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Adhesives are widely used in electronic industry, from micro circuit positioning to giant generator coil bonding. Once the adhesive fails, the consequences will be very serious, the computer will stop running, the city will be dark, or it will be difficult for the missile to launch.
In addition to mechanical fixation, the application of adhesive in electronic industry also requires heat conduction, conductivity and insulation, and meets the requirements of impact resistant assembly, sealing and protecting substrate. The characteristics required for different applications include: service life ranging from a few seconds to a few years, dosage ranging from less than micrograms to more than 1 ton, etc.
1、 Application of different kinds of adhesives in electronic industry
2、 Three main applications of adhesives in Microelectronics
1. Pipe core bonding;
2. Bonding between circuit elements and substrate;
3. Encapsulation. Another main application is printed circuit board. Because the welding temperature of 250 ° C must be resistant, the adhesive is limited to the bonding between steel foil and laminated printed circuit board.
3、 Application of adhesive in large equipment
For example, generators, transformers and other equipment operating under high temperature, as well as equipment that must operate under harsh environment and high temperature conditions for 20-40 years. The size of many devices precludes the possibility of oven curing. The heat conduction of copper and other metals makes local heating impossible. Therefore, room temperature curing adhesive must be used.
4、 Application of adhesive in electronic equipment
Adhesive applications can be found in almost all electronic equipment, such as the bonding of radar antenna composites, which provides heat conduction and conductivity for the work of electronic components. And the bonding of the front cone ring of the missile. Typical applications include:
(1) Antenna reflector for tracking / illuminating radar in ship air defense system;
(2) Cobra Daye phased array radar system for bonding external dielectric window to substrate;
(3) Drill various electronic components of Trident MKS missile guidance computer with thermal conductive adhesive film;
(4) In the air traffic command radar, the cured epoxy laminate is bonded to the metal frame.
5、 Application of adhesive in printed circuit board
Printed circuit boards, whether rigid or flexible, are inseparable from adhesives.
For epoxy glass plate, acetal phenolic, nitrile phenolic or modified epoxy can be used, and the maximum service temperature is about 150 ° C. When used at a high temperature of 260 ° C, glass silicone laminate or copper / polytetrafluoroethylene composite plate shall be used.
The laminated assembly of rigid printed circuit board can be bonded together with plastic film coated with thermoplastic or thermosetting adhesive.
Sometimes complex assemblies require thin and flexible printed circuits. At this time, RTV silicone rubber coating can not only be used as insulating coating, but also reduce vibration, which will increase unwanted fatigue load on welded joints.
In addition, epoxy adhesive and organic silica gel are coated on the stressed components to reduce the impact and vibration.