Conformal Coatings for Thin Film/Thick Film
One-part silicone, conformal protective coatings for thin film and thick film resistor networks in microelectronic circuits.
HYBRISIL – 200
High power resistor silicone coating
Elevated temperature cure
Thermal class 350 °C
Hybrisil conformal coating is designed to protect and stabilize thick and thin film resistor networks. The Hybrisil coatings are one-part systems, silicone based and easily applied. These silicone materials provide a low cost yet reliable process for resistor encapsulation. The need for high temperature firings with cermet encapsulations is avoided.
Hybrisil 200 is a silicone-mica filled system which cures at elevated temperature.
PROPERTIES OF HYBRISIL CONFORMAL COATINGS
|Composition||One-part silicone filled|
|Flash Point||90 °F|
|Shelf Life||6 months|
|Bond Strength (peel lbs./in2)||125|
|Durometer||70 (shore D)|
|Dielectric Constant (1000 Hz)||4.8|
|Dissipation Factor (1000 Hz)||.002|
|Volume Resistivity (ohm-cm)||> 1016|
|Water Absorption (7 days) ASTM-D570-54T||< 0.1|
|Temperature Rating (Continuous)||-65 °C to + 250 °C|
|Max. Oper. Temp.||350 °C|
Hybrisil conformal coating is conveniently applied by horizontal flooding technique or brushing.
Hybrisil-200 is first baked at 65 °C for 20 minutes then heated for ½ hour at 125 °C followed by a post cure of ½ hour at 220 °C.
High Temperature Conformal Coatings
Solution type insulation coatings formulated with dielectric aluminum silicates in a special silicone base – for power resistors, capacitors and other electrical components.
RESISTOR COATING – TYPE 100
Thermal Class – 350 °C
For very high temperature applications
RESISTOR COATING – TYPE 150
Thixotropic modification of type 100
For single coat application
RESISTOR COATING – TYPE 200
Thermal class – 250 °C
For applications requiring very high adhesion and chemical resistance
RESISTOR COATING – TYPE 250
Thixotropic modification of type 200
For single coat application
- Single component systems
- High insulation resistance
- High reliability performance
- Moisture resistant
- Fire resistant
Transene conformal resistor coatings are specially formulated from insulation materials designed to pass rigid, high reliability performance standards for military and space applications. The coatings are particularly advantageous for precision power resistors as well as for other electrical components used in high temperature applications. The coatings are fire resistant and highly protective towards moisture and ambient.
Transene Resistor Coatings contain modified, high temperature silicone resins combined with dielectric grade aluminum silicate materials. These coatings exhibit excellent insulating properties, notably high dielectric strength and high electrical resistivity. Furthermore, these characteristics are maintained at elevated temperatures- as high as 350 °C continuous. A feature of these resistor coatings is their superior adhesion.
Two basic types of resistor coatings are offered based upon their temperature rating, adhesion, quality and chemical resistance. In addition, thixotropic modification of these two types allows single coat application.
RESISTOR COATING – Type 100 was developed specifically for high temperature application; consequently it demonstrates exceptional thermal stability. Color black or green.
RESISTOR COATING – Type 150 is a thixotropic modification of type 100 to permit single coat application. Color black or green.
RESISTOR COATING – Type 200 is designed to withstand chemical attack. Its resistance to solvents is excellent while adhesion is extremely high. Color black or green.
RESISTOR COATING – Type 250 is a thixotropic modification of type 200 for single coat application. Color black or green.
PROPERTIES OF RESISTOR COATINGS
|PHYSICAL PROPERTIES||Type 100 and 150||Type 200 and 250|
|Appearance||Liq Susp.||Liq. Susp.|
|Color||Black or green||Black or green|
|Solids % by wt.||80%||80%|
|Sp.Gr.||1.21 blk, 1.12 grn||1.18 blk, 1.10 grn|
|Thinner||Xylene or toluol||Xylene or toluol|
|Flash Point (solvent)||90 °F||90 °F|
|Shelf Life||6 months||6 months|
|Temperature Rating (10,000 hrs)||350 °C (cont.)||250 °C (cont.)|
|Temperature Cycling||-65 °C to + 250 °C||-65 °C to + 250 °C|
|Coverage/gal/mil/thickness||650 sq. ft.||650 sq. ft.|
|Bond Strength, peel lbs./in2||125||225|
|Lap Shear Strength lbs/in2||250||> 1000|
|Dielectric Strength (volts/mil)||700||700|
|Dissipation Factor @ 1 mHz.||.002||.01|
|Dielectric Constant @ 1 mHz.||4.85||5.25|
|Volume Resistivity(ohm-cm)||> 1016||> 1016|
|Air Drying (also between coats)||20 min||20 min|
|Bake at 65 °C||20 min||20 min|
|Cure||½ hr. at 125 °C||½ hr at 150 °C|
|Post Cure||½ hr at 225 °+C||½ hr at 225 °C|
|Alternate Cure and Post Cure||———||6 hrs at 135 °C|
Coatings can be applied by dip or roll dip. Type 100 and type 200 yield a coat thickness of about 2 mils on single application. Two or three coatings are recommended. Type 150 and 250 permit single coat application of about 7 mils, permitting greater economy and process simplification.
The coatings should be (1) air dried and baked at 65 °C for 20 minutes followed by (2) one half hour at 125 °C (or 150 °C), then (3) post cured for one-half hour at 220 °C. Alternated lower temperature cure may be used for Types 200 and 250.