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US 5,638,598 AGranted
Process for producing a printed wiring board
AssigneeHitachi Chemical Company, Ltd.
InventorsAkishi Nakaso, Kouichi Tsuyama, Akinari Kida, Shuichi Hatakeyama, Naoyuki Urasaki
Life of this patent
Estimating the term…
Abstract
A process for producing a wiring board involves laminating a metal foil on both sides of an insulating substrate not completely cured, followed by pressing with heating; drilling holes in the resulting laminate for connecting circuits therein; removing portions of the metal foils in narrow areas around the holes to form hollow portions in the metal foils; and filling a flowable electroconductive substance in the holes and the hollow portions.
Claims26
A process for producing a wiring board, which comprises
- laminating a pair of metal foils, one on each side of an insulating substrate not completely cured, followed by pressing with heating,
- drilling holes in the resulting laminate necessary for connecting circuits,
- removing the metal foil in narrow areas around the holes to form hollow portions within the metal foil, and
- filling a flowable electroconductive substance in the holes and the hollow portions.
1 more element
A process for producing a wiring board which comprises
- laminating a prepreg and a metal foil on both sides of one or more inner layer circuit substrates, followed by pressing with heating,
- drilling holes in the resulting laminate necessary for connecting circuits,
- removing the metal foil in narrow areas around the holes to form hollow portions within the metal foil, and
- filling a flowable electroconductive substance in the holes and the hollow portions.
1 more element
A process for producing a wiring board, which comprises
- laminating a pair of metal foils, one on each side of an insulating substrate not completely cured, followed by pressing with heating,
- drilling holes in the resulting laminate necessary for connecting circuits,
- removing the metal foil in narrow areas around the holes to form hollow portions within the metal foil,
- filling a flowable electroconductive substance in the holes and the hollow portions, followed by hardening thereof,
- removing protuberant portions of the electroconductive substance above a surrounding level,
- covering with a resist surface portions necessary for forming circuit conductors including the hardened electroconductive substance,
- removing exposed portions from the resist by etching to form an inner layer circuit substrate,
- laminating a prepreg and a metal foil on both sides of one or more inner layer circuit substrates thus produced, followed by pressing with heating,
- drilling holes in the resulting laminate necessary for connecting circuits,
- forming a metal layer on inner walls of the holes by plating,
- covering with a resist the outer metal foils necessary for forming circuits, and
- removing unnecessary metal foils by etching to form outer circuit layers.
9 more elements
A process for producing a wiring board, which comprises
- laminating a pair of metal foils, one on each side of an insulating substrate not completely cured, followed by pressing with heating,
- drilling holes in the resulting laminate necessary for connecting circuits,
- removing the metal foil in narrow areas around the holes to form hollow portions within the metal foil, and
- filling a flowable electroconductive substance in the holes and the hollow portions, followed by hardening thereof,
- removing protuberant portions of the electroconductive substance above a surrounding level,
- covering with a resist surface portions necessary for forming circuit conductors including the hardened electroconductive substance,
- removing exposed portions from the resist by etching to form an inner layer circuit substrate,
- laminating a prepreg and a metal/oil on both sides of one or more inner layer circuit substrates thus produced, followed by pressing with heating,
- drilling holes in the resulting laminate necessary for connecting circuits, said holes being smaller in diameter than those drilled in the inner layer circuit substrates,
- removing the metal foil in narrow areas around the holes to form hollow portions in the metal foil, and
- filling a flowable electroconductive substance in the holes and the hollow portions.
8 more elements
A process for producing a wiring board, which comprises
- laminating a pair of metal foils, one on each side of an insulating substrate not completely cured, followed by pressing with heating,
- forming a circular hollow portion in each of the metal foils by etching,
- drilling holes in individual hollow portions necessary for connecting circuits, and
- filling a flowable electroconductive substance in the holes and the hollow portions.
1 more element
A process for producing a wiring board which comprises
- laminating a prepreg and a metal foil on both sides of one or more inner layer circuit substrates, followed by pressing with heating,
- forming a circular hollow portion in each of the metal foils by etching,
- drilling holes in individual hollow portions necessary for connecting circuits, and
- filling a flowable electroconductive substance in the holes and the hollow portions.
1 more element
A process for producing a wiring board, which comprises
- laminating a pair of metal foils, one on each side of an insulating substrate not completely cured, followed by pressing with heating,
- forming a circular hollow portion in each of the metal foils by etching,
- drilling holes in individual hollow portions necessary for connecting circuits,
- filling a flowable electroconductive substance in the holes and the hollow portions, followed by hardening thereof,
- removing protuberant portions of the electroconductive substance above a surrounding level,
- covering with a resist surface portions necessary for forming circuit conductors including the hardened electroconductive substance,
- removing exposed portions from the resist by etching to form an inner layer circuit substrate,
- laminating a prepreg and a metal foil on both sides of one or more inner layer circuit substrates thus produced, followed by pressing with heating,
- drilling holes in the resulting laminate necessary for connecting circuits,
- forming a metal layer on inner walls of the holes by plating,
- covering with a resist the outer metal foils necessary for forming circuits, and
- removing unnecessary metal foils by etching to form outer circuit layers.
9 more elements
A process for producing a wiring board, which comprises
- laminating a pair of metal foils one on each side of an insulating substrate not completely cured, followed by pressing with heating,
- forming a circular hollow portion in each of the metal foils by etching,
- drilling holes in individual hollow portions necessary for connecting circuits,
- filling a flowable electroconductive substance in the holes and the hollow portions, followed by hardening thereof,
- removing protuberant portions of the electroconductive substance above a surrounding level,
- covering with a resist surface portions necessary for forming circuit conductors including the hardened electroconductive substance,
- removing exposed portions from the resist by etching to form an inner layer circuit substrate,
- laminating a prepreg and another metal foil on both sides of one or more inner layer circuit substrates thus produced, followed by pressing with heating,
- drilling holes in the resulting laminate necessary for connecting circuits, said holes being smaller in diameter than those drilled in the inner layer circuit substrates,
- removing metal foil in narrow areas around the holes to form hollow portions in the other metal foils, and
- filling a flowable electroconductive substance in the holes and the hollow portions.
8 more elements
Dependencies are inferred from the claim text.