公开(公告)号：US5183692A

公开(公告)日：1993-02-02

申请号：US724029

申请日：1991-07-01

Applicant: Prosanto K. Mukerji ,  Russell Mallen ,  George Demet ,  Harry Fuerhaupter

Inventor： Prosanto K. Mukerji ,  Russell Mallen ,  George Demet ,  Harry Fuerhaupter

IPC: C23C18/28 ,  H05K1/03 ,  H05K3/18 ,  H05K3/38

CPC classification number: C23C18/28 ,  H05K1/0346 ,  H05K3/181 ,  H05K3/381

Abstract: A method for producing a coating composed of an electroless metal plate, such as a copper plate, tightly bonded to a polyimide layer comprises a multi-step cure of the polyimide layer carried out in combination with a palladium-catalyzed electroless deposition process. A solution of a polyamic acid compound that is the precursor for the desired polyimide resin in a vaporizable solvent is applied to a substrate and heated preferably to temperature below 250.degree. C., to form a soft-cured polyimide film. The film is immersed in an aqueous palladium-tin colloidal suspension to deposit the colloidal particles thereon, which particles are then activated to form palladium nuclei dspersed on the surface. The soft-cured film is then heated, preferably above about 250.degree. C., to vaporize residual solvent and form a hard-cured polyimide layer having the palladium nuclei dispersed on the surface. The hard-cured layer is immersed in an electroless metal plating solution, whereupon the palladium nuclei catalyze deposition of the metal to form a continuous plate. In one aspect of the method, the metal-clad layer is further heated between about 350.degree. C. and 450.degree. C. to final cure the polyimide. It is found that the plate of the coating formed by this multi-cure method strongly adheres to the polymer layer to permit extended deposition and thereby form a relatively thicker plate without catastrophic separation from the polymer.

Abstract translation: 用于与由聚酰亚胺层紧密接合的铜板等化学金属板构成的涂层的制造方法包括与钯催化的无电沉积工艺结合进行的多层聚酰亚胺层的固化。 将作为所需聚酰亚胺树脂的前体的聚酰胺酸化合物在可汽化溶剂中的溶液施加到基底上，并优选加热至低于250℃，形成软固化的聚酰亚胺膜。 将膜浸入钯 - 锡胶体悬浮液中以沉积其上的胶体颗粒，然后将该颗粒活化以形成在表面上分散的钯核。 然后将软化固化膜加热，优选高于约250℃，蒸发残余溶剂，并形成具有分散在表面上的钯核的硬固化聚酰亚胺层。 将硬固化层浸渍在无电镀金属溶液中，由此钯核催化金属沉积形成连续板。 在该方法的一个方面，金属包覆层在约350℃至450℃之间进一步加热以最终固化聚酰亚胺。 发现通过这种多固化方法形成的涂层的板强烈地粘附到聚合物层以允许延长的沉积，从而形成相对较厚的板，而没有与聚合物的灾难性分离。

公开(公告)号：US5320272A

公开(公告)日：1994-06-14

申请号：US42227

申请日：1993-04-02

Applicant: Cynthia Melton ,  Harry Fuerhaupter ,  George Demet

Inventor： Cynthia Melton ,  Harry Fuerhaupter ,  George Demet

IPC: B23K35/00 ,  B23K35/26 ,  H05K3/24 ,  H05K3/34

CPC classification number: H05K3/3484 ,  B23K35/007 ,  B23K35/264 ,  H05K3/3463 ,  H05K2201/0317 ,  H05K2201/10636 ,  H05K2201/10992 ,  H05K2203/0435 ,  H05K2203/054 ,  H05K3/243 ,  H05K3/3442 ,  H05K3/3452 ,  H05K3/3473 ,  Y02P70/611

Abstract: In an electronic package, a solder connection for bonding faying surfaces is formed of tin-bismuth alloy comprising a tertiary metal, preferably gold or silver, in an amount effective to increase the melting temperature of the alloy and enhance mechanical properties of the connection at elevated temperatures typically encountered during operation. A process for forming the solder connection comprises applying a film of the tertiary metal onto at least one faying surface and thereafter applying tin-bismuth solder paste onto the film. Preferably, a plate of tin-bismuth alloy is first electroplated onto the faying surface, onto which the tertiary metal is plated. During heating to reflow the solder, the tertiary metal dissolves to produce a uniform liquid that forms the connection.

Abstract translation: 在电子封装中，用于焊接接合表面的焊接连接由含有第三金属，优选金或银的锡 - 铋合金形成，其量有效地增加合金的熔融温度并增强连接处的升高的机械性能 操作中通常遇到的温度。 用于形成焊接连接​​的工艺包括将第三金属的膜施加到至少一个引线表面上，然后将锡 - 铋焊膏施加到膜上。 优选地，将锡 - 铋合金板首先电镀在第三金属被电镀的引线表面上。 在加热回流焊料期间，第三金属溶解以产生形成连接的均匀液体。