Methods of patterning a conductor on a substrate

• US 8,425,792 B2
• Filed: 02/26/2009
• Issued: 04/23/2013
• Est. Priority Date: 02/28/2008
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Zu, Lijun, Frey, Matthew H.
• Primary Examiner(s): Tran, Binh X
• Assistant Examiner(s): CATHEY JR, DAVID A
• Application Number:
  US12/393,201
• Publication Number:
  US 20090218310A1
• Time in Patent Office: 1,517 Days
• Field of Search: None
• US Class Current: 216/67
• CPC Class Codes: B41M 5/52 Macromolecular coatings
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C23F 1/02 Local etching
• CPC Class Codes: C23F 1/30 for etching other metallic material
• CPC Class Codes: G03F 7/0002 Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: H05K 1/0296 Conductive pattern lay-out details not covered by sub groups H05K1/02 - H05K1/0295 H05K1/11 takes precedence; lay-out adapted to mounted component configuration H05K1/18
• CPC Class Codes: H05K 1/032 consisting of one material
• CPC Class Codes: H05K 2201/0108 Transparent
• CPC Class Codes: H05K 2201/0133 Elastomeric or compliant polymer
• CPC Class Codes: H05K 2203/0108 Male die used for patterning, punching or transferring
• CPC Class Codes: H05K 2203/0537 Transfer of pre-fabricated insulating pattern
• CPC Class Codes: H05K 3/0079 characterised by the method of application or removal of the mask H05K3/0091 takes precedence
• CPC Class Codes: H05K 3/061 Etching masks
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]

Abstract

A method of patterning a conductor on a substrate includes providing an inked elastomeric stamp inked with self-assembled monolayer-forming molecules and having a relief pattern with raised features. Then the raised features of the inked stamp contact a metal-coated visible light transparent substrate. Then the metal is etched to form an electrically conductive micropattern corresponding to the raised features of the inked stamp on the visible light transparent substrate.

Claims

1. A method of patterning a conductor on a substrate, comprising:

providing an inked elastomeric stamp inked with self-assembled monolayer-forming molecules and having a relief pattern with raised features, the relief pattern having a low density region with a fill factor between 0.5% and 4%, measuring at least 5 square millimeters comprising;

a two-dimensional mesh of raised linear features having an average area density value of raised features between 0.5 to 4%, wherein the raised linear features have a width value between 0.5 to 25 micrometers;

a distance value between adjacent raised linear features of less than 1 millimeter;

the relief pattern further having a raised feature measuring at least 50 micrometers in width, wherein for a junction formed between the raised linear features and a larger raised feature, the raised linear feature width is widened by tapering before making contact to the larger raised feature;

contacting the raised linear features of the inked elastomeric stamp to a metal-coated visible light transparent substrate; and

etching the metal to form an electrically conductive micropattern corresponding to the raised features of the inked elastomeric stamp on the visible light transparent substrate.

2. A method according to claim 1, wherein the contacting step has a contact time in a range from 0.1 to 30 seconds.

3. A method according to claim 1, wherein a concentration of self-assembled monolayer-forming molecules in the stamp adjacent to the printing surface is between 0.05 and 20 millimolars and the contacting step has a contact time in the range from 0.1 to 10 seconds.

4. A method according to 3, wherein the self-assembled monolayer forming molecules comprise octadecylthiol.

5. A method according to claim 1, wherein a concentration of self-assembled monolayer-forming molecules in the inked elastomeric stamp adjacent to the printing surface is between 0.05 and 5 millimolars, the contacting step has a contact time in the range from 0.1 to 10 seconds, and the self-assembled monolayer-forming molecules comprise hexadecanethiol.

6. A method according to claim 1, wherein the low density region has a uniform average area density value of raised features.

7. A method according to claim 1, wherein the linear segments have a width value between 1 to 5 micrometers.

8. A method according to claim 1, wherein the distance value between low density region adjacent raised linear features is less than 500 micrometers.

9. A method according to claim 1, wherein all non-raised points in the relief pattern have a maximum separation distance from a raised linear feature of less than 1 millimeter for any direction in a plane containing the non-raised points.

10. A method according to claim 1, wherein all non-raised points in the relief pattern have a maximum separation distance from a raised linear feature of less than 500 micrometers for any direction in a plane containing the non-raised points.

11. A method according to claim 1, wherein the stamp is inked with self-assembled monolayer-forming molecules selected from the group consisting of thiols, dialkyl disulfides, dialkyl sulfides, alkyl xanthates, dithiophosphates, and dialkylthiocarbamates.

12. A method according to claim 1, wherein the low density region of the electrically conductive micropattern comprises an electrically conductive mesh micropattern.

13. A method according to claim 1, further comprising electrically connecting the electrically conductive micropattern to a touch sensor drive device.

14. A method according to claim 11, wherein the monolayer-forming molecules comprise octadecylthiol, the concentration of self-assembled monolayer-forming molecules in the inked elastomeric stamp adjacent to the printing surface is between 0.5 and 10 millimolars and the contacting step has a contact time in the range from 0.5 to 5 seconds.

15. A method according to claim 11, wherein the monolayer-forming molecules comprise hexadecylthiol, the concentration of self-assembled monolayer-forming molecules in the stamp adjacent to the printing surface is between 0.5 and 1 millimolar and the contacting step has a contact time in the range from 0.5 to 5 seconds.

19. A method according to claim 1, wherein the raised linear features have an arc length that is at least 3 times greater than the width value.

16. A method of manufacturing a touch screen sensor, comprising:

providing a metal-coated visible light transparent substrate having a relief pattern with raised features, the relief pattern having a low density region with a fill factor between 0.5% and 4%, measuring at least 5 square millimeters comprising;

a two-dimensional mesh of raised linear features having an average area density value of raised features between 0.5 to 4%;

wherein the raised linear features have a width value between 0.5 to 25 micrometers;

a distance value between adjacent raised linear features of less than 1 millimeter;

the relief pattern further having a raised feature measuring at least 50 micrometers in width, wherein for a junction formed between the raised linear features and a larger raised feature, the raised linear feature width is widened by tapering before making contact to the larger raised feature;

contacting an inked elastomeric stamp inked with self-assembled monolayer-forming molecules to the metal-coated visible light transparent substrate; and

etching the metal to form an electrically conductive micropattern on the visible light transparent substrate raised features.

17. A method of patterning conductors on a substrate, comprising:

providing an inked stamp with a relief pattern with raised features, the inked stamp comprising linear organosulfur self-assembled monolayer-forming molecules with chain length from 16 to 18 atoms at a concentration within the stamp of 1 to 10 millimolars, the relief pattern having a low density region with a fill factor between 0.5% and 4%, measuring at least 5 square millimeters comprising;

a two-dimensional mesh of raised linear features having an average area density value of raised linear features between 0.5 to 4%, wherein the raised linear features have a width value from approximately 1 to 4 micrometers;

a distance value between adjacent raised linear features of less than 500 micrometers;

a raised feature measuring at least 25 micrometers in width, wherein for a junction formed between the raised linear features and a larger raised feature, the raised linear feature width is widened by tapering before making contact to the larger raised feature;

contacting the inked stamp to a metal-coated visible light transparent substrate for a period of time, the period of time being in a range from 0.5 to 10 seconds, thereby depositing a pattern of self-assembled monolayer; and

etching the metal to form a transparent electrically conductive micropattern corresponding to the raised features of the inked stamp on the visible light transparent substrate.

18. A method according to claim 17, wherein the self-assembled monolayer-forming molecules comprise octadecanethiol.