Issue link: https://iconnect007.uberflip.com/i/1537616
40 PCB007 MAGAZINE I JULY 2025 D R I V I N G I N N OVAT I O N cific equipment, process control, and production requirements. Understanding the nuances of each is essential for making informed decisions. Pin-lam: Pin-lam technology begins by creat- ing precise tooling holes in the inner layers. The process carefully inserts these layers and pre- preg sheets onto the fixed pins within the press tool. This mechanical locking ensures that all lay- ers remain accurately registered during the high- temperature and high-pressure lamination cycle. While various techniques exist for creating these initial tooling holes, the most common and efficient method is punching the inner layer using a special- ized post-etch punch machine. This method offers several advantages: • High productivity • Material flexibility: Pin-lam allows users to work with all PCB substrate materials, from standard FR-4 and rigid-flex boards to more exotic combinations of materials. • Extreme accuracy: When combined with optimal positions of pins and holes and a precision-engineered punching machine, pin-lam can be extremely accurate, allowing material to flow predictably, thereby ensuring high-level process control. Mass-lam: Mass-lam methods aim to reduce or eliminate the need for pins during the final lami- nation by focusing on pre-fixing the inner layers before pressing. Mass-lam with two machines: This technique, based on initial pin alignment, involves two dis- tinct stages. After the first stage, where it's often a punch machine that prepares the inner layers with holes, operators place these layers, along with pre- preg sheets, onto pins on a specialized "pre-fixing" machine. This machine then performs a preliminary bond or rivet to hold the stack together. Following this initial fixation, the operator removes the pins and transfers the pre-fixed stack to the lay-up zone of a pin-less press tool for final lamination. Mass-lam with one machine (automated lay-up): The most automated variant of mass-lam involves machines that automatically load inner layers and prepreg, align them without physical pins, and per- form pre-fixation via bonding or riveting. These systems typically do not measure individual lay- ers before lay-up, but instead, align them relative to the position of the first layer loaded. While this method offers automation benefits, it relies heav- ily on the consistency of incoming material and sta- bility of alignment to the first layer. Despite some automation, an operator is still required to feed the machine with raw layers and prepreg. Improving Accuracy and Quality The introduction of mass-lam initially led many factories to consider it the future of inner layer alignment because of its automation potential, and several manufacturers adopted the tech- nology. However, there is now a shift away from ▼ F i g u re 2 : P re s s to o l fo r t h e m a s s - l a m .