Keyword: PCB process, PCB manufacturing
2 in front of the post process defects and solutions mainly talked about the base material and negative aspects, this paper focused on some problems about drilling process and the solution! Drilling is an important process in PCB process, looks very simple, but in fact is a critical process. Also easy to produce all sorts of problems.
1. The hole deviation, para phrase
(1) drilling bit in its process of the solution: A. Check whether the spindle deflection b. reduce number of laminated. Usually according to the number of double panel laminated for 5 times the diameter of the drill bit, and the number of multilayer laminated for two to three times the diameter of the drill bit. C. increase drilling speed or lower feed speed rate; D. to check whether the bit is conform to the requirements of the process, otherwise to grinding; E. check bit top good concentricity; F. check between drill bit and collet chuck fixed state whether fastening; G. to detection and correction borehole stability and stability of the workbench.
(2) the cover plate improper material selection, soft hard is not the solution: select composite plate (upper and lower layer is the thickness of 0.06 mm aluminum foil, fiber core, is among a total thickness of 0.35 mm).
(3) the base material to produce higher shrinkage caused by the displacement solution: check the other homework after drilling, such as drying process should be done before Kong Hua
(4) with the positioning tool adopted by the inappropriate use of the solution: inspection or testing tool hole size precision and the position of the locating pin on whether there is a deviation.
(5) hole inspection procedures for the solution: detection inspection hole equipment and tools.
(6) in the process of drilling operation produce resonance solution: select the appropriate drilling speed
(7) collet chuck not clean or damage the solution: clean or replace collet chuck.
(8) drilling program failure solution: to check the tape, floppy disk and tape reader, etc.
(9) positioning tool system precision insufficient solution: tool hole position detection and precision of aperture.
(10) bit sliding during operation in contact with the cover plate on the solution: select the appropriate feed rate or choose better bit flexural strength.
2. The aperture
(1) bit size error solution: operation should be checked before the bit size and instructions of the control system is normal.
(2) feed rate, or speed inappropriate solution: adjust the feed rate and rotational speed to the ideal state
(3) bit excessive wear solution: change the bit, and limit the number of each bit drilling. Usually according to the double panel (every fold three block) can drill holes, 6000-9000; High density multilayer can drill 500 holes; For FR - 4 (every fold three block) to 3000 holes; For harder FR - 5, lost an average 30% less.
(4) the amounts of drills resharpening and crumbs slot back long solution: limit the number of drills resharpening and heavy grinding degree is lower than the standard grinding size changes. 500 per drill for drilling sandwich plate hole grinding time, allow grinding 2-3 times; Once every 1000 holes can be grinding; For double panel 3000 per drill holes, grinding time, and then 2500 holes; Sharpening again 2000 holes. Bit timely resharpening, can increase the number of drills resharpening and increase the bit life. Through measuring tool microscope, wear depth within the two main cutting blade length should be less than 0.2 mm. When heavy grinding mill to 0.25 mm. The shank drill can resharpening 3 times; Spade bit resharpening twice.
(5) drill spindle is excessive deflection solution: using dynamic deflection tester monitor the deflection of the main shaft running process or serious when by a professional supplier for repair.
3. The intraclast drill hole wall too much
(1) feed rate or speed not appropriate solution: adjust the feed rate or speed to the best state.
(2) substrate resin polymerization incomplete solution: before drilling should be placed in the oven temperature to 120 ℃, bake for four hours.
(3) bit struck several times too much loss excessive solution: should limit the number of each bit drilling.
(4) the amounts of drills resharpening and chip back slot length less than technical standard solution: shall be carried out according to the number of heavy grinding process and technical standards.
(5) the cover plate and the poor quality of plate material solution: use technology of plate and plate material.
(6) bit geometry shape have problem solving methods: detection bit geometry shape should comply with technical standards.
(7) bit stay within the base material time is too long the solution: increase the feed rate, reduce the laminated layer.
4. The hole glass fiber
(1) the rate of return slow solution: should choose the best rate of return.
(2) the depletion of bit solution: should be in accordance with the technological rules limit the number of drill hole and resharpening after testing.
(3) the spindle speed is too slow to solve method: according to the formula and practical experience to adjust the feed rate and spindle speed between the best data.
(4) feed rate too fast solution: reduce the feed rate to the appropriate rate data.
5. The inner layer of the grommet nail head too much
(1)The solution: check out the knife too slowly increase the rate of return to the best state.
(2) the amount of feed solution set of inappropriate: reset the feeding quantity to achieve the best.
(3) bit excessive wear or use not appropriate solution: according to the regulations of the process limits the number of drilling bit, bit after detecting and choose the suitable grinding bit again.
(4) the spindle speed and feed rate does not match the solution: according to the experience and reference data, reasonable adjust feed rate and bit rotation speed to the best state and detection of spindle speed and feed rate changes.
(5) the intrinsic defects in the substrate such as hollow solution: base material itself defects should be replaced immediately the base board of high quality material.
(6) the surface tangent speed fast solution: check and correction surface tangent velocity.
(7) laminated layer too much solution: reduce the laminated layer. Can be according to the diameter of the drill bit to determine the thickness of laminated, such as double panel for 5 times the diameter of the drill bit; A multilayer laminated thickness for two to three times the diameter of the drill bit.
(8) The poor quality of plate and plate the solution: use less produce high temperature, plate material.
6. The orifice hole edge appears white ring (hole copper layer and base material separation)
(1) drilling when local fracture caused by thermal stress and mechanical stress substrate solution: check the abrasion of the bit, and then replace or resharpening.
(2) glass cloth weaving yarn size coarser solution: should choose fine glass yarn woven glass fiber fabric.
(3) the poor quality of substrate material solution: replace the substrate material.
(4) the large amount of feed solution: check the setting of feed quantity is correct.
(5) bit loose not tight fixed solution: check the drill shank diameter and the tension of collet chuck.
(6) laminated layer solution: too much to adjust according to the lamination process data.
7. The hole wall roughness
(1) the amount of feed too much change the solution: to keep the best amount of feed.
(2) feed rate fast solution: according to the experience and reference data to adjust feed rate and rotational speed, to achieve the best match.
(3) the cover plate material selection improper solution: replace the cover material.
(4) lack of fixed bit vacuum solution: check the nc drill vacuum system and check the spindle speed for changes.
(5) the return rate is not suitable for the solution: adjust the return rate and bit rotation speed to achieve the best state.
(6) bit apex Angle of cutting front break or damage the solution: check the bit use state, or be replaced.
(7) the main shaft to produce too much deflection solution: inspection on spindle, collet chuck and cleaned up.
(8) chip discharge properties of the solution: improve chip chip removal performance, check the status of clearance groove and cutting edge.
8. Burr hole wall is too large, have more than standard data
(1) bit is not sharp or first Angle () refers to the cutting edge of appear wear solution: according to the inspection situation decided to sharpening or replacement new drill bit. Before use must be into the detection.
(2) there is foreign body between laminated or fixed not only cause the solution: must be carefully check before laminated surface clean. Pack pack to tighten, to reduce the laminated between a foreign body.
(3) the amount of feed too much choice solution: should be based on experience and reference data to select the best feed quantity.
(4) to incorrect plate thickness (too thin) solution: using thicker hardness appropriate cover plate material.
(5) drilling pressure foot pressure too low (portion of surface orifice produce burr) solution: check the drilling pressure gas supply line pressure, spring and seal
(6) the substrate material poor quality of the drill (the substrate panel holes in burr) solution: select suitable hardness level of cover plate material.
(7) positioning pin loosening or vertical degree of poor solution: change the positioning pin and repair the wear of the mold.
(8) positioning pin hole in dander solution: must be carefully cleaned up before locating pin.
(9) substrate material curing incomplete (appear burrs at the exit hole plate) solution: before drilling should be 120 ℃ in the oven, bake 4-6 hours.
(10) plate hardness is not enough, the chip back into the hole solution: choose hardness suitable plate material.
9. The hole wall in debris
(1) cover board or substrate material is not the appropriate solution: select or change the suitable plate and substrate materials.
(2) the cover plate lead to bit damage solution: select suitable hardness cover plate material. Such as 2 antirust aluminium or composite plate.
(3) fixed bit collet chuck of the vacuum pressure less than the solution: check the machine vacuum system (vacuum degree, piping, etc.).
(4) the foot pressure gas pipeline jam solution: replace or clean up the pressure on the foot.
(5) bit of spiral Angle is too small solution: check whether drill with the standard technical requirements.
(6) laminated layer solution: too much should reduce the laminated layer according to process requirements.
(7) drilling process parameters is not correct solution: choosing the best drilling speed and feed speed.
(8) solution: environment too dry electrostatic adsorption should be stipulated in the technical requirements to humidity requirements should reach humidity above 45% RH.
(9) return rate is too fast solution: select appropriate rate of return.
10. Hole shape roundness phrase
(1) the main shaft was slightly bent deformation solution: inspection or replacement of spindle bearing.
(2) center of bit eccentric or two cutting edge width is not consistent the solution: the clamping drill before 40 times microscopic examination should be adopted.
11. Laminate panel found that coupling broken wires above the volume of curvy debris
(1) Without using cover the solution: should adopt appropriate cover plate.
(2) improper drilling technical parameters selection solution: usually should choose to reduce the feed rate or increase the drilling speed.
12. The bit is easy to break
(1) Excessive solution:the main shaft deflection response to the main shaft for maintenance, should be restored.
(2) improper operation during drilling solution: A. Check whether there is stress beriberi pipeline jam b. according to the state of the bit to adjust pressure foot c. inspect the spindle speed variation situation d. drilling operation to check the stability of the spindle.
(3) bit selection inappropriate means of settlement: detection bit geometric shape, the wear conditions and choose appropriate bit crumbs slot length.
(4) the speed of the bit is insufficient, the feed rate is too big to solve method: choose the right amount of feed, reduce feed rate.
(5) the laminated layer high solution: cut to the appropriate number of laminated.
13. Hole deviation cause broken or partial ring
(1) swing drill bit center can't aim at the solution: A. Reduce the number of laminated to diamond substrate. B. increase speed, reduce the feed rate. C. detection bit Angle and concentricity. D. observe bit on spring clamp head position is correct. E. bit crumbs slot length is not enough. F. correction and adjustment of drilling rig alignment and stability.
(2) the cover plate of high hardness material difference solution: should choose smooth and material which has the function of heat dissipation, positioning plate.
(3) substrate deformation after drilling the hole deviation solution: according to the production experience dealing with drilling of the substrate before baking.
(4) positioning system error solution: to test the GPS positioning hole precision.
(5) when the manual programming aimed at sex difference solution: check the operating procedures.
14. The aperture size error
(1) data input error occurred while programming solution: inspection procedures by the aperture of input data are correct.
(2) wrong with the dimension of the drill for drilling the solution: wrong detection bit diameter, change the size of the correct bit.
(3) bit improper use, serious wear and tear the solution: replacement of new drill, should be in accordance with the restrictions on the number of drill bit drilling process.
(4) the use of the number of drills resharpening solution: too much should strictly check the geometry size of the bit changes after resharpening.
(5) the wrong size or imperial conversion error metric solution: should carefully review the figure and conversion in earnest.
(6) automatic bit change, due to the bit alignment error solution: check carefully before drilling bit the size of the sequence.
15. Bit easily broken
(1) CNC drill improper operation solution: A. Check the pressure of pressure foot pressure data. B. carefully adjust the pressure between the feet and bit. C. detection, the change of the spindle speed and stability of the spindle. D. test the parallel degree of mesa drilling and stability.
(2) the cover plate, plate bending uneven solution: should choose suitable surface hardness, flat cover and plate.
(3) the feed speed is too fast compression by means of settlement: decrease the feed rate.
(4) the bit into the depth of the plate too deep in hanging solution: should adjust good bit depth.
(5) the fixed base board tape does not stick fast solution: should carefully check the fixed state.
(6) especially when reperforating improper operation solution: operation should pay attention to the correct hole location.
(7) laminated layer too much solution: reduce the laminated layer
16. Blocking
(1) the length of the bit is not the solution: according to the thickness of laminated selecting proper bit length.
(2) the drill into the depth of the plate is deep solution: should choose reasonable laminated thickness and plate thickness.
(3) substrate material problem (with water and sewage) solution: should choose the substrate material with good quality, drilling should be baked.
(4) as a result of plate reusable solution: plate should be replaced.
(5) the improper processing conditions by means of settlement: should choose the best processing conditions.
17. The aperture expanding
(1)Is problem solving methods: the bit diameter drill bit diameter must carefully before detection.
(2) bit broken in the hole dug up pore size bigger solution: will break in the hole of the drill bit part adopts the method of ejection.
(3) when bare hole to cause the solution: attention should be paid to the bit diameter sizes in the hole.
(4) repeat positioning holes caused by the error of the solution: should choose to positioning hole position and dimensional accuracy.
(5) repeated drilling caused the solution: the diameter of the hole size should be especially careful.
18. The hole is not through
(1) the DN setting error solution: before drilling program is set correctly.
(2) the plate thickness uneven problem solving methods: choosing the best uniform, plate thickness.
(3) bit set length has a problem solving methods: should be set according to the thickness of laminated or select the appropriate length.
(4) bit broken in the hole by means of settlement: before drilling should check the laminated and the clamping condition and process conditions
(5) the cover plate thickness to incorrect solution: should choose appropriate uniform thickness, thickness plate material.
Source: //www.seekic.com
