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First, find the problem
Rather than any number of PCB manufacturing some of the problems encountered is not possible, mainly attributed to PCB copper clad laminate materials. In the actual manufacturing process quality problems, it seems because of PCB substrate materials often causes a problem. Even a carefully written and has been the effective implementation of the PCB laminate technical specifications, there is no provision for determining the PCB laminate production process led to problems because the test items must be carried out. Here are some of the most common problems encountered in PCB laminates, and how to verify their methods.
Once the problems encountered in PCB laminates, they should consider updating to the PCB laminate material to specification. Usually, if not to enrich the work of this technical specification, it will continue to produce quality changes caused, and subsequently lead to product obsolescence.
Typically, for PCB laminate material quality changes resulting from problems occurred in the different manufacturers or different batches of raw materials created by the suppression of load products. Few users to hold large enough to record, so that it can distinguish a particular place in the processing load or suppression of material batches. So often this happens to: PCB is constantly produced and installed components, and the warp in the solder tank continuously, wasting a lot of labor and expensive components.
If the lot number can immediately check on loading, PCB laminate resin manufacturer that is able to check out the batch number,Printed Circuit Boards Recycle, lot number of copper foil, curing cycles. That is, if the user can not provide the PCB laminate manufacturer's quality control system to maintain continuity, so that the user's long-term will suffer. Here in the PCB manufacturing process, and general issues related to the substrate material.
Second, surface the problem
Symptoms: poor adhesion of printed materials, coating adhesion is poor, some parts are not etched away, and some parts are not soldered.
Screening method can be used: usually used in the plate surface to form a visual inspection to see the Watermark:
Possible reasons: because the mold release film is very dense and smooth due to the surface, resulting in copper surface is not too bright. Not usually copper laminate side, laminate manufacturers did not remove the release agent. Copper foil on the pinhole, resulting in resin flow, and accumulated in the foil surface, which usually appears in more than 3 / 4 ounce weight, thinner size copper foil. The producer of copper foil coated over the anti-oxidants on the surface of copper. Laminate manufacturer changed the resin system, stripping thin, or brushing methods.
Due to improper operation, there are many fingerprint or grease. In punching, cutting or drilling operations stained oil.
Possible solutions:
The manufacturer recommends use of fabric-like laminate film or other mold release material. And laminate manufacturers contact the elimination of the use of mechanical or chemical methods. And laminate manufacturers to contact fail the inspection of each batch of copper foil; obtain a copy of the expense to remove resin recommended solution. Request to remove the laminate manufacturer's method. Always recommended hydrochloric acid, followed by mechanical grinding method to remove brush. In the manufacture of laminated board before making any changes, with the same laminate manufacturer, and provides the user the pilot project.