Study And Application Of The Automatic Inspection Technology For Products Quality Of The Electronic Components

In resent years,the electronic component products in our country developed rapidly,the quality inspection and screening of electronic components is one of the most important steps for improving the products quality and realiability.Currently,the main quality inspection method in most companys is sampling inspection which is carried out by spectial workers.But this method is labor-intensive operation with low efficiency,and it can not inspect all electronic components in this way. This paper adopted several normal components(quartz crystal oscillators,resistors,capacitors ect.) as research objects, and developed an antomatic quality inspection equipment for electronic components,the inspection methods were studied and analysised deeply.An automatic feeding device drived by electromagnetic vibration was adoped in the equipment. A positioning and inspection mechanisim drived by electromagnetic was designed which located the components by combining linear electromagnetic and spring block.The inspection leads maked the component pins connected with the quality inspection system,then the components were inspected.In order to achieve the purpose of multi-parameters inspection with one positioning process,inspection circuit of the quality inspection system adopted a modular designed approach.Firstly,each inspection circuit modular was designed independently.Secondly,the component pins were cut into each modular one by one through switches and relays which were controlled by MCU.Thirdly,inspection results were read into MCU which determined integratively whether the quality of the component was fine.At last, MCU controlled the selection mechanisim according to the judged result.There are several innovative points in quality inspection system as follows:1) The equivalent resistance and capacitance of the electronic components were inspected in transition process method,which transfered the value of the resistance and capacitance into the value of the MCU timing.2) A dry-method in measuring solderability of electronic components leads was pointed out,and breakdown voltage measuring circuit based on MCU was designed,which was used to assess the solderability of the components leads in quantity.3) A new leakprooftness detection method was pointed out for the quartz crystal. Ethanol infiltration was operated at first, then inspected the equivalent resistance of the crystal oscillator by inspecting circuit controlled by MCU to assess the leakprooftness. 4) The shape of the electronic components pins were non-contacted measured by CCD image sensor which can automatically removed the defective components in shape. In addition, PC control software was designed by using MSComm activex in Microsoft VB6.0 programming platform to achieve the data communication between PC serial ports amd MCU.This software can improve the human-computer interaction function and display,statistic,save, look through the inspection data of the electronic components.