JPH01182745A - Apparatus for detecting through-hole defect - Google Patents

Abstract

PURPOSE:To ensure the inspection of a defect in a through-hole with a simple combination of a heat source probe and an infrared-ray sensor, by comparing the temperature of the land of the through-hole part, which is measured with the infrared-ray sensor, with the temperature of a non-defective product, which is stored in a memory part. CONSTITUTION:A heat probe 2 having a constant temperature is positioned at a through-hole with an X-Y driving part 3 on one side of the land of the through-hole 9 in a high density printed wiring board 1. Then the probe is brought into contact with the land. At the same time, the image of the other land of the through hole 9 is formed on the surface of an infrared- ray sensor 5 through an image forming lens 4. The amount of the infrared rays is transduced into temperature. When a defect is present in the through-hole 9, the thermal resistance at that part becomes large. The temperature increase of the through-hole land, which is not in contact with the heat source probe 2, becomes gentle in comparison with the time when the defect is not present. Meanwhile, the transduced temperature is compared with the temperature of the good through-hole, which is stored beforehand in a memory part 6 and read out of it, in a comparing and judging part 7. When both values agree, it is judged as the good product. When both values do not agree with each other, it is judged as defective and the fact is outputted through an output terminal 8.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a through-hole defect inspection device, particularly a through-hole defect inspection device for inspecting defects such as voids and defects in minute through-holes of high-density printed wiring boards. Regarding equipment.

[Conventional technology]

There are almost no conventional through-hole defect inspection devices, and even if you use a two-dimensional image using a TV right camera, for example, there is a drawback that you cannot see inside the through-hole.

[Means for solving problems]

The through-hole defect detection device of the present invention includes a heat source probe maintained at a constant temperature, an imaging lens for forming a land image of the through-hole portion, and a lens for measuring the temperature of the land of the through-hole portion. It is configured to include an infrared sensor, a storage section that stores the temperature of the non-defective product of the land of the through-hole section, and a comparison determination section that compares the temperature of the non-defective product in the storage section and the temperature of the test object.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram containing one embodiment of the present invention.

A constant temperature on one side of the land of the through hole 9 of the high-density printed wiring board 1 (a predetermined temperature of 50°C to 80°C)
After positioning the heat source probe 2 at the position of the through hole 9 by the X-Y drive unit 3, the heat source probe 2 is brought into contact with the through hole 9. At the same time, an image of the other land of the through hole 9 is formed on the sensor surface of the infrared sensor 5 by the imaging lens 4, and the amount of infrared rays is converted into temperature.

If there is a defect in the through-hole, the thermal resistance of that portion will increase, and the temperature of the through-hole land that is not in contact with the heat source probe will rise more slowly than when there is no defect.

On the other hand, the converted temperature is stored in advance in the storage unit 6.
The temperature of the non-defective product of the through hole being inspected is compared with the temperature of the non-defective product read from the through-hole being inspected by the comparison/judgment section 7, and if they match, the product is considered to be non-defective, and if they do not match, it is output to the output terminal 8 as a defective product.

〔Effect of the invention〕

The through-hole defect inspection device of the present invention has the advantage that defects in through-holes can be inspected with a simple combination of a heat source probe and an infrared sensor.

[Brief explanation of the drawing]

FIG. 1 is a block diagram containing one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... High-density printed wiring board, 2... Heat source probe, 3... X-Y drive unit, 4... Imaging lens, 5...
- Infrared sensor, 6... Storage section, 7... Comparison/judgment section, 8... Output terminal.

Claims (1)

[Claims] An imaging lens for forming an image of the land in the through-hole section using a heat source probe kept at a constant temperature, an infrared sensor for measuring the temperature of the land in the through-hole section, and an infrared sensor for measuring the temperature of the land in the through-hole section. A through-hole defect detection device comprising: a storage section that stores a temperature of a non-defective product of a land; and a comparison determination section that compares the temperature of a non-defective product in the storage section with a temperature of an object to be inspected.