Thursday, November 28, 2013
Printed Circuit Board (PCB) Blanking
According to PCB material, hole and shape processing can adopt the method of mould cutting, to a simple PCB processing or request is not high PCB can be used in a cutting way.Suitable for low level and the requirements of the mass is not very high PCB PCB production and appearance requirements is not very high, the cost is low.
Production batch is big, the amount and type of hole and more complicated shape of single-sided paper substrate and non-metallic hole of epoxy glass cloth substrate double-sided, usually USES one or a few pay mold punching.
PCB production batch of the appearance of single panel and double panel, usually USES the mould .According to the size of the PCB, can be divided into the blanking die and whereabouts is expected to die.
The composite processing:
PCB hole and hole, hole and shape between the requirement of high precision, at the same time in order to shorten the manufacturing cycle, increase productivity, the composite mould machining hole and the appearance of the single panel at the same time.
With mold processing, PCB, the key is to mold design, processing, need professional knowledge, in addition to this, the mould installation and debugging is also very important, at present most of the PCB factory molds are made outside the factory processing.
Mould installation considerations:
1. According to the mold design and calculation of blanking force, the size of the mould, such as height choose punch (including type, tonnage).
2. Start the punch press, comprehensive review include the clutch, brake, slider, etc. Each part is normal, whether the operating mechanism and reliable, and should have no impact phenomena.
3. Die under the pad iron, generally is 2 pieces, must on the grinding machine grinding out at the same time, to ensure that the mold installation parallel and vertical.Shim placed leap put namely don't hamper blanking and near the center of the mould, as far as possible, at the same time.
4. To prepare a few sets of platen and T head clamp screw, so that the corresponding use and die.Linking piece without touching lower die straight front wall.The interface between should pad cloth, must tighten the screw.
5. Be very careful when mould installation on the screw, nut don't meet lower die mould (upper die down, closed).
6. Adjust the mould using hand as much as possible, instead of motor.
7. To improve the cutting performance of base material, paper board to be hot.The temperature at 70 ~ 70 ℃.
Die cutting of the PCB hole and shape, its quality defect has the following several:
Around the hole of the bump or copper foil case become warped or layers;Between holes and hole crack;Partial or hole itself is not a vertical hole position;Burr;The section coarse;Coining the PCB into the bottom of the pot shape warping;Waste jumping;Waste blocked.
The check analysis steps are as follows:
Check if the punch blanking force, rigid enough;Mold design is reasonable, whether rigid enough;The convex and concave die and machining precision of the guide pin, guide sleeve, if, if installation concentric, vertical.Fit clearance is uniform.Convex and concave of the gap is too small or too metropolitan produce quality defects, is a mold design, processing, and debugging, using one of the most important question.Don't allow the rounded edge convex and concave die, chamfering .Taper is not permitted in punch, especially when punching both positive cone and cone are not allowed.In production to pay attention to whether convex and concave die blade wear at any time.The discharging mouth is reasonable, small resistance.Pushing plate, a feed rod is reasonable, strength enough.Washed the plate thickness and the substrate binding force, the gel content, and the adhesion strength of the copper foil, to hot humidity and time is also cutting quality defects such as analysis of factors to consider.
Mr. Sam Duan