Mutliple lamination high density interconnect process and structure employing thermoplastic adhesives having sequentially decreasing T.sub.G ' s
AssigneeGeneral Electric Company
InventorsHerbert S. Cole, Jr., James W. Rose, Charles W. Eichelberger, Robert J. Wojnarowski
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Abstract
A high density interconnect structure incorporating a plurality of laminated dieletric layers is fabricated using thermoplastic adhesive layers of progressively lower glass transition temperature in order to maintain the stability of the already fabricated structure during the addition of the later laminations. This structure also facilitates the removal of only a portion of the high density interconnect structure where a fault in the system can be corrected in one of the upper layers of the high density interconnect structure.
Claims16
A high density interconnect structure comprising:
- a plurality of semiconductor chips each having contact pads on a first surface thereof;
- a first layer of dielectric material bonded to said semiconductor chips, said first layer of dielectric material comprising first lower and first upper sublayers, said first lower sublayer being thermoplastic and having a first glass transition temperature T.sub.g1, said first upper sublayer being stable over a range of temperatures above said first glass transition temperature, said first layer of dielectric material having via holes therein disposed in alignment with at least some of said contact pads;
- a patterned first metallization layer disposed on said first layer of dielectric material and extending into contact with at least some of said contact pads in said via holes in said first layer of dielectric material;
- a second layer of dielectric material bonded to said first metallization layer and exposed portions of said first layer of dielectric material, said second layer of dielectric material comprising second lower and second upper sublayers, said second lower sublayer being thermoplastic and having a second glass transition temperature T.sub.g2, said second upper sublayer being stable over a range of temperatures above said second glass transition temperature;
- and
- said first glass transition temperature being higher than said second glass transition temperature.
In a method of fabricating a high density interconnected system of the type including a plurality of electronic chips, a high density interconnect structure including a layer of dielectric material bonded to said chips and a pattern of conductors disposed on or in said dielectric material, the conductors of said high density interconnect structure electrically interconnecting said electronic chips, the improvement comprising:
- a) laminating a first dielectric layer to said chips using a first thermoplastic adhesive having a first glass transition temperature T.sub.g1 ;
- b) forming via holes in said first dielectric layer and said first adhesive in alignment with at least some contact pads of said chips;
- c) forming a patterned first metallization layer on said first dielectric layer, said first metallization layer including conductors which extend into ohmic contact with contact pads in said via holes;
- d) laminating a second dielectric layer to said first metallization layer and exposed portions of said first dielectric layer using a second thermoplastic adhesive having a second glass transition temperature T.sub.g2 which is lower than said first glass transition temperature, this laminating step being performed at a low enough temperature that said first dielectric layer remains fixed, whereby said first metallization layer and its contacts to said contact pads are not adversely affected by this laminating step.
Dependencies are inferred from the claim text.