Problem When Producing HDI Boards And BGA

Most of the PCB manufacturers are facing these problems when producing HDI boards and BGA

The first problem is Hole position accuracy，if the hole position accuracy not well,it may cause plug-in offset and unable to weld.

so how to improve the hole position accuracy is a question that every PCB manufacture need to think about!

as we know Many factors can affect the results of drilling,Especially the following ones.

• Drilling Ｍachine --we know pcb drilling machine has very important influence 

• Spindle -- Westwind spindle has the most stable performance

• Drill bits --coating drill bits  is a growing trend

• AL entry sheet--lubrication aluminum entry sheet Is the inevitable choice

The drilling machine is the biggest factor affecting the hole position. As the hole requirements become smaller and smaller, 
the ring width also becomes smaller and smaller. Today, drilling machine position accuracy measurement and closed-loop feedback 
control systems, workbench stability and repeatability Accuracy has a great influence on the drilling position. 
On the premise that the spindle position accuracy is consistent, The axial runout of SPINDLE is most directly related to the hole position. 
The following are the methods used by different drilling rigs: 0.77H/H copper clad laminate, 1.4mm new drill bit,
the test results are as follows: As can be seen from the hole location map below, different drilling rigs will have hole locations
under the same conditions. The situation is very different, which requires ensuring that the transmission part of the machine tool itself 
and the feedback system are precise and accurate. More importantly, when the machine tool wears out, timely upgrade of the software
and maintenance of the transmission screw are required. The wear gap is compensated accordingly to achieve precise control
and high motion position accuracy.