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Thermal Interface Insulating Silicone Rubber Sheets

Q: Can I use the TC-TA insulating silicone sheet India to replace mica on a TO-220 power transistor?

Yes — that is one of the primary design applications for TC-TA-1 and TC-TAG-2 grades. The sheet is positioned between the transistor body and heatsink, then clamped by the mounting screw. Unlike mica, the silicone sheet does not crack under clamp load, conforms slightly to surface roughness without grease, and at 1.0–1.8 W/m·K offers materially better thermal conductivity than mica (~0.7 W/m·K). Pantronics India supplies cap and tube pre-moulded shapes to fit TO-220 and TO-247 packages directly.

Q: What is the dielectric breakdown voltage of the TC-TAG and TC-TAP insulating silicone sheets?

Dielectric breakdown voltage in air (JIS C 2110) ranges from 6 to 15 kV depending on grade: TC-TA-1 and TC-BG offer 15 kV; TC-TAG grades measure 7–10 kV; TC-TAP-2 measures 8 kV breakdown (6 kV JIS). For designs requiring the highest insulation distance, TC-TAP-2's triple-insulated structure or TC-TA-1/BG's 15 kV rating are the most suitable. Always confirm the required creepage and clearance distance for your working voltage against the full datasheet — available from Pantronics India.

Q: What LMW siloxane limit should I specify for PCB contact applications?

For designs where migrating siloxane could contaminate nearby relay contacts, connector pins or optical components, specify grades rated <10 ppm total D3–D10 LMW siloxane: TC-TAP-2, TC-TAG-3 and TC-TAG-6 all meet this threshold. TC-TA-1 and TC-TAG-2 are rated at 30–40 ppm and should not be used adjacent to contact-sensitive components.

Q: Can the insulating silicone sheet India be die-cut to custom shapes and sizes

Yes. Pantronics India can advise on tooling and minimum order quantities for custom-cut parts.

The most trusted insulating silicone thermal sheet India engineers specify — Shin-Etsu TC-TA series: thin, flexible single-layer, glass-cloth reinforced and polyimide-laminated grades providing simultaneous electrical insulation and thermal conduction from 1.0 to 8.0 W/m·K. A superior replacement for mica and insulating paper.

1.0–8.0

W/m·K

0.20–0.80mm

Thickness

V-0

UL94 (TAG / BG)

<10 ppm

LMW Siloxane (TAG-3/6/8)

Overview

What Is the TC-TA Series?

The TC-TA series is Shin-Etsu’s family of thermal interface insulating silicone rubber sheets. Each sheet is a compound of silicone rubber loaded with thermally conductive ceramic fillers, supplied as a thin, flexible sheet that can be die-cut, pinched onto components, or moulded into caps and tubes.

The sheet sits between a heat-generating device and a heatsink, conducting heat away while maintaining a guaranteed electrical creepage distance — effectively replacing traditional insulating paper or mica with a thermally conductive alternative that also reduces junction temperature.

Three structural variants are offered: TC-TA-1 (single-layer silicone rubber, 0.20–0.45 mm), TC-TAG-2/3/6/8 (glass-cloth reinforced for dimensional stability, 0.20–0.80 mm), and TC-TAP-2 (polyimide-film reinforced triple-insulated at only 0.11 mm). A high-conductivity white variant, TC-BG, targets LED backlight applications.

Application Scenes

Where TC-TA Sheets Are Used

The TC-TA family covers a broad range of power electronics applications where a flat thermal interface plus electrical isolation is needed in a single thin layer.

TO-Package Mounting

Sheet pinched between TO-220 or TO-247 package and heatsink, then screw-fastened. Provides electrical isolation and thermal path in a single layer, replacing mica or insulating paper at significantly higher conductivity.

Power Modules & IGBTs

TC-TAG-6 and TC-TAG-8 grades (6.0–8.0 W/m·K rubber conductivity) are the preferred choice for high-density power modules, inverters and IGBTs in industrial drives and EV powertrains where thermal budget is tight.

LED Lighting TC-BG Grade

TC-BG is a white, glass-cloth reinforced grade with 7.3 W/m·K rubber conductivity optimised for LED backlight and LED luminaire applications where the substrate is thermally conductive but the LED PCB is electrically live.

Moulded Cap

Shin-Etsu also supplies TC sheets pre-moulded into caps and tube shapes that slip directly over TO-92, TO-220 and similar package bodies, eliminating manual sheet alignment during assembly and reducing placement errors.

Datasheet

General Properties — TC-TA / TC-TAG / TC-TAP / TC-BG Series

Representative product properties — test methods: ISO 22007-2 (thermal), JIS K 6249 (electrical/mechanical), ASTM D-149 (dielectric)

Parameter	TC-TA-1	TC-TAG-2	TC-TAP-2	TC-TAG-3	TC-TAG-6	TC-TAG-8	TC-BG
Color	Black brown	Purple	Light purple	Dark gray	Pink	Light gray	White
Reinforcement layer	None	Glass cloth	Polyimide film	Glass cloth	Glass cloth	Glass cloth	Glass cloth
Standard size (mm)	300×1000	300×1000 Roll	320×1000 Roll	300×1000 Roll	420×500	420×500	210×270
Thickness (mm)	0.20, 0.30, 0.45	0.20, 0.30, 0.45, 0.80	0.11	0.20, 0.30, 0.45	0.20, 0.30, 0.45	0.20, 0.30, 0.45	0.20, 0.30, 0.45
Thermal conductivity, rubber (W/m·K)	1	1.8	1.8	3.4	6	8	7.3
Thermal conductivity, product (W/m·K)	1.1	1.4	0.9	2.1	4	4.7	4
Thermal resistance 50°C / 100 psi (cm²·K/W)	3.8	2.5	2	1.7	1.2	1	1.9
Density at 23°C (g/cm³)	1.7	1.86	1.65	2.84	1.63	1.56	1.66
Hardness, Durometer A	70	91	87	90	88	83	91
Dielectric breakdown voltage, air (kV)	15	10	8	9	9	8	15
Dielectric strength, air (kV) JIS C 2110	15	7	6	7	7	7	13
Volume resistivity (TΩ·m)	5.4	3.5	14	0.9	6.4	5.4	68
Flame retardance UL94	—	—	—	V-0 (UL file No. E48923)
LMW siloxane ΣD₃–D₁₀ (ppm)	40	30	<10	<10	<10	20	<10

Grade selection tip: For maximum conductivity with insulation → TC-TAG-8 (8.0 W/m·K). For ultra-thin triple-insulated layer → TC-TAP-2 (0.11 mm). For LED backlights → TC-BG. For the lowest siloxane content → TC-TAP-2 or TC-TAG-3/6 (<10 ppm). Cap and tube moulded shapes available on request from Pantronics India.

Grade Selector

Which Insulating Silicone Sheet India Engineers Should Specify

Choosing the right TC-TA grade comes down to four factors: thermal conductivity needed, thickness available, electrical insulation level required, and whether the design demands low LMW siloxane for contact-protection.

If your priority is…	Recommended Grade	Conductivity	Key Advantage
Lowest cost, general insulation	TC-TA-1	1.0 W/m·K (rubber)	Single-layer, easy to cut and position
Dimensional stability on large modules	TC-TAG-2	1.8 W/m·K (rubber)	Glass cloth prevents stretch during assembly
Triple insulation at minimum thickness	TC-TAP-2	1.8 W/m·K (rubber)	Only 0.11 mm; polyimide-film reinforced, <10 ppm LMW
Mid-range conductivity + UL94 V-0	TC-TAG-3	3.4 W/m·K (rubber)	V-0 rated, <10 ppm LMW siloxane
High power modules, inverters	TC-TAG-6	6.0 W/m·K (rubber)	Best conductivity-to-thickness ratio in V-0 glass cloth format
Maximum conductivity silicone sheet	TC-TAG-8	8.0 W/m·K (rubber)	Highest thermal conductivity in the TC-TA family
LED backlight / luminaire applications	TC-BG	7.3 W/m·K (rubber)	White colour, LED-optimised, 15 kV dielectric breakdown

FAQ

Insulating Silicone Sheet India — Common Engineer Questions

Can I use the TC-TA insulating silicone sheet India to replace mica on a TO-220 power transistor?

Yes — that is one of the primary design applications for TC-TA-1 and TC-TAG-2 grades. The sheet is positioned between the transistor body and heatsink, then clamped by the mounting screw. Unlike mica, the silicone sheet does not crack under clamp load, conforms slightly to surface roughness without grease, and at 1.0–1.8 W/m·K offers materially better thermal conductivity than mica (~0.7 W/m·K). Pantronics India supplies cap and tube pre-moulded shapes to fit TO-220 and TO-247 packages directly.

What is the dielectric breakdown voltage of the TC-TAG and TC-TAP insulating silicone sheets?

Dielectric breakdown voltage in air (JIS C 2110) ranges from 6 to 15 kV depending on grade: TC-TA-1 and TC-BG offer 15 kV; TC-TAG grades measure 7–10 kV; TC-TAP-2 measures 8 kV breakdown (6 kV JIS). For designs requiring the highest insulation distance, TC-TAP-2’s triple-insulated structure or TC-TA-1/BG’s 15 kV rating are the most suitable. Always confirm the required creepage and clearance distance for your working voltage against the full datasheet — available from Pantronics India.

What LMW siloxane limit should I specify for PCB contact applications?

For designs where migrating siloxane could contaminate nearby relay contacts, connector pins or optical components, specify grades rated <10 ppm total D3–D10 LMW siloxane: TC-TAP-2, TC-TAG-3 and TC-TAG-6 all meet this threshold. TC-TA-1 and TC-TAG-2 are rated at 30–40 ppm and should not be used adjacent to contact-sensitive components.

Can the insulating silicone sheet India be die-cut to custom shapes and sizes

Yes. Pantronics India can advise on tooling and minimum order quantities for custom-cut parts.