Apparatus and method for stripping solder metals during the recycling of waste electrical and electronic equipment

• US 9,731,368 B2
• Filed: 07/20/2015
• Issued: 08/15/2017
• Est. Priority Date: 12/15/2011
• Status: Expired due to Fees

• Current Assignee: Entegris Incorporated
• Original Assignee: Entegris Incorporated
• Inventors: Korzenski, Michael B., Jiang, Ping, Chen, Tianniu
• Primary Examiner(s): STONER, KILEY SHAWN
• Application Number:
  US14/803,962
• Publication Number:
  US 20150322540A1
• Time in Patent Office: 757 Days
• Field of Search: None
• CPC Class Codes: B09B 3/00 Destroying solid waste or transforming solid waste into something useful or harmless
• CPC Class Codes: B09B 5/00 Operations not covered by a single other subclass or by a single other group in this subclass
• CPC Class Codes: B23K 1/018 Unsoldering; Removal of melted solder or other residues
• CPC Class Codes: B23K 3/08 Auxiliary devices therefor cleaning pipes or tubes or systems of pipes or tubes, e.g. before soldering, B08B9/02
• CPC Class Codes: B23K 37/00 Auxiliary devices or processes, not specially adapted to a procedure covered by only one of the preceding main groups eye-shields for welders worn on the operator's body or carried in the hand A61F9/00 , i.e. A61F9/02; applicable to metal-working machines other than soldering, welding, or flame-cutting machines B23Q; laser protective screens B23K26/706; protective shields for other welding methods F16P1/06
• CPC Class Codes: C22B 1/005 Preliminary treatment of scrap C22B1/02 - C22B1/26 take precedence
• CPC Class Codes: C22B 11/046 from manufactured products, e.g. from printed circuit boards, from photographic films, paper or baths
• CPC Class Codes: C22B 3/02 Apparatus therefor
• CPC Class Codes: C22B 3/04 by leaching C22B3/18 takes precedence
• CPC Class Codes: C22B 4/00 Electrothermal treatment of ores or metallurgical products for obtaining metals or alloys obtaining iron or steel C21B, C21C
• CPC Class Codes: C22B 7/006 Wet processes
• CPC Class Codes: C25C 1/00 Electrolytic production, recovery or refining of metals by electrolysis of solutions C25C5/00 takes precedence
• CPC Class Codes: H05K 2203/178 Demolishing, e.g. recycling, reverse engineering, destroying for security purposes; Using biodegradable materials
• CPC Class Codes: H05K 3/22 Secondary treatment of printed circuits H05K3/1283 takes precedence; embedding circuits in grooves by pressure H05K3/107
• CPC Class Codes: Y02P 10/20 Recycling
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y02W 30/82 Recycling of waste of electrical or electronic equipment [WEEE]

Abstract

Apparatuses and processes for recycling printed wire boards, wherein electronic components, precious metals and base metals may be collected for reuse and recycling. The apparatuses generally include a mechanical solder removal module and/or a thermal module, a chemical solder removal module, and a precious metal leaching module, wherein the modules are attached for continuous passage of the e-waste from module to module.

Claims

1. An apparatus for removing solder and/or epoxy and/or at least one casing and/or at least one printed wire board (PWB) component from a surface of a PWB having at least one casing and/or at least one PWB component affixed thereto by solder and/or epoxy, the apparatus comprising:

(a) a heating module, wherein the heating module comprises a heating mechanism and means for moving the PWB through the heating mechanism, wherein the means for moving comprise a roller chain, tracks, belts, or link chains;

(b) a chemical solder removal module comprising a container comprising a first composition, wherein the first composition effectuates the chemical removal of solder from the PWB and/or PWB components,

wherein the first composition comprises at least one oxidizing agent;

solder material;

optionally at least one lead and/or tin complexing agent;

optionally at least one organic solvent; and

optionally at least one passivating agent for passivating precious metals, tantalum-containing metals, and/or base metals, wherein the solder material comprises lead and/or tin ions dissolved and/or suspended in the composition, wherein the heating module and the chemical solder removal module are in series with one another.

2. The apparatus of claim 1, wherein the apparatus further comprises:

(c) a rinsing module; and

(d) a drying module.

3. The apparatus of claim 2, wherein the apparatus further comprises a PWB component collector positioned subsequent to the drying module.

4. The apparatus of claim 1, wherein the heating mechanism comprises agitation means for removing the PWB component(s) and/or casing(s) from the PWB, wherein the agitation means are selected from the group consisting of brushes, pressurized gases, pressurized liquids, rakes, sonic energy and laser energy.

5. The apparatus of claim 1, wherein the heating module comprises an attachment region for attaching the PWB to the means for moving.

6. The apparatus of claim 1, wherein the heating module comprises a disattachment region for disattaching the PWB from the means for moving.

7. The apparatus of claim 1, wherein the means for moving further comprises holding means.

8. The apparatus of claim 7, wherein the holding means comprise clips or clamps.

9. The apparatus of claim 7, wherein the PWB is attached to the holding means manually or automatically.

10. The apparatus of claim 6, wherein the disattachment region comprises a trough to collect the disattached PWB.

11. The apparatus of claim 1, wherein the heating module further comprises a parts drawer that the removed casing(s) and/or PWB component(s) can drop into.

12. The apparatus of claim 1, wherein the heating mechanism comprises resistance heating coils.

13. The apparatus of claim 1, wherein the heating mechanism further comprises at least one of a vent, an air scrubber and a filter.

14. The apparatus of claim 2, wherein the rinsing module effectuates rinsing by spraying a rinsing composition on the PWB and/or PWB components, dipping the PWB and/or PWB components in a volume of the rinsing composition, contacting the PWB and/or PWB components with a pad or fibrous sorbent applicator element having the rinsing composition absorbed thereon, or contacting the PWB and/or PWB components with the rinsing composition that is recirculating.

15. The apparatus of claim 1, wherein the solder comprises lead, tin, alloys thereof, and combinations thereof.

16. The apparatus of claim 1, further comprising conveying the PWB(s) and/or PWB component(s) and/or casing(s) from module to module.

17. The apparatus of claim 1, wherein the container further comprises an agitator.

19. The apparatus of claim 1, wherein the at least one oxidizing agent comprises a species selected from the group consisting of ozone, nitric acid, bubbled air, cyclohexylaminosulfonic acid, hydrogen peroxide, oxone, ammonium peroxomonosulfate, ammonium chlorite, ammonium chlorate, ammonium iodate, ammonium perborate, ammonium perchlorate, ammonium periodate, ammonium persulfate, ammonium hypochlorite, sodium persulfate, sodium hypochlorite, potassium iodate, potassium permanganate, potassium persulfate, potassium persulfate, potassium hypochlorite, tetramethylammonium chlorite, tetramethylammonium chlorate, tetramethylammonium iodate, tetramethylammonium perborate, tetramethylammonium perchlorate, tetramethylammonium periodate, tetramethylammonium persulfate, tetrabutylammonium peroxomonosulfate, peroxomonosulfuric acid, urea hydrogen peroxide, peracetic acid, sodium nitrate, potassium nitrate, ammonium nitrate, sulfuric acid, methanesulfonic acid, ethanesulfonic acid, 2-hydroxyethanesulfonic acid, n-propanesulfonic acid, isopropanesulfonic acid, isobutenesulfonic acid, n-butanesulfonic acid, n-octanesulfonic acid, benzenesulfonic acid, 4-methoxybenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, 4-aminobenzenesulfonic acid, 4-nitrobenzenesulfonic acid, toluenesulfonic acid, hexylbenzenesulfonic acid, heptylbenzenesulfonic acid, octylbenzenesulfonic acid, nonylbenzenesulfonic acid, decylbenzenesulfonic acid, undecylbenzenesulfonic acid, dodecylbenzenesulfonic acid, tridecylbenzenesulfonic acid, tetradecylbenzene sulfonic acid, hexadecylbenzene sulfonic acid, 3-nitrobenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 2-nitronaphthalenesulfonic acid, 3-nitronaphthalenesulfonic acid, 2,3-dinitrobenzenesulfonic acid, 2,4-dinitrobenzenesulfonic acid, 2,5-dinitrobenzenesulfonic acid, 2,6-dinitrobenzenesulfonic acid, 3,5-dinitrobenzenesulfonic acid, 2,4,6-trinitrobenzenesulfonic acid, 3-aminobenzenesulfonic acid, 2-aminobenzenesulfonic acid, 2-aminonaphthalenesulfonic acid, 3-aminonaphthalenesulfonic acid, 2,3-diaminobenzenesulfonic acid, 2,4-diaminobenzenesulfonic acid, 2,5-diaminobenzenesulfonic acid, 2,6-diaminobenzenesulfonic acid, 3,5-diaminobenzenesulfonic acid, 2,4,6-triaminobenzenesulfonic acid, 3-hydroxybenzenesulfonic acid, 2-hydroxybenzenesulfonic acid, 2-hydroxynaphthalenesulfonic acid, 3-hydroxynaphthalenesulfonic acid, 2,3-dihydroxybenzenesulfonic acid, 2,4-dihydroxybenzenesulfonic acid, 2,5-dihydroxybenzenesulfonic acid, 2,6-dihydroxybenzenesulfonic acid, 3,5-dihydroxybenzenesulfonic acid, 2,3,4-trihydroxybenzenesulfonic acid, 2,3,5-trihydroxybenzenesulfonic acid, 2,3,6-trihydroxybenzenesulfonic acid, 2,4,5-trihydroxybenzenesulfonic acid, 2,4,6-trihydroxybenzenesulfonic acid, 3,4,5-trihydroxybenzenesulfonic acid, 2,3,4,5-tetrahydroxybenzenesulfonic acid, 2,3,4,6-tetrahydroxybenzenesulfonic acid, 2,3,5,6-tetrahydroxybenzenesulfonic acid, 2,4,5,6-tetrahydroxybenzenesulfonic acid, 3-methoxybenzenesulfonic acid, 2-methoxybenzenesulfonic acid, 2,3-dimethoxybenzenesulfonic acid, 2,4-dimethoxybenzenesulfonic acid, 2,5-dimethoxybenzenesulfonic acid, 2,6-dimethoxybenzenesulfonic acid, 3,5-dimethoxybenzenesulfonic acid, 2,4,6-trimethoxybenzenesulfonic acid, and combinations thereof.

21. The apparatus of claim 2, wherein the drying module effectuates drying using nitrogen gas, isopropanol, regenerative air, hot air, or spin process technology.

22. The apparatus of claim 1, wherein the chemical solder removal module exposes the PWB and/or PWB components to the first composition by spraying the first composition on the PWB and/or PWB components, dipping the PWB and/or PWB components in a volume of the first composition, contacting the PWB and/or PWB components with a pad or fibrous sorbent applicator element having the first composition absorbed thereon, or contacting the PWB and/or PWB components with the first composition that is recirculating.

23. The apparatus of claim 1, further comprising a precious metal leaching module.

24. The apparatus of claim 1, wherein the first composition is an aqueous composition.

25. The apparatus of claim 1, wherein the first composition comprises at least one lead and/or tin complexing agent selected from the group consisting of as acetylacetonate, 1,1,1-trifluoro-2,4-pentanedione, 1,1,1,5,5,5-hexafluoro-2,4-pentanedione, formate, acetate, bis(trimethylsilylamide) tetramer, glycine, serine, proline, leucine, alanine, asparagine, aspartic acid, glutamine, valine, lysine, citric acid, acetic acid, maleic acid, oxalic acid, malonic acid, succinic acid, phosphonic acid, hydroxyethylidene diphosphonic acid (HEDP), 1-hydroxyethane-1,1-diphosphonic acid, nitrilo-tris(methylenephosphonic acid), nitrilotriacetic acid, iminodiacetic acid, etidronic acid, ethylenediamine, ethylenediaminetetraacetic acid (EDTA), (1,2-cyclohexylenedinitrilo)tetraacetic acid (CDTA), uric acid, tetraglyme, pentamethyldiethylenetriamine (PMDETA), 1,3,5-triazine-2,4,6-thithiol trisodium salt solution, 1,3,5-triazine-2,4,6-thithiol triammonium salt solution, sodium diethyldithiocarbamate, disubstituted dithiocarbamates (R¹(CH₂CH₂O)₂NR²CS₂Na) with one alkyl group (R²=hexyl, octyl, deceyl, dodecyl) and one oligoether (R¹(CH₂CH₂O)₂, where R¹=ethyl, butyl), ammonium sulfate, monoethanolamine (MEA), diethylenetriamine penta(methylene phosphonic acid), diethylenetriamine pentaacetic acid, propylenediamine tetraacetic acid, 2-hydroxypyridine 1-oxide, ethylendiamine disuccinic acid (EDDS), N-(2-hydroxyethyl)iminodiacetic acid (HEIDA), sodium triphosphate penta basic, ammonium chloride, sodium chloride, lithium chloride, potassium chloride, ammonium sulfate, hydrochloric acid, sulfuric acid, and combinations thereof.

26. The apparatus of claim 1, wherein the PWB and/or PWBs components are conveyed using a conveyer belt, conveying rollers, or conveying wheels from the heating module to the chemical solder removal module.

18. The apparatus of 1, wherein the container comprises a drum.

20. The apparatus of claim 18, wherein the drum is agitated such that the first composition flows past the surface of the PWB and/or PWB components.