JPH0385456A - Prober - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to a prober, and more particularly to an inspection prober used for continuity or insulation testing of printed wiring boards.

[Prior Art] In printed wiring boards used in electronic computers and the like, defects such as disconnections, short circuits, or deterioration of insulation in wiring patterns are absolutely unacceptable. On the other hand, continuity and insulation tests are performed after the wiring pattern is formed.

FIG. 2(a) shows an example of a printed wiring board 2, in which a wiring pattern 2b having a constant interval and width is printed on the surface of an epoxy base plate 2a with reference to lattice points.

FIG. 2(b) explains the method for testing the printed wiring board 2. The board 2 to be tested is placed on the mounting table 3, and the wiring pattern is placed on the probe board la made of insulating material. An inspection blow μ1 having a probe pin 1b implanted at a position corresponding to each grid point of 2b is provided. Figure (C) shows this. Each probe pin 1b is connected to the data processing unit 5 by a connection cable 4, and the inspection blow μ1 is moved in the direction of the arrow, and the tip of each probe pin 1b is pressed into contact with a grid point of the wiring pattern 2b for testing. will be held. In Figure (b), the substrate 2 to be inspected is placed below and the inspection blow μ1 is pressed against it from above, but conversely, the inspection blow μ1 is placed below and the substrate 2 is pressed from above. There are cases where more pressure is applied, but the principle is the same.

FIG. 3 is an axial cross-sectional view showing the structure of a conventionally used inspection blow μ1. In the figure, a metal cylinder receptacle 1c passes through a through hole provided at each lattice point of the probe board 1a, and a core wire 4a of a connecting cable 4 is connected to the upper end of the receptacle 1c. A metal barrel 1d with a closed upper end is fitted into the receptacle 1c, and a probe pin 1b biased downward by a spring 1e is inserted into the barrel 1d. The reason for this so-called triple structure is to replace the probe pin 1b together with the barrel 1d when it becomes defective. A test voltage for inspection is applied to the receptacle 1c from the core m4a of the connection cable, and is conducted to the probe pin 1b via the barrel 1d.

[Problem to be solved] In the conventional inspection blow μl shown in Fig. 3, since it has a triple structure, the probe pin 1 is
The positional accuracy of b is low. That is, in addition to the positional accuracy of the through hole with respect to the probe board 1a, there are gaps gt + g2 + g3 between the through hole and the receptacle, between the receptacle and the barrel, and between the barrel, respectively.
The center position accuracy is at most ±50 μm. Therefore, if the pad diameter of the lattice point is 100 μm or less, the tip of the probe pin may not come into contact with it.

On the other hand, in recent years, the wiring patterns of printed wiring boards have been gradually becoming shorter and smaller.

For example, a so-called grid array package that mounts an LSI has a much smaller wiring pattern. FIGS. 4(a) and 4(b) show an example of the grid array package 6. In FIG. 4(a), an LSI is mounted in the center with a ceramic base 6a, and connected pieces 8b are arranged at the terminals of the wiring pattern. has been done. Correspondingly, grid pins 6c are set up on the opposite side of the base at the positions of the grid points as shown in Figure (b), and the size of the connecting butt or grid pin in this case is as shown in the print Very small compared to the grid points on the wiring board.

Such a grid array package is also a printed wiring board in a broad sense, and in order to inspect it, the positional accuracy of the probe pins needs to be much better than the above. In addition to the above, there are liquid crystal panels that have minute connection butts, and it is considered that they can be inspected in the same way as above.

As described above, there is a need for an inspection blow μ that allows probe pins to contact various printed wiring boards having smaller lattice points than conventional ones with high positional accuracy. This invention is
The object of the present invention is to provide an inspection blow μ for a printed wiring board that has improved positional accuracy by improving the area around the probe pin.

[Means for Solving the Problems] In the present invention, probes are arranged on a probe board corresponding to each grid point of a printed wiring board to be inspected, one end is connected to a data processing section by a connecting cable, and the other end is This test blow μ is applied to a test device having a probe pin that elastically contacts each lattice point of the board to conduct a continuity or insulation test of the wiring pattern of the board. A connection board for connection cables is provided adjacent to the probe board. A through hole is provided in the probe board at a position corresponding to each lattice point of the substrate, and a metal conductive cylinder is inserted into the through hole with an appropriate gap. An actuator consisting of a plunger and a probe pin, which come into elastic contact with the connection point of the connection cable provided on the connection board through compression, is inserted into the conductive cylinder with an appropriate gap, and then inserted into the base of the probe board. A guide plate is fixedly provided on the surface of the corresponding side, and has a through hole drilled therein into which each probe bin can be fitted with high precision.

The above-mentioned actuator has a plunger and a probe pin that are elastically connected by a spring.A groove having an appropriate width in the axial direction is provided on each side of the plunger and probe pin, and a groove is formed in the conductive cylinder. A protrusion is provided on the inner surface and fitted into the groove to limit the range of movement of the plunger and probe pin, respectively.

[Function] In the inspection prober with the above configuration, the probe pin is directly inserted into the through-hole of the probe board, so its positional accuracy depends on the positional accuracy of the through-hole on the probe board and the relationship between the through-hole and the probe pin. Depends only on the gap,
Compared to the conventional three-layer probe bin structure, it is possible to achieve a much higher precision of ±20 μm or less. Appropriate gaps are provided between the blower board and the conduction cylinder, and between the conduction cylinder and the actuator, but these gaps have nothing to do with the positional accuracy of the probe pin and are intended to ensure smooth operation of the actuator. be. Furthermore, the protrusion provided on the conductive cylinder and the groove provided on the plunger and probe pin limit their movement within a certain range and prevent them from falling off.

Then, the test voltage in the test is first transmitted to the plunger, which contacts the connection point of the connection board by pressing. With respect to the gaps between the plunger and the receptacle and probe pin, respectively, they are in contact somewhere circumferentially, so that the plunger voltage is conducted to the probe pin as a result. Note that in this case, the spring that elastically connects the plunger and probe pin has a large electrical resistance and is therefore not useful for continuity.

[Embodiment] Fig. 1 is an axially sectional view showing the structure of an embodiment of a printed wiring board inspection prober according to the present invention. A board 8a is used, through-holes are drilled at the lattice points, and a metal conductive cylinder 8b is inserted into the board 8a.An actuator in which a plunger 8C and a probe pin 8d are elastically coupled by a spring 8e is inserted into the interior of the board 8a. In this case, provide an appropriate gap between the through hole, the conductive cylinder, and the actuator to prevent friction or excessive force from occurring with respect to the operation of the actuator. High-precision through-holes for probe pins 8d are drilled on the surface at positions corresponding to each grid point, and the board 8f is fixed, and the probe pins 8d are inserted into each through-hole. Cover the conductive cylinder 8b by attaching a lid 8g with a hole of an appropriate diameter on the surface of the cylinder.If the actuator becomes defective, remove the lid 8g and replace it.Also, each grid is attached to the top of the plunger 8C. A connection board 8h having connection points 81 is provided at a position corresponding to each connection point 81. When the connection board 8h1 (or the printed wiring board 2°6 to be inspected) is pressed by a suppressing mechanism (not shown), each connection point 81
Plunger 8c comes into contact with the connection. Pull core wire 4
The test voltage from a is transmitted to the probe pin 8d via the conducting cylinder 8b. When pressed further, the probe pin 8d
The test is performed by contacting the wiring pattern 2b1 of a conventional printed circuit board or the wiring bat 6b of the grid array package 6. Note that a groove 8k of an appropriate width is provided on each side surface of the plunger 8c and probe pin 8d, and a protrusion 8j provided inside the conductive cylinder 8b is fitted into the groove 8k to limit the movement range of the actuator. This prevents it from falling off from the conductive cylinder 8b.

[Effects of the Invention] As is clear from the above explanation, in the printed wiring board inspection prober according to the present invention, the positional accuracy of the probe pin is simply the positional accuracy of the through hole of the probe board,
It depends only on the gap between the through hole and the probe pin, and by manufacturing both with high precision, it can contact the wiring pattern of the board to be inspected or the lattice points of the wiring bat with much higher positional accuracy than before. Therefore, it has great effects when applied to inspection equipment for printed wiring boards with minute wiring patterns, grid array packages, and the like.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of a printed wiring board inspection prober according to the present invention, and FIGS.
) is an explanatory diagram of a printed wiring board and an inspection prober for insulation and continuity testing on the printed wiring board, FIG. 3 is a sectional view of a conventional inspection prober, and FIGS. 4(a) and (b) are external views of the grid array package. FIG. 1... Inspection prober, la... probe board, 1b... probe pin, IC... receptor, ld... barrel, 1e... spring, 2... printed wiring board, 2a...・Base board, 2b... Wiring pattern, 3... Mounting table, 4...
...Connection cable, 4a...Cable core wire, 5
...Data processing unit, 6...Grid array package, ea...Base, 6b...Connection butt, 6C...Grid pin, 8...Inspection prober, 8b...Continuity cylinder, 8d ...Probe pin, 8f...Guide board, 8h...Connection board, 8j...Protrusion, ...Probe board, ...Plunger...Spring, ...Lid, ...・Connection point, ...groove.

Claims (1)

[Claims] (1) The probes are arranged on a probe board corresponding to each inspection point on the board to be inspected, one end is connected to the data processing section by a connection cable, and the other end is elastically contacted with each inspection point on the board by pressing. In an inspection device having probe pins for testing a board, a connection board for the connection cable is provided close to the probe board, and a suitable through hole is provided in the probe board at a position corresponding to each of the grid points. A metal conductive cylinder is inserted with a gap formed therebetween, and a plunger and the probe pin are placed inside the conductive cylinder and come into elastic contact with a connection point for the connection cable provided at a lattice point of the connection board by pressing. A guide plate having through-holes into which each of the probe pins can be fitted with high precision is fixed to the surface of the probe board on the side corresponding to the substrate. A prober characterized by: