- Peel strength test: peel strength of glue should not be less than 8N / 25mm.
- Check the size: the drawings did not note tolerance to allow the scope of the standard, the rest in line with the drawings
- Bubble detection: a high degree of equalization, the intensity of balance, plane type: 57 ~ 284g force, touch feeling: 170-397g force.
- Shape contrast: shape, conductor lines, insulation, liner combinations, etc. should meet the requirements of the drawings or provide physical samples
- Check the color: the visual method, with the sample or color card to see if there is color contrast, color requirements are particularly strict contrast with the colorimeter.
- Hardness test: with H-level writing, 45 degrees to impose 1kg thrust line, the line may not have conductive ink peeling or produce light transmission.
- Material inspection: panel, substrate, silver paste, carbon ink, septa, then the adhesive, adhesive, reinforced board, insulation printing should be consistent with the drawings
- Lifetime test: no shrapnel per-touch contact conduction times, should be 100 million times, there are shrapnel and tactile conduction times, should be 500,000 times.
- Low temperature test: membrane switch to withstand -10 ± 3 ℃, which lasted 16 hours of low temperature effect, under normal atmospheric conditions to restore 2 hours, erase the surface of the water droplets, the resistance should be in line with regulation
- loop resistance detection: resistance value should not be greater than 100Ω, the total length of the loop is greater than 150cm and the special requirements of the circuit resistance in the drawings otherwise provided, does not allow any broken, short circuit.
- Insulation resistance test: In the normal temperature and humidity environment, the insulation resistance of the conductor circuit is greater than 500MΩ (500VDC1 minutes), in the high temperature and humidity test, salt spray test should not be less than 20MΩ.
- High temperature test: membrane switch withstand 55 ± 2 ℃, after 72 hours of high temperature, check the appearance of quality should be consistent with the drawings, in the normal atmospheric conditions to restore 2 hours to measure the insulation resistance should be in line with regulations.
- Salt spray test: membrane switch to 5% sodium chloride salt solution, the test space temperature 35 ± 2 ℃, (connector seal) lasted 72 hours after salt spray test, under normal atmospheric conditions to restore 2 hours, Insulation resistance should meet the
- Constant Damp Heat Test: The membrane switch was subjected to a constant damp heat test of 40 ± 2 ° C and a relative humidity of 93 (+ 2% -3%) for 96 hours and then recovered under normal atmospheric conditions for 2 hours to measure the insulation resistance, Resistance, key intensity should be in line with regulations.
- Check appearance: the panel can not have obvious defects, such as character missing strokes, stains, translucent spots, deinking, stains, scratches, transparent window overflow glue, residual plastic, such as printing , On-line and key-line combination, line and keypad, panel and key combination, the panel buttons at the bubble and the substrate, stamping and crimping burr size should not be greater than 0.2mm, and the position should be no conductor side.
- Adhesion of the ink: the ink by transparent tape attached to the hand pressure to ensure that no bubbles 10 seconds after the rapid stripping, not ink drop phenomenon, the insulating ink drying, the ink surface to each other and then by the weight of 24 hours, Ensure that the insulation surface is not sticky, with pressure-sensitive adhesive tape attached to hand pressure no bubbles for 1 minute, quickly peeled off, no ink off.
- Resistance to folding strength testing: After drying the silver paste, carbon ink lines, should first determine the loop resistance, and then to do its 180-degree line folding, and finger pressure 2kg / 2 seconds, and then to restore the plane , So back and forth to implement 5 back, and then measure the resistance, the folded back after 5 to increase the resistance, not more than 300% of the original resistance.
Membrane switch inspection procedures
Thursday, 01 December 2016 / Published in Blogs
Tagged under: Membrane switch