MASK-LESS FABRICATION OF THIN FILM BATTERIES

• US 20170214062A1
• Filed: 03/10/2017
• Published: 07/27/2017
• Est. Priority Date: 06/17/2011
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: JIANG, Chong, SONG, Daoying, KWAK, Byung-Sung Leo
• Application Number:
  US15/456,007
• Publication Number:
  US 20170214062A1
• Time in Patent Office: Days
• CPC Class Codes: B01J 19/121 Coherent waves, e.g. laser beams lasers per se H01S3/00
• CPC Class Codes: B01J 2219/0879 Solid
• CPC Class Codes: B01J 2219/12 Processes employing electromagnetic waves
• CPC Class Codes: C01B 21/097 containing phosphorus atoms
• CPC Class Codes: C01G 51/42 containing alkali metals, e.g. LiCoO2
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: H01M 10/0404 Machines for assembling batteries
• CPC Class Codes: H01M 10/0436 Small-sized flat cells or batteries for portable equipment
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: H01M 10/0585 of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 2300/0068 inorganic
• CPC Class Codes: H01M 4/04 Processes of manufacture in general
• CPC Class Codes: H01M 4/0426 Sputtering
• CPC Class Codes: H01M 4/139 Processes of manufacture
• CPC Class Codes: H01M 4/1395 of electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/382 Lithium H01M4/405 takes precedence
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 50/536 characterised by the method of fixing the leads to the electrodes, e.g. by welding
• CPC Class Codes: H01M 6/005 : Devices for making primary cells
• CPC Class Codes: H01M 6/185 : with oxides, hydroxides or oxysalts as solid electrolytes
• CPC Class Codes: H01M 6/186 : Only oxysalts-containing solid electrolytes
• CPC Class Codes: H01M 6/40 : Printed batteries , e.g. thin film batteries
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49108 : Electric battery cell making

Abstract

Thin film batteries (TFB) are fabricated by a process which eliminates and/or minimizes the use of shadow masks. A selective laser ablation process, where the laser patterning process removes a layer or stack of layers while leaving layer(s) below intact, is used to meet certain or all of the patterning requirements. For die patterning from the substrate side, where the laser beam passes through the substrate before reaching the deposited layers, a die patterning assistance layer, such as an amorphous silicon layer or a microcrystalline silicon layer, may be used to achieve thermal stress mismatch induced laser ablation, which greatly reduces the laser energy required to remove material.

Claims

1. A thin film battery, comprising:

a stack of patterned layers on a substrate, the stack comprising a cathode current collector layer, a cathode layer, an electrolyte layer, an anode layer, and an anode current collector layer, wherein the stack is laser die patterned, and wherein the stack is laser patterned to reveal a cathode current collector area and a portion of the electrolyte layer adjacent to the cathode current collector area, and wherein a part of the thickness of the portion of the electrolyte layer is laser removed to form a step in the electrolyte layer; and

an encapsulation layer over the stack of patterned layers.

2. The thin film battery of claim 1, wherein the substrate comprises glass.

3. The thin film battery of claim 1, wherein the cathode layer comprises LiCoO₂.

4. The thin film battery of claim 1, wherein the electrolyte layer comprises LiPON.

5. The thin film battery of claim 1, wherein the anode layer comprises lithium metal.

6. The thin film battery of claim 1, wherein the encapsulation layer comprises a polymer.

7. The thin film battery of claim 1, further comprising a die patterning assistance layer on the substrate between the substrate and the stack, the stack of patterned layers being deposited on the die patterning assistance layer, wherein the substrate is transparent to laser light and wherein the die patterning assistance layer includes a layer of material for achieving thermal stress mismatch between the die patterning assistance layer and the substrate.

8. The thin film battery of claim 7, wherein the die patterning assistance layer comprises a material selected from the group consisting of amorphous silicon, microcrystalline silicon and LiCoO₂.

9. The thin film battery of claim 1, further comprising a bonding pad layer covering the encapsulation layer and the cathode current collector area.

10. The thin film battery of claim 9, wherein the bonding pad layer comprises aluminum.

11. The thin film battery of claim 9, further comprising a dielectric layer covering the stack, the dielectric layer being deposited over the bonding pad layer.

12. The thin film battery of claim 11, wherein the dielectric layer comprises silicon nitride.

13. The thin film battery of claim 11, further comprising a bonding pad covering the stack, the bonding pad being deposited over the dielectric layer, the dielectric layer electrically isolating the bonding pad layer and the bonding pad, the bonding pad being electrically connected to the anode current collector layer through an aperture in the encapsulation layer and the dielectric layer.

14. The thin film battery of claim 13, wherein the bonding pad comprises aluminum.