label: PCB board,Printed-circuit board
PCB board drilling processes encountered in hole size allowed, how to deal with the distortion, the first cause of the problem analysis: drill bits specification error; feed speed or inappropriate speed; drill bit excessive wear; excessive number of drill bits regrinding or back end below the standard flute length requirements; spindle itself excessive deflection; drill bits sharp collapse, drilling diameter larger; mistaken aperture; unmeasured aperture when changing drill bits; drill bits arranged in error; changing drill bits inserted position wrong; Not checked aperture diagram; spindle fit knife, causing pressure knife; parameters in the wrong serial number.
And then prescribe the right medicine, to find the solution:
(1) Before operating the drill size should be checked whether the command and control system error has occurred.
(2) to adjust the feed rate and speed to the ideal state.
(3) replacement of drill bits, drill bits and drilling to limit the number of each. Generally in accordance with double panel (each stack of four) holes can be drilled from 3000 to 3500; drilling 500 holes on the high-density multilayer; For FR-4 (each stack of three) can be drilled 3,000 holes; while the harder FR-5, reduced by an average 30%.
(4) limit the number of drill regrinding and resharpening size change. Drill for drilling 500 holes each multilayer grinding time, 2 to 3 times to allow the sharpening; each grinding a hole may be drilled 1000; 3000 for drilling holes for each pair of panels, a grinding and drilling holes 2500; further sharpening a 2000 drill hole. Drill timely regrinding, regrinding increase the frequency and increase drill bit life. By measuring microscope, in the two main cutting edge wear depth should be less than the full length 0.2mm. When regrinding to be rubbed 0.25mm. Shank drills can be reground three times; spade bit regrinding 2 times.
(5) maintenance carried back to the deflection of the spindle dynamic deflection tester to check the operation of the process, from the serious professional supplier for repairs.
Before (6) drill flank with 20 times endoscopy, sharpening drill bits will be bad or scrapped.
(7) several times to check, measure.
(8) when changing drill bits drill bits can be replaced measurements, measurements of drill bits have been replaced by the first hole drilled.
(9) drill bit to a few clearly arranged magazine location.
(10) look at the serial number when replacing the drill bit.
(11) When the knife to prepare one by one to check the actual aperture aperture map.
(12) cleaning clip Tsui, causing the knife to carefully measure the pressure and check flank circumstances.
(13) when the input tool to check the serial number to be repeated.
Source://www.seekic.com
