SMT patch machine is a common production machine of electronic components, but for some novice operators or technicians, when facing such a large machine as SMT patch machine, there are likely to be some small problems or failures in the early operation process if there is no understanding and analysis of the machine before operation. This will not only lead to the machine can not work normally, but also very likely to cause some unnecessary injuries to the human body. When we meet some faults, how should we solve them? SMT processing professionals summed up some experience to share with you.
1, if there are some minor faults in the machine, first of all, do not panic, avoid too panic resulting in careless operation of the human body caused some unnecessary harm. Secondly, to check the machine itself, in accordance with the orderly order and the correct analysis of the idea to analyze the cause of the failure, so as to effectively solve the problem. Generally, if the SMT patch fails, first of all, we should determine whether there is any abnormal situation when we operate before it happens. Secondly, we should carry out a careful inspection on the parts where the fault occurs, such as some links, procedures and internal noise phenomenon.
2. The phenomenon of some wear or loosening of the SMT patch machine is a common problem in SMT patch processing. This situation may be caused by a large amount of dust or oil dirt produced inside the machine. This situation is easy to affect the normal work of the patch machine, and even lead to the damage of parts inside the machine or some accidents. At this time, it is necessary to clean the machine on a large scale, thoroughly clean the dust and grease on the surface, and thoroughly disassemble and clean the internal gas path, solenoid valve and vacuum device.
3. The common fault causes are due to the offset of SMT patch machine parts. If the problem is due to the equipment, it is necessary to check the condition of the equipment and then repair it. If it is due to the operation, it should adjust the operation method and master the correct operation mode to operate. This can effectively avoid some unnecessary failures.
The above is the introduction of some faults that are easy to occur in the working process of SMT SMT machine. Only by truly understanding the causes of these faults can we fundamentally solve the faults so as to prevent them from happening again.
PCB pressing process control. After PCB has been pressed and baked, the Tg values of the samples can be measured twice by the same method and the same machine. If the △Tg of Tg2-Tg1 exceeds 2 ~ 3°C (Hardening including polymerization and cross-linking), the hardening reaction (including cross-linking) of the hardening process is not in the hardening position. These unseasoned slabs are prone to water absorption and rupture.
The Tg values of problem plates were measured by TMA method according to Section 188.8.131.52 of TM-650 Test manual, and compared with the specifications of the supplier. If the measured value is more than 5°C below the specification value, it indicates that the problem plate has water absorption lesions. The moisture in the resin acts as a plasticizer, which will not only lower Tg, but also make the rubber state arrive earlier.
Multilayer PCBS stored for more than three months may exhibit stress concentration (from pressing) and water absorption (which will increase Z-expansion). Explosion-proof baking (105°C+24 hours) is required before welding, or a stack of 50 cell phone plates is pressed and baked in N2 at 185°C+70PSI for 2 hours using a leveler. The client side of the plate more than three months to bake before welding will reduce the plate explosion, baking not only increases the cost and adverse to OSP. When baking, it is necessary to separate a single piece of baking, so as to fully discharge the water.