Wednesday, September 25, 2013

Common Problems And Treatment To PCB Board Drilling Process - B

     As we know, there’re many steps for PCB board fabrication. During the process, drilling is one of the most important process, many problems may happen during the process. Here I make introduction on the main problems and relative treatment.

1、drilling bit broken---introduced before.
2、via damage
Root cause includes:
Taking the drill bit after broken; Drilling without aluminum or clamp the blank; Parameter error; Drill bit elongate; valid length of drill bit can’t meet the requirements of drilling pile layer thickness; Hand drilling; Burred caused because of special raw material.
(1) according to the previous problem, ruling out cause of knife breaking, make the right treatment.
2) aluminum and back plane perform as protection to the via, must be used during production, distinguish the available and unavailable back plane, put them at the same direction, need to be taken double check before using.
(3) before drilling, must check if the drilling depth is in accordance with the drilling bit, check parameters of every drill bit are set correctly.
(4) check the location of the drill bit is correct when drilling machine catching the drill bit, then start the machine, boot drill tip generally can not exceed the presser foot when machine start.
(5) Check the valid length of the drill bit by visual before put onto machine, and measure the fold number of the available working laminates.
(6) If the accuracy, rotate speed of hand drilling can’t meet the the requirement, manual drilling should be forbidden.
(7) When setting the parameters to special raw material, proper selection of parameters should be taken according to the situation of quality, feed should not be too fast.

3、via location offset
Root cause includes:In the process of PCB board drilling, bit location moved; Improper selection to material of cover plate, softness or hardness discomfort; harmomegathus to material cause the offset of via; improper use to the adopted setting tool;improper setting on presser foot, it hit the pin and lead the remove of working laminates;resonance happen during the working to drill bit;Collect chuck not clean or damaged;slid caused by the touching of drill bit to cover plate during running; no pin; different base point; tape not sticked firmly; movement deviation happen to the Drilling machine's X, Y axis; problem with procedure.

Solution to problem 3 will be introduced in next document.

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