Adhesives in the electronics industry

Reading Volume：【 136 】

Time：【 2023-07-20 】

Adhesives in the electronics industry is widely used, from micro-circuit positioning until the giant generator coil bonding. Once the adhesive failure, the consequences are very serious, the computer will stop running, the city will be dark, or make the missile is difficult to launch into the air.

Adhesive applications in the electronics industry, in addition to doing mechanical fixing, but also requires thermal conductivity, electrical conductivity, insulation, and adapt to impact assembly, sealing and protection of substrates and other requirements. The characteristics required for its different applications include: service life ranging from a few seconds to several years, the amount of less than micrograms to more than 1 ton, etc..

01 different kinds of adhesives in the electronics industry application picture

1, epoxy adhesive: the most widely used in the electronics industry, because of its versatility, excellent bonding, wide adaptability, easy to use, good electrical properties, and aging resistance.

2、Organic silicone adhesive: suitable for the requirements of flexibility, wide temperature range, high frequency, high temperature and atmospheric pollution.

3, hot melt adhesive: in the requirements of rapid assembly, lower strength and working temperature is not high conditions, available hot melt adhesive.

4, acrylate adhesive: the selection of acrylate adhesive is mainly considered to have excellent electrical properties, stability, good aging resistance and transparency, and can be quickly cured.

5, polyurethane adhesive: from low temperature to 121 ° C always remain soft, tough and firm.

6, pre-coated polyvinyl butyral: can form a tough and easy to assemble joints.

02 adhesive in the field of microelectronics in three major applications

1、Tube core bonding;

2, circuit components and substrate bonding;

3, encapsulation. Another major application is printed circuit boards. The need to withstand soldering temperatures of 250°C limits the use of adhesives for bonding steel foils to laminated printed circuit boards.

03 Pictures of adhesives in large equipment applications

Examples include generators, transformers and other equipment operating at high temperatures, as well as equipment that must operate in harsh environments and at high temperatures for 20-40 years. The size of much of the equipment precludes oven curing. In turn, the heat conduction of copper and other metals makes localized heating impossible. Therefore, room-temperature curing adhesives must be used.

04 Pictures of adhesives on electronic devices

Adhesives can be found in almost all electronic devices, such as the bonding of radar antenna composites, which provide thermal and electrical conductivity for the work of electronic components. There is also the bonding of missile front cone rings. Typical applications are also:

(1) Antenna reflectors for tracking/illuminating radars in air defense systems for ships and boats;

(2) Used for external dielectric window and substrate bonding U.S. Danish eyes snake (CobraDaYe) phased array radar system;

(3) drilled with thermally conductive adhesive film to connect the Trident MKs (TridentMKs) missile guidance computer various electronic components;

(4) Bonding cured epoxy laminates to metal frames in air traffic command radars.

05 adhesive in the printed circuit board application picture

Printed circuit boards, whether rigid or flexible, are inseparable from adhesives.

For epoxy-glass boards, acetal-phenolic, nitrile-phenolic or modified epoxy can be used, with a maximum operating temperature of about 150°C. When used at high temperatures of 260°C, glass-silicone laminates or copper / PTFE composite boards should be used.

Stacked assembly of rigid printed circuit boards can be coated with thermoplastic or thermosetting adhesive plastic film bonded together.

Sometimes complex assemblies require thin, flexible printed circuits, when the use of RTV silicone rubber coating, not only as an insulating coating layer, but also vibration damping, for this vibration will be in the soldered joints to increase the unwanted fatigue load.

In addition, in the stressed components coated with epoxy adhesive and silicone to reduce the impact of shock and vibration.

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