US3951602A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spectrophotometric formaldehyde-copper monitor
Assignee: FCI Americas Technology LLC
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Filing: 1974-06-25
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Granted: 1976-04-20
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Expires: 1994-06-25
Abstract
Abstract In an apparatus comprising a spectrophotometer, an inspection cell, and an electroless copper plating bath containing copper ions and formaldehyde for measuring the copper ion concentration of the bath spectrophotometrically, the improvement which comprises method and apparatus for spectrophotometrically measuring the formaldehyde concentration of the bath. The improved apparatus includes a source of reagent reactive with formaldehyde and a reaction vessel, useful for reacting the reagent with formaldehyde to produce a reaction product photoindicative of formaldehyde concentration.
Inventors
- 👤 Douglas Stuart Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:22
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/75; G01N21/77; G01N21/78; C; C23; C23C; C23C18/00; C23C18/16; C23C18/1601; C23C18/1619; C23C18/1633; C23C18/1675; C23C18/1683; C23C18/31; C23C18/38; C23C18/40; C23C18/405; Y; Y10; Y10T; Y10T436/00; Y10T436/20; Y10T436/200833; Y10T436/202499
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
62 words
In a method for the spectrophotometric measurement of the concentration of copper ion in an electroless copper plating bath containing copper ions and formaldehyde, the improvement which comprises: reacting a reagent containing acetylacetone and ammonium salt with said formaldehyde to produce a reaction product photoindicative of formaldehyde concentration in said bath, and spectrophotometrically measuring said reaction product to indicate said formaldehyde concentration.
Claim 2
Dependent Claim
62 words
In a method for the spectrophotometric measurement of the concentration of copper ion in an electroless copper plating bath containing copper ions and formaldehyde, the improvement which comprises: reacting a reagent containing acetylacetone and ammonium salt with said formaldehyde to produce a reaction product photoindicative of formaldehyde concentration in said bath, and spectrophotometrically measuring said reaction product to indicate said formaldehyde concentration.
Claim 3
Dependent Claim
16 words
The improvement as claimed in claim 1 wherein the reagent is further comprised of acetic acid.
Claim 4
Dependent Claim
94 words
In an apparatus including an electroless copper plating bath containing copper ions and formaldehyde, a spectrophotometer, and an inspection cell adjacent to the spectrophotometer and in communication with said bath for the determination of copper ion concentration in samples from the bath, the improvement comprising: a source of reagent reactive with said formaldehyde to produce a reaction product photoindicative of said formaldehyde concentration; a reaction vessel communicating with said source; means for delivering samples of said bath solution to said reaction vessel; and means for delivery of said reaction product to said inspection cell.
Claim 5
Dependent Claim
94 words
In an apparatus including an electroless copper plating bath containing copper ions and formaldehyde, a spectrophotometer, and an inspection cell adjacent to the spectrophotometer and in communication with said bath for the determination of copper ion concentration in samples from the bath, the improvement comprising: a source of reagent reactive with said formaldehyde to produce a reaction product photoindicative of said formaldehyde concentration; a reaction vessel communicating with said source; means for delivering samples of said bath solution to said reaction vessel; and means for delivery of said reaction product to said inspection cell.
References Cited (Backward Citations)
US3532519A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-20 | 1979-10-20 | 1980-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-20 | 1983-10-20 | 1984-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-20 | 1987-10-20 | 1988-04-20 | $7700.00 | Window Closed / Lapsed |