What Is Measling and Delamination?
Circular white spots and small hole-like areas that appear in your printed circuit boards are typically measling and delamination errors that can occur during the production or use of PCBs. These errors can interfere with normal operations and may ruin your PCB. It is easy to control for these errors when identified, and leading PCB brands like MCL can even design your boards in a way that limits delamination and measling errors.
What Is the Difference Between Delamination and Measling?
While measling and delamination may appear similar, there are some noteworthy differences to keep in mind.
Delamination is when the layers of your PCB base materials experience a partial separation. This will cause gaps or bubbles that look like blisters. Delamination typically occurs in the production process when unwanted heat or humidity are present.
Measling is the presence of white spots in the PCB weave interior. They signal a destruction of the elements in the board, but some small measling can be within your tolerance as long as they are not very frequent or you don’t have measling that bridges conductors and soldering eyes. Stress and production can produce measling.
What Causes Measling and Delamination?
Measling occurs most often when there is not enough resin applied during the lamination process. Using proper production techniques can help limit its development. However, some PCB measling will occur during the life of the board due to mechanical stress placed on your equipment.
Because measling is common and may occur over time, small amounts are generally considered safe for PCBs. This means your manufacturer should work to reduce printed circuit board measling so that future development will not do significant harm.
Printed circuit board delamination is typically restricted to occurring during the production process. If humidity builds up in the laminate, it can bubble up and create gaps in your layers. The humidity is often caused by heating elements that can release a gas, so inorganic materials may also produce delamination when there is excessive thermal stress caused by soldering.
Other delamination causes include thermal shock, a poorly controlled lamination process and using the wrong glass transition temperature.
How Is It Prevented?
PCB Measling and PCB Delamination can typically be prevented by managing the manufacturing process and ensuring proper temperature and resin controls are in place. You can also decrease the likelihood of their occurrence by storing all PCBs in a dry space, ensuring the quality of the oxide layer on your inner layers, baking boards before they undergo thermal processing and working with a high-quality manufacturing partner.
MCL has tight control guidance and processing requirements that work to eliminate printed circuit board measling and printed circuit board delamination in every order we produce. Whether it’s a single prototype or a large-scale production that’s ready for your customers, our engineered solutions will maintain the quality of your PCBs.
Contact MCL today for a better, safer and stronger PCB.