How to solve the problem of copper clad laminate of PCB

Here are some of the most common PCB board problems and how to confirm them. Once the problem of PCB laminate is encountered, it should be considered to add it to the PCB Laminate specification. How to solve the problem of copper clad laminate of PCB?

PCB circuit board copper clad laminate problem i. To be able to search

It is impossible to manufacture any number of PCB without encountering some problems, which is mainly due to the material of PCB copper-clad laminate. When quality problems occur in the actual manufacturing process, it seems that the PCB substrate material is often the cause of the problem. Even a carefully written and implemented technical specification for PCB laminates does not specify the test items that must be carried out to determine that PCB laminates are the cause of production process problems. Here are some of the most common PCB Laminate problems and how to confirm them.

Once the problem of PCB laminate is encountered, it should be considered to add it to the PCB Laminate specification. Usually, if this technical specification is not enriched, it will cause continuous quality changes and lead to product scrapping. Generally, the material problem caused by the change of PCB Laminate quality occurs in the products manufactured with different batches of raw materials or different pressing loads. Few users have enough records to distinguish a specific pressing load or material batch at the processing site. So it often happens that PCB is constantly produced and installed with components, and warpage is continuously generated in the solder groove, which wastes a lot of labor and expensive components. If the loading batch number can be found immediately, the PCB Laminate manufacturer can check the batch number of resin, copper foil, curing cycle, etc. In other words, if the user cannot provide continuity with the quality control system of the PCB Laminate manufacturer, the user itself will suffer losses for a long time. The following describes the general problems related to substrate materials in the manufacturing process of PCB.

PCB circuit board copper clad laminate problem 2. Surface problem

Symptoms: poor adhesion of printing materials, poor adhesion of coatings, some parts cannot be etched, and some parts cannot be soldered.

Possible inspection methods: visual inspection is usually carried out by forming visible water marks on the plate surface:

Possible causes:

Because of the very dense and smooth surface caused by the demoulding film, the uncoated copper surface is too bright.

Usually, the laminate manufacturer does not remove the release agent on the uncoated side of the laminate.

Pinholes in copper foil cause resin to flow out and accumulate on the surface of copper foil, which usually occurs on copper foil thinner than 3 / 4 oz weight specification.

Copper foil makers apply excess antioxidants to the surface of copper foil.

Laminate manufacturers have changed resin systems, release sheets, or brushing methods.

Due to improper operation, there are many fingerprints or oil stains.

Oil is stained during punching, blanking or drilling operations.

Possible solutions:

Cooperate with the laminate manufacturer and specify the user’s test items before any changes are made to the laminate manufacturing.

It is recommended that laminate manufacturers use fabric like films or other release materials.

Contact the laminate manufacturer to inspect each batch of copper foil that fails to pass the inspection; Ask for a solution to remove the recommended resin.

Ask the laminate manufacturer for the method of removal. It is generally recommended to use hydrochloric acid, and then remove it by mechanical grinding and brushing.

Contact the laminate manufacturer to use mechanical or chemical elimination methods.

Educate all process personnel to wear gloves and take copper clad laminates. Make sure whether the laminate is properly padded or packed in the bag during transportation, and the sulfur content of the padded paper is low, and the packaging bag is free of dirt. Pay attention to ensure that no one contacts the copper foil when using detergent containing silicone.

Degrease all laminates before plating or graphic transfer process