Reverse side film laser circuit etching

• US 20080083715A1
• Filed: 10/05/2006
• Published: 04/10/2008
• Est. Priority Date: 10/05/2006
• Status: Active Grant

• Current Assignee: Mu-Gahat Enterprises LLC
• Original Assignee: Mu-Gahat Enterprises LLC
• Inventors: Kirmeier, Josef
• Granted Patent: US 7,633,035 B2
• Time in Patent Office: Days
• US Class Current: 219/121.69
• CPC Class Codes: B23K 2103/172 wherein at least one of the layers is non-metallic
• CPC Class Codes: B23K 26/009 using a non-absorbing, e.g. transparent, reflective or refractive, layer on the workpiece using a mask on the workpiece B23K26/066
• CPC Class Codes: B23K 26/0846 for moving elongated workpieces longitudinally, e.g. wire or strip material
• CPC Class Codes: B23K 26/361 for deburring or mechanical trimming B23K26/351 takes precedence
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved
• CPC Class Codes: H05K 1/0393 Flexible materials H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups
• CPC Class Codes: H05K 2201/0108 Transparent
• CPC Class Codes: H05K 2203/082 Suction, e.g. for holding solder balls or components
• CPC Class Codes: H05K 2203/1545 Continuous processing, i.e. involving rolls moving a band-like or solid carrier along a continuous production path
• CPC Class Codes: H05K 3/027 the conductive material being removed by irradiation, e.g. by photons, alpha or beta particles

Abstract

A direct-write laser lithography system comprises a reel-to-reel feed system in a vacuum chamber that presents the clear film-side of a single-sided metal-clad tape to a laser for direct patterning of the metal. The laser beam is swept laterally across the tape by rotating mirrors, and is intense enough to ablate the metal but not so strong as to destroy the tape substrate. In one instance, two specialized lasers are used, one set to ablate large field areas, and the other tuned to scribe fine features and lines. The ablated metal blows off in a downward direction and is collected for recycling.

Claims

1. A method for etching metal on a substrate, comprising:

placing a laminated sheet of metal and dielectric substrate in a vacuum;

directing a beam from laser, also disposed in said vacuum, at the laminated sheet from the side of its dielectric substrate; and

causing said laser beam to pass through said dielectric substrate and to ablate portions of said metal from underneath.

2. The method of claim 1, further comprising:

configuring said laminated sheet into a tape; and

winding said tape in a reel-to-reel transport system disposed in said vacuum.

3. The method of claim 1, further comprising:

orienting said laminated sheet such that the metal side is down and gravity helps move ablated material away for recycling.

4. The method of claim 1, further comprising:

using two beams from separate lasers wherein one is tuned to ablate wide field areas of metal and the other laser is optimized for scribing fine lines and features, and wherein the two lasers are coordinated to provide a single result.

5. The method of claim 1, further comprising:

rotating a mirror in the path of said laser beam to provide for transverse movement of the points being ablated in the metal across said laminated sheet.

6. The method of claim 1, further comprising:

pre-heating said laminated sheet and/or mechanically stressing it to reduce the laser power needed to ablate said metal.

7. The method of claim 1, further comprising:

disposing a laser energy absorbing material between said dielectric substrate and said metal in the laminated sheet that assists in an underside laser ablation of the metal.

8. A flexible circuit etching system, comprising:

a vacuum chamber in which all other components are disposed;

a laser for providing a laser beam sufficient to ablate metal from a laminated film;

a rotating laser beam mirror positioned to receive light from the laser; and

a reel-to-reel tape system for linearly presenting a laminated tape of a single side of metal on a dielectric substrate, and with said substrate facing up and to receive a transverse scan by the rotating laser-beam mirror;

wherein, laser energy is directed through the dielectric substrate of the laminated tape to ablate said metal from underneath.

9. The flexible circuit etching system of claim 8, further comprising:

a collection and recycling system positioned to catch and recycle metal being ablated from the laminated tape.

10. A dual-laser reel-to-reel direct write lithography system, comprising:

a vacuum chamber in which all other components are disposed;

a first laser for providing a laser beam sufficient to ablate wide areas of metal from a laminated film;

a first rotating laser beam mirror positioned to receive light from the first laser;

a second laser for providing a laser beam sufficient to ablate fine lines and features of metal from said laminated film;

a second rotating laser beam mirror positioned to receive light from the second laser; and

a reel-to-reel tape system for linearly presenting a laminated tape of a single side of metal on a dielectric substrate, and with said substrate facing up and to receive a transverse scan by the rotating first and second laser-beam mirrors;

wherein, laser energy is directed through the dielectric substrate of the laminated tape to ablate said metal from underneath.

11. A method for patterning metal cladding on a dielectric substrate, comprising:

placing a laser over a laminated sheet of metal and dielectric substrate;

directing a beam from said laser at the laminated sheet from the side of its dielectric substrate; and

causing said laser beam to pass through said dielectric substrate and to ablate portions of said metal from underneath.

12. The method of claim 11, further comprising:

controlling the operation and placement of said laser in relation to said laminated sheet to write patterns in metal carried on said dielectric substrate.

13. The method of claim 11, further comprising:

operating said laser near enough to said laminated sheet such that a vacuum atmosphere is unnecessary to obtain metal ablation by laser.

14. The method of claim 11, further comprising:

including a wavelength-specific energy absorbing material intermediate to said metal and dielectric substrate that will assist in laser ablation when exposed to said beam after it passes through said dielectric substrate.

15. A laser ablation machine for patterning metal cladding on a dielectric substrate, comprising:

means for placing a laser over a laminated sheet of metal and dielectric substrate;

means for directing a beam from said laser at the laminated sheet from the side of its dielectric substrate; and

means for causing said laser beam to pass through said dielectric substrate and to ablate portions of said metal from underneath.

16. The laser ablation machine of claim 15, further comprising:

means for controlling the operation and placement of said laser in relation to said laminated sheet to write patterns in metal carried on said dielectric substrate.

17. The laser ablation machine of claim 15, further comprising:

means for operating said laser near enough to said laminated sheet such that a vacuum atmosphere is unnecessary to obtain metal ablation by laser.

18. The method of claim 15, further comprising:

means for including a wavelength-specific energy absorbing material intermediate to said metal and dielectric substrate that will assist in laser ablation when exposed to said beam after it passes through said dielectric substrate.