In the high-precision PCB manufacturing process, lamination is one of the core processes that affect the final product quality. However, common issues such as bubbling, warping, delamination, and copper surface damage during lamination often perplex engineers. Beyond stack-up design, equipment parameters, and lamination programs, there is another easily overlooked "hidden contributor" playing a crucial role—namely, the lamination cushion pad. The PCB lamination process is essentially a thermal compression bonding process: multiple layers of materials (such as copper foil, core boards, prepreg, etc.) are bonded under high temperature and pressure to form a complete multi-layer circuit board structure.

In the manufacturing of multi-layer PCBs, the success or failure of the lamination process directly determines the yield and performance stability of the product. In the lamination process, a crucial auxiliary material that is easily overlooked is the compression cushion pad (Cushion Pad/Press Pad), which often determines whether the finished board is "flat, non foaming, and non pressure damaged". This article will systematically explain "how to choose a cushion pad" from five aspects: the principle of cushion pad, material selection, matching strategy, common problems, and selection suggestions. It will help you improve the quality of compression and make your multi-layer board more stable and flat!

In the PCB manufacturing process, the most commonly focused aspects are typically "key process steps" such as etching accuracy, lamination stability, conductivity quality, and AOI inspection. However, a "minor player"—the release film—often goes overlooked. In fact, although the release film does not directly participate in circuit conduction, it plays an indispensable role in multiple stages, including dry film lamination, pattern transfer, lamination alignment, and finished product protection. If this film is not chosen properly, it may lead to issues such as film blistering, pattern misalignment, lamination delamination, surface scratches, and ultimately result in batch rework and yield reduction. So, how exactly does a "good" roll of release film help improve PCB manufacturing yield?

In high-precision manufacturing fields such as electronic die-cutting, FPC processing, OCA lamination, display module assembly, and semiconductor material transfer, release film serves as a "surface carrier," consistently positioned at the forefront of the production process. Although it does not directly form part of the product, it plays an extremely critical role in the manufacturing process—supporting, isolating, positioning, and protecting. Behind all these functions, "cleanliness" stands as the core foundation ensuring the stable operation of all processes.

In the daily production of industries such as electronic die-cutting, FPC manufacturing, label backing, optical bonding, etc., "release film residue" is a common and headache problem. It not only pollutes the surface of the product, but also causes poor die-cutting, bonding failure, functional abnormalities, and even leads to customer complaints and large-scale rework. However, truly solving the problem of residual glue is not as easy as simply changing a roll of film. Many engineers and procurement personnel often blame "poor film quality" and "too sticky glue" when encountering problems, but overlook the details hidden behind the process, formula, environmental control, and so on. Whether a release film has residual adhesive is actually the result of the coupling of multiple factors such as material system and process conditions. This article will provide in-depth analysis from below perspectives to help you systematically solve the pain point of "resin residue".

Release film is widely used in various industries such as electronic die-cutting, label backing, optical bonding, FPC lamination, protective film, etc. It is a "invisible assistant" for the processing of many adhesive materials. However, many companies often only focus on peel strength when purchasing or developing release films, neglecting a more fundamental selection factor - the substrate. The different substrate materials (such as PET, PE, BOPP, CPP, etc.) directly determine the mechanical properties, thermal stability, processing adaptability, and final use effect of the release film.

In industries such as electronic die-cutting, labels, protective films, PCBs, and optical materials, release film is an indispensable functional material. The "peel force," as one of the most critical performance indicators of release film, directly determines whether it can efficiently match adhesive materials, whether it can peel smoothly, and whether it will cause adhesive residue or product defects. Choosing the wrong peel force not only affects yield rates but also leads to process rework and cost wastage.

With the continuous development of electronic devices towards miniaturization, high density, and high precision, the importance of electronic die-cutting technology is increasing day by day. In the entire die-cutting process, release film plays a crucial role as an "auxiliary carrier" for adhesive materials. High quality release film not only affects the die-cutting accuracy and yield of products, but also directly affects the stability and efficiency of the entire automated processing. So, among numerous release film products, how can companies choose high-precision release films that are truly suitable for electronic die-cutting? The most commonly used release film substrates in electronic die-cutting are PET (polyester film), BOPP (biaxially oriented polypropylene), PE (polyethylene), etc. Among them, PET substrates are widely used due to their high strength, high temperature stability, and good size control ability, especially suitable for application scenarios that require high die-cutting accuracy and strong carrier stiffness.

In the manufacturing process of printed circuit boards (PCBs), release films play an inconspicuous but crucial role. As a type of functional thin film material, release film is widely used in various processes such as dry film bonding, multi-layer board lamination, finished product protection, and flexible circuit die-cutting due to its excellent "controllable peeling" characteristics. Its surface is treated with special treatments such as silicone oil or fluorine, allowing it to "easily detach" within the required time after bonding with the adhesive material, without leaving residue or damaging the functional layer.

High-temperature release films are widely used in the electronics, new energy, optics, and semiconductor industries, with PET (polyester) and PI (polyimide) being the two most common base materials. These materials each have their advantages in terms of temperature resistance, peel strength, mechanical strength, chemical stability, and cost. However, how to choose the right material to optimize production efficiency and ensure product quality?

High temperature release films are widely used in high-precision industries such as electronic manufacturing, semiconductor packaging, lithium battery production, and optical device manufacturing. Different application scenarios have different requirements for the substrate type, temperature resistance, surface treatment, etc. of high-temperature release films. Therefore, it is crucial to choose a suitable high-temperature release film reasonably. The substrate determines the key properties of high-temperature release film, such as temperature resistance, mechanical strength, and chemical corrosion resistance. At present, common high-temperature release film substrates include PET (polyester), PI (polyimide), PTFE (polytetrafluoroethylene), PPS (polyphenylene sulfide), etc. Each material has different characteristics and is suitable for different industry needs.

High temperature release films are widely used in high-precision industries such as electronic manufacturing, semiconductor packaging, lithium battery production, and optical device manufacturing. Different application scenarios have different requirements for the peeling force, substrate type, temperature resistance, surface treatment, etc. of high-temperature release films. Therefore, it is crucial to choose a suitable high-temperature release film reasonably. Peel strength is one of the core indicators for selecting high-temperature release films, usually divided into three types: light release, medium release, and heavy release. The choice of peeling force affects the stability of processes such as die-cutting, lamination, pressing, and protection. Excessive or insufficient peeling force can affect the quality of the final product.