US4865877A
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US
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Method for roughening ceramic substrate surface and method for manufacturing printed circuit board using surface-roughened ceramic substrate
Assignee: Panasonic Electric Works Co Ltd
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Filing: 1987-10-27
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Granted: 1989-09-12
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Expires: 2007-10-27
Abstract
Abstract A method for roughening a ceramic substrate surface includes a step of sequentially taking out part of roughening a treatment bath of phosphoric acid into which the ceramic substrate is dipped prior to a formation on the substrate of conductor a layer, and subjecting the part of the bath taken out sequentially to regeneration treatment. Any increase in the viscosity due to dehydrating condensation of the roughening bath can be thereby effectively restrained to prolong effective life of the bath. Further, the surface roughened ceramic substrate can be provided thereon with conductor layers smoothly formed by means of a plating and eventually with a circuit pattern as well as a resistor formed on the pattern within an inert gas atmosphere.
Inventors
- 👤 Noboru Yamaguchi
- 👤 Satoru Ogawa
- 👤 Susumu Kajita
- 👤 Izuru Yoshizawa
- 👤 Kiyotaka Waki
- 👤 Masayuki Ishihara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:03
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/38; C; C04; C04B; C04B41/00; C04B41/009; C04B41/53; C04B41/5338; C04B41/5353; C04B41/80; C04B41/91; C23; C23C; C23C18/00; C23C18/16; C23C18/18; C23C18/1851; C23C18/1862; C23C18/1865; C23C18/1872; C23C18/1886; C23C18/1893; H05K3/381; C04B2111/00; C04B2111/00474; C04B2111/00844; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K2203/00; H05K2203/11; H05K2203/1105; H05K3/10; H05K3/18; H05K3/181
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
80 words
A method for roughening ceramic substrate surfaces, comprising the steps of dipping a ceramic substrate in a heated phosphoric acid bath prior to a formation of conductor layers on said ceramic substrate surfaces to provide a ceramic printed-circuit board, sequentially taking out phosphoric acid from said bath, hydrolyzing said phosphoric acid to prevent viscosity increase of said bath due to dehydration condensation of said phosphoric acid, and returning the hydrolyzed phosphoric acid to said bath to sequentially regenerate the bath.
Claim 2
Independent Claim
80 words
A method for roughening ceramic substrate surfaces, comprising the steps of dipping a ceramic substrate in a heated phosphoric acid bath prior to a formation of conductor layers on said ceramic substrate surfaces to provide a ceramic printed-circuit board, sequentially taking out phosphoric acid from said bath, hydrolyzing said phosphoric acid to prevent viscosity increase of said bath due to dehydration condensation of said phosphoric acid, and returning the hydrolyzed phosphoric acid to said bath to sequentially regenerate the bath.
Claim 3
Dependent Claim
21 words
A method according to claim 1, wherein said phosphoric acid bath is kept at a temperature of 250° to 360° C.
Claim 4
Dependent Claim
17 words
A method according to claim 1, wherein said phosphoric acid bath is prevented from becoming turbid white.
Claim 5
Dependent Claim
22 words
A method according to claim 1, wherein said dipping of said ceramic substrate into said bath is for 3 to 10 minutes.
Claim 6
Dependent Claim
25 words
A method according to claim 1, wherein said phosphoric acid bath is made to maintain its aluminum concentration to be less than 1 wt %.
Claim 7
Dependent Claim
27 words
A method according to claim 1, wherein said phosphoric acid is made to maintain its more than tetraphosphoric acid concentration to be less than 5 mol %.
Claim 8
Dependent Claim
16 words
A method according to claim 1, wherein said treating step includes a step of hot dehydration.
Claim 9
Dependent Claim
22 words
A method according to claim 7, wherein said hot dehydration step is performed substantially at a temperature of 160° to 240° C.
Claim 10
Dependent Claim
15 words
A method according to claim 7, wherein said treating step includes a step of hydrolysis.
Claim 11
Dependent Claim
24 words
A method according to claim 9, wherein said hydrolyzation step is performed substantially with a hot bath of the room temperature to 100° C.
Claim 12
Dependent Claim
51 words
A method according to claim 1, wherein said taking out, treating and returning steps are performed by maintaining a rate at which said phosphoric acid is partly taken out from said bath and a rate at which treated acid is returned to the bath for said dipping to be substantially identical.
Claim 13
Dependent Claim
33 words
A method according to claim 1, wherein said treating step is performed in a recirculating cycle of sequentially performed partial acid taking-out, hydrolyzing, fresh phosphoric acid supplying, hot dehydrating and regenerated-bath returning steps.
Claim 14
Dependent Claim
25 words
A method according to claim 12, wherein said cycle of recirculation includes a step of cooling said acid taken out prior to said hydrolyzing step.
Claim 15
Dependent Claim
23 words
A method according to claim 1, wherein said ceramic substrate is an alumina substrate having a grain size of 1 to 5 μm.
Claim 16
Dependent Claim
54 words
A method according to claim 1, wherein said ceramic substrate is an alumina substrate of a composition of 92 to 99.5 wt % of Al 2 O 3 , and 0.5 to 8 wt % in the sum of CaO, MgO and SiO 2 , in which CaO being 0 to 1 wt %.
Claim 17
Independent Claim
81 words
A method for manufacturing a ceramic printed-circuit board, comprising the steps of dipping a ceramic substrate in a surface roughening bath to roughen surfaces of said substrate prior to forming conductor layers on said surfaces for providing said ceramic printed-circuit board, and forming said conductor layers by means of an elctroless plating while providing to the layers exteriorly communicating interstices in thickness direction of the layers, thereby to permit discharge of any gases generated during subsequent heat treatment of said board.
Claim 18
Independent Claim
81 words
A method for manufacturing a ceramic printed-circuit board, comprising the steps of dipping a ceramic substrate in a surface roughening bath to roughen surfaces of said substrate prior to forming conductor layers on said surfaces for providing said ceramic printed-circuit board, and forming said conductor layers by means of an elctroless plating while providing to the layers exteriorly communicating interstices in thickness direction of the layers, thereby to permit discharge of any gases generated during subsequent heat treatment of said board.
Claim 19
Dependent Claim
15 words
A method according to claim 16, wherein said surface roughening bath is of phosphoric acid.
Claim 20
Dependent Claim
20 words
A method according to claim 16, wherein said ceramic substrate having said conductor layers is subjected to a heat treatment.
Claim 21
Dependent Claim
19 words
A method according to claim 18, wherein said heat treatment is carried out substantially at 500° to 1,083° C.
Claim 22
Dependent Claim
24 words
A method according to claim 16, wherein said conductor layers are formed to have at least one of grain, spherical and pillar crystal structures.
Claim 23
Dependent Claim
19 words
A method according to claim 17, wherein said surface roughening bath is heated substantially at 250° to 360° C.
Claim 24
Dependent Claim
23 words
A method according to claim 16, wherein said surface roughened ceramic substrate is subjected to an activation treatment to act as a catalyst.
Claim 25
Dependent Claim
20 words
A method according to claim 22, wherein said activation treatment is performed by a sensitizing activation process of two-pack type.
Claim 26
Dependent Claim
21 words
A method according to claim 22, wherein said activation treatment is performed by a catalyst acceleration process of a single-pack type.
Claim 27
Dependent Claim
27 words
A method according to claim 20, wherein said electroless plating is carried out with a plating bath of a basic composition of Cu, EDTA, NaOH and HCHO.
Claim 28
Independent Claim
98 words
A method for manufacturing a ceramic both-surface printed-circuit board, comprising the steps of dipping a ceramic substrate in a heated phosphoric acid bath to roughen surfaces of said substrate prior to forming conductor layers on said surfaces for providing a ceramic printed-circuit board, forming a circuit pattern on said roughened substrate by means of an electroless plating performed while providing to said conductor layers exteriorly communicating interstices in thickness direction of the layers, thereby to permit discharge of any gases generated during subsequent heat treatment of said board, and forming predetermined resistors with respect to said circuit pattern.
Claim 29
Independent Claim
98 words
A method for manufacturing a ceramic both-surface printed-circuit board, comprising the steps of dipping a ceramic substrate in a heated phosphoric acid bath to roughen surfaces of said substrate prior to forming conductor layers on said surfaces for providing a ceramic printed-circuit board, forming a circuit pattern on said roughened substrate by means of an electroless plating performed while providing to said conductor layers exteriorly communicating interstices in thickness direction of the layers, thereby to permit discharge of any gases generated during subsequent heat treatment of said board, and forming predetermined resistors with respect to said circuit pattern.
Claim 30
Dependent Claim
28 words
A method according to claim 26, which further comprises a step of forming holes in said ceramic substrate for being used as through-holes, prior to said surface roughening.
Claim 31
Dependent Claim
23 words
A method according to claim 26, wherein said step of forming said resistors include steps of applying, drying and firing a resistor paste.
Claim 32
Dependent Claim
20 words
A method according to claim 28, wherein said firing of said resistor paste is performed within an inert gas atmosphere.
Claim 33
Dependent Claim
19 words
A method according to claim 29, wherein said firing of said resistor paste is performed within a nitrogen atmosphere.
Claim 34
Dependent Claim
29 words
A method according to claim 30, wherein said firing of said resistor paste at a temperature at which glass frits contained in the paste melt onto said substrate surface.
Claim 35
Dependent Claim
21 words
A method according to claim 26, wherein said firing of said resistor paste is performed substantially at 500° to 1,083° C.
Claim 36
Dependent Claim
28 words
A method according to claim 26, wherein said resistor formed with said circuit pattern of said conductor layers is subjected to a trimming into a predetermined resistance value.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-11 | 1993-03-13 | 1993-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-11 | 1997-03-13 | 1997-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-11 | 2001-03-13 | 2001-09-12 | $7700.00 | Window Closed / Lapsed |