# US 2025/0098121 A1 · Non-Condensing Thermal Materials With Low Sulfur Content

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2025/0098121 A1
- Document ID: US20250098121A1
- Status: Published application
- Kind: A1
- Application number: 18/885,167
- Filed: 2024-09-13
- Published: 2025-03-20
- Earliest claimed: 2023-09-19
- Assignees: Laird Technologies, Inc.
- Applicants: Laird Technologies, Inc.
- Inventors: Karen J. BRUZDA; John D. Ryan; Jason L. Strader
- Web page: https://patentgrep.com/patent/US20250098121A1

## CPC

- C09K 5/14: Solid materials, e.g. powdery or granular
- H05K 7/20481: {characterised by the material composition exhibiting specific thermal properties}
- H10W 40/251: {Organics}
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

The present disclosure relates to non-condensing thermal materials (e.g., thermal interface materials (TIMs), thermally-conductive pads, thermally-conductive EMI absorbers, etc.) with low sulfur content. In exemplary embodiments, a thermal interface material has a thermal conductivity of at least 4.5 Watts per meter per Kelvin (W/mK). The thermal interface material includes less than 50 parts per million (PPM) sulfur. And the thermal interface material is configured to be non-condensing. The thermal interface material may comprise a thermally-conductive EMI absorber; and/or the thermal interface material may be silicone free and/or have no detectable silicone.

## Claims

### Claim 1

A thermal interface material comprising a matrix or base resin and at least one functional filler in the matrix or base resin, the thermal interface material having a thermal conductivity of at least 4.5 Watts per meter per Kelvin (W/mK), the thermal interface material including less than 50 parts per million (PPM) sulfur, and the thermal interface material configured to be non-condensing, wherein:
the thermal interface material comprises a thermally-conductive EMI absorber; and/or
the thermal interface material is silicone free and/or does not include detectable silicone.

### Claim 2 (depends on 1)

The thermal interface material of claim 1, wherein the thermal interface material includes less than 2 parts per million (PPM) sulfur.

### Claim 3 (depends on 1)

The thermal interface material of claim 1, wherein the thermal interface material is sulfur free and/or has a sufficiently low sulfur content such that sulfur is not detectable in the thermal interface material by a spectrometer having a detection limit of 2 ppm.

### Claim 4 (depends on 1)

The thermal interface material of claim 1, wherein the thermal interface material is sulfur free and/or has a sufficiently low sulfur content such that the thermal interface material does not include a sufficient amount of sulfur to interact and/or react with another material within a device when the thermal interface material contacts the another material, which interaction and/or reaction could otherwise form an undesirable substance.

### Claim 5 (depends on 1)

The thermal interface material of claim 1, wherein the thermal interface material is sulfur free and/or has a sufficiently low sulfur content such that the thermal interface material does not include a sufficient amount of sulfur to react with silver within a device when the thermal interface material contacts the silver within the device, which reaction could otherwise form silver sulfide causing the device to not operate optimally.

### Claim 6 (depends on 1)

The thermal interface material claim 1, wherein the thermal interface material is configured to be non-condensing such that there is no condensation from the thermal interface material that is visible or felt by a finger on a watch glass after exposure of the thermal interface material on a hotplate to 85° C.+/−2° C. for 1000 hours.

### Claim 7 (depends on 1)

The thermal interface material claim 1, wherein the thermal interface material is configured to be non-condensing such that there is no condensation from the thermal interface material that is visible or felt by a finger on a watch glass after exposure of the thermal interface material on a hotplate to 120° C.+/−2° C. for 72 hours.

### Claim 8 (depends on 1)

The thermal interface material of claim 1, wherein the thermal interface material is configured to be non-condensing with less than a predetermined level of condensable volatile components over a predetermined time period at a predetermined temperature.

### Claim 9 (depends on 1)

The thermal interface material of claim 1, wherein the thermal interface material comprises a non-condensing thermal interface material usable with an optical device without condensation from the thermal interface material interfering with optical aspects of the optical device.

### Claim 10 (depends on 1)

The thermal interface material of claim 1, wherein the thermal interface material has:
an attenuation of at least 87 dB/cm at a frequency of 13 GHz;
an attenuation of at least 142 dB/cm at a frequency of 25 GHz; and
an attenuation of at least 138 dB/cm at a frequency of 40 GHz.

### Claim 11 (depends on 1)

The thermal interface material of claim 1, wherein the thermal interface material has a thermal conductivity of at least 9 Watts per meter per Kelvin (W/mK) as determined by Hot Disk Thermal Constants Analyzer.

### Claim 12 (depends on 1)

The thermal interface material of claim 1, wherein the thermal interface material comprises a thermally-conductive pad, a thermally-conductive gap filler, a phase change thermal interface material, a dispensable material, a bulk putty, a thermal grease, a sheet of thermal interface material, a thermally-conductive EMI absorber pad and/or a thermally-conductive absorber sheet material.

### Claim 13 (depends on 1)

The thermal interface material of claim 1, wherein:
the thermal interface material comprises a thermally-conductive EMI absorber pad having a thermal conductivity of at least 9 W/mK; and
the thermally-conductive EMI absorber pad is silicone free and/or does not include detectable silicone.

### Claim 14 (depends on 1)

The thermal interface material of claim 1, wherein the thermal interface material is silicone free, has less than 2 parts per million silicone and/or has a sufficiently low silicone content such that silicone is not detectable in the thermal interface material by a spectrometer.

### Claim 15 (depends on 1)

The thermal interface material of claim 1, wherein the thermal interface material is entirely free of silicone and/or entirely free of sulfur.

### Claim 16 (depends on 1)

The thermal interface material of claim 1, wherein the thermal interface material does not include any polysiloxane in the matrix or base resin or in additive components of the thermal interface material.

### Claim 17 (depends on 1)

The thermal interface material of claim 1, wherein:
the thermal interface material is silicone based; and/or
the at least one functional filler comprises aluminum oxide and silicon carbide.

### Claim 18 (depends on 1)

The thermal interface material of claim 1, wherein:
the thermal interface material has a thermal resistance according to ASTM-D5470 of:
0.72° C.*cm2/W or less at 69 kilopascals (kPa), 50° C., and 0.5 millimeter (mm) starting thickness;
1.44° C.*cm2/W or less at 69 kPa, 50° C., and 1 mm starting thickness; and
2.32° C.*cm2/W or less at 69 kPa, 50° C., and 2.5 millimeter (mm) starting thickness.

### Claim 19 (depends on 1)

The thermal interface material of claim 1, wherein:
the thermal interface material has a hardness according to ASTM D2240 of 56 Shore 00 or less at 30 seconds for a thickness of 1 millimeter or more; and/or
the thermal interface material has a deflection at 1 mm starting thickness according to ASTM D575 of 5% at 69 kPa and 36% at 345 kPa; and/or
the thermal interface material has a breakdown voltage at 2.5 mm thickness according to ASTM D149 of 0.66 kV (AC) and 0.64 kV (DC); and/or
the thermal interface material has a volume resistivity according to ASTM D257 of 1.6×1012 Ω*cm.

### Claim 20 (depends on 1)

The thermal interface material of claim 1, wherein:
the thermal interface material comprises the thermally-conductive EMI absorber; or
the thermal interface material is silicone free and/or does not include detectable silicone.