JPS5880891A - Method of inspecting printed circuit board - 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 The present invention relates to a method for inspecting a cylinder wiring board using a convenience store machine.

Conventionally, printed wiring board inspection equipment prepares a reference printed wiring board that has been confirmed to be a defective product and a test fixture that has contact holes corresponding to the land hole positions of the reference printed wiring board. , overlap the test fixture and the reference printed wiring board, bring the contact bottle into contact with the land hole of the printed wiring board, and sequentially electrically scan the contact bottle to first touch the reference printed wiring board. Preparation for inspection is completed by reading and memorizing the wiring information of the reference printed wiring board, and then a printed wiring board to be inspected of unknown quality having land holes and wiring patterns in the same arrangement as the reference printed wiring board is used instead of the reference printed wiring board. Then, the contact pins are shaken against the land holes of the printed wiring board, and the contact pins are sequentially electrically scanned in the same manner as above to increase the wiring information of the printed wiring board to be inspected. R
Is the wiring of the standard printed circuit board memorized? They compared it with #report and judged whether it was the same or not.

The contact wire has a structure that is stretched by applied pressure, and the wiring information is, for example.

Indicates whether the connection between one contact pin number and another contact bottle number is electrically open or open.

However, with this kind of inspection equipment, it is necessary to prepare and replace test fixtures for each i*1kKp of the printed wiring board to be inspected. This was difficult due to cost.

In order to overcome the above problems, a general-purpose test fixture 3 was devised, as shown in FIG. 1, in which contact bottles 1 are arranged on an insulating substrate 2 in a grid of, for example, 2.54 m. If this method is adopted, the number of contact points of the test fixture for inspecting a printed wiring board with effective dimensions of approximately 32 m x 40 m, for example, will be approximately 20,000. There is no need to pay for separate test image textures for each type of printed wiring board. And the kfil bin l of this general purpose test fixture 3
However, in order to prevent malfunctions or damage to locations other than the land holes of the tested board,
As shown in the figure, the land hole of the printed wiring board 4 to be inspected! '
,6. ? A mask 9 made of a thin insulating plate with holes 8 corresponding to
, 1bll@..., only the contact bin corresponding to the large position of 40 lands of the printed wiring board to be inspected is brought into contact with the printed wiring board, and the other contact bins are prevented from contacting by the mask 9. do.

In this state, all of the contact bins are sequentially electrically scanned to store the wiring information of the skeleton printed wiring board, or to add the wiring information to the memory that has already been stored. It is thought that the hole may be inspected by comparing it with certain wiring information.

However, with this advanced testing method, e.g.

Even if the printed wiring board to be inspected has 4,000 land holes, all 20,000 land holes are electrically scanned! l! Actually, it has nothing to do with the inspection. 6. Scanning for OU 0 contacts resulted in wasted time.

Generally, fcl! reads wiring information from a reference printed wiring board! In many cases, it takes a much longer time than the inspection time required to determine the quality of the printed wiring board.

Therefore, an object of the present invention is to provide a printed wiring board calibration method that can read wiring information from a reference printed wiring board in a short time by scanning only the contact bins that are actually necessary. That is.

Hereinafter, the details of the present invention will be explained based on the direction. Figure 3 shows an example of the configuration of a general-purpose printed wiring board inspection device for controlling a condenser used for the above purpose, and 39 is the contact bin mentioned above. Test fixture with groups, 3141
32 is a console for operation, 33 and 34 are storage units, 33 is a software area necessary for control, and 34 is a RAM area capable of writing and starting. 35 is an interface section, 36
37 is a wiring information storage section, and 38 is a scanning section that sequentially electrically scans each contact pin of the test fixture 39.

First, # shown in the %M4 diagram is a test fixture 3 having contact bins 1 arranged in a grid pattern as described above, and a thin edge plate with holes 8 formed at positions corresponding to the land holes of the printed wiring board to be tested. A mask 9 and a shorting plate 10 are prepared.

The shorting plate lO is made of a conductor and is connected to the fc contact pin l as described above.
When in contact with the bottle 1, it has the property of electrically conducting with the bottle 1, and in order to improve the contact condition, a hole 1 pipe is formed at a position corresponding to the contact bottle 1 as shown in ○. φ. Therefore, when a plurality of contact bottles 1 come into contact with the short circuit plate 1G,
The contact pins are electrically connected to each other.

In the 41st step, when the contact bottle l is pressed against the short circuit plate 10 through the mask 9, only the contact bottle at the position corresponding to the mask hole contacts the short circuit plate 10, and the contact bottles are electrically connected to each other. However, since the hole in the mask 9 is formed at the position 11 corresponding to the land hole of the printed wiring board to be inspected, the distance between the fitting pins at the position corresponding to the land hole of the printed wiring board to be handled and inspected is as follows. Becomes conductive.

Therefore, if we electrically eclipse all the contact bins in sequence,
Since it is possible to identify the contact bottle codes that are electrically connected to each other, the software area 334 of the storage unit
By running the "contact bin number registration program" stored in C, the scanning s38 is controlled via the interface 35 and control (81g36), and the contact bin numbers whose mutual connection is in a conductive state KTo are stored in the RAM area 34. stage t-r
It shall be referred to as "Registration".

Next, the shorting plate IO is removed, a reference printed wiring board 4 is prepared instead as shown in FIG.
When pressed to 4 through
b, lc... will come into contact, but as mentioned above, the contact pin number has already been registered in the RAM area tIR34 in Figure 3, so run the "wiring information detection program". While sequentially reading out the registered pin numbers, only the contact bins of the registered pin arm numbers are sequentially scanned, @ is read in the alignment ↑, and the result is stored in the alignment information storage section 37IIc.

In addition, in FIG. 3, the track wiring information storage section 37 is the processor 3
1 and an independent hardware 37 via an interface 35, it is also possible to allocate a RAM area 34 that can be accessed directly from the processor 31.

In addition, wiring information regarding registered unshielded contact bins is available at
3, assuming that everything is open, regardless of the wiring information detection program? All you have to do is store it in LC.

This stage will be referred to as "embedding wiring information".
This completes the preparation for testing the printed wiring board to be tested.

By performing the above-mentioned "registration" and "reading wiring information", the number of contact bins scanned by the "wiring information detection program" will be greatly reduced, so the time required for inspection preparation will be greatly reduced. It is clear that there are savings.

In addition, when preparing for the next inspection, the above "registration" and "
In order to save the trouble of repeatedly reading the wiring information, the store shown in the figure transfers the data stored in the wiring information section 37 to a computer-controlled magnetic tape, etc. Of course, if you store the energy from the Semi-Qi deep into 37 at the time of the next Kousha Saya, it will be possible to further shorten the time.

1-Inspection'' stage, in Figure 2, in place of the reference printed wiring board 40, the printed wiring board 4 to be inspected, which has land holes and arrangement III/2 turns in the same arrangement as the reference printed wiring board, is used. Prepare □.

Then, in the same way as ``Insertion of distribution information'', press the contact hole 1 to 4 through the mask 9, run the ``inspection program'' stored in the software area 334C of FIG. 3, The wiring information between the contact bins is distributed 11iil+1.
# It is sequentially compared with the wiring information of the reference printed wiring board stored in the information storage s37 to judge whether it is good or bad.

Generally, the time required for inspection at the "inspection" stage is "
In many cases, the time taken to read the wiring information is shorter, so in reality, there are cases where it is not necessary to limit the number of contacts and scan, but only the fc "registration" bin is used as described above. Of course, 4I can shorten the inspection time by scanning the 4I.

As described above, the present invention includes a test fixture in which shaking bottles are arranged in a grid pattern, a perforated mask corresponding to a temporary test printed wiring board, and pins that contact the land holes of the printed wiring board. Since the number is "registered" and then "registered" contact pins are scanned only to "incorporate wiring information", the time required to read the wiring information of the reference printed wiring board is greatly reduced. You can shorten it to width by ◆.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of a general-purpose test fixture, #! 2
Figure 1 shows an explanation of the printed wiring board to be inspected being pressed against a general-purpose test fixture through a mask, Figure 3 shows an example of the configuration of a computer-controlled general-purpose printed wiring board inspection device, and Figure 4 shows short circuits. An explanatory diagram when using a plate.

Claims (1)

[Claims] l A general-purpose test fixture with contact bins arranged in a grid to enable inspection of various print placement mm, and holes formed corresponding to the land hole positions of the printed wiring board to be inspected. A mask made of an insulator, a shorting plate that electrically shorts between the contact bottles when they come into contact with each other, and a reference printed wiring board for the printed wiring board to be inspected are prepared, and first, a mask is placed on the mask. and the short-circuiting plate, pass through the hole of the mask, bring the contact point of the death fixture into contact with the short-circuiting plate, and make a first fist that touches the shorting plate. 1. Next, insert several contact bottles of the test fixture through the holes in the mask.
Inspection of a printed wiring board characterized in that test preparation is completed by shaking the land hole of the semi-printed wiring board and reading the wiring information between the mounted wires as @2 steps. Method.