Multilayer circuit board, process of manufacturing same, board for multilayer circuitry, and electronic apparatus
First Claim
1. A multilayer circuit board comprising a laminate of at least one insulating layer and a plurality of wiring layers separated from one another by the insulating layer, wherein at least one of the wiring layers is formed by a composite material including a first metal layer and a second metal layer formed on one or both sides of the first metal layer, the first metal layer having a smaller coefficient of thermal expansion than the second metal layer, the second metal layer having a higher electric conductivity than the first metal layer, wherein the insulating layer in contact with the second metal layer has a blind via-hole whose bottom portion is formed by a surface of the second metal layer, and the composite material and the wiring layers are in a layer-to-layer interconnection with one another through a layer-to-layer interconnection portion which is in contact with the second metal layer formed in the blind via-hole.
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Accused Products
Abstract
A multilayer circuit board having a high level of reliability in terms of electric connection against temperature changes caused by the actual operation of electronic equipment, a manufacturing process, a substrate for multilayer circuitry, and an electronic apparatus. The multilayer circuit board comprises a laminate of at least one insulating layer and at least one wiring layer, wherein the wiring layer is formed by a composite member comprising a first metal layer and a second metal layer formed on one or both sides of the first metal layer, the first metal layer having a smaller coefficient of thermal expansion than the second metal layer, the second metal layer having a higher electric conductivity than the first metal layer, wherein the insulating layer has a blind via-hole with a bottom provided by a surface of the second metal layer, the circuit board further comprising a layer-to-layer interconnection portion on the surface of the insulating layer and in the blind via-hole, wherein the layer-to-layer interconnection portion in the blind via-hole is formed in such a manner as to be in contact with the surface of the second metal layer.
17 Citations
13 Claims
- 1. A multilayer circuit board comprising a laminate of at least one insulating layer and a plurality of wiring layers separated from one another by the insulating layer, wherein at least one of the wiring layers is formed by a composite material including a first metal layer and a second metal layer formed on one or both sides of the first metal layer, the first metal layer having a smaller coefficient of thermal expansion than the second metal layer, the second metal layer having a higher electric conductivity than the first metal layer, wherein the insulating layer in contact with the second metal layer has a blind via-hole whose bottom portion is formed by a surface of the second metal layer, and the composite material and the wiring layers are in a layer-to-layer interconnection with one another through a layer-to-layer interconnection portion which is in contact with the second metal layer formed in the blind via-hole.
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6. A multilayer circuit board comprising at least one wiring layer formed in insulating layers, wherein at least one of the wiring layers is formed by a composite material comprising a first metal layer and a second metal layer formed on either side of the first metal layer, the first metal layer having a smaller coefficient of thermal expansion than the second metal layer, the second metal layer having a higher electric conductivity than the first metal layer, wherein the insulating layers facing one another via the composite material have a blind via-hole whose bottom portion is formed by a surface of the second metal layer, wherein the circuit board further comprises a layer-to-layer interconnection portion on the surface of the insulating layer and in the blind via-hole, wherein the layer-to-layer interconnection portion in each blind via-hole is formed in such a manner as to be in contact with the second metal layer surface.
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7. A multilayer circuit board comprising a laminate of at least one insulating layer and a plurality of wiring layers separated one another by said insulating layer, wherein at least one of the wiring layers is formed by a composite material comprising an iron-nickel alloy layer having a copper layer formed on one or both sides thereof, wherein the insulating layer in contact with a surface of the copper layer has a blind via-hole whose bottom portion is constituted by a surface of the copper layer, wherein a layer-to-layer interconnection portion is provided on the surface of the insulating layer and in the blind via-hole, the layer-to-layer interconnection portion being formed in such a manner as to be in contact with the copper layer surface.
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8. A multilayer circuit board comprising insulating layers in which at least one wiring layer is formed, wherein at least one of the wiring layers is formed by a composite material of an iron-nickel alloy having a copper layer formed on both sides thereof, wherein each of the insulating layers facing one another via the composite material has a blind via-hole whose bottom portion is constituted by a surface of the second metal layer, wherein the circuit board further comprises a layer-to-layer interconnection portion on the surface of the insulating layer and in the blind via-hole, wherein the layer-to-layer interconnection portion in each blind via-hole is formed in such a manner as to be in contact with the second metal layer surface.
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9. A process of manufacturing a multilayer circuit board in which at least one insulating layer and a plurality of wiring layers separated from one another by the insulating layer are laminated, the process comprising the steps of:
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forming a wiring on the wiring layer in a composite material including the wiring layer and the insulating layer integrally formed on the wiring layer, the wiring layer including a second metal layer formed on one or both sides of a first metal layer, wherein the second metal layer has a larger coefficient of thermal expansion than the first metal layer; forming a blind via-hole in the insulating layer such that a bottom portion of the via-hole is formed by a surface of the second metal layer;
forming a layer-to-layer interconnection portion on the surface of the insulating layer, and in the blind via-hole and the composite material and the wiring layers are in a layer-to-layer interconnection with one another through a layer-to-layer interconnection portion which is in contact with the second metal layer formed in the blind via-hole. - View Dependent Claims (10)
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11. A process of manufacturing multilayer circuit board comprising an insulating layer in which at least one wiring layer is formed, the process comprising the steps of:
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forming a wiring on the wiring layer in a composite material including the wiring layer and the insulating layer integrally formed on the wiring layer, the wiring layer comprising a second metal layer formed on one or both sides of a first metal layer, wherein the second metal layer has a larger coefficient of thermal expansion than the first metal layer; forming a blind via-hole in each insulating layer on the opposite surface between which the wiring layer is inserted, the blind via-hole having a bottom portion formed by a surface of the second metal layer; and forming a layer-to-layer interconnection portion on the surface of the insulating layers in each blind via-hole and the composite material and wiring layers are in a layer-to-layer interconnection with one another through a layer-to-layer interconnection portion which is in contact with the second metal metal layer formed in the blind via-hole.
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12. A process of manufacturing a multilayer circuit board comprising the steps of:
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preparing a wiring layer formed by a composite material including a first metal layer and a second metal layer formed on one or both sides of the first metal layer, the second metal layer having a higher electric conductivity and a greater coefficient of thermal expansion than the first metal layer; forming a substrate for multilayer circuitry by laminating the wiring layer on one or both sides of an insulating resin layer; forming a predetermined wiring on the wiring layer; covering the wiring formed in the wiring forming step with an insulating layer; forming a blind via-hole in the insulating layer, or the insulating layer and insulating resin layer, the blind via-hole having a bottom portion formed by a surface of the second metal layer; and
forming a layer-to-layer interconnection portion on the surface of the insulating layer and in the blind via-hole and the composite material and wiring layers are in a layer-to-layer interconnection with one another through a layer-to-layer interconnection portion which is in contact with the second metal layer formed in the blind via-hole.
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13. A process of manufacturing a multilayer circuit board comprising the steps of:
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preparing a wiring layer formed by a composite material comprising a first metal layer and a second metal layer formed on both sides of the first metal layer, the second metal layer having a higher electric conductivity and a greater coefficient of thermal expansion than the first metal layer; forming a substrate for multilayer circuitry by laminating the wiring layer on both sides of an insulating layer; forming a predetermined wiring on the wiring layer formed in the wiring preparing step; covering the wiring formed in the wiring forming step with an insulating layer; forming a blind via-hole in each insulating layer, or the insulating layer and insulating resin layer on the opposite surfaces between which the insulating layer is inserted, the blind via-hole having a bottom portion formed by a surface of the second metal layer; and forming a layer-to-layer interconnection portion on the surface of the insulating layer and in the blind via-hole and the composite material and wiring layers are in a layer-to-layer interconnection with one another through a layer-to-layer interconnection portion which is in contact with the second metal layer formed in the blind via-hole.
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Specification