Types and innovative applications of electronic adhesives

Adhesives have the same or different kinds of materials that can be firmly bonded together, adhesive joint without stress concentration, high bonding strength, and easy-to-realize automatic operation, so it has been widely used in many fields (especially as one of the auxiliary materials in electronic industry production). With the increasing demand for miniaturization, lightweight, and high performance of electronic products, the variety and amount of adhesive used in the electronic industry are increasing, and the performance is getting better and better. Although the total amount of adhesives used in the electronic industry is less than 1% of the total amount of adhesives, the variety of electronic adhesives, strict performance requirements, and high added value, have a very important position in the adhesive industry.

First, the main varieties of electronic glue:

1. Universal adhesive

The so-called “universal type” is the glue that can be bonded to a variety of metals, plastics, etc., including the following:
the second-generation acrylic ester gum
Including two main dosage forms and base glue type two. It is characterized by fast curing and high bond strength.
alpha cyanoacrylate glue
It is representative of fast-setting adhesive. It can bond to most materials, cooperate with base glue, and can even bond polyolefin and engineering plastics.

hot melt adhesive
The main varieties are EVA, polyamide (nylon), and polyester. EVA hot melt adhesive is used a lot, but its heat resistance is not good, the latter two heat resistance is better. The biggest advantage of hot melt adhesive is fast curing and no pollution.

silicone adhesive
Silicone adhesive has a single component, two components of two categories, each of which has many varieties. In the electronic industry, one-component wet-cured rubber is used more. Its main uses are as follows: high voltage line insulation seal, various electronic components, mixed integrated circuits, power components, picture tube and other high voltage components, and heat-resistant glass products bond seal.

2. Thermal conductivity adhesive
Thermal conductivity adhesive is usually used when assembling some components with high heat dissipation and heat dissipation requirements on the electronic chassis and circuit board. Such as transformers, transistors, CPU chips, etc., usually need to use heat conduction glue to stick to the shell, circuit board cold plate, or radiator.
Thermal conductive adhesive is generally a single component, good thermal conductive adhesive not only has good thermal conductivity, cold and thermal alternating resistance, aging resistance, and electrical insulation, and has excellent moisture, earthquake resistance, corona resistance, leakage resistance, and chemical media resistance, can be used in -60~280℃ and maintain performance, Does not swell and has good adhesion to most metal and non-metal materials.

3. Conductive adhesive
In the field of microelectronics assembly, conductive adhesives are generally used to connect fine wires with printed lines, plating plates, metal layers of ceramic adhesives, metal chassis, bonding wires with tube seats, bonding elements with flat faces passing through printed lines, bonding waveguide tuning and hole repair.
According to different curing systems, conductive adhesives can be divided into room-temperature curing conductive adhesives, medium-temperature curing conductive adhesives, high-temperature curing conductive adhesives, UV-curing conductive adhesives, etc.

4. Potting glue
Potting adhesive is usually used in bonding, sealing, potting, and coating protection of electronic components. Potting glue is liquid before curing. After curing, it can play the role of waterproof, moisture-proof, dustproof, insulation, heat conduction, sealing, corrosion resistance, temperature resistance, and shock resistance.
From the type of material, the most commonly used at present are mainly three types, that is, epoxy resin potting glue, silicone resin potting glue, and polyurethane potting glue.