Circuit board having deformation interrupting section and circuit board forming method
AssigneeOlympus Corporation
InventorTakanori Sekido
Life of this patent
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Abstract
The invention provides a circuit board that includes a flat core plate, a buildup layer having insulation layers and conductor layers alternately stacked on each other, and surface conductor layers provided on the buildup layer. The circuit board further includes deformation-interrupting sections extending through the insulation layers between the conductor layers as electric wires. The deformation-interrupting sections adjust the thermal expansion coefficient of the whole circuit board, and enhance the rigidity of the circuit board. The invention also provides a method for forming the-circuit board.
Claims8
A circuit board comprising:
- a core plate;
- a buildup layer including insulation layers and conductor layers alternately stacked on each other;
- and
- a deformation-interrupting section extending through the insulation layers between the conductor layers in contact with the conductor layers, the deformation-interrupting section being formed of a material having a lower thermal expansion coefficient and a higher Young's modulus than the insulation layers, the deformation-interrupting section interrupting deformation of the insulation layers when there is a change in ambient temperature or an external force is applied to the circuit board.
A method of forming a circuit board comprising:
- forming an first inner conductor layer on a core plate;
- forming an first interlevel insulator layers on the inner conductor layer;
- forming a hole through the first interlevel insulator layers;
- filling the hole with an insulator or a conductor, thereby forming a deformation-interrupting section, the insulator or the conductor having a lower thermal expansion coefficient and a higher Young's modulus than the first interlevel insulator layers;
- forming an second inner conductor layer on the first interlevel insulator layers with the deformation-interrupting section;
- forming a buildup layer having the interlevel insulator layers and the inner conductor layers are alternately stacked upon each other;
- and
- forming the wire or the electrode on the buildup layer.
Dependencies are inferred from the claim text.