The manufacturing of insulation boards, especially copper-clad laminates used for printed circuit boards, is a precise and continuous process. The core goal is to perfectly combine reinforcement materials with resin systems to form a stable and insulating matrix, and provide a solid foundation for subsequent circuit fabrication. The manufacturing process can be summarized into three main stages:
Preparation of adhesive solution
Raw materials: Mix resin, curing agent, solvent, and possible additives in strict proportions.
Purpose: Resin is the core of insulation and bonding; Curing agent changes it from liquid to solid state; Solvent adjustment of viscosity facilitates infiltration; Additives are used to improve specific properties such as flame retardancy and heat resistance.
Key controls: accuracy of proportioning, uniformity of mixing, and viscosity of the adhesive solution.
Glue application and drying
Process: The rolled reinforcement material is soaked thoroughly in an immersion tank filled with adhesive solution, and then enters a drying tunnel.
Purpose: Drying does not completely cure, but evaporates the solvent and causes the resin to react to a pre cured state called the "B-stage". At this point, the material is semi cured and still has plasticity, making it easy to laminate.
Output: The material processed through this process is called a "semi cured sheet".
2、 Second half: lamination and curing
This is the molding stage of transforming semi-finished products into sturdy and flat boards.
Overlapping
Process: According to the thickness requirements of the finished product, stack several semi cured sheets with copper foil. The usual structure is: steel plate → copper foil → semi cured sheet → copper foil → steel plate.
Objective: To construct the basic structure of copper-clad laminates.
hot pressing
Process: Send the stacked materials into a high-temperature and high-pressure laminating machine.
Purpose: Under high temperature, the resin in the semi cured sheet melts and flows, completely saturates and releases bubbles; Under high pressure, each layer is tightly compacted; Under a precisely controlled temperature time curve, the resin undergoes cross-linking reaction and fully solidifies into a hard solid.
Key control: The laminating parameters are core secrets, including heating rate, pressure curve, and curing time, which directly determine the thickness uniformity, dimensional stability, and electrical performance of the board.
3、 Post processing and quality control
post-processing
Cutting and trimming: Cut the pressed large board into standard sizes or sizes required by the customer.
Appearance inspection: Check the surface for scratches, pits, resin spots, and other defects.
performance testing
Conduct sampling testing on finished products to ensure they meet specifications. The key test items include:
Voltage resistance: Verify its insulation capability.
Peel strength: Test the adhesion between copper foil and substrate.
Immersion welding resistance: testing its ability to resist high welding temperatures.
Summary:
The manufacturing of insulation board is essentially a precise process of transforming "liquid resin" into "solid insulation substrate" through "infiltration reinforcement material" and "high temperature and high pressure curing". The precise control of every step, especially the ratio of adhesive solution and laminating process, is fundamental to ensuring consistent, stable and reliable product performance.
