| Transient suppression devices(Transient Voltage Suppressor)DFN1610 is a diode in the form of highly efficient protection device,the device in the circuit does not undertake any power or signal processing tasks,so its whether or not does not affect the function of main circuit in the circuit and the characteristic,therefore does not belong to just need such devices,but for the application of surge risk plays an enough to protect the main circuit are not even burned surge current interference,can greatly improve the reliability of the circuit system function,is to protect the cell phone,Ideal for digital cameras,audio players,and many other portable applications.Transient suppressor and other high-end power semiconductor devices is given priority to with import for a long time,By the international semiconductor discrete device manufacturers monopoly,with a long cycle with high price,logistics and customized ability weak,restricted the rapid upgrading of China electronic information industry development needs.The key to affect the performance and reliability of TVS device mainly lies in the chip design and the assembly and test process.This paper mainly studies and discusses how to improve the yield and performance of TVS device through the optimization of assembly and test process.The Production and manufacturing of TVS device include wafer saw,die attach Wire Bonding,molding,Singulation,reflow,product testing and reliability analysis,thereinto die attach,wire bonding,molding,singulation,product testing these three procedures play a decisive role in the production and manufacturing of TVS devices,so the optimization of these three processes is the focus of this paper.The main research direction of this paper is to reduce the parasitic resistance between the chip and the lead frame through the experimental design and optimization of packaging raw materrials,equipment characteristics and process parameters,etc,reduce the chance of defects in the packaging process,achieve TVS device yield and performance improvement,meet the conditions of stable mass production.The key conclusions of this paper are: 1.Through experiments and the establishment of a regression model,Bond Z offset Level the key parameters of the welding sheet of the crystal fixing machine is set to 10 um,so as to ensure the consistency of the silver slurry thickness;2.According to theoretical analysis and experimental data: a reasonable silver slurry storage temperature of-40 ° c and a thawing time of 30 minutes at room temperature should be set to avoid the separation of solid silver slurry from the cylinder wall.Meanwhile,employees are forbidden to directly touch the syringe with their hands,so as to avoid the problems of bubbles and stratification of silver slurry caused by thermal shock.3.Add plasma cleaning to the frame before bonding.The high-speed Ar ions break the chemical bonds of organic pollutants and make them turn into gas and leave the pad and lead.After plasma cleaning,the wire pull and ball shear of the first and second solder joints were significantly increased,and the copper residue could reach more than 80%.4.Based on the results of DOE test,the "one-step in place" ultrasonic output mode was adopted before the abandonment of ultrasonic welding,and the "weak to strong" stepped mode was adopted to improve the efficiency of electric leakage caused by the crack of the welding pad. |
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