Choosing the right thermopress silicone sheet and using and maintaining it correctly is crucial for ensuring production quality and controlling costs. Here are some key considerations and practical suggestions.
Part 1: How to Choose – Focus on Five Key Indicators
Temperature Resistance Rating: This is the primary indicator. Ensure the silicone sheet's long-term operating temperature is at least 20-30°C higher than the actual maximum temperature of your process, allowing for a safety margin.
Substrate Type and Thickness:
Fiberglass Cloth Substrate: High strength, dimensional stability, puncture resistance, suitable for applications with high pressure and sharp objects (such as PCB lamination).
Polyimide (PI) Film Substrate: Smoother and flatter, excellent release properties, low surface residue, suitable for optical or precision electronics applications with extremely high surface finish requirements.
Thickness typically ranges from 0.18mm to 1.0mm, depending on pressure, flatness requirements, and equipment clearance.
Surface Treatment: Glossy surfaces offer lower release force, while matte/frosted (embossed) surfaces aid in venting and prevent air bubbles. Choose based on resin flowability and venting requirements in the process.
Dimensional Stability: High-quality silicone sheets should exhibit extremely low shrinkage (<0.5%) after repeated hot pressing, ensuring accurate positioning and effective coverage.
Brand and Reputation: Choose reputable brands with strong technical capabilities, providing professional application support and quality assurance to avoid losses due to costly choices.
Part Two: Use and Maintenance – Secrets to Extending Service Life
Before Use:
Clean Environment: Ensure the silicone sheet, mold, and working environment are clean to prevent hard particles from causing permanent pitting.
Proper Cutting: Use a sharp tool to cut clean edges to avoid tearing due to rough edges during use.
During Use:
Stable Placement: Lay it flat to avoid wrinkles. When using multiple layers, ensure alignment. Process Control: Strictly adhere to recommended temperature, pressure, and time parameters to avoid overload operation due to excessive temperature or pressure.
Regular Rotation: When permissible, periodically rotate the silicone sheet to ensure even wear.
Post-Use Maintenance:
Cleaning: After cooling, gently wipe away any resin residue on the surface with a soft cloth or sponge dampened with a dedicated silicone cleaner or mild alcohol. Never use sharp metal scrapers!
Inspection: Regularly inspect the surface for cracks, bulges, excessive thinning, or loss of adhesiveness. Replace immediately if any of these issues are found.
Storage: After cleaning, store rolled up (recommended diameter not less than 20cm) or hung flat in a cool, dry place. Avoid folding, heavy pressure, and direct sunlight.
Choose the right "partner" and give it careful care; the thermoforming silicone sheet will reward your production with greater loyalty and longer-lasting performance, becoming a reliable partner for improving quality, efficiency, and cost reduction.
