A Top Performer Before, During and After Application
Featuring 3M™ High Performance Acrylic Adhesive 200MP, 3M™ Membrane Switch Spacer 7945MP is ideal for the stresses of switch actuation over long periods. The adhesive on this double-sided spacer is formulated for excellent shear strength — forming a durable bond with plastics and other smooth surfaces with less oozing at the edges. This allows for easier slitting and die-cutting, faster part processing and minimal waste. The adhesive is applied at 2.0 mils to each side of a 1.0 mil polyester film carrier which adds structural strength.

Double 4.2 mil 58# polycoated kraft (PCK) paper lay-flat liners are designed to cover adhesive consistently for full bonding performance after application. Liners resist curling, tunneling and buckling, increase dimensional stability and hold up even under high humidity for efficient storage and processing. Liner design also enables improved rotary die-cutting at high speeds, as well as improved sheet processing.

Recommended Applications

• Membrane switch spacers
• Switch mounting
• Circuit layer assembly
• Metal dome placement
• Lead protection
• Die-cut laminations

Resilient and Ready
3M™ Membrane Switch Spacer 7945MP is constructed with 2.0 mil high performance acrylic adhesive that is coated on each side of a 1.0 mil polyester film carrier. This membrane switch spacer comes double-linered with a 4.2 mil, 58# moisture-resistant, lay-flat, PCK paper. Designed to separate switch circuitry until actuation, 3M Membrane Switch Spacer 7945MP provides excellent temperature resistance (up to 400°F/204°C short-term heat resistance), solvents and UV resistance.

About 3M High Performance Acrylic Adhesive 200MP
3M™ High Performance Acrylic Adhesive 200MP is an industry standard for graphic attachment and general industrial joining applications. It features outstanding adhesion to metal, polycarbonate (PC), ABS and polyester (PET). making it a popular choice across many industries. This adhesive provides some initial repositionability for placement accuracy when bonding to plastics. It also performs well after exposure to humidity and hot/cold cycles, providing confidence that the switch will perform through difficult environmental conditions (PDF, 619.19 Kb) and millions of actuations.

The Right Choice for a Range of Applications
With low cost, long life, outstanding environmental performance and eye-catching graphics, membrane switches are found in more and more applications. They range from farm tractors and medical test systems to microwave ovens and fish finders. Whatever the need, 3M has a membrane switch construction suited for the job. 3M has a full range of spacers to meet most membrane switch design requirements.

Better Science for Better Adhesives from 3M
Since 1925 when one of the 3M lab assistants invented masking tape, 3M has been applying science