Adhesives electrically insulative

Organosiloxanes are very heat resistant, so they do not easily melt, like most other organic compounds. They are also water-repellant and can withstand extremes of sunlight, moisture, cold, and attack by most chemicals. These properties make them useful for protective coatings, electrical insulation, adhesives, lubricants, paints, and rubber-like materials. Some silicones are also used to make nonstick... 

Nonconductive or electrically insulative adhesives are used where electrical shorting may be a problem or where electrical isolation is required. Nonconductive adhesives are available in either paste or film form and are generally filled with silica or alumina to provide optimum flow properties for dispensing and to improve their thermal conductivities. 

It is convenient to compare and select adhesives in terms of their resistivities because these values reduce resistance measurements to a common denominator. Volume resistivity, which is the ohmic resistance of a cube of bulk material 1 cm per side, is frequently used to compare the electrical properties of both electrically conductive and electrically insulative adhesives. 

Dispensible electrically insulative adhesive 20 0% epoxy resin, 10-20% epoxy resin modifier, 15% amine, and >50% silica filler Ablebond 84-3 (Henkel)... 

In this approach, entire wafers or segments of wafers containing ICs are stacked. Interconnections are formed from vias in the silicon. In vertically stacking memory chips or other IC chips, the chips are first thinned to several mils (4 mils or less), then adhesive bonded, and electrically interconnected directly from chip-to-chip, either from the edges or through vias in the silicon. In these approaches, both electrically conductive and electrically insulative adhesives are used. Thermally conductive preform adhesives or thin thermoplastic films are used to bond and isolate the chips within the stack and to dissipate heat. Several processes are available to vertically stack and interconnect chips of the same size and function such as SRAM, flash, and DRAM memory chips. Other processes have been developed to vertically stack chips of different sizes and functions, or to horizontally interconnect different chips in one layer, then vertically stack the layers. ... 

Thermal conductivity requirements are specified in both military and industry specifications generally as 1.5 W/m K or greater for electrically conductive adhesives and 0.15 W/mK or greater for electrically insulative adhesives. 

To function as electrical conductors, epoxies and other polymer resins, because they are inherently insulators, must be filled with electrically conductive particles such as metals. The selection of electrically conductive or insulative adhesives is based largely on their conductivities or, conversely, on their volume resistivities. Electrically conductive adhesives should have low resistivities initially and retain those values on aging, moisture exposure, thermal cycling, and other operating and test conditions. The resistivities of metal-filled epoxy adhesives can range firom 10 to 10 ohm-cm. Electrically insulative adhesives should have high volume resistivities ranging fi om 10 to 10 ohm-cm. 

Dispensible electrically insulative adhesive Epoxy Resin (Bisphenol-F) 15-25% Diepoxide diluent 8-15% Aromatic amines 1-5% Filler 40-50% Ablebond 84-3 and 84-3 LV... 

The measurement of the dielectric constant and dissipation factor for electrically insulating adhesives is performed in accordance with ASTM D150 at 1 kHz and 1 MHz at 25 °C. The requirement for the... 

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