Substrate structure, a method and an arrangement for producing such substrate structure
View Patent ↗The present invention relates to a substrate structure comprising at least two substrate layers extending in substantially parallel planes, which substrate layers are (Z-)interconnected in a direction substantially perpendicular to said planes. It comprises at least one adhesive film layer for interconnecting said at least two substrate layers, said adhesive film layer(s) comprising non-conductive portions and conductive portions. The position(s) of conductive portions is controllable such as to admit positioning of conductive portions at locations in the substrate layers where electrical conductivity is needed in a direction substantially perpendicular to the planar extension of, and between, two interconnected substrate layers.
1. A substrate structure comprising:
at least two substrate layers extending in substantially parallel planes, which substrate layers are Z-interconnected in a direction substantially perpendicular to said planes,
at least one adhesive film layer for interconnecting said at least two substrate layers, that said adhesive film layer(s) comprise(s) non-conductive portions and conductive portions, wherein position(s) of conductive portions is controllable such as to admit positioning of conductive portions at locations in the substrate layers where electrical conductivity is needed in a direction substantially perpendicular to a planar extension of, and between, two interconnected substrate layers, conductive portions being provided at locations to provide for electrical, e.g. DC/RF contact between adjacent substrate layers at said locations and
wherein the substrate layers comprise through vent holes (vias) at least at areas requiring electrical conductive connection between substrate layers for allowing encapsulated air to escape, wherein the conductive adhesive film portions comprise conductive particles.
2. A substrate structure according to claim 1 , wherein the conductive particles comprise Ag, Au, Cu or a material with similar properties.
3. A substrate structure according to 1 , wherein the adhesive film comprises a polymer material, an epoxy or a cyanate film composition.
4. A substrate structure according to claim 1 , wherein the adhesive film layer is selectively conductive at the design stage whereby the location(s) of conductive portions are controllable/selectable at the design stage.
5. A substrate structure according to claim 1 , comprising more than two substrate layers, an adhesive film layer being provided to interconnect each pair of adjacent substrate layers, allowing electrically conductive connection between substrate layers at selected portions.
6. A substrate structure according to claim 5 , further comprising a microwave Multi Chip Module (MCM).
7. A substrate structure according to claim 5 , wherein substrate layers are interconnected consecutively in any order.
8. A substrate structure according to claim 1 , wherein the substrate layers comprise ceramic or organic materials provided with recesses/cavities for electrical components/IC boards.
9. A substrate structure according to claim 1 , wherein the structure comprises a TILE multi-chip module.
10. A substrate structure according to claim 1 , wherein the diameter of a through vent hole (via) is about 200 μm.
11. A substrate structure according to claim 1 , wherein the substrate layers are flexible so as to allow for one substrate layer to adapt to another in case of unevenness.
12. A substrate structure according to claim 1 , further comprising large area substrate layers having an area up to 100×100 mm 2 or more.
13. A substrate structure according to claim 11 , wherein the substrate layers comprise an organic or ceramic material, teflon, LCP (Liquid Crystalline Polymer) or a material with similar properties.
14. A substrate structure comprising:
at least two substrate layers extending in substantially parallel planes, which substrate layers are Z-interconnected in a direction substantially perendicu 1 ar to said planes,
at least one adhesive film layer for interconnecting said at least two substrate layers, that said adhesive film layer(s) comprise(s) non-conductive portions and conductive portions, wherein position(s) of conductive portions is controllable such as to admit positioning of conductive portions at locations in the substrate layers where electrical conductivity is needed in a direction substantially perpendicular to the planar extension of, and between, two interconnected substrate layers, conductive portions being provided at locations to provide for electrical, e.g. DC/RF contact between adjacent substrate layers at said locations and
wherein the substrate layers comprise through vent holes (vias) at least at areas requiring electrical conductive connection between substrate layers for allowing encapsulated air to escape;
wherein the adhesive film layer comprises an Area Bonding Conductive film.
15. A method for interconnecting at least two substrate layers while allowing electrical contact between the substrate layers in a direction substantially perpendicular to a substrate layer planar extension, of the method comprising:
establishing where on a substrate layer an electrical contact is to be provided to the adjacent substrate layer,
providing a selectively conducting adhesive film with conductive portions and non-conductive portions on the said substrate layer such that the conductive portions will be disposed where electrical contact is to be provided, and
providing electrically conductive DC/RF connections between a plurality of multilayer substrate layers,
joining said at least two substrate layers, and
providing each substrate layer with through vent holes (vias) at least in the areas requiring electrically conductive interconnection in order to allow for escape of encapsulated air, wherein the conductive portions of the adhesive film comprise conductive particles.
16. A method according to claim 15 , further comprising:
adding a further layer to the substrate layer structure comprising at least two interconnected layers.
17. A method according to claim 16 , wherein each interconnection of a substrate layer to another is performed in consecutive steps.
18. A method according to claim 15 , wherein the substrate layers are somewhat flexible whereby during compression in a lamination step, a substrate layer substantially assumes the shape of the adjacent substrate layer.
19. A method according to claim 15 , further comprising:
laminating the substrate layers by providing the substrate layers on a flexible (rubber) plate provided on a rigid (steel) plate, thus
exerting the required pressure homogeneously and applying the appropriate heat.
20. A method according to claim 15 , further comprising using an Area Bonding Conductive film as adhesive film.
21. A method according to claim 15 , further comprising producing microwave Multi Chip Modules.
22. A method according to claim 15 , wherein the substrate layers comprise large multilayer substrate layers having a size up to 100×100 mm 2 or more, of any shape.
23. An arrangement for carrying out the method according to claim 15 , comprising a fixture with a flexible plate provided on a first rigid plate cooperating with another rigid plate, pressuring means for exerting a pressure on the substrate layers provided between the rigid plate and the rubber plate provided on the first rigid plate and heating means for heating in order to anneal the adhesive film(s) and Z-interconnect the substrate layers.
24. A method according to claim 15 , wherein the conductive portions of the adhesive film comprise conductive particles of Ag, Au.