How to choose PCB test fixture material?
2024-09-23
The production of the fixture should choose the appropriate material according to the actual situation, which can greatly reduce the cost, and the universal reusable base can also greatly reduce the cost, and make the fixture production standardized and convenient, improve the quality of the fixture. The selection of test needles and related materials in the test frame is very important to the quality and cost of the test fixture.
1. Selection of test probe:
The choice of the needle of the test fixture has the greatest relationship with the cost of the fixture. At present, the test probe is divided into domestic, Taiwan, Hong Kong and imported three kinds. Imported products are generally German, American, Japanese products, brands INGUN, Huarong, Zhongtan, LH and so on. The quality of the probe is mainly reflected in the material, coating, spring, sleeve diameter precision and manufacturing process. The main reason is the difference in technological level, and the domestic probe coating with poor wear resistance is easy to fall off. If the use time and test times of the test fixture are more than 50,000 times, it is more appropriate to choose imported products, but the imported probes are more expensive. At present, the domestic production level and technology have gradually improved, and in the current price war, many agents sell domestic needles posing as imported or Taiwanese probes. If the test requirements and test times are not high, it is recommended to choose domestic probes. The quality of the probe is mainly related to the number of tests and whether the contact is good in the manufacture of the test fixture.
2 Selection of test line:
At present, the test lines are imported from abroad or produced in Taiwan and Hong Kong, and the difference between their products seems to be small. The price is about 120 yuan per roll.
3 Selection of plates for testing:
The plate selected in the test fixture is generally acrylic (plexiglass), epoxy resin plate, etc. Ordinary probe aperture greater than 1.00mm fixture, its plate is mostly plexiglass, plexiglass price is cheap, while plexiglass is relatively soft when drilling expansion and shrinkage probe sleeve and hole combination is tight, because plexiglass is transparent fixture problem inspection is very easy. However, ordinary plexiglass is prone to melt and break the bit when drilling, especially when the drilling aperture is less than 0.8 mm, the problem is very big, generally when the drilling aperture is less than 1 mm, epoxy resin sheet is used, epoxy resin sheet drilling is not easy to break the bit, its toughness and rigidity are good, but the price is more expensive. The epoxy sheet does not expand and shrink, so if the hole diameter is not accurate, it will cause the probe sleeve to loosen and shake. If the epoxy resin board is opaque, it is more difficult to check if there is a problem with the fixture, and the temperature difference deformation of the plexiglass is larger than that of the epoxy resin board. If the density of the test is very high, the epoxy resin board should be used. The selection of plate and the precision of drilling play a key role in the accuracy of the whole test fixture.
There is a modified plexiglass which has the advantages of small deformation, high temperature resistance 5 mm thickness 0.6 mm drill bit can drill through continuous drill bit at one time, the price is slightly higher than ordinary plexiglass but lower than epoxy sheet is a very good choice.
Most of the base of the fixture is made of bakelite, most of the manufacturers make the fixture base according to the size of the test plate temporary production, so the production cycle is long, our company adopts semi-standardized design, greatly reducing customer costs.
The production of the fixture should choose the appropriate material according to the actual situation, which can greatly reduce the cost, and the universal reusable base can also greatly reduce the cost, and make the fixture production standardized and convenient, improve the quality of the fixture.
1. Selection of test probe:
The choice of the needle of the test fixture has the greatest relationship with the cost of the fixture. At present, the test probe is divided into domestic, Taiwan, Hong Kong and imported three kinds. Imported products are generally German, American, Japanese products, brands INGUN, Huarong, Zhongtan, LH and so on. The quality of the probe is mainly reflected in the material, coating, spring, sleeve diameter precision and manufacturing process. The main reason is the difference in technological level, and the domestic probe coating with poor wear resistance is easy to fall off. If the use time and test times of the test fixture are more than 50,000 times, it is more appropriate to choose imported products, but the imported probes are more expensive. At present, the domestic production level and technology have gradually improved, and in the current price war, many agents sell domestic needles posing as imported or Taiwanese probes. If the test requirements and test times are not high, it is recommended to choose domestic probes. The quality of the probe is mainly related to the number of tests and whether the contact is good in the manufacture of the test fixture.
2 Selection of test line:
At present, the test lines are imported from abroad or produced in Taiwan and Hong Kong, and the difference between their products seems to be small. The price is about 120 yuan per roll.
3 Selection of plates for testing:
The plate selected in the test fixture is generally acrylic (plexiglass), epoxy resin plate, etc. Ordinary probe aperture greater than 1.00mm fixture, its plate is mostly plexiglass, plexiglass price is cheap, while plexiglass is relatively soft when drilling expansion and shrinkage probe sleeve and hole combination is tight, because plexiglass is transparent fixture problem inspection is very easy. However, ordinary plexiglass is prone to melt and break the bit when drilling, especially when the drilling aperture is less than 0.8 mm, the problem is very big, generally when the drilling aperture is less than 1 mm, epoxy resin sheet is used, epoxy resin sheet drilling is not easy to break the bit, its toughness and rigidity are good, but the price is more expensive. The epoxy sheet does not expand and shrink, so if the hole diameter is not accurate, it will cause the probe sleeve to loosen and shake. If the epoxy resin board is opaque, it is more difficult to check if there is a problem with the fixture, and the temperature difference deformation of the plexiglass is larger than that of the epoxy resin board. If the density of the test is very high, the epoxy resin board should be used. The selection of plate and the precision of drilling play a key role in the accuracy of the whole test fixture.
There is a modified plexiglass which has the advantages of small deformation, high temperature resistance 5 mm thickness 0.6 mm drill bit can drill through continuous drill bit at one time, the price is slightly higher than ordinary plexiglass but lower than epoxy sheet is a very good choice.
Most of the base of the fixture is made of bakelite, most of the manufacturers make the fixture base according to the size of the test plate temporary production, so the production cycle is long, our company adopts semi-standardized design, greatly reducing customer costs.
The production of the fixture should choose the appropriate material according to the actual situation, which can greatly reduce the cost, and the universal reusable base can also greatly reduce the cost, and make the fixture production standardized and convenient, improve the quality of the fixture.
//sznewmeto.com/
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