Quality inspection of membrane switches is a very important task. The first task of a successful membrane switch manufacturer is to establish a complete quality assurance system. In the quality inspection of membrane switches. In addition to paying attention to the color rendering of the ink that workers are very familiar with and the color reproducibility required by customers, it is more important to pay attention to the inherent quality of the membrane switch, such as key operation force, life, peel strength, and high temperature, low temperature, constant temperature and humidity. . Return line cathode, insulated cathode and test indicator for withstand voltage.
Membrane switch consists of four parts: panel, upper circuit, insulating isolation layer and lower circuit. It is a light touch-on normally open switch. Under normal circumstances, the two contacts of the membrane switch are in a disconnected state. When an external force is applied to the membrane switch, the two normally open contacts are instantly connected. After the external force disappears, the switch contacts return to the normally open state. Usually the upper circuit contacts are bulged or dome pieces are added (good feel). When the membrane switch is pressed, the contacts of the upper circuit are deformed downward, and are in contact with the pole plate of the lower circuit. After the finger is released, the contacts of the upper circuit bounce back, the circuit is disconnected, and the circuit triggers a signal. The membrane switch has strict structure, beautiful appearance and good sealing performance. It has the characteristics of moisture resistance and long service life (up to more than 1 million times).
1. Membrane switch disconnection, short circuit, jumper: All jumper parts are in accordance with the requirements of line conductors, and all jumper products must undergo 100% open, short-circuit test and insulation resistance test. Make sure there is no open, short circuit and insulation resistance should be greater than 500MΩ.
2. Conductor thickness of membrane switch: Generally, the thickness of the conductor is controlled at 7-12μm, and it should be uniform and smooth.
3. The position deviation of the upper and lower lines of the membrane switch: the allowable tolerance of the mutual deviation of the center positions of the switch contacts of the upper and lower lines is Ф0.5mm.
4. Membrane switch foreign matter: The line must not have any foreign matter attached to it.
5. Membrane switch material: substrate, silver paste, carbon ink, spacer, adhesive, adhesive, reinforcing plate, and insulation printing should comply with the drawings.
6. Shape of membrane switch: shape, conductor circuit, insulation treatment, lining board combination, etc. should comply with the drawings or provide physical samples.
7. Defects and pinholes of membrane switch conductors: Judging according to the following graphic standards, one is allowed within each 50mm range.
8. Membrane switch carbon ink: The carbon ink covering the silver paste circuit should ensure that the silver paste is completely covered, and its thickness is 8-10μm, and there should be no obvious protrusion of the silver paste.
9. The size of punching burr and die extrusion of the membrane switch: the size of punching burr and extrusion bending should not be greater than 0.2mm, and the position should be towards the side without conductors.
10. All contact points of the membrane switch: There should be no insulating ink attached, and the insulating ink surface should be flat to avoid any defects such as bubbles or pinholes that affect the insulating effect.
11. Membrane switch combination: the surface should not have residual material chips, foreign objects, stains, bumps, grease attached to the surface and inside, fingerprints on the circuit, and burrs on the punched shape.
12. Scratches: All lines and contacts must not have nicks that run through the inside and outside (that is, the nicks are cut from the substrate on the line), and the principle of slight scratches is not to affect its impedance. The surface of the carbon ink is very easy to have scratches. , the scratches are based on the principle of not affecting the conduction of the line.
13. Membrane switch adhesion strength: After the insulating ink is dried, the ink surfaces are pressed against each other for 24 hours to ensure that the insulation does not stick to each other. After sticking with pressure-sensitive tape for 1 minute without air bubbles, peel off quickly, and no ink should fall off.
Since the establishment of the factory in 2010, we have been committed to the principle of reputation first, customer first, and timely provide our customers with qualified and satisfactory products: adhere to the policy of quality first, continuous improvement, pay close attention to quality management, and have won the recognition of customers: fulfilling The tenet of integrity and reciprocity has won the support and trust of customers. At present, the company has advanced screen printing equipment, skilled business and technical backbone and new and applicable workshops, providing hundreds of millions of qualified products to customers all over the country every year. We take "integrity, pragmatism, refinement and innovation" as our corporate tenet, and implement the business philosophy of "people-oriented, excellence" in business management; strictly follow the ISO9001 quality system in production management to implement production; in the process of serving customers Provide a variety of design solutions according to the classification of products, so that our products can better reflect the concept of customers.
In order to better improve and improve the company, we sincerely welcome customers to come to our company for consultation and guidance, and all the staff of the company will provide you with excellent products and services. Let us all seek common development together!
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