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How to Spec Power-Module Thermal Parts: What to Send H-O for a Quote
Thermal parts attract underspecified RFQs because the geometry looks like the whole story: a pad with holes, a blanket panel, a strip of film on a liner. What the quote actually prices is the duty behind the geometry: the gap the pad must fill, the pressure that will close it, whether the joint must isolate, how hot the location runs, and whether the part is a path part or a boundary part.
This is the ten-item checklist the H-O applications team works from for TIM pads, gap fillers, adhesive films, graphite spreaders, aerogel blankets, and fire barriers, drawn from the parent application page's own engineering-review list, plus what engineering does with each item and what comes back.
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The ten things to send, and what each decides
| Send this | What it decides |
|---|---|
| 1. The job: path or boundary | The fundamental split. Path parts (TIM, spreaders) are judged per ASTM D5470 at pressure; boundary parts (blankets, barriers) per ASTM C177, ASTM C411, and the fire methods. They are not compared in one column. |
| 2. Worst-case gap and flatness | Reinforced pad versus gap filler. Component height spread, baseplate bow, and torque relaxation open the nominal; the filler is sized to the worst case at the available pressure. |
| 3. Clamping force, or its absence | Pads need clamping force to work; where hardware is absent, crowded out, or untrustworthy over the stack's life, the answer moves to a thermally conductive adhesive film, a permanent assembly decision. |
| 4. Electrical role of the joint | Isolated joints restrict the choice to insulating families with ASTM D149 data; grounded joints admit electrically conductive graphite, which usually wins the thermal comparison there. |
| 5. Thermal budget and comparison basis | Candidates compared per ASTM D5470 impedance at your pressure and thickness, not by the headline W/m·K column. |
| 6. Service temperature, continuous and local | The TDS ceiling sorts the families: silicone TIM windows, graphite to 400 °C on conductive joints per TDS, and blanket territory past that, with the hottest blanket duty rated to 650 °C per the dossier. |
| 7. Boundary requirements, named separately | Steady-state insulation (k per ASTM C177) and fire performance (ASTM E84, UL 1709 class methods) are different requirements; naming both lets each layer do its own job, often as a two-layer lamination. |
| 8. Installed condition for aerogel | Cut geometry with clearance for blanket loft, fastening that locates without crushing, and facings or edge treatment where moisture is real; compressed or soaked aerogel loses what you bought it for. |
| 9. Geometry and liner presentation: DXF, STEP, or PDF | Footprint, fastener clearances, kiss-cut-on-liner format, tab placement, and lamination order, the items that decide line speed more than the material does. |
| 10. Prototype and production volumes | Converting method and price structure. Every part is made to order; prototype quantities through full production runs are equally accepted, and MOQ varies by material and part. |
What engineering does with the list
Items 1 through 5 pick the path construction: a thin reinforced insulator (PROTECT, Sil‑Pad TSP) for flat clamped joints, a soft Gap Pad filler for uneven stacks, eGRAF graphite where item 4 says the joint is grounded, a SpreaderShield film where the heat needs to move sideways to real sink area, or a SECURE adhesive film where item 3 says hardware is absent.
Items 6 through 8 sort the boundary: ArmaGel blanket or Pyrogel XTE for hot compartments, thin aerogels where there is no room for blanket, and ManniGlas or specialty silicone foams where item 7 names a fire-barrier duty. Items 9 and 10 become the converting plan and the price structure. The reply cites each recommended grade's TDS values with the method named, and flags anything the checklist left open.
What happens after you send it
- Drawing review. Engineering reviews the stack against the vendor TDS: gap and flatness, clamping force, thermal budget, electrical role, service temperature, and the boundary insulation or fire-barrier requirement.
- Material direction and quote. A family and grade direction with the TDS attached, the converted format (die-cut, kiss-cut on liner, laminated, knife-cut blanket), and pricing at your quantities.
- Samples. Typically 3 to 5 business days for common die-cut configurations on materials we keep on hand.
- Production. Standard runs ship about two weeks after drawing approval, including kiss-cut-on-liner and laminated configurations; expedited service is available. Ongoing parts run with material traceability and lot-code TDS records.
Documentation available on request: material technical data sheet, certificate of conformance, lot traceability, and first-article inspection, under our ISO 9001:2015 certified quality management system. H-O is a die-cut converter, not a raw-material producer: we do not manufacture the raw pads, films, blankets, or foams, we do not independently certify them, and assembly-level outcomes belong to the finished equipment's standards (IEC 61439 / IEEE C37.20).
The mistakes this checklist prevents
| Spec mistake | What it causes | Checklist item that catches it |
|---|---|---|
| Pad thickness chosen from the catalog | Bridged gap or strangled path; the junction pays either way | Items 2 and 5 |
| Conductivity-first comparison | The W/m·K column inverts at your pressure and thickness | Item 5, ASTM D5470 at pressure |
| Spreader with no destination | The hot spot spreads into a closed box and the neighbors inherit it | Items 1 and 6 |
| Graphite on an isolated joint | An electrical fault with excellent thermal conductivity | Item 4 |
| Fire barrier asked to be an insulator (or the reverse) | The thin barrier lets the compartment cook, or the insulation misses the fire rating | Item 7, both requirements named |
| Aerogel cut tight and forced into place | Compressed blanket; conductivity above the number the design was sold on | Item 8, installed condition specified |
Frequently asked questions
What if I do not know the worst-case gap or the clamping pressure?
Send what you do know: the stack drawing, component heights, baseplate or sink flatness callouts, and the fastener pattern. Engineering frames the gap and pressure questions from those, and the thickness band is chosen to cover the credible worst case at the available force. The parent page's failure-modes section shows both directions of guessing wrong, which is why an honest tolerance is worth more than a precise-looking nominal.
Can H-O cross-reference the TIM or insulation grade on my print?
In most cases, yes. If your drawing calls out a thermal pad, gap filler, graphite film, aerogel blanket, or barrier material by a brand part number, engineering identifies a comparable grade from the lines we convert, matching on impedance class per ASTM D5470 at your pressure, thickness and softness, electrical role, service temperature, and the fire or insulation methods the wall requires. It is an industry cross-reference, not a guaranteed drop-in, verified against the vendor TDS before quoting.
How should aerogel blanket parts be specified so they install correctly?
Specify the installed condition, not just the material: cut geometry with clearance for blanket loft, fastening that locates without crushing, and facings or edge treatment where wash-down or condensation is real. Steady-state conductivity is measured dry and uncompressed per ASTM C177, so a panel forced flat or soaked performs above the number the design was sold on. H-O cuts blanket and thin-aerogel parts to geometry that installs the way the TDS was tested.
What lead time should I expect for samples and production?
Every thermal part is made to order, including samples. Samples typically ship in 3 to 5 business days for common die-cut configurations on materials we keep on hand; standard production runs ship about two weeks after drawing approval, including kiss-cut-on-liner and laminated configurations; expedited service is available when timing is critical. MOQ varies by material and part, and prototype quantities through full production runs are equally accepted.
Send the checklist, get a thermal-part quote
Attach the geometry and as many of the ten items as you have. If something is unknown, say so; the review proceeds with the assumption flagged.
Samples typically ship in 3 to 5 business days for common die-cut configurations on materials we keep on hand; standard production runs about two weeks after drawing approval; expedited service is available. MOQ varies by material and part.
Family-owned in Winsted, Connecticut since 1971 · ISO 9001:2015 certified · OEMs worldwide send us a drawing — and get back their part.
Related reading
ApplicationPower Module Thermal ManagementRead →
Sub-applicationServer & Network Thermal InterfaceRead →
GuideTIM Pads, Gap Fillers, Graphite Spreaders, or Aerogel: Choosing Power-Module Thermal MaterialsRead →
GuideW/m·K Is Not the Answer: Thermal Impedance, Contact, and the Pad-Thickness TradeoffRead →
IndustryElectromechanical & Switchgear hubRead →
Request a quote for your power-module thermal management part
Send H-O your drawing or describe the part—engineering reviews every RFQ and converts samples on your geometry.
Last updated · Reviewed by H-O Products engineering (ISO 9001:2015 certified converter, Winsted, CT).
References
- ASTM D5470 (thermal impedance at pressure, the path-side comparison basis); ASTM D149 (dielectric strength for isolated joints).
- ASTM C177 and ASTM C411 (boundary insulation methods); ASTM E84 and UL 1709 class methods (fire behavior, as cited per grade); UL 94 (flammability classes, per grade).
- IEC 61439 / IEEE C37.20 (assembly standards for the finished equipment).
- Manufacturer technical data sheets for the pad, filler, graphite, spreader, adhesive-film, aerogel, and barrier grades named on the parent application page.
This checklist supports a quotation workflow; it does not constitute design guidance for any specific equipment, and thermal comparisons belong to the ASTM D5470 impedance data at your pressure on each grade's current technical data sheet. Grade-level values are confirmed on the manufacturer's current TDS at quote time. All parts are custom manufactured to order; minimum production run quantities vary by material and part. H-O is a die-cut converter, not a raw-material producer, and does not certify finished equipment.