Discussion on drop test and knock test of PCB production line

　　Generally speaking,in its production line,in addition to the normal assembly and test process,the electronic finished product assembly plant will also set up more or less several test inspection control levels to ensure the quality of its products.The most commonly seen are the following two levels,which are set up in the intermediate stations of product assembly and electrical testing.
　　Tapping test
　　The main purpose of percussion is to check whether the finished product has any improper assembly,including the empty,false soldering,tin ball,tin bead,and mechanism,screw assembly in place.
　　On test bars are usually use an elastic ball on sticks】done with the end of the stick when knock is to to the finished product with elastic ball percussive action,tap on a product is best to open the power supply,have a picture of the product must check for abnormal images appear,because of some bad welding electronic components,might only be open or short circuit occurs on tap.Generally,the knock test will be placed at the first level of the electric test,because we do not know whether the product has been knocked out after the knock.If there is no electric check after the knock,it is likely that the defective product will flow out to the customer's hand.The location of the knock is very important,because different locations knock out the effect is different,to knock in the product solid can generate resonance place,the general test should be knocked three times;It is best to find the most vulnerable part of the product design for the tapping.In addition,the size and weight of the elastic ball will affect the effect of the stroke.
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　　Drop test
　　The falling test here refers to the Quality verification before the product is shipped,not the falling test of DQ(Design Quality).The dropping test shall be subject to the product's bare damage.The purpose is to check whether there is any assembly defect in the finished product as mentioned above.This test and tapping test can be complementary.Falling is done only once.The dropped table is made of solid wood with a 3-5mm electrostatic table mat.The drop test is free to drop,without power or power.As with the percussion test,an electrical test must be performed after dropping the test to ensure that the product functions well and is free of apparent damage.The falling height is usually from 76.2mm(3 inch)to 300mm,which is usually distinguished by the weight of the product.The heavier the weight,the lower the falling height.The following table is just a rough idea,just for reference,everything should be subject to the actual products of each company.
　　Personal experience of online production,workers are not dare to cast products,so the test will be more and more low,actually should let operators know,drop test purpose is to pick out the defective products,rather than letting bad product outflow to the customer's hand,is to return in the future,it is better to first online Q it down in production,the product fell dead should be rewarded.In addition,when R&D is doing product research and development,a lot of machine should fall to 76Cm above deathless,and still be six face four(8)horn drop on cement ground,need not be afraid to fall so can break product,afraid of is to drop to the ground carelessly,injure reach appearance