JPH06160433A - Probe for inspecting circuit board and its manufacture - Google Patents

Abstract

PURPOSE:To provide a probe for inspection which can efficiently inspect high- density circuit board for disconnection or short-circuiting of foil. CONSTITUTION:The title probe 10 is constituted of a multilayered flexible circuit board 12 which is formed by sticking a plurality of flexible circuit boards 12 respectively provided with both-surface bumps 13 and patterns of foil 11 to each other by heating and pressurizing with hot-fusing films 14 in between. Therefore, the intervals between contacts become extremely short, because the intervals approach the diameters of the bumps 13, and the bumps 13 can be brought into contact with a material to be inspected in an excellent state when the probe 10 is pressed against the material even when the material has an uneven thickness, because the probe 10 has flexibility.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe for inspecting a circuit board, which is suitable for detecting breakage or short circuit of a foil of a high-density circuit board having a small electronic component to be mounted and a small terminal pitch such as an LSI to be mounted. The manufacturing method is related.

[0002]

2. Description of the Related Art A conventional circuit board inspection probe will be described below. FIG. 9 is a cross-sectional view of an essential part of the circuit board inspection probe. Conventionally, the contact pin 3 of the inspection probe held by the holding plate 1 and the holding plate 2 is brought into contact with the foil 5 of the circuit board 4 to form a foil. The disconnection or short circuit of No. 5 was detected by the presence or absence of electrical continuity.

However, in recent years, the mounting density of components has been increased, and the density of the foils 5 of the circuit board 4 has also been increased accordingly. For this reason, the foil 5 is becoming thinner, and the interval between the electrode terminals of the component is becoming smaller, and the holding interval of the contact pin 3 is becoming smaller accordingly, and the contact pin 3 is becoming thinner. As a result, there is a problem that the contact pin 3 becomes thin and easily bends, and there is also a problem that it is difficult to perform the hole processing of the holding plates 1 and 2 with high accuracy.

The inspection probe is composed of a socket composed of a socket tube 6 and a stranded wire 7 with a coating, and a plunger composed of a contact pin 3, a coil spring 8 and a pin tube 9.

[0005]

That is, in the above-described conventional circuit board inspection probe, it is difficult to further reduce the distance between the contact pins 3, and the bending of the contact pins 3 and the holding plate 1, There is a problem that it is difficult to assemble the contact pin 3 with high accuracy due to the hole processing of 2 and the like.

The present invention solves the above problems, and an object of the present invention is to provide a circuit board inspection probe and a method for manufacturing the same, which can efficiently inspect a high-density circuit board.

[0007]

In order to solve the above problems, a probe for circuit board inspection of the present invention is formed on both surfaces by penetrating a plurality of bumps on a flexible wiring board having a foil formed on one surface, A plurality of the flexible wiring boards are laminated via an adhesive sheet material so that the bumps come into contact with each other.

The method of manufacturing a probe for inspecting a circuit board according to the present invention has the steps (1) to (8) below. (1) A hole is formed in the unprocessed one-sided foil flexible circuit board, leaving the foil at a necessary place. (2) The formed holes are plated with a conductor to form bumps on the side of the flexible wiring board having no foil. (3) Etching the foil to form a required pattern. (4) The bumps are formed by plating the areas having no pattern on the bump-free surface of the flexible wiring board. (5) The steps shown in (1) to (4) above are carried out for a plurality of flexible wiring boards. (6) The heat-fusible film as the adhesive sheet material is perforated at necessary positions to carry out the heat-fusible films. (7) Thermal fusion is performed so that the bumps of the flexible circuit board enter into the holes of the heat-fusible film while performing necessary positioning between the plurality of flexible circuit boards processed by the above (1) to (5). Put the adhesive film on top of each other. (8) A plurality of flexible circuit boards laminated via these heat-fusible films are bonded together by heating and pressing.

[0009]

With the above structure, the distance between the contact points of the electrodes and the foil of the circuit board is close to the diameter of the bumps, so that the distance is extremely small, and a high contact point position accuracy can be stably ensured. In addition, since a plurality of flexible wiring boards are laminated with an adhesive sheet material interposed therebetween and have flexibility,
Even if there is unevenness in the thickness of the circuit board to be inspected or the foil to be inspected, the bump can be satisfactorily brought into contact with the site to be inspected by pressing the circuit board inspection probe against the circuit board to be inspected. Further, since a plurality of flexible wiring boards are laminated, it is easy to draw out the printed wiring that is electrically connected to the bumps, and it is possible to deal with a case where there are many inspection target locations.

Further, the circuit board inspection probe having the above-mentioned structure can be manufactured well by the above manufacturing method.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, in a circuit board inspection probe 10, a plurality of bumps 13 are formed on both sides of a flexible wiring board 12 having a foil 11 formed on one side thereof to form the flexible wiring board 12 on both sides.
It is configured by laminating via a heat-fusible film 14 as an adhesive sheet material so that they come into contact with each other. That is, in the multilayer flexible wiring board 12 in which the heat-fusible film 14 is interposed, the flexible wiring board 12
The conductor bump 13 is formed on the land of the
Another flexible wiring board 1 is provided by the via hole 15 or the through hole 16 and the conductor line which are electrically connected to each other.
The foil 1 that is electrically connected to the bump 13 that contacts the inspection target portion
1 is drawn out.

Next, a method of manufacturing the circuit board inspection probe 10 will be described with reference to FIGS. FIG. 2 is a cross-sectional view of the flexible circuit board 12 after the completion of the first step processing in the method of manufacturing the circuit board inspection probe 10 according to the embodiment of the present invention. In this first step, the holes 17 are formed in the flexible circuit board 12 in which a copper foil is placed on the base of a polyimide film, leaving the foil 11.

FIG. 3 is a cross-sectional view of the flexible circuit board 12 after the second process is completed. In the second step, the holes 17 processed in the first step are plated with a conductor such as nickel and gold to form the bumps 13.

FIG. 4 is a cross-sectional view of the flexible circuit board 12 after the completion of the third process. In this third step, a foil pattern is formed on the opposite surface of the bump 13 formed in the second step by etching.

FIG. 5 is a sectional view of the flexible circuit board 12 after the completion of the fourth step processing. In this fourth step, the bumps 13 are formed by plating the holes 17 with nickel, gold or the like on the surface of the flexible circuit board 12 on which the foil patterns are formed.

FIG. 6 is a sectional view of the heat-fusible film 14 after completion of the fifth step processing. In the fifth step, the heat fusible film 14 made of polyethylene naphthalate is perforated at the bumps 13 formed in the first to fourth steps. In FIG. 6, 18 is a hole formed in the heat-fusible film 14.

FIG. 1 shows a multilayer flexible circuit board after completion of the sixth step, that is, a circuit board inspection probe 1
It is sectional drawing of 0. In this sixth step, the flexible circuit boards 12 stacked with the heat-fusible film 14 interposed therebetween are heated and pressed to be laminated. As a result, the predetermined bumps 13 are brought into contact with each other to be electrically connected.

In this embodiment, a polyethylene naphthalate film is used as the heat-fusible film 14 as an example, but other heat-fusible films such as polyether imide and polyether sulfone may be used.

FIG. 8 is a cross-sectional view showing a use state of the circuit board inspection probe 10 manufactured in the first to sixth steps. Here, 20 is a circuit board to be inspected, 21 is a foil formed on the circuit board to be inspected 20, 22 is a pressure plate, 23 is rubber, and 24 is a stand.

The operation of the circuit board inspection probe 10 will be described with reference to FIG. Foil 2 of circuit board 20 to be inspected
First, the bumps 13 of the circuit board inspection probe 10 are aligned with the upper and lower surfaces, respectively, and the pressure plate 22 is lowered. As a result, the bump 13 and the foil 21 of the circuit board 20 to be inspected are brought into contact with each other for electrical conduction, and the bump 13 passes through the via hole 15, the through hole 16 (see FIG. 1) and the foil 11 of the flexible circuit board 12. The foil 21 of the circuit board 20 to be inspected.
Measure the disconnection and short circuit.

As a result, the foil 21 of the circuit board 20 to be inspected
Since the contact point interval to the contact point becomes a value close to the diameter of the bump 13, it becomes extremely small, and stable and high contact point position accuracy can be secured. Further, since the circuit board inspection probe 10 is flexible, the circuit board inspection probe 10 is used for the foil 21 of the circuit board 20 to be inspected even if the thickness of the circuit board 20 to be inspected or the foil 21 is uneven. The bump 13 can be satisfactorily brought into contact with the portion to be inspected by pressing. Furthermore, since a plurality of flexible wiring boards 12 are laminated, it is easy to draw out the printed wiring that is electrically connected to the bumps 13, and it is possible to deal with the case where there are many inspection target locations.

In the fifth step described in the above embodiment, holes 18 are formed in the heat-fusible film 14 and, as shown in FIG. 7, the holes 18 are subjected to a low temperature curing type conductive paste by a printing method. 19, for example, a silver paste or a copper paste may be filled and dried. In this case, there is no problem in stacking without using the conductive paste 19, but the conductive paste is used in order to increase the reliability of connection. Other procedures are the same as those in the above embodiment.

[0023]

As described above, according to the present invention, a plurality of bumps are formed through a flexible wiring board having a foil formed on one surface thereof so that the plurality of flexible wiring boards contact each other. By stacking the adhesive sheet materials, the distance between the contact points of the electrodes and the foil of the circuit board is close to the diameter of the bumps, so it is extremely small, and stable and high contact point position accuracy can be secured. . Also,
This circuit has a structure in which a plurality of flexible wiring boards are laminated via an adhesive sheet material, and has flexibility, so that even if there is unevenness in the thickness of the circuit board or foil to be inspected that is the object of inspection, this circuit By pressing the board inspection probe against the circuit board to be inspected, the bumps can be brought into good contact with the inspection target portion. Further, since a plurality of flexible wiring boards are laminated, it is easy to draw out the printed wiring that is electrically connected to the bumps, and it is possible to deal with a case where there are many inspection target locations.

Further, by filling the contact portion between the bumps with the conductive paste, the reliability of the circuit board inspection probe can be improved. Also, holes are formed by leaving the foil in the necessary places on the flexible circuit board that is unprocessed single-sided foil, the conductor is plated in the formed holes, and bumps are formed on the side of the flexible wiring board where there is no foil. Etching is performed to form the required pattern, and bumps are formed by plating on the areas without patterns on the bump-free surface of the flexible wiring board, and holes are formed on the heat-meltable film as the adhesive sheet material at the necessary locations. The heat-fusible film so that the bumps of the flexible circuit board fit into the holes of the heat-fusible film. By bonding a plurality of flexible circuit boards laminated via a fusible film by heating and pressurizing the flexible circuit boards, the circuit board inspection professional having the above configuration is joined. It can be satisfactorily produce drive.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a circuit board inspection probe according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a first step in a method of manufacturing the same circuit board inspection probe.

FIG. 3 is a cross-sectional view showing a second step in the method for manufacturing the probe for inspecting the circuit board.

FIG. 4 is a cross-sectional view showing a third step in the method of manufacturing the circuit board inspection probe.

FIG. 5 is a cross-sectional view showing a fourth step in the method of manufacturing the circuit board inspection probe.

FIG. 6 is a cross-sectional view showing a fifth step in the method of manufacturing the circuit board inspection probe.

FIG. 7 is a sectional view of a usage example of the same circuit board inspection probe.

FIG. 8 is a cross-sectional view showing another embodiment of the method for manufacturing the circuit board inspection probe of the present invention.

FIG. 9 is a cross-sectional view of a conventional circuit board inspection probe.

[Explanation of symbols]

 10 Circuit Board Inspection Probe 11 Foil 12 Flexible Wiring Board 13 Bump 14 Heat-Fusable Film (Adhesive Sheet Material) 17, 18 Holes 19 Conductive Paste

Claims (4)

[Claims] 1. A flexible wiring board having a foil formed on one surface thereof is formed on both surfaces by penetrating a plurality of bumps, and the plurality of flexible wiring boards are laminated with an adhesive sheet material so that the bumps contact each other. Probe for circuit board inspection. 2. The probe for inspecting a circuit board according to claim 1, wherein a contact portion between the bumps is filled with a conductive paste. 3. A method of manufacturing a probe for inspecting a circuit board, comprising the steps of (1) to (8) below. (1) A hole is formed in the unprocessed one-sided foil flexible circuit board, leaving the foil at a necessary place. (2) The formed holes are plated with a conductor to form bumps on the side of the flexible wiring board having no foil. (3) Etching the foil to form a required pattern. (4) The bumps are formed by plating the areas having no pattern on the bump-free surface of the flexible wiring board. (5) The steps shown in (1) to (4) above are carried out for a plurality of flexible wiring boards. (6) The heat-fusible film as the adhesive sheet material is perforated at necessary positions to carry out the heat-fusible films. (7) Thermal fusion is performed so that the bumps of the flexible circuit board enter into the holes of the heat-fusible film while performing necessary positioning between the plurality of flexible circuit boards processed by the above (1) to (5). Put the adhesive film on top of each other. (8) A plurality of flexible circuit boards laminated via these heat-fusible films are bonded together by heating and pressing. 4. A hole formed in a heat-fusible film is filled with a low-temperature curable conductive paste, and bumps of a flexible wiring board are brought into contact with each other through the low-temperature curable conductive paste to connect a plurality of flexible circuit boards to each other. The method for manufacturing a probe for inspecting a circuit board according to claim 3, wherein the probes are joined together.