# US 10,375,835 B2 · Methods of treating metal surfaces and devices formed thereby

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,375,835 B2
- Document ID: US10375835B2
- Status: Granted
- Kind: B2
- Application number: 15/238,881
- Filed: 2016-08-17
- Published: 2016-12-08
- Granted: 2019-08-06
- Earliest claimed: 2009-07-06
- Assignees: Atotech Deutchland GmbH
- Applicants: Atotech Deutschland GmbH
- Inventors: Jen-Chieh Wei; Zhiming Liu; Steven Z. Shi; Werner G. Kuhr
- Web page: https://patentgrep.com/patent/US10375835B2

## CPC

- H05K 3/385: {by conversion of the surface of the metal, e.g. by oxidation, whether or not followed by reaction or removal of the converted layer}
- C08J 5/12: Bonding of a preformed macromolecular material to the same or other solid material such as metal, glass, leather, e.g. using adhesives
- C09J 5/02: involving pretreatment of the surfaces to be joined
- C23C 8/12: using elemental oxygen or ozone
- C23C 8/16: using oxygen-containing compounds, e.g. water, carbon dioxide
- C23C 8/40: using liquids, e.g. salt baths, liquid suspensions
- C23C 8/80: After-treatment
- C23C 22/63: Treatment of copper or alloys based thereon
- C23C 22/83: Chemical after-treatment
- C08J 2363/00: Characterised by the use of epoxy resins; Derivatives of epoxy resins
- C09J 2400/163: in the substrate
- C09J 2400/166: in the pretreated surface to be joined
- C09J 2400/20: Presence of organic materials
- H05K 3/389: {by the use of a coupling agent, e.g. silane}
- H05K 3/4673: {Application methods or materials of intermediate insulating layers not specially adapted to any one of the previous methods of adding a circuit layer (similar methods for protective coatings H05K3/28)}
- H05K 2203/0315: Oxidising metal
- H05K 2203/065: Binding insulating layers without adhesive, e.g. by local heating or welding, before lamination of the whole PCB
- H05K 2203/1157: Using means for chemical reduction
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H)
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)

## Abstract

The present invention relates to methods of treating metal surfaces to enhance adhesion or binding to substrates, and devices formed thereby. In some embodiments of the present invention, methods of achieving improved bonding strength without roughening the topography of a metal surface are provided. The metal surface obtained by this method provides strong bonding to resin layers. The bonding interface between the treated metal and the resin layer exhibits resistance to heat, moisture, and chemicals involved in post-lamination process steps, and therefore can suitably be used in the production of PCB's. Methods according to some embodiments of the present invention are especially useful in the fabrication of high density multilayer PCB's, in particular for PCB's having circuits with line/spacing of equal to and less than 10 microns. Methods according to other embodiments of the present invention are particularly useful in the coating of metal surfaces in a wide variety of applications.

## Claims

### Claim 1

A method of fabricating a printed circuit board, comprising the steps of:
a. stabilizing a copper surface by forming a copper oxide layer thereon;
b. conditioning the copper oxide layer with a reducing agent, the reducing agent is selected from any one or more of formaldehyde, sodium thiosulfate, sodium borohydride, a borane reducing agent represented by the general formula BH3NHRR′, wherein R and R′ are each selected from the group consisting of H, CH3 and CH2CH3, dimethylamine borane (DMAB), a cyclic borane, morpholine borane, pyridium borane, and piperidine borane; and
c. coupling one or more organic molecules to the copper oxide layer, the one or more organic molecules comprising a thermally stable base bearing one or more binding groups configured to bind the copper oxide surface and one or more attachment groups configured to attach to a resin,
wherein the stabilizing and the conditioning are carried out so as to not roughen the metal surface relative to the roughness of the metal surface prior to the stabilizing.

### Claim 2 (depends on 1)

The method of claim 1 characterized in that the copper surface is pre-cleaned with an alkaline and/or peroxide solution.

### Claim 3 (depends on 1)

The method of claim 1 characterized in that the treated copper surface is bonded to the resin.

### Claim 4 (depends on 1)

The method of claim 1 characterized in that the formed stabilization layer has a thickness of about 200 nanometers or less.

### Claim 5 (depends on 1)

The method of claim 1 characterized in that the stabilization layer has a morphology comprised of a substantially amorphous structure.

### Claim 6 (depends on 1)

The method of claim 1 characterized in that the stabilization layer has a highly distributed grain structure, and after conditioning the grains have a size in the range of 200 nanometers or less.

### Claim 7 (depends on 1)

The method of claim 1 characterized in that the copper oxide has grains, and after conditioning the grains are substantially randomly oriented.

### Claim 8 (depends on 1)

The method of claim 1 characterized in that the stabilizing the copper surface by forming a copper oxide is by exposing the copper surface to an oxidant selected from sodium chlorite, hydrogen peroxide, permanganate, perchlorate, persulphate, ozone or mixtures thereof.

### Claim 9 (depends on 1)

The method of claim 1 characterized in that the step of stabilizing the metal surface may be carried out at a temperature in the range of room temperature to about 80° C.

### Claim 10 (depends on 1)

The method of claim 1 characterized in that the conditioning of the copper oxide layer is carried out at a temperature in the range of room temperature to about 50° C.

### Claim 11 (depends on 1)

The method of claim 1 characterized in that the entire method is carried out for a time in the range of about 2 to 20 minutes.

### Claim 12 (depends on 1)

The method of claim 1 characterized in that the one or more organic molecules is selected from a porphyrin, a porphyrinic macrocycle, an expanded porphyrin, a contracted porphyrin, a linear porphyrin polymer, a porphyrinic sandwich coordination complex, or a porphyrin array.

### Claim 13 (depends on 1)

The method of claim 1 characterized in that the at least one attachment group comprises an alcohol or a phosphonate.

### Claim 14 (depends on 1)

The method of claim 1 characterized in that the at least one attachment group comprises any one of more of: amines, alcohols, ethers, other nucleophile, phenyl ethynes, phenyl allylic groups, phosphonates and combinations thereof.

### Claim 15 (depends on 1)

The method of claim 1 characterized in that the one or more organic molecules is a surface modifier moiety.

### Claim 16 (depends on 15)

The method of claim 15 characterized in that the surface modifier moiety is selected from the group consisting of a macrocyclic proligand, a macrocyclic complex, a sandwich coordination complex and polymers thereof.

### Claim 17 (depends on 15)

The method of claim 15 characterized in that the surface modifier moiety is comprised of a porphyrin.

### Claim 18 (depends on 15)

The method of claim 15 characterized in that the one or more surface modifier moieties is selected from a porphyrin, a porphyrinic macrocycle, an expanded porphyrin, a contracted porphyrin, a linear porphyrin polymer, a porphyrinic sandwich coordination complex, a porphyrin array, a silane, a tetraorgano-silane, aminoethyl-aminopropyl-trimethoxysilane, (3-Aminopropyl)trimethoxysilane, (I-[3-(Trimethoxysilyl)propyl]urea), (3-Aminopropyl) triethoxysilane, ((3-Glycidyloxypropyl)trimethoxysilane), (3-Chloropropyl) trimethoxysilane, (3-Glycidyloxypropyl)trimethoxysilane, Dimethyldichlorosilane, 3-(Trimethoxysilyl)propyl methacrylate, Ethyltriacetoxysilane, Triethoxy(isobutyl)silane, Triethoxy(octyl) silane, Tris(2-methoxyethoxy)(vinyl)silane, Chlorotrimethylsilane, Methyltrichlorosilane, Silicon tetrachloride, Tetraethoxysilane, Phenyltrimethoxysilane, Chlorotriethoxysilane, ethylene-trimethoxysilane, an amine, a sugar or any combination of the above.

### Claim 19 (depends on 15)

The method of claim 15 characterized in that the one or more surface modifier moieties is selected from the group consisting of molybdates, tungstates, tantalates, niobates, vanadates, isopoly or heteropoly acids of molybdenum, tungsten, tantalum, niobium, vanadium, and combinations of any of the foregoing.

### Claim 20 (depends on 1)

The method of claim 1 characterized in that the one or more attachment group is comprised of an aryl functional group and/or an alkyl attachment group.

### Claim 21 (depends on 20)

The method of claim 20 characterized in that the aryl functional group is comprised of a functional group selected from acetate, alkylamino, allyl, amine, amino, bromo, bromomethyl, carbonyl, carboxylate, carboxylic acid, dihydroxyphosphoryl, epoxide, ester, ether, ethynyl, formyl, hydroxy, hydroxymethyl, iodo, mercapto, mercaptomethyl, Se-acetylseleno, Se-acetylselenomethyl, S-acetylthio, S-acetylthiomethyl, selenyl, 4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl, 2-(trimethylsilyl)ethynyl, vinyl, and combinations thereof.

### Claim 22 (depends on 20)

The method of claim 20 characterized in that the alkyl attachment group comprises a functional group selected from acetate, alkylamino, allyl, amine, amino, bromo, bromomethyl, carbonyl, carboxylate, carboxylic acid, dihydroxyphosphoryl, epoxide, ester, ether, ethynyl, formyl, hydroxy, hydroxymethyl, iodo, mercapto, mercaptomethyl, Se-acetylseleno, Se-acetylselenomethyl, S-acetylthio, S-acetylthiomethyl, selenyl, 4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl, 2-(trimethylsilyl)ethynyl, vinyl, and combinations thereof.