IP Library › Granted Patent US 12,262,468
Granted Patent B2
US 12,262,468 · App. 17/443,386 · Granted Mar 25, 2025

Copper-clad laminate and method of forming the same

Inventors: Jennifer Adamchuk (Marlborough, MA); Gerard T. Buss (Bedford, NH); Theresa M. Besozzi (Milford, MA)
Assignee: VERSIV COMPOSITES LIMITED
H05K1/056C09D5/24C09D127/12H05K3/44C08K3/34C08K3/36C08K2201/005C08K2201/006H05K2201/0355H05K2201/0358
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12,262,468
App. No.
17/443,386
Granted
Mar 25, 2025
Kind
B2
Abstract

The present disclosure relates to a copper-clad laminate that may include a copper foil layer and a dielectric coating overlying the copper foil layer. The dielectric coating may include a resin matrix component, and a ceramic filler component. The ceramic filler component may include a first filler material. The dielectric coating may have an average thickness of not greater than about 20 microns.

Claims (43)

1. A copper-clad laminate comprising:

a copper foil layer, and a dielectric coating overlying the copper foil layer, wherein the dielectric coating comprises:

a resin matrix component; and

a ceramic filler component,

wherein the ceramic filler component comprises a first filler material wherein the content of the ceramic filler component is at least 30 vol. % for a total volume of the dielectric coating,

wherein the dielectric coating has an average thickness of not greater than about 20 microns, and

wherein the first filler material comprises silica and has a D 50 particle size distribution of at least about 0.5 microns and not greater than about 2.7 microns, and

wherein the dielectric coating has a porosity of not greater than about 8 vol. %.

2. The copper-clad laminate of claim 1 , wherein the first filler material further comprises a mean particle size of at not greater than about 10 microns.

3. The copper-clad laminate of claim 1 , wherein the first filler material comprises a particle size distribution span (PSDS) of not greater than about 5, where PSDS is equal to (D 90 -D 10 )/D 50 , where D 90 is equal to a D 90 particle size distribution measurement of the first filler material, D 10 is equal to a D 10 particle size distribution measurement of the first filler material, and D 50 is equal to a D 50 particle size distribution measurement of the first filler material.

4. The copper-clad laminate of claim 1 , wherein the first filler material

further comprises an average surface area of not greater than about 10 m 2 /g.

5. The copper-clad laminate of claim 1 , wherein the first filler material comprises a silica based compound.

6. The copper-clad laminate of claim 1 , wherein the resin matrix comprises a perfluoropolymer.

7. The copper-clad laminate of claim 6 , wherein the perfluoropolymer

comprises a copolymer of tetrafluoroethylene (TFE); a copolymer of hexafluoropropylene (HFP); a terpolymer of tetrafluoroethylene (TFE); polytetrafluoroethylene (PTFE), perfluoroalkoxy polymer resin (PFA), fluorinated ethylene propylene (FEP), or any combination thereof.

8. The copper-clad laminate of claim 1 , wherein the content of the resin matrix component is at least about 50 vol. % and not greater than about 63 vol. % for a total volume of the dielectric coating.

9. The copper-clad laminate of claim 1 , wherein the content of the ceramic filler component is not greater than about 57 vol. % for a total volume of the dielectric coating.

10. The copper-clad laminate of claim 1 , wherein the content of the first filler material is at least about 80 vol. % and not greater than about 100 vol. % for a total volume of the ceramic filler component.

11. The copper-clad laminate of claim 1 , wherein the dielectric coating comprises a dissipation factor (5 GHz, 20% RH) of not greater than about 0.005.

12. The copper-clad laminate of claim 1 , wherein the dielectric coating

comprises a coefficient of thermal expansion (all axes) of not greater than about 80 ppm/° C.

13. The copper-clad laminate of claim 1 , wherein the copper-clad laminate comprises a peel strength between the copper foil layer and the dielectric coating of at least about 6 lb/in.

14. A printed circuit board comprising a copper-clad laminate, wherein the copper-clad laminate comprises:

a copper foil layer, and a dielectric coating overlying the copper foil layer, wherein the dielectric coating comprises:

a resin matrix component; and

a ceramic filler component,

wherein the ceramic filler component comprises a first filler material wherein the content of the ceramic filler component is at least 30 vol. % for a total volume of the dielectric coating, and

wherein the dielectric coating has an average thickness of not greater than 20 microns, and

wherein the first filler material comprises silica and has a D 50 particle size distribution of

at least about 0.5 microns and not greater than about 2.7 microns, and

wherein the dielectric coating has a porosity of not greater than about 8 vol. %.

15. The printed circuit board of claim 14 , wherein the first filler material further comprises a mean particle size of at not greater than about 10 microns.

16. The printed circuit board of claim 14 , wherein the first filler material comprises a particle size distribution span (PSDS) of not greater than about 5, where PSDS is equal to (D 90 -D 10 )/D 50 , where D 90 is equal to a D 90 particle size distribution measurement of the first filler material, D 10 is equal to a D 10 particle size distribution measurement of the first filler material, and D 50 is equal to a D 50 particle size distribution measurement of the first filler material.

17. The printed circuit board of claim 14 , wherein the first filler material further comprises an average surface area of not greater than about 10 m 2 /g.

18. The printed circuit board of claim 14 , wherein the first filler material comprises a silica based compound.

19. A method of forming a copper-clad laminate, wherein the method comprises:

providing a copper foil layer,

combining a resin matrix precursor component and a ceramic filler precursor component to form a forming mixture,

forming the forming mixture into a dielectric coating overlying the copper foil, wherein the dielectric coating has an average thickness of not greater than about 20 microns

wherein the ceramic filler precursor component comprises a first filler material wherein the content of the ceramic filler component is at least 30 vol. % for a total volume of the dielectric coating,

wherein the first filler material comprises silica and has a D 50 particle size distribution of at least about 0.5 microns and not greater than about 2.7 microns, and

wherein the dielectric coating has a porosity of not greater than about 8 vol. %.

Assignments (3)
CHANGE OF NAME Recorded Apr 12, 2024
From: SAINT-GOBAIN PERFORMANCE PLASTICS IRELAND LIMITED
To: VERSIV COMPOSITES LIMITED
Reel/Frame 067095/0019 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 12, 2024
From: SAINT-GOBAIN PERFORMANCE PLASTICS CORPORATION
To: SAINT-GOBAIN PERFORMANCE PLASTICS IRELAND LIMITED
Reel/Frame 067096/0147 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 24, 2021
From: ADAMCHUK, JENNIFER; BUSS, GERARD T.; BESOZZI, THERESA M.
To: SAINT-GOBAIN PERFORMANCE PLASTICS CORPORATION
Reel/Frame 057273/0056 →
Continuity (2)
Provisional Application 63057667 · Jul 28, 2020
Related Publication 20220039256A1 · Feb 3, 2022
References Cited (214)
US 4335180A · Traut · 1982 [cited by applicant]
US 4634631A · Gazit et al. · 1987 [cited by applicant]
US 4647508A · Gazit et al. · 1987 [cited by applicant]
US 4661301A · Okada et al. · 1987 [cited by applicant]
US 4784901A · Hatakeyama et al. · 1988 [cited by applicant]
US 4849284A · Arthur et al. · 1989 [cited by applicant]
US 4869956A · Bridges et al. · 1989 [cited by applicant]
US 4987274A · Miller et al. · 1991 [cited by applicant]
US 5055342A · Markovich et al. · 1991 [cited by applicant]
US 5061548A · Arthur et al. · 1991 [cited by applicant]
US 5075065A · Effenberger et al. · 1991 [cited by applicant]
US 5194326A · Arthur et al. · 1993 [cited by applicant]
US 5281466A · Arthur et al. · 1994 [cited by applicant]
US 5312576A · Swei et al. · 1994 [cited by applicant]
US 5354611A · Arthur et al. · 1994 [cited by applicant]
US 5374453A · Swei et al. · 1994 [cited by applicant]
US 5384181A · Arthur et al. · 1995 [cited by applicant]
US 5440805A · Daigle et al. · 1995 [cited by applicant]
US 5506049A · Swei et al. · 1996 [cited by applicant]
US 5607744A · Diener et al. · 1997 [cited by applicant]
US 5879794A · Korleski, Jr. · 1999 [cited by applicant]
US 5889104A · Rosenmayer · 1999 [cited by applicant]
US 5922453A · Horn, III et al. · 1999 [cited by applicant]
US 6172139B1 · Swei et al. · 2001 [cited by applicant]
US 6373717B1 · Downes, Jr. et al. · 2002 [cited by applicant]
US 6500529B1 · McCarthy et al. · 2002 [cited by applicant]
US 7981504B2 · Nelson · 2011 [cited by applicant]
US 8187696B2 · Paul et al. · 2012 [cited by applicant]
US 8314005B2 · Purushothaman et al. · 2012 [cited by applicant]
US 8530746B2 · Zheng et al. · 2013 [cited by applicant]
US 8652641B2 · Wang et al. · 2014 [cited by applicant]
US 8835770B2 · Oyama et al. · 2014 [cited by applicant]
US 9258892B2 · Crosley · 2016 [cited by applicant]
US 9462688B2 · Park et al. · 2016 [cited by applicant]
US 9962907B2 · Price et al. · 2018 [cited by applicant]
US 10096398B2 · Janah et al. · 2018 [cited by applicant]
US 10164326B2 · Urcia et al. · 2018 [cited by applicant]
US 10194528B2 · Su · 2019 [cited by applicant]
US 10236092B2 · Restuccia et al. · 2019 [cited by applicant]
US 10485102B2 · Kaimori et al. · 2019 [cited by applicant]
US 11549035B2 · Adamchuk et al. · 2023 [cited by applicant]
US 20040109298A1 · Hartman et al. · 2004 [cited by applicant]
US 20050244662A1 · Horn, III · 2005 [cited by examiner]
US 20060062976A1 · Sohn et al. · 2006 [cited by applicant]
US 20070107629A1 · Zheng et al. · 2007 [cited by applicant]
US 20070206364A1 · Swei et al. · 2007 [cited by applicant]
US 20090038828A1 · Hou et al. · 2009 [cited by applicant]
US 20090128912A1 · Okada et al. · 2009 [cited by applicant]
US 20100015404A1 · Paul et al. · 2010 [cited by applicant]
US 20120069288A1 · Das et al. · 2012 [cited by applicant]
US 20120123021A1 · Yano · 2012 [cited by examiner]
US 20120189826A1 · Hayashi · 2012 [cited by applicant]
US 20130163253A1 · Saito et al. · 2013 [cited by applicant]
US 20150014028A1 · Lee et al. · 2015 [cited by applicant]
US 20150030824A1 · Crosley · 2015 [cited by applicant]
US 20150079343A1 · Nakabayashi et al. · 2015 [cited by applicant]
US 20150195921A1 · Onodera et al. · 2015 [cited by applicant]
US 20160007452A1 · Yan et al. · 2016 [cited by applicant]
US 20160113113A1 · Sethumadhavan et al. · 2016 [cited by applicant]
US 20160242274A1 · Hosoda et al. · 2016 [cited by applicant]
US 20160280979A1 · Uchiyama et al. · 2016 [cited by applicant]
US 20170145182A1 · Horn, III et al. · 2017 [cited by applicant]
US 20170273188A1 · Su · 2017 [cited by applicant]
US 20180019177A1 · Harada et al. · 2018 [cited by applicant]
US 20180052488A1 · Posner et al. · 2018 [cited by applicant]
US 20180339493A1 · Chen et al. · 2018 [cited by applicant]
US 20190104612A1 · Amla · 2019 [cited by applicant]
US 20190136109A1 · Agapov et al. · 2019 [cited by applicant]
US 20200053877A1 · Liu et al. · 2020 [cited by applicant]
US 20200270413A1 · Koes et al. · 2020 [cited by applicant]
US 20200307162A1 · Remy et al. · 2020 [cited by applicant]
US 20200404782A1 · Chen et al. · 2020 [cited by applicant]
US 20200413536A1 · Amla et al. · 2020 [cited by applicant]
US 20210059048A1 · Wang et al. · 2021 [cited by applicant]
US 20210060900A1 · Huang et al. · 2021 [cited by applicant]
US 20210101366A1 · Nagata et al. · 2021 [cited by applicant]
US 20220033617A1 · Adamchuk et al. · 2022 [cited by applicant]
US 20220039254A1 · Adamchuk et al. · 2022 [cited by applicant]
US 20220186081A1 · Adamchuk et al. · 2022 [cited by applicant]
US 20220186082A1 · Adamchuk et al. · 2022 [cited by applicant]
US 20220195253A1 · Adamchuk et al. · 2022 [cited by applicant]
US 20230191750A1 · Adamchuk et al. · 2023 [cited by applicant]
US 20230191761A1 · Adamchuk et al. · 2023 [cited by applicant]
CN 101365294B · 2010 [cited by applicant]
CN 102471590B · 2012 [cited by applicant]
CN 102719043A · 2012 [cited by applicant]
CN 101838431B · 2012 [cited by applicant]
CN 102275341B · 2013 [cited by applicant]
CN 104053302A · 2014 [cited by applicant]
CN 104149420A · 2014 [cited by applicant]
CN 104476847A · 2015 [cited by applicant]
CN 105453705A · 2016 [cited by applicant]
CN 105802186A · 2016 [cited by applicant]
CN 105820481A · 2016 [cited by applicant]
CN 106188998A · 2016 [cited by applicant]
CN 106604536A · 2017 [cited by applicant]
CN 106671517A · 2017 [cited by applicant]
CN 106928744A · 2017 [cited by applicant]
CN 104647868B · 2017 [cited by applicant]
CN 107172819A · 2017 [cited by applicant]
CN 107177245A · 2017 [cited by applicant]
CN 107278031A · 2017 [cited by applicant]
CN 107493653A · 2017 [cited by applicant]
CN 107509308A · 2017 [cited by applicant]
CN 106009428B · 2018 [cited by applicant]
CN 107722518A · 2018 [cited by applicant]
CN 207083283U · 2018 [cited by applicant]
CN 106113802B · 2018 [cited by applicant]
CN 106313840A · 2018 [cited by applicant]
CN 108456387A · 2018 [cited by applicant]
CN 106633180A · 2018 [cited by applicant]
CN 107474312B · 2019 [cited by applicant]
CN 106800733B · 2019 [cited by applicant]
CN 112519357A · 2021 [cited by applicant]
EP 0211979A1 · 1987 [cited by applicant]
EP 0275070A2 · 1988 [cited by applicant]
EP 0279769A2 · 1988 [cited by applicant]
EP 0442363A1 · 1991 [cited by applicant]
EP 0769788A2 · 1997 [cited by applicant]
EP 1434068A2 · 2004 [cited by applicant]
EP 1529812A1 · 2005 [cited by applicant]
EP 2179631A2 · 2010 [cited by applicant]
EP 2706088A1 · 2014 [cited by applicant]
EP 3028851A1 · 2016 [cited by applicant]
EP 3162561A1 · 2017 [cited by applicant]
JP H0349291A · 1991 [cited by applicant]
JP H08153940A · 1996 [cited by applicant]
JP 10017838A · 1998 [cited by applicant]
JP 2890747B2 · 1999 [cited by applicant]
JP 2001358415A · 2001 [cited by applicant]
JP 2002151844A · 2002 [cited by applicant]
JP 2005001274A · 2005 [cited by applicant]
JP 4129627B2 · 2008 [cited by applicant]
JP 2009152489A · 2009 [cited by applicant]
JP 4598408B2 · 2010 [cited by applicant]
JP 2011021068A · 2011 [cited by applicant]
JP 4815209B2 · 2011 [cited by applicant]
JP 2016003260A · 2016 [cited by applicant]
JP 2016020488A · 2016 [cited by applicant]
JP 2016046433A · 2016 [cited by applicant]
JP 2016102563A · 2016 [cited by applicant]
JP 2018039260A · 2018 [cited by applicant]
JP 6564517B1 · 2019 [cited by applicant]
JP 2019155853A · 2019 [cited by applicant]
KR 20050090560A · 2005 [cited by applicant]
KR 20060027666A · 2006 [cited by applicant]
KR 20060127172A · 2006 [cited by applicant]
KR 100823998B1 · 2008 [cited by applicant]
KR 20130074955A · 2013 [cited by applicant]
KR 20150006713A · 2015 [cited by applicant]
KR 20150113050A · 2015 [cited by applicant]
KR 101775287B1 · 2017 [cited by applicant]
KR 20170134610A · 2017 [cited by applicant]
TW I268859B · 2006 [cited by applicant]
TW I590722B · 2017 [cited by applicant]
TW 201922905A · 2019 [cited by applicant]
TW 202100354A · 2021 [cited by applicant]
WO 9609339A1 · 1996 [cited by applicant]
WO 9845880A1 · 1998 [cited by applicant]
WO 2004085550A2 · 2004 [cited by applicant]
WO 2006078889A2 · 2006 [cited by applicant]
WO 2008004399A2 · 2008 [cited by applicant]
WO 2015182696A1 · 2015 [cited by applicant]
WO 2016104297A1 · 2016 [cited by applicant]
WO 2016201076A1 · 2016 [cited by applicant]
WO 2019031071A1 · 2019 [cited by applicant]
WO 2020091026A1 · 2020 [cited by applicant]
WO 20158604A1 · 2021 [cited by applicant]
WO 2022026989A1 · 2022 [cited by applicant]
WO 2022026990A1 · 2022 [cited by applicant]
WO 2022026991A1 · 2022 [cited by applicant]
WO 2022133402A1 · 2022 [cited by applicant]
WO 2022133403A1 · 2022 [cited by applicant]
WO 2022133404A1 · 2022 [cited by applicant]
WO 2023114838A1 · 2023 [cited by applicant]
WO 2023114843A1 · 2023 [cited by applicant]
International Search Report and Written Opinion for PCT Application No. PCT/US2022/081548, dated Apr. 18, 2023, 9 pages. [cited by applicant]
International Search Report and Written Opinion for PCT Application No. PCT/US2022/081554, dated Apr. 26, 2023, 9 pages. [cited by applicant]
International Search Report and Written Opinion for PCT Application No. PCT/US2021/072819, dated Mar. 31, 2022, 9 pages. [cited by applicant]
International Search Report and Written Opinion for PCT Application No. PCT/US2021/072820, dated Mar. 31, 2022, 10 pages. [cited by applicant]
International Search Report and Written Opinion for PCT Application No. PCT/US2021/072822, dated Apr. 5, 2022, 10 pages. [cited by applicant]
International Search Report and Written Opinion for PCT Application No. PCT/US2021/070953, dated Nov. 16, 2021, 9 pages. [cited by applicant]
International Search Report and Written Opinion for PCT Application No. PCT/US2021/070954, dated Nov. 16, 2021, 9 pages. [cited by applicant]
International Search Report and Written Opinion for PCT Application No. PCT/US2021/070955, dated Nov. 16, 2021, 9 pages. [cited by applicant]
Jawitz, M.W. et al., “Chapter 6: High-Speed/High-Frequency Laminates,” In Materials for Rigid and Flexible Printed Wiring Boards, First Edition. CRC Press: New York, NY, pp. 113-131, dated 2006. [cited by applicant]
Murali, K.P. et al., “Preparation and properties of silica filled PTFE flexible laminates for microwave circuit applications,” Elsevier, Composites: Part A, vol. 40, pp. 1179-1185, dated 2009. [cited by applicant]
Ratheesh, R. et al., “Chapter 11: Polymer-Ceramic Composites for Microwave Applications,” In Microwave Materials and Applications, First Edition. Sebastian, M. T.; Ubic, R.; Jantunen, H.; John Wiley & Sons: Chichester, … [cited by applicant]
Sebastian, Mailadil T. et al., “Polymer-Ceramic Composites of 0-3 Connectivity for Circuits in Electronics: A Review,” International Journal of Applied Ceramic Technology, vol. 7, No. 4, pp. 415-434, dated 2010. [cited by applicant]
Zhuravlev, L.T., “The Surface Chemistry of Amorphous Silica. Zhuravlev Model,” Colloids and Surfaces, A: Physiochemical and Engineering Aspects, vol. 173, pp. 1-38, dated Feb. 21, 2000. [cited by applicant]
Tsai, I-Shou et al., “A Study on the Fabrication Parameters and Dielectric Properties of PTFE Composites Filled with Al2O3 and Si)2 Nanoparticles,” Journal of Industrial Textiles, vol. 40, No. 4, Apr. 20, 2011, pp. 361-… [cited by applicant]
Yuan, Y. et al., “TiO2 and SiO2 Filled PTFE Composites for Microwave Substrate Applications,” Journal of Polymer Research, vol. 21, Jan. 31, 2014, 6 pages. [cited by applicant]
Han, Kunkun et al., “Effect of Filler Structure on the Dielectric and Thermal Properties of SiO2/PTFE Composites,” Journal of Materials Science: Materials in Electronics, Apr. 25, 2020, 7 pages. [cited by applicant]
Yuan, Ying et al., “Effect of Sintering Temperature on the Crystallization Behavior and Properties of Silica Filled PTFE Composites,” Journal of Materials Science: Materials in Electronics, vol. 27, Aug. 5, 2016, pp. 13… [cited by applicant]
Yuan, Ying et al., “Effects of Compound Coupling Agents on the Properties of PTFE/SiO2 Microwave Composites,” Journal of Materials Science: Materials in Electronics, vol. 28, Oct. 25, 2016, pp. 3356-3363. [cited by applicant]
Jiang, Zehua et al., “Effects of Particle Size Distribution of Silica on Properties of PTFE/SiO2 Composites,” Materials Research Express, vol. 5, Jun. 22, 2018, 10 pages. [cited by applicant]
Xiang, Pang et al., “Effects of SiO2 Content on the Properties of PTFE/SiO2 Composites,” Piezoelectrics & Acoustooptics, vol. 34, No. 4, Aug. 2012, pp. 577-580. [cited by applicant]
Yong, Xiao et al., “Effects of TiO2 Content on the Properties of PTFE/TiO2 Microwave Dielectric Composites,” Piezoelectrics & Acoustooptics, vol. 34, No. 5, Oct. 2012, pp. 768-771. [cited by applicant]
Fields, Jeffrey T. et al., “Fluoroalkylsilanes in Silica/Fluoropolymer Composites,” Polymer Composites, vol. 17, No. 2, Apr. 1996, pp. 242-250. [cited by applicant]
Chen-Yang, Yui Whei et al., “High-Performance Circuit Boards Based on Mesoporous Silica Filled PTFE Composite Materials,” Electrochemical and Solid-State Letters, vol. 8, No. 1, dated 2005, pp. F1-F4. [cited by applicant]
Yuan, Ying et al., “Influence of SiO2 Addition on Properties of PTFE/TiO2 Microwave Composites,” Journal of Electronic Materials, vol. 47, No. 1, Oct. 4, 2017, pp. 633-640. [cited by applicant]
Yan, Xiangyu et al., “Influences of Sintering Process on the Properties of SiO2—TiO2/PTFE Composites,” Piezoelectrics & Acoustooptics, vol. 36, No. 2, Apr. 2014, pp. 270-274. [cited by applicant]
Rajesh, S. et al., “Microwave Dielectric Properties of PTFE/Rutile Nanocomposites,” Journal of Alloys and Compounds, vol. 477, dated 2009, pp. 677-682. [cited by applicant]
Zhang, Dong-na et al., “Preparation and Characterization of PTFE-g-GMA modified PTFE/SiO2 Organic-Inorganic Hybrids,” Journal of Polymer Research 19:9873, Apr. 25, 2012, 10 pages. [cited by applicant]
Zhang, Yao et al., “Preparation and Mechanical Properties of SiO2/Polytetrafluoroethylene Composite Films,” Acta Materiae Compositae Sinica, vol. 36, No. 3, Mar. 2019, pp. 624-629. [cited by applicant]
Chen, Yung-Chih et al., “Preparation and properties of Silyated PTFE/SiO2 Organic-Inorganic Hybrids via Sol-Gel Process,” Journal of Polymer Science: Part A: Polymer Chemistry, vol. 42, dated 2004, pp. 1789-1807. [cited by applicant]
Rajesh, S. et al., “Rutile Filled PTFE Composites for Flexible Microwave Substrate Applications,” Materials Science and Engineering B, vol. 163, dated 2007, 7 pages. [cited by applicant]
Huang, Shi-Ing et al., “Study on the Composites of Two Sized Silica Filled in PTFE,” Journal of Reinforced Plastics and Composites, vol. 25, No. 10, dated 2006, pp. 1053-1058. [cited by applicant]
Rajesh S. et al., “Temperature Stable Low Loss PTFE/Rutile Composites Using Secondary Polymer,” Applied Physics A, Material Science & Processing, vol. 104, Nov. 4, 2010, pp. 159-164. [cited by applicant]
Chen, Yung-Chih et al., “The Effects of Filler Content and Size on the Properties of PTFE/SiO2 Composites,” Journal of Polymer Research, vol. 10, dated 2003, pp. 247-258. [cited by applicant]
Chen, Yung-Chih et al., “The Effects of Phenyltrimethoxysilane Coupling Agents on the Properties of PTFE/Silica Composites,” Journal of Polumer Research, vol. 11, dated 2004, pp. 1-7. [cited by applicant]
Luo, Fuchuan et al., “The Effects of TiO2 Particle Size on the Properties of PTFE/TiO2 Composites,” Journal of Materials Science and Chemical Engineering, vol. 5, dated 2017, pp. 53-60. [cited by applicant]
Tsai, I-Shou et al., “The Study of the Low K of PTFE Composites with Hollow Glass Spheres,” Journal of Industrial Textiles, vol. 40, No. 3, Jan. 2011, pp. 261-280. [cited by applicant]
European Search Report for European Application No. 21849051.4; dated May 16, 2024; 10 pages. [cited by applicant]
Japanese Office Action for Japanese Application No. 2023505356; dated May 7, 2024; 6 pages; with English translation. [cited by applicant]