contact probes 4 and 6 are provided by selecting the installation positions of the contact probes 4 and 6 so that the tips of the contact probes 4 and 6 contact the inspection point. In such a contact state, various tests are performed by applying voltage or passing current through the contact probes 4 and 6. After the test is completed, the upper fixture 1 is lifted and the mounting board 10 is removed.

Next, referring to FIGS. 6 and 7, the electronic component 1 will be described.
A method of inspecting the soldered state of the second lead 20 and the land 21 on the substrate 11 will be described. When inspecting the soldered state, the lead 20 is contacted with two contact probes 4a and 4b, and the land 21 is contacted with two contact probes 4c and 4d. The stabilized power supply 23 is connected to the contact probes 4a and 4d, and the ammeter 22 is connected between the contact probes 4b and 4c.

When good soldering is performed, the resistance R between the lead 20 and the land 21 is as small as a few mΩ, and no current flows through the ammeter 22. When the soldering is bad and so-called "foot floating" occurs, the resistance R is several Ω, which is on the order of 10 ³ times the resistance value when good soldering is performed.
Current flows through. Therefore, by detecting that a current flows through the ammeter 22, it is possible to find a defect with soldering.

[0007]

As described above, in order to inspect the floating of electronic parts, four contact probes are required at each location. However, as the mounting density of electronic components mounted on the mounting board increases, it becomes physically impossible to stand four contact probes in one place.

In view of the above-mentioned conventional technique, it is an object of the present invention to provide a contact probe of a mounting board inspection apparatus capable of inspecting a floating foot of an electronic component with a smaller number of contact probes than the conventional one.

[0009]

The structure of the present invention for solving the above-mentioned problems is such that a mounting board having electronic components mounted thereon is sandwiched by a fixture having a contact probe, and the tip of the contact probe is used as an inspection point of the mounting board. In the inspection device for inspecting the electrical characteristics of the mounting substrate in a contact state, the contact probe is formed of a conductive material and a rod-shaped first plunger having a sharp tip and a conductive material. A second plunger having a ring-like shape, a sharpened tip, a tip position aligned with a tip position of the first plunger, and concentrically arranged with respect to the first plunger; a first plunger and a second plunger And an insulating material provided between and.

[0010]

In the present invention, one contact probe has two
Since the book plunger is integrally provided, a single contact probe of the present invention can exhibit the functions of two conventional contact probes.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a contact probe 30 of a mounting board inspection apparatus according to an embodiment of the present invention. The contact probe 30 includes a first plunger 31 in the center. The plunger 31 is formed of an elastic linear conductive material, and its tip (lower end) is sharp. The entire outer circumference of the plunger 31 is coated with the insulating material 32, and the entire outer circumference of the insulating material 32 is coated with the conductive material 33. Further, an insulating material 34 is coated on the outer surface of the conductive material 33 excluding the upper and lower portions.

A second plunger 35 is concentrically arranged below the first plunger 31 with an insulating material 32 and a conductive material 33 interposed therebetween. The plunger 35 is made of a conductive material and has a crowned pipe shape with a sharp tip (see FIG. 2). A power supply terminal ring 36 is provided on the first plunger 35 with an insulating material 32 and a conductive material 33 interposed therebetween.

A lead wire 37 connected to an ammeter is connected to the first plunger 31. On the other hand, the second plunger 35 includes a conductive material 33 and a power supply terminal ring 3.
The lead wire 38 connected to the stabilized power supply is connected via 6.

Next, referring to FIG. 3, the state of the foot floating inspection is shown. In this embodiment, one contact probe 30 is erected on the lead 20, one contact probe 30 is erected on the land 21, a stabilizing power source 23 is connected to the lead wire 38, and an ammeter 22 is connected to the lead wire 37. Connecting. Moreover, since the plunger 31 has elasticity, the two contact probes 30 are pressed until they are bent. The bending at this time pushes the plungers 31 and 35 with a good contact pressure, and the tip of the plunger contacts the lead 20 and the land 21.

When a voltage is applied from the stabilizing power supply 23 in the state of FIG. 3, it can be determined that the lead 20 and the land 21 are soldered well if the ammeter 22 does not detect the current. When the current is detected, it can be determined that the soldering is defective and the foot is floating. After all, 2 per place
The foot floating test can be performed only by using the contact probe 30 of the book.

[0017]

According to the present invention as described in detail with reference to the above embodiments, since one contact probe is integrally provided with two plungers while ensuring mutual insulation, two contact probes are provided. A so-called foot float test can be performed simply by using. Therefore, in the past, four contact probes were required to perform a foot float inspection.
Since only two contact probes are required in the present invention,
It is possible to inspect the mounting board mounted with high density.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a contact probe according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a plunger provided in the contact probe of the embodiment.

FIG. 3 is a configuration diagram showing an inspection device for performing a foot float inspection using the contact probe of the embodiment.

FIG. 4 is a perspective view showing a mounting board inspection apparatus.

FIG. 5 is a perspective view showing a mounting board inspection device.

FIG. 6 is a configuration diagram showing a conventional contact probe and a foot float inspection portion.

FIG. 7 is a circuit diagram showing an inspection circuit for performing a foot float inspection.

[Explanation of symbols]

 1 Upper Fixture 2 Lower Fixture 3 Positioning Holes 4, 4a, 4b, 4c, 4d Contact Probe 5 Positioning Pin 6 Contact Probe 7 Board Positioning Pin 8 Base 10 Mounting Board 11 Board 12 Electronic Component 13 Reference Hole 20 Lead 21 Land 22 Ammeter 23 Stabilized power supply 30 Contact probe 31,35 Plunger 32,34 Insulation material 33 Conductive material 36 Power supply terminal ring 37,38 Lead wire

Claims (1)

[Claims] 1. A mounting board on which electronic components are mounted is sandwiched by fixtures having contact probes, and the electrical characteristics of the mounting board are inspected with the tip of the contact probe being in contact with an inspection point of the mounting board. In the inspection device, the contact probe has a first plunger formed of a conductive material and having a sharp tip, and a first plunger formed of a conductive material having a ring shape and a sharp tip and a first tip position. A second plunger that is aligned with the tip position of the plunger and is concentrically arranged with respect to the first plunger, and an insulating material provided between the first plunger and the second plunger. A contact probe for a mounting board inspection device, which is characterized by: