Circuit module and method of manufacturing the same
Manufacturing method and circuit module, which comprises an insulator layer ( 1 ) and, inside the insulator layer ( 1 ), at least one component ( 6 ), which comprises contact areas ( 7 ), the material of which contains a first metal. On the surface of the insulator layer ( 1 ) are conductors ( 22 ), which comprise at least a first layer ( 12 ) and a second layer ( 32 ), in such a way that at least the second layer ( 32 ) contains a second metal. The circuit module comprises contact elements between the contact areas ( 7 ) and the conductors ( 22 ) for forming electrical contacts. The contact elements, for their part, comprise, on the surface of the material of the contact area ( 7 ), an intermediate layer ( 2 ), which contains a third metal, in such a way that the first, second, and third metals are different metals and the contact surface area (A CONT 1 ), between the intermediate layer ( 2 ) and the contact area ( 7 ) is less that the surface area (A PAD ) of the contact area ( 7 ).
1. Circuit module, which comprises;
an insulator layer,
inside the insulator layer, at least one component, which comprises contact areas, the material of which contains a first metal,
on the surface of the insulator layer, conductors, which comprise a first layer of copper on the surface of the insulator layer, and a second layer of copper on the surface of the first copper layer, and
contact elements between the contact areas and the conductors for forming electrical contacts, which contact elements comprise an intermediate layer, which contains a third metal, on the surface of the material of the contact area,
wherein the first, second, and third metals are different metals, and
the contact surface area between the intermediate layer and the contact area is less than the surface area of the contact area.
2. Circuit module according to claim 1 , in which the first metal is aluminium, the second metal is copper, and the third metal is at least one of the metals zinc and nickel.
3. Circuit module according to claim 1 , in which the first metal is gold, the second metal is copper, and the third metal is nickel.
4. Circuit module according to claim 1 , in which the material of the contact areas is mainly aluminium.
5. Circuit module according to claim 1 , in which the intermediate layer comprises a layer containing zinc.
6. Circuit module according to claim 5 , in which the intermediate layer comprises, in addition to the layer containing zinc, at least one second intermediate metal layer.
7. Circuit module according to claim 6 , in which the at least one second intermediate metal layer is of copper grown by a chemical growing process.
8. Circuit module according to claim 7 , in which the intermediate layer comprises at least one layer of nickel and/or of nickel and aluminium between the layer containing zinc and the copper layer.
9. Circuit module according to claim 5 , in which the layer containing zinc contains zinc, copper, nickel, and iron.
10. Circuit module according to claim 1 , in which the width of the contact surface between the contact element and the contact area of the component is 0-20% less than the greatest width of the contact element in the same direction.
11. Circuit module according to claim 1 , in which the height of the contact element is less than or equal to the greatest width of the contact element.
12. Circuit module according to claim 1 , in which the insulator layer contains at least one layer of fibre material, in which there is an opening in the fibre material for the component, as well as a unified polymer layer, which is attached to the fibre material and to the component.
13. Circuit module according to claim 1 , which comprises a polymer layer, between the conductors and the component, in which layer there are contact holes for the contact elements, and in which the contact elements fill the contact holes completely.
14. Circuit module according to claim 13 , in which the polymer layer between the conductors and the component comprises a first and a second polymer layer, in which the first polymer layer is of a first polymer and the second polymer layer is of a hardened adhesive.
15. Circuit module according to claim 14 , in which the first polymer layer and the second polymer layer are local, in such a way that they exist essentially only at the location of the component.
16. Circuit module according to claim 1 , in which the component comprises a passivation layer on the surface of the component and the contact areas are located inside openings in the passivation layer, in which case the intermediate layer extends through the opening in the passivation layer.
17. A circuit module, which Comprises;
an insulator layer,
inside the insulator layer, at least one component, which comprises contact areas, the material of which contains a first metal,
on the surface of the insulator layer, conductors, which comprise at least a first layer and a second layer, in such a way that at least the second layer contains a second metal, and
contact elements between the contact areas and the conductors for forming electrical contacts, which contact elements comprise an intermediate laver, which contains a third metal, on the surface of the material of the contact area, in which part of the intermediate layer extends along the side walls of the contact elements between the contact areas and the conductors,
wherein the first, second, and third metals are different metals, and
the contact surface area between the intermediate layer and the contact area is less than the surface area of the contact area.
18. Circuit module according to claim 17 , in which the contact elements comprise a copper core made using an electrochemical growing method, which, in the direction of the side wall and component, is bounded by the intermediate layer and, in the direction of the conductor connects continuously, i.e. without an interface, to the material of the second layer of the conductor.
19. Circuit module according to claim 17 , in which the part of the intermediate layer extending along the side walls of the of the contact elements contains copper grown by a chemical growing method, or nickel grown by a chemical growing method.
20. A circuit module which comprises;
an insulator layer,
inside the insulator layer, at least one component, which comprises contact areas, the material of which contains a first metal,
on the surface of the insulator layer, conductors, which comprise a first layer of copper on the surface of the insulator layer, an intermediate layer on the surface of the first copper layer, and a second layer of copper on the surface of the intermediate layer, and
contact elements between the contact areas and the conductors for forming electrical contacts, which contact elements comprise an intermediate layer, which contains a third metal, on the surface of the material of the contact area,
wherein the first, second, and third metals are different metals, and
the contact surface area between the intermediate layer and the contact area is less than the surface area of the contact area.
21. Circuit module according to claim 20 , in which the part of the intermediate layer between the first and second coppers layers comprises copper grown by a chemical growing method or nickel grown by a chemical growing method.
22. Circuit module according to claim 20 , in which the intermediate layer comprises a layer containing zinc.
23. Circuit module according to claim 20 , which comprises a polymer layer, between the conductors and the component, in which layer there are contact holes for the contact elements, and in which the contact elements fill the contact holes completely.
24. Method for manufacturing a circuit module, the method comprising;
taking a conductor foil,
making contact openings in the conductor foil for the manufacture of contact elements,
taking a first component, which comprises contact areas, the material of which contains a first metal,
attaching the first component to the conductor foil by means of a first polymer layer,
attaching at least one additional component within the circuit module by means of a second polymer layer, said second polymer layer differing from the first polymer layer by at least one property of the polymer layers,
manufacturing an insulator layer around the component attached to the conductor foil,
making contact holes in the polymer layer at the positions of the contact areas, in such a way that the contact surface area between each contact hole and the corresponding contact area is less than the surface area of the contact area, and
growing an intermediate layer at least on the surface of the contact areas in the contact holes, the intermediate layer containing at least a third metal,
growing a layer of a second metal, which layer is in contact with the surface of the intermediate layer and extends along the conductors being made, and
forming conductors by patterning the conductor foil, and, if necessary, also the intermediate layer on the surface of the conductor foil and/or the layer of a second metal.
25. Method according to claim 24 , in which
the contact openings are manufactured before the attachment of the component,
the component is attached to a conductor foil equipped with contact openings, and
after the attachment of the component, contact holes are opened through the contact openings.
26. Method according to claim 25 , in which the contact holes are opened through the contact openings using a CO 2 laser, in which case the conductor foil is used as a mask.
27. Method according to claim 24 , in which the first metal is aluminium, the second metal is copper, and the third metal contains at least one of the metals zinc and nickel.
28. Method according to claim 24 , in which the first metal is gold, the second metal is copper, and the third metal is nickel.
29. Method according to claim 24 , in which the intermediate layer comprises a layer containing zinc, which is manufactured using a double zincate process.
30. Method according to claim 24 , in which the intermediate layer comprises a layer containing nickel, which is manufactured using a chemical nickel-growing method.
31. Method according to claim 24 , in which the intermediate layer comprises a layer containing copper, which is manufactured using a chemical copper-growing method.
32. Method according to any of claim 24 , in which the insulator layer is manufactured in such a way that at least one insulator sheet containing a fibre material and a pre-hardened polymer is taken,
a hole for the component is made in the insulator sheet containing a fibre material, and
the insulator sheet or insulator sheets are laminated together with the conductor foil and its related structures.
33. Method according to claim 24 , in which the surface of the conductor foil, to which the component is attached, comprises a uniform insulator layer.
34. Method according to claim 24 , in which a spacer is placed between the component and the conductor foil.
35. Method according to claim 24 , in which the component to be attached is a bumpless component.