JPS58117440A - Automatic inspecting apparatus for through-hole in printed circuit board - Google Patents

Abstract

PURPOSE:To improve the accuracy of the inspection results and substantially shorten the time required for inspection, by a method wherein the quality of through holes in a printed board is inspected by detecting and measuring the level of light quantity. CONSTITUTION:A printed board 1b is set on a printed board feeder 21 through an operation panel 24. The light which is projected from a projector 1a and reflected by the inner wall of a through hole 1c in the printed board to pass therethrough is detected by a light detector 1d and converted into an electric level. A controller 23 makes comparison and judgement as to whether the through hole is good or bad, and drives a defective part marking device 26 when the through hole is bad. Such a series of operations is continuously and repeatedly conducted at the through hole reference lattice pitch to complete the inspection of all the through holes in the printed board. This judgement of the quality is comprehensively made, and non-defective and non-conforming articles are selected and sorted by a selector 22.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inspection device that automatically inspects the condition of through holes in a printed board.

Conventionally, through-holes in printed circuit boards are inspected by placing an object on the back side of the printed board and visually observing changes in reflected light from the inner wall of the through-holes to determine whether the shims are good or bad. Therefore, the operator's eye is ripe! Test results were affected by f, and it was accompanied by physical and mental bone destruction.

An object of the present invention is to provide an inspection device that automatically detects defective through holes in printed circuit boards.

The automatic detection device of the present invention includes a light projection means for projecting a constant amount of light onto an inner wall, a light amount detection means for detecting reflected light from the inner wall, a device for supplying printed boards, a device for sorting out good and bad printed boards, and a device for sorting out good and bad printed boards. It has a device for marking through holes and a control device for controlling each of the devices, according to input/output results via the control device.

The first feature is that defective through holes are detected.

Next, one embodiment of the present invention will be described in detail with reference to the drawings.

FIGS. 1(a) and 1(b) are diagrams of the principle of optical detection according to the present invention. (a) In the figure, a fixed amount of focused light source Lin is projected onto a through-hole plating 1c of a printed board 1b from a light projecting device (means) 1 m, and one reflected light Lout is received and detected by a source detection device ld. This detection result is converted to an electrical level and defective through holes are measured. 9 (b) Figure F
i In the same way as described above, light is emitted into the defective through hole 1 of the printed board lb, and the reflected light toutt is detected by the source detection device 1d.
The light was detected at 7tJIII. In this figure (b), since the defective through hole 1e is not plated, the input source Lin is diffusely reflected and one reflected light tou
t decreases. That is, (a) Lout in the figure and (Aout in the figure is the level of light intensity) A
There is an out relationship.

Therefore, by detecting and measuring the level of the % light amount, it is possible to inspect whether the through holes in the printed board are good or bad.

Figure 2 shows an example of an inspection device using this principle tube.
The printed board 1b set on the printed board supply device 121 by the operation panel 24 is illuminated by the light projecting device 1 and the source of the light is reflected on the inner wall of the through hole 1c of the printed board and is detected by the light detection device 1d. and converted to electrical level. The control device w, 23 compares and determines whether the through hole is good or bad, and if it is defective, it drives the defective spot marking device 26 and marks the printed board 1b with ink, for example.
At the same time as making a mark on the through hole lc.

The control device 23 uses the printer 25 to output the aS value (x, y) of the through hole of the printed board. This series of operations is repeated continuously at the pitch of the through-hole reference grid to complete the inspection of all the through-holes on the printed board. This judgment of good and bad is done comprehensively, °
- Unsatisfactory and defective products are sorted and sorted by the sorting device 22. It goes without saying that in this device, the drive timings of the tie erecting device for detecting and measuring the amount of light and the printed board supply device are synchronized.

It goes without saying that the p1 inspection speed can be improved by installing a plurality of light projectors and light detection devices in correspondence and at the same time operating the % printed board supply device at high speed.

As explained above, according to the present invention, it is possible to mechanize the conventional visual inspection of through-holes on printed circuit boards, thereby improving the accuracy of the inspection results.

In addition, it is possible to achieve a significant reduction in inspection time, which greatly contributes to the improvement of artificial production conditions.

[Brief explanation of drawings]

m1 diagrams (a) and (b) are optical explanatory diagrams explaining the uninvented calibration principle of Fi-1.
Figure 2 is a block diagram of a printed board through hole inspection system according to an embodiment of the present invention. 1 is a light projector, 1b is a niblint plate %lc varnished through-hole plated inner wall, 1d is a photodetector, 1e is a defective through hole, Lin is input light s Lout 5tout is reflected light, 21 is a niblint plate supply device, 22 is a sorting device , 23
: Control #device% 24: Operation panel, 25: Printer, 26
; Defective marking device. 1st! ¥] Figure 2 Procedural Amendment (Voluntary) Commissioner of the Patent Office 1, Indication of Case 1981 Patent Application No. 486
No. 2, Title of the invention: Automatic through-hole inspection device for printed garden road boards 3, Relationship with the person making the amendment: Applicant: 5-33-1-4 Shiba, Minato-ku, Tokyo, Agent: 108 Minato-ku, Tokyo 37-8 Shiba 5-chome Resident Mita Bi J & Column 6 of the detailed description of the invention in the specification subject to amendment, Contents of amendment (1) ``Defective through hole'' on page 3, line 3 of the specification Correct "Yes" to "Good through hole".

Claims (1)

[Claims] A light projecting means for projecting light onto the inner wall of the through hole of the printed board, a light detecting means for detecting and measuring the amount of light reflected inside, a means for marking defective areas, a means for supplying the printed board, and all other means. 4? It has a control circuit to control the input through the control circuit and is pressed to output the inspection result of the defective through hole. Automatic through-hole inspection equipment for printed circuit boards that contain mold.