1. How to check the eligibility of custom membrane switches?
We need to inspect custom membrane switches during raw materials, production and after production. Neither electrical switches nor mechanical switches or membrane switches, we have to check whether they are qualified and meet our requirements. And we membrane switch manufacturers have always been strict with ourselves so that we can produce high quality membrane switch panels. Below we will understand the membrane switch panel in which aspects of inspection is eligible.
2. How to check the qualified membrane switch and panel?
First of all, there should be no residual material scraps, foreign bodies or stains on the surface. Also, grease on the outside and inside, fingerprints on wires, burrs on the outside while punching the graphic overlay shape are not allowed. , all lines and contacts must not have cut through the table. Also, subtle scratches are based on the principle that they do not affect their impedance. The appearance of carbon conductive inks is easy to have scratches. But, scratches must not interfere with line conduction. Thirdly, there should be no foreign objects attached to printed circuit layers.
2.2 Line conductor section
Firstly, the membrane switch manufacturer controls the conductor thickness between 7-12μm. Furthermore, the conductor should be uniform and lubricated. As for conductor defects and pinholes, print one for each 50mm range according to the membrane switch design. And we should ensure that carbon inks covered on the conductive silver paste can totally cover the silver paste. In general, the thickness is about 8-10μm. Also, there must be no obvious conductive silver paste protruding. Besides, do not allow the conductor to have any broken or short-circuited appearance.
2.3 Insulation printing graphic overlays
For tactile switches, they always have embossments on positions of metal domes. We require there must be no insulating ink adhesive on membrane keypads touchpoints. Sometimes, customers need rubber keypads, which surface should also have no ink. The insulating ink surface should be flat to prevent any air bubbles or pinholes from affecting the insulation. After the insulating ink is dry, put the ink surface to each other, and press them for 24 hours. So that the insulation will not mutually sticky.
Then, use pressure-sensitive tape to attach and press for 1 minute, then peel quickly. What’s more, all jumper parts are required according to the line conductor. They must pass the 100% open, short test and insulation resistance test. Membrane switch manufacturer needs to ensure that there are no open and short circuit. And the insulation resistance should be greater than 500MΩ (500VDC 1 minute).
2.4 Mechanical behavior of the tactile switch
Stamping burrs and mold extrusion dimensions should not be greater than 0.2mm. And the orientation should be toward the side without conductors. Besides, the skewing between the membrane switch contacts of the upper and lower circuits is Ф0.5mm.
2.5 Raw material and shape
The substrate, conductive silver paste, carbon ink, separator, adhesive, reinforcing plate, and insulation printing should conform to the drawing rules. Also, the shape, conductor circuit layers, insulation treatment, and lining combination should conform to the membrane switch design. If we design and manufacture a custom membrane switch sample, it is the standard.
3. Issues to be aware of during the production process
Membrane switch manufacturers will always pay attention to the production situation during each procedure. Only in this way, we can solve problems in time once they occur. Thus, it avoids waste of materials and delays in the date of custom membrane switches delivery. So, what should the membrane switch manufacturer pay attention to in production? Let’s take a look at the following.
Firstly, is the appearance of the film dirty? Sometimes the liquid medicine and the rail roller may stain the surface. And it can affect the high quality of the printing down.
Secondly, check positioning points and corners, whether the version is complete and each film is strictly aligned. Also, due to the film and accuracy of film setter, the monochrome version later produced can’t be strictly compatible with the before version. In a word, all screen printed films of membrane switch and panel must be output together, otherwise, there may be a mismatch.
Thirdly, design engineers need to know the planned useful scale and the film request. Also, membrane switch circuit layers, front and back screen printing need to be exceptionally corrected, together with the requested network cable and dot shape. If the customer requires to spell a large version, confirm whether the direction of imposition is accurate.
Next, for font questions, the fonts used must be equipped with the output base. If you use a remote font, you must turn the curve. Last, inspect if there is any error on user interfaces. In general, they include whether the font is garbled, graphic overlays are color separation, there is static electricity, the film has scratches, and so on.
4. Problems to be paid attention to during transportation and storage
At first, taking care of the outlet of the membrane switch and panel when packing and placing. Make sure that the outlet of custom membrane switch is on the top. If tactile switches have windows or touch screens, be careful when taking and storing them. Otherwise, there will be creases that cannot be recovered. Thus, it causes damage to the membrane switch and panel. In general, we place a layer of air bubble film on custom membrane switches to work. So it can reduce the damage, please keep it. Also, there will be a transparent film on the front and back of the membrane switch to protect it from a flash window. You’d better not tear it off during use.
Be careful when taking the membrane switch, and do not scratch. After taking some screen printed switch panels, place the rest neatly and restore to the original state. When the number of custom membrane switches is relatively large, be careful not to put switch panels flat when packing, but to stand up. In this way, it is possible to effectively prevent membrane switch buttons on the touch screen from being damaged under heavy pressure for a long time.
The above are the precautions for the membrane switch and panel during the sealing and transportation process. But what are the notes for membrane switch storage? When storing, it should be treated with dust and moisture. Make sure that there are no strong acids, strong bases or other corrosive gases and substances in the storage environment. At the same time, we must do a good job in prevention of pests.