JPH0452692Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an apparatus suitable for inspecting a printed circuit board having circuits formed on both sides, particularly a film-shaped printed circuit board.

[Prior Art] In a so-called double-sided printed circuit board in which electric circuits are formed on both sides of an insulating substrate, if the resistance of through-hole conductive parts or other circuit patterns is locally high, electricity will conduct to the circuit during use. During this time, it may generate heat and cause the wire to break. In particular, the above-mentioned problem occurs because the through-hole conduction portion is highly likely to have high resistance due to variations. Because of the above problems, it is necessary to inspect the through-hole conduction parts and other circuit patterns to ensure that there are no abnormalities.

When testing the resistance of a pattern on a double-sided printed circuit board as shown in Figure 2, with conventional testing equipment, if probes are placed above and below so as to be in pressure contact with the patterns on both sides, the biasing force of the probes may cause the board to locally wave. , measurement becomes unstable. In particular, if the double-sided printed circuit board is made of film, the board will be damaged. Therefore, the probe can only be provided on one side of the printed circuit board as shown in FIG. The inspection was carried out by touching the upper probe of the inspection device.

The conventional inspection apparatus shown in FIG. 3 will be explained. This figure is a cross-sectional view schematically showing a measuring section of the inspection device, and a guide post 24 and a guide pin for positioning a printed circuit board (not shown) are provided upright on a base material 23. The probe fixing plate 25 is mounted so as to be movable up and down by the guide post. Further, a linear motion bearing 26 is mounted on the portion where the probe fixing plate is inserted and slid. An upper probe 27 is implanted in the probe fixing plate 25 and urged downward.

[Problems to be solved by the invention] With conventional methods, it is not possible to test the resistance of only the through-hole conduction portion. Because the test was performed using a resistor that included a pattern other than the through-hole conduction area, the test specs were based on a relatively large resistance that included a pattern other than the through-hole conduction area, which could cause product failure in the through-hole conduction area. In some cases, even if there were abnormalities such as localized microcracks, they could not be detected.

Further, if one of both ends of the pattern to be inspected is on the back side, the inspection itself cannot be performed.

Furthermore, in various tests other than testing the resistance of through-hole conductive parts, the inability to apply probes to both sides of the printed circuit board causes problems in testing because accurate measurements cannot be made.

Therefore, in view of the drawbacks of the above-mentioned prior art, the present invention solves the following problems:
To provide a printed circuit board inspection device capable of inspecting the resistance of only through-hole conduction parts of a printed circuit board, and capable of stably measuring from both sides even if the printed circuit board is in the form of a film, for example. With the goal.

[Means for Solving the Problems] In order to solve the above-mentioned drawbacks of the prior art, the present invention provides an inspection apparatus for a printed circuit board in which circuits are formed on both sides. A board mounting table on which a board is placed and a board holding plate are each provided to be movable up and down, and by pushing down the board holding plate from above, the printed circuit board is placed between the top surface of the board mounting table and the bottom surface of the board holding plate. An upper probe is biased downward and implanted in the substrate holding plate, a lower probe is implanted in the support base while biased upward; The mounting table is provided with a through hole through which the lower probe is inserted so as to be movable up and down, and when the substrate mounting table is located above, the lower probe does not protrude from the top surface of the substrate mounting table, and the lower probe does not protrude from the upper surface of the substrate mounting table. When the mounting table is located below, it is configured to protrude and be able to be pressed against the circuit on the lower surface of the printed circuit board.

[Effect] The above technical means works as follows.

When a printed circuit board with circuit patterns formed on both sides is placed on the board mounting table and the board holding plate is lowered, the upper probe first comes into pressure contact with the measurement point of the pattern on the top surface of the printed circuit board, and then When the holding plate moves downward, the upper probe remains in pressure contact with the measurement point of the pattern on the top surface of the printed circuit board, the upper probe is buried in the board holding plate, and the bottom surface of the board holding plate comes into contact with the top surface of the printed circuit board. Therefore, the printed circuit board is held between the board holding plate and the board mounting stand, and when the board holding plate moves downward, the printed circuit board and the board holding stand also move downward together, and as a result, the lower probe is held against the printed circuit. It comes into pressure contact with the measurement point of the pattern on the bottom surface of the substrate. At this time, the opposite side of the printed circuit board to the part of the printed circuit board that is pressed into contact with the probe is supported by a board holding plate or a board mounting table, so the biasing force of the probe does not cause the board to wave or damage the board. As a result, measurements will not become unstable.

[Example] The present invention will be explained below with reference to FIGS. 1 and 2.

FIG. 2 is a diagram showing the main parts of a double-sided printed circuit board, and is the same as that in the description of the prior art. In the figure, 1 is a double-sided printed circuit board, in which an insulating board 2 is formed with a through-hole conduction portion 3, a front lead pattern 4 located on the front surface, and a back lead pattern 5 located on the back surface. The lead pattern 5 is electrically connected via the through-hole conductive portion 3. More specifically, the double-sided printed circuit board 1 is constructed by forming printed resistors 4c and printed switches (not shown) on a film-like insulating substrate 2 made of polyester or polyester terephthalate resin, and further forming through holes with conductive ink. conductive part 3 and lead pattern 4,
5 is formed.

In the inspection device of the present invention, the through-hole conduction portion 3
In order to measure only the resistance of
The probe can be brought into contact with.

FIG. 1 is a cross-sectional view of essential parts of an inspection device for a double-sided printed circuit board 1 according to the present invention.

A support base 9 consisting of a base material 7 and a lower probe fixing member 8 fixed on the base material 7 is fixed on the base 6. A jacket 10a of a lower probe 10 is implanted in the lower probe fixing member 8, and a spring inside the jacket 10a allows the lower probe 10 to slide up and down and is biased upward. Further, the lower probe fixing member 8 includes guide pins 11 for positioning a double-sided printed circuit board 1, which is an object to be inspected, and a board holding plate 2, which will be described later.
A pilot pin 12 for guiding the pilot pin 1 is fixed in a protruding manner. A substrate mounting table 13 is placed above the lower probe fixing member 8 with a gap therebetween so as to be movable up and down by a guide post 14 erected on the lower probe fixing member 8, and a compression coil spring 15 supports the lower probe. It is urged upward against the fixing member 8. Note that the substrate mounting table 1
3, a linear motion bearing 16 is attached to the portion through which the guide post 14 slides. The substrate mounting table 13 has a through hole 17 through which the lower probe 10 passes, and escape holes through which the guide pin 11 and the pilot pin 12 pass.

A guide post 18 is erected on the outer side of the pedestal 6, and an upper support member 19 is attached to the guide post 1.
8 and is slidable up and down and the pedestal 6
is placed parallel to. A linear motion bearing 20 is attached to a portion of the upper support member 19 through which the guide post 18 slides.

A substrate holding plate 21 is fixed to the lower side of the upper support member 19 and is positioned above the substrate mounting table 13 with a gap therebetween. The outer cover 22a of the upper probe 22 is embedded in the substrate holding plate 21,
A spring inside the outer cover 22a causes the upper probe 22 to
protrudes from the lower surface of the board holding plate 21 so as to be slidable up and down and urged downward.

The board holding plate 21 has a guide hole for engaging with the pilot pin 12, and a guide hole for engaging the pilot pin 12.
1 escape hole has been opened.

The operation of the inspection apparatus of the present invention having the above configuration will be explained.

The upper support member 19 is initially lifted upward by a vertical drive source (not shown) fixed to the upper support member 19.

In this state, the double-sided printed circuit board 1 is placed on the board mounting table 13 by engaging the guide pins 11 and aligning the board.

Next, the upper support member 19 is lowered by the vertical drive source. Then, the upper probe 22 protruding from the lower surface of the board holding plate 21 contacts the front side measurement point 4a of the double-sided printed circuit board 1, and when the upper support member 19 is further lowered, the upper probe 22 sinks into the board holding plate 21, and the board The lower surface of the presser plate 21 contacts the surface of the double-sided printed circuit board 1. When the upper support member 19 is further lowered, both sides of the double-sided printed circuit board 1 are placed between the board holding plate 21 and the board mounting table 13.
Sandwiched between them, the three descend as one. Then, the lower probe 10 comes into contact with the back side measurement point 5a on the back side of the double-sided printed circuit board 1 through the escape hole of the board mounting table 13. Then, the lowering of the upper support member 19 is stopped, and the resistance is measured.

In the above explanation, the inspection of through-hole conduction parts was described, but the present invention is effective not only for inspection of through-hole conduction parts but also for inspection of other patterns. An object to be inspected with components mounted thereon can also be inspected by appropriately providing recesses for the components in the substrate mounting table and the substrate holding plate 21.

[Effects of the invention] As described above, according to the invention, in an inspection apparatus for a printed circuit board having circuits formed on both sides, a board mounting table on which the printed circuit board is mounted and a board mounting table on which the printed circuit board is placed are provided above the support table. Board holding plates are provided to be movable up and down, and the printed circuit board can be held between the top surface of the board mounting table and the bottom surface of the board holding plate by pressing down the board holding plates from above, and the board An upper probe is urged downward and implanted on the holding plate, and a lower probe is implanted on the support base while being urged upward,
The substrate mounting table is provided with a through hole through which the lower probe is vertically movably inserted, and when the substrate mounting table is positioned upwardly, the lower probe does not protrude from the upper surface of the substrate mounting table; When the board mounting table is positioned downward, it is configured so that it protrudes and can be pressed into contact with the circuit on the bottom surface of the printed circuit board, so even if measurement probes are placed on both sides, the printed circuit board does not touch the board holding plate during measurement. The surface opposite to the part of the printed circuit board that is held between the bottom surface and the top surface of the board mounting table and where the measurement probe comes into pressure contact with the printed circuit board is supported by the board holding plate or the board mounting table, so it is easy to measure. The substrate will not wave due to the biasing force of the probe, resulting in unstable measurements or damage to the substrate.
Since the resistance of only the through-hole conduction portion can be tested, reliable testing is possible.
In addition, various tests other than resistance tests for through-hole conduction parts can be performed by applying probes to both sides of the printed circuit board, making it possible to perform accurate tests.

Furthermore, since the structure is simple, the device is easy to manufacture and can be provided at low cost.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts of an embodiment of the printed circuit board inspection device of the present invention, Fig. 2 is a perspective view of the main parts of the printed circuit board, and Fig. 3 is a conventional printed circuit board inspection device. FIG. 2 is a sectional view of a main part of the device. 1...Printed circuit board, 7...Base material, 8...
Lower probe fixing member, 9... Support stand, 10...
Lower probe, 13... Substrate mounting stand, 17... Through hole, 21... Substrate holding plate, 22... Upper probe.

Claims (1)

[Claims for Utility Model Registration] In an inspection device for a printed circuit board having circuits formed on both sides, a board mounting table on which the printed circuit board is placed and a board holding plate are mounted above the support stand, each of which is movable up and down. The printed circuit board can be held between the upper surface of the board mounting table and the lower surface of the board holding plate by pressing down the board holding plate from above, and the board holding plate has an upper probe attached below. The lower probe is urged upward and planted on the support stand, and the substrate mounting table has a through hole through which the lower probe is inserted so as to be movable up and down. is provided, the lower probe does not protrude from the top surface of the board mounting table when the board mounting stage is located above, and protrudes when the board mounting stage is located below, A printed circuit board inspection device characterized by being configured so that it can be pressed into contact with a circuit on the bottom surface.