Coating for the structured production of conductors on the surface of electrically insulating substrates

• US 5,955,179 A
• Filed: 07/23/1997
• Issued: 09/21/1999
• Est. Priority Date: 09/21/1995
• Status: Expired due to Fees

• Current Assignee: LPKF Laser & Electronics AG
• Original Assignee: LPKF Laser & Electronics AG
• Inventors: Kickelhain, Joerg, Vitt, Bruno
• Primary Examiner(s): TURNER, ARCHENE A
• Application Number:
  US08/836,812
• Time in Patent Office: 790 Days
• Field of Search: 428/697, 428/699, 428/701, 428/702, 428/336, 428/432, 428/446, 428/195, 428/210, 338/34, 338/35, 65/60.5, 204/192.25, 204/192.29, 204/192.35, 204/298, 204/31, 219/203, 296/84.1, 359/359, 359/580, 359/585, 427/162, 427/165, 427/168, 427/343, 427/110, 427/126.1, 427/126.2, 427/126.3
• US Class Current: 428/210
• CPC Class Codes: C03C 17/253 Coating containing SnO2
• CPC Class Codes: C03C 2217/211 SnO2
• CPC Class Codes: C03C 2217/23 Mixtures
• CPC Class Codes: C03C 2217/241 with halides
• CPC Class Codes: C03C 2217/244 with Sb
• CPC Class Codes: C03C 2218/11 from solutions or suspensions
• CPC Class Codes: C04B 35/10 based on aluminium oxide
• CPC Class Codes: C04B 41/0036 Laser treatment working by laser beam B23K26/00
• CPC Class Codes: C04B 41/009 characterised by the material treated
• CPC Class Codes: C04B 41/4543 by spraying, e.g. by atomising
• CPC Class Codes: C04B 41/455 the coating or impregnating process including a chemical conversion or reaction
• CPC Class Codes: C04B 41/4572 Partial coating or impregnation of the surface of the substrate
• CPC Class Codes: C04B 41/505 Tin oxide
• CPC Class Codes: C04B 41/5346 Dry etching
• CPC Class Codes: C04B 41/87 Ceramics
• CPC Class Codes: H01L 21/4846 Leads on or in insulating or insulated substrates, e.g. metallisation H01L21/4821 takes precedence; metallisation of ceramics in general C04B41/51; printed circuits H05K3/00
• CPC Class Codes: H01L 23/49872 the conductive materials containing semiconductor material
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H05K 1/0306 : Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 1/09 : Use of materials for the conductive, e.g. metallic pattern
• CPC Class Codes: H05K 3/027 : the conductive material being removed by irradiation, e.g. by photons, alpha or beta particles
• CPC Class Codes: Y10T 428/24802 : Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/24926 : including ceramic, glass, porcelain or quartz layer
• CPC Class Codes: Y10T 428/265 : 1 mil or less

Abstract

A coating for the structured production of conductors on the surface of electrically insulating substrates, in particular for producing sensor elements and printed circuit boards. The coating is formed from a doped tin oxide layer having the composition Sn_1-(y+z) A_y B_z O₂, in which A is Sb or F and B is In or Al. The relative proportions in the coating of the dopants antimony (or fluorine) and indium (or aluminum) are defined by the limits 0.02<y+z<0.11 and satisfy the condition 1.4<y/z<2.2. The coating can be structured by ablation using electromagnetic laser radiation in the wavelength range 157-1064 nm. The creates an economical means for high resolution and waste-free structuring of insulating channels in thin, electrically conductive layers having high chemical, mechanical and thermal resistance on glass or ceramic substrates.

Claims

1. An article of manufacture comprising an electrically insulating substrate having deposited thereon a doped tin oxide layer having the composition:

space="preserve" listing-type="equation">Sn.sub.1-(y+z) A.sub.y B.sub.z O.sub.2

wherein

A represents at least one first dopant element selected from the group consisting of Sb and F, and

B represents at least one second dopant element selected from the group consisting of In and Al, and

wherein the proportions of the dopants satisfy the relationships;

3. An article according to claim 1, wherein said doped tin oxide layer has the composition:

space="preserve" listing-type="equation">Sn.sub.0.919 Sb.sub.0.052 In.sub.0.029 O.sub.2.

4. An article according to claim 1, wherein said doped tin oxide layer has a thickness in the range from 50 nm to 500 nm.

5. An article according to claim 1, wherein said doped tin oxide layer is ablatable by targeted excimer laser radiation having a wavelength in the range from 157 nm to 308 nm.

6. An article according claim 1, wherein said doped tin oxide layer is ablatable by targeted krypton-fluoride excimer laser radiation with a wavelength of 248 nm.

7. An article according to claim 1, wherein the substrate is selected from the group consisting of quartz glass, glass ceramic, hard glass, soft glass, aluminum oxide ceramic and semiconductive silicon.

8. An article according to claim 6, wherein the substrate is a hard borosilicate glass.

10. A method according to claim 8, wherein said doped tin oxide layer has the composition:

space="preserve" listing-type="equation">Sn.sub.0.919 Sb.sub.0.052 In.sub.0.029 O.sub.2.

11. A method according to claim 8, wherein the substrate is selected from the group consisting of quartz glass, glass ceramic, hard glass, soft glass, aluminum oxide ceramic and semiconductive silicon.

12. A method according to claim 8, wherein the substrate is manufactured by a process which includes a cooling phase, and said doped tin oxide layer is deposited on the substrate during said cooling phase.

14. A method according to claim 12, wherein the doped tin oxide layer has the composition:

space="preserve" listing-type="equation">Sn.sub.0.919 Sb.sub.0.052 In.sub.0.029 O.sub.2.

15. A method according to claim 12, wherein the substrate is selected from the group consisting of quartz glass, glass ceramic, hard glass, soft glass, aluminum oxide ceramic and semiconductive silicon.

16. A method according to claim 12, wherein the doped tin oxide layer has a thickness in the range from 50 nm to 500 nm.

17. A method according to claim 12, wherein the selected areas of the doped tin oxide layer are exposed to excimer laser radiation having a wavelength in the range from 157 nm to 308 nm.

18. A method according claim 12, wherein the selected areas of the doped tin oxide layer are exposed to krypton-fluoride excimer laser radiation having a wavelength of 248 nm.

19. An article of manufacture comprising an electrically insulating substrate having a structured layer of doped tin oxide thereon produced by the process of claim 12.

20. An article of manufacture according to claim 18, wherein said article comprises a moisture sensor.

21. An article of manufacture according to claim 19, wherein said substrate comprises an automobile windshield.

2. 02<

y+z<

0.11

and

space="preserve" listing-type="equation">1.4<

y/z<

2.2;

said doped tin oxide layer being selectively ablatable by targeted electromagnetic laser radiation having a wavelength in the range from 157 nm to 1064 nm to produce structured conductive paths on the substrate.

9. A method for producing a coated article comprising applying a layer of doped tin oxide by aerosol spray pyrolysis to an electrically insulating substrate at a surface temperature of 400°

C. to 600°

C., said layer having a thickness between 50 nm and 500 nm, and said doped tin oxide having a composition;

space="preserve" listing-type="equation">Sn.sub.1-(y+z) A.sub.y B.sub.z O.sub.2

wherein

A represents at least one first dopant element selected from the group consisting of Sb and F, and

B represents at least one second dopant element selected from the group consisting of In and Al, and

wherein the proportions of the dopants satisfy the relationships;

space="preserve" listing-type="equation">0.02<

y+z<

0.11

and

space="preserve" listing-type="equation">1.4<

y/z<

2.2.

13. A method of producing a structured layer on a substrate, said method comprising

providing an electrically insulating substrate having a layer of doped tin oxide deposited thereon, and

ablating selected areas of the doped tin oxide layer by exposing the selected areas to electromagnetic laser radiation having a wavelength in the range from 157 nm to 1064 nm;

said doped tin oxide layer having the composition;

space="preserve" listing-type="equation">Sn.sub.1-(y+z) A.sub.y B.sub.z O.sub.2

wherein

A represents at least one first dopant element selected from the group consisting of Sb and F, and

B represents at least one second dopant element selected from the group consisting of In and Al, and

wherein the proportions of the dopants satisfy the relationships;

space="preserve" listing-type="equation">0.02<

y+z<

0.11

and

space="preserve" listing-type="equation">1.4<

y/z<

2.2.