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Phase Change Materials — Thermal Softening Sheets

The preferred phase change thermal material India engineers select — Shin-Etsu PCS series. Solid, handleable sheets at room temperature that soften to a grease-like state at ~50°C, combining the positioning ease of a sheet with ultra-low BLT and pumpout resistance. 2.0–3.0 W/m·K, suitable for ceramic and aluminium base plates.

2.0–3.0

W/m·K

~50°C

Softening Point

0.08 cm²·K/W

Min Thermal Resistance

10–30µm

BLT After Compression

Overview

What Are Phase Change Materials?

Phase change materials (PCMs) are thermally conductive sheets that change from solid to a grease-like material at ~50°C. At room temperature they are solid and handleable — you can die-cut them, place them on a component and pre-assemble. Once the device heats up to ~50°C, the PCM softens and flows into microscopic surface asperities, dramatically reducing BLT and contact thermal resistance.

Three variants are available: PCS-CR-10 (non-insulated, 2.0 W/m·K, ceramic base plate use), PCS-LT-30 (non-insulated, 3.0 W/m·K, lowest BLT grade), and PCS-PL-30 (insulated with polyimide film, 1.7 W/m·K, aluminium base plate use). All are supplied in 300×400 mm sheets and roll formats.

Sheet handling at room temperature + grease-like performance at operating temperature
Softens at ~50°C — fills fine surface gaps and dramatically reduces BLT
Excellent pumpout resistance — far more stable than conventional grease under thermal cycling
PCS-LT-30 achieves BLT of 28 µm after compression for minimum contact resistance
PCS-CR-10 achieves BLT of only 10 µm — the lowest in the series
PCS-PL-30 adds polyimide film insulation for aluminium base plates requiring isolation

Application Scenes

Where Phase Change Materials Are Used

Server CPU / GPU TIM-2 Position

PCS-LT-30 (3.0 W/m·K, BLT 28 µm) is widely used as a TIM-2 material between the heat spreader lid and heatsink in server and workstation processors, where screws provide clamping force and the phase change on first boot fills micro-gaps.

Optical Disc & PC Peripherals

PCMs are the TIM of choice for DVD / BD drives, PSUs and desktop PC chipsets where the screwed heatsink provides clamping force and the grease-like fill after first warm-up eliminates the need for any manual grease application on the production line.

LED Light Source on Aluminium Base

PCS-PL-30 includes a polyimide insulating film for applications where the LED board mounts on a conductive aluminium substrate and electrical isolation is needed. The film maintains sheet integrity during assembly before the PCM softens.

Notebook PC & Consumer Electronics

PCS-CR-10 (2.0 W/m·K, BLT 10 µm) provides the minimum contact resistance configuration for thin-profile laptop heat pipes and heatsinks, where the low BLT directly translates to lower CPU thermal resistance and higher boost performance.

Datasheet

General Properties — PCS Series

PCS Series properties (ASTM E-1461 thermal, Shin-Etsu method for BLT, JIS K 6249 electrical)

ameter	PCS-PL-30	PCS-CR-10	PCS-LT-30
Thermal conductivity (W/m·K) — ASTM E-1461	1.7*	2.0	3.0
Thermal resistance (cm²·K/W) — 50 psi / 100°C / 1 h	0.73	0.08	0.11
Type	Insulated (polyimide)	Non-insulated	Non-insulated
Color	White	White	Gray
Initial thickness (µm)	120	200	120
BLT after compression (µm)	30	10	28
Density at 23°C (g/cm³)	2.7	2.9	2.4
Dielectric breakdown voltage, air (kV)	5.5*	—	—
Softening point (°C)	~50	~50	~50
Standard size / form	320×400 mm, Roll	300×400 mm, Roll	300×400 mm, Roll
Flame resistance UL94	V-0 equiv.	V-0 equiv.	V-0 equiv.

Grade selection: Ceramic (insulating) base plates → PCS-CR-10 (lowest BLT 10 µm) or PCS-LT-30 (highest conductivity 3.0 W/m·K). Aluminium (conductive) base plates needing electrical isolation → PCS-PL-30. *PCS-PL-30 conductivity measured after polyimide film removal.

Grade Selector

Selecting the Right Phase Change Thermal Material India Grade

All PCS grades are handleable solid sheets at room temperature and reach grease-like performance above 50°C. Grade selection is driven primarily by target conductivity and base plate material compatibility.

Parameter	PCS-TF2	PCS-TF3	PCS-HA
Thermal conductivity (W/m·K)	2.0	3.0	3.0
Phase change temperature (°C)	~50	~50	~50
Standard thickness (mm)	0.1–0.25	0.1–0.25	0.1–0.25
Compatible base plates	Aluminium, ceramic	Aluminium, ceramic	Aluminium, ceramic (halogen-free)
Key advantage	Lower cost, moderate conductivity	Higher conductivity at same BLT	Halogen-free formulation for stricter compliance
Pumpout resistance vs grease	Significantly better — no migration after thermal cycling

Phase change material vs. thermal grease: Phase change thermal material India offers grease-like BLT and surface wetting after the device reaches operating temperature, but with the pre-assembly handling ease of a solid sheet. It is the preferred choice where grease dispensing is impractical or where pumpout over thousands of cycles is a concern — such as high-cycle-count servers, GPU coolers and power amplifiers.

FAQ

Phase Change Thermal Material India — Common Engineer Questions

How does phase change thermal material India compare to thermal grease at the same BLT?

At equivalent bond line thickness after reflow, PCS series phase change materials achieve thermal resistance values comparable to mid-range thermal grease. Their primary advantage is pumpout resistance: because the material re-solidifies when the device cools, it does not migrate out of the interface over thousands of thermal cycles the way low-viscosity grease can. This makes them particularly valuable in high-cycle-count applications such as server CPUs and power amplifiers.

Does the phase change material need to be pre-heated before installation?

No. PCS sheets are positioned on the heatsink or component at room temperature — the material is solid and fully handleable. The first power-on cycle raises the device temperature above 50°C, at which point the material softens, wets into the surface, and achieves its rated BLT. No pre-heating, dispensing equipment or mixing is required, which simplifies both manual and automated assembly.

Can phase change thermal material India be reworked after installation?

Yes, with care. Once the device cools and the PCS material re-solidifies, the heatsink can be removed and the material can be peeled off and replaced. This makes PCS sheets suitable for field-serviceable assemblies. However, re-wetting quality on a second installation may be slightly lower than the first — for critical applications, replacing the sheet on rework is recommended. Contact Pantronics India for grade-specific rework guidance.