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Electroless Initial Copper Deposition

IP.com Disclosure Number: IPCOM000100206D
Original Publication Date: 1990-Mar-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 1 page(s) / 22K

Publishing Venue

IBM

Related People

Faix, W: AUTHOR [+3]

Abstract

For plating, cards or boards having holes and which are seeded and activated with stannous chloride/palladium chloride (SnCl2/PdCl2) are immersed in a bath containing copper sulfate (CuSO4$5H2O), formaldehyde (HCHO), ethylenediaminetetracetic acid (EDTA), cyanide (CN-) and oxygen (O2). For a good take in the bath, i.e., a homogeneous initial copper layer on the hole walls and a minimum amount of voids, a HCHO content of 11 to 15 mmoles/l and a CuSO4$5H2O content of 6 - 8 g/l, with the mmoles : g ratio being between about 1.3 and about 1.8, and an Emix ranging from about -600 to about -630 mV are maintained. The EDTA, the CN- and the O2 concentration, the pH value and the temperature in the bath are kept within conventional ranges.

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Electroless Initial Copper Deposition

       For plating, cards or boards having holes and which are
seeded and activated with stannous chloride/palladium chloride
(SnCl2/PdCl2) are immersed in a bath containing copper sulfate
(CuSO4$5H2O), formaldehyde (HCHO), ethylenediaminetetracetic acid
(EDTA), cyanide (CN-) and oxygen (O2).  For a good take in the bath,
i.e., a homogeneous initial copper layer on the hole walls and a
minimum amount of voids, a HCHO content of 11 to 15 mmoles/l and a
CuSO4$5H2O content of 6 - 8 g/l, with the mmoles : g ratio being
between about 1.3 and about 1.8, and an Emix ranging from about -600
to about -630 mV are maintained.  The EDTA, the CN- and the O2
concentration, the pH value and the temperature in the bath are kept
within conventional ranges.