Tag: Electronic component adhesive construction

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LOCA glue construction process requirements in the assembly of the touch screen

LOCA glue construction process requirements in the assembly of the touch screen
There are more and more applications of touch screens, such as smart phones, PADs use touch screens, and more and more touch screens for notebook computers and even TV sets. At present, the touch screen market mainly has two types of resistive and capacitive. The touch screen is made up of two pieces of glass, which are glued together by liquid optical UV glue or double-sided tape. Compared with OCA tape, LOCA liquid UV glue has the advantages of stronger bonding force, flexible control of the thickness of the glue layer, better solution to the fit of the large and medium screen, reduction of light refraction, and elimination of visual phenomena such as rainbow lines. Enhance display contrast, reduce battery consumption, and more.
1, LOCA glue performance requirements, generally LOCA glue is generally soft, requires 80%

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Electronic component three anti adhesive vibration, insulation, anti-adhesion

Electronic component three anti adhesive vibration, insulation, anti-adhesion

After the SMT soldering process, in order to make the components anti-vibration, insulation, anti-glare, especially for coil components, it must be fixed and sealed. It is also necessary to use an adhesive that acts as a positioning seal. The positioning sealant should have the following characteristics:

1, the appropriate viscosity, easy to sizing operation.
2, moisture-proof, anti-vibration, good insulation performance.
3, the surface drying time should not be too short, usually about 30min is appropriate, in order to facilitate the adjustment of components such as coils during this period.
4, according to the needs of the product, sometimes need to use a fully cured adhesive, and sometimes need to use a self-adhesive type to facilitate the replacement and repair of components.

Electronic component three anti adhesive is various synthetic rubbers and polyesters that can be used as adhesives for positioning sealants. These rubbers have high cold resistance, air tightness and electrical insulation, and high bond strength and elongation. These glues are used for positioning and sealing. The glue should be formulated into a solvent-based adhesive when used. When the viscosity changes, it can be diluted with a solvent at any time. When applying glue, hand-coating is carried out using a pneumatic injection device and a watering can, a brush or a brush.
However, because such glues contain solvents, which are harmful to the atmosphere and the human body, there is a tendency to be replaced by RTV organic silica gel. As a positioning seal, a one-component room temperature vulcanized silicone rubber is used, which has good electrical insulation. Adhesive, plastic cylinder packaging, can be directly sized.

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Electronic components packaging and PCB board protection with glue

Electronic components packaging and PCB board protection with glue

PCB circuit board protection
1, components fixed: RTV organic silicone sealing glue; radiator connection: thermal plastic, thermal paste;
Conformal coating: silicone, UV, acrylate, polyurethane, etc. (brush, dip, spray, etc.)
Jumper fixed/coil terminal fixed: Instant dry glue, UV glue.

2, COB chip encapsulation: single-component medium temperature curing epoxy glue, manual dispensing / automatic dispenser, for electronic watches, electric toys, calculators, telephones, remote controls, PDA, etc. on the PCB chip package seal.
3, SMT patch: single component medium temperature curing epoxy glue, dispensing (semi-automatic dispensing machine and automatic dispenser) or scraping glue (pad printing)
Flip Chip Underfill: Paste: One-component medium temperature curing epoxy glue, manual dispensing/auto dispensing machine for various flip chip, data processor; conductive connection: single component epoxy conductive Silver glue.
5, bare die bonding Die Attach: single component medium temperature curing epoxy glue, instantaneous dry glue; conductive connection: single-component epoxy conductive silver plastic
6, Liquid crystal display LCD package: Sealed UV glue has a certain toughness, good adhesion, resistant to alcohol and water; pin (PIN) UV glue; conductive connection: single-component epoxy conductive silver plastic
7, light-emitting diode LED package: Potting: Epoxy, silicone, UV glue, the required transmittance of 98%; Conductive: One-component epoxy conductive silver plastic
8, Relay / switch package: Edge: UV glue; Potting: One-component glue or two-component glue.
9, DC/DC power module package: Potting: Addition type 1:1 medium temperature curing silicone rubber.