Organosilicon SIEL Compounds for Electronics

Chemical purity (ionogenic compounds impurities and heavy and radioactive metal compounds content - 1·10-4% max.) and high dielectric parameters within the temperature range of -60 (-80) +200 (+300)°C provided good prospects for SIEL compounds employment as elastic sub layers for the protection of semiconductor device p-n junctions for printed circuit boards, blocks and modules, protection of electronic circuits with high integration degree and other purposes The compounds provide good and stable properties of electronic devices operating in wide temperature range, under high humidity conditions, heat shocks, corrosive environment, vacuum, strong vibration, high impact and electrical loading.

Both non-filled and filled compounds have good adhesion to various electronic materials: metals and alloys, glass, plastics etc.

Compound shrinkage in the process of curing does not exceed 0.1%; moisture absorption - 0.1-0.2%; water vapor permeability - (0.5-1.0)·106 g/cm·Torr·h; modulus of elasticity for non-filled compounds excluding 159-356 B and 159-431 brands varies within the range of 0.8-2.0 MPa, for filled ones - 3-15 MPa; coefficient of linear thermal expansion is 1.0·104 K-1 for non-filled compounds and from 1.5 to 3.5·104 K-1 for filled ones.

Initially SIEL compounds are single or two-component compositions.

SIEL compounds of 159-190, 159-190A, 159-256, 159-414, 159-421, 159-438 and 159-442 brands are single-component.

SIEL compounds of 159-167, 159-191, 159-307 and 159-327 brands consist of major part (base) where the calculated quantities of catalysts P-1 and AP-1 are added before application.

The rest compounds consist of parts A and B mixed before application in 1:1 (159-356B and 159-431), 6:1 (159-376), 10:1 (159-254, 159-254M, 159-306, 159-322A, 159-322B, 159-390, 159-377 and 159-406), 15:1 (159-407) and 20:1 (159-440 and 159-360) ratios.

SIEL compounds of 159-356B and 159-431 brands form low-modulus (0.001-0.01 MPa) gel like products having \"self-healing\" effect and used for potting of electronic blocks fit for repair, strain-sensing elements and chips.

The peculiarities of SIEL compounds of 159-254M, 159-322A and 159-377 consist in decreased content of ionogenic and radioactive element compound impurities (1·10-6% max), high electrical insulation properties. They are used for protection and sealing of products with high electrical insulation requirements.

SIEL compounds of 159-421 and 159-442 brands are thixotropic compositions recommended for application when compound spreading over the product surface must be avoided.

SIEL compounds of 159-407, 159-417 and 159-438 brands are used as \"kontactols\" - products providing electrical contact in tools and devices for electronics and watchmaking, they are characterized by high thermal conductivity within the whole operating temperature range.

SIEL compounds of 159-190, 159-256, 159-306, 159-360, 159-406, 159-431 and SIEL 159-307 brands in particular are noted for high heat resistance, and they are used as coatings for various elements of electronics and electrical engineering equipment operating at 220-300°C during a long period of time.

The compounds of the above-mentioned grades provide for stable operation of the protected products within wide temperature range high yield of effective items reliability and stability of tools electrical parameters under the conditions of continuous duty.