Patent DE-102013200868-A1 (DE)
Title: Forming bonded connection between first and second joining members, comprises applying protective layer on protected surface portion of first connecting member, and forming bonded connection between connecting surfaces of members
Inventor: BÖWER LARS
IPC: B22F7/08
Filed: 2013-01-21
Abstract: The method comprises applying a protective layer (3) on a protected surface portion of a first connecting member (1) such that the protected surface portion is completely covered by the protective layer, forming a bonded connection between a first metallic connecting surface of the first connecting member and a second connecting surface of a second connecting member (2) in a state in which the protective layer is applied, and partially removing the protective layer of the protected surface portion after production of the material connection. The method comprises applying a protective layer (3) on a protected surface portion of a first connecting member (1) such that the protected surface portion is completely covered by the protective layer, forming a bonded connection between a first metallic connecting surface of the first connecting member and a second connecting surface of a second connecting member (2) in a state in which the protective layer is applied, and partially removing the protective layer of the protected surface portion after production of the material connection. The forming step comprises pressing the first and second connecting members to each other with a predetermined contact pressure of 0-30 MPa such that a paste is arranged between the first and second joining surfaces and contains a metal powder and a solvent so that the first connection surface contacts the second connecting surface, and sintering the paste at a temperature of 150-280[deg] C and predetermined pressure. The protective layer is: applied over the entire surface of the protected surface portion; performed by a physical vapor deposition method; formed as a nitride layer, an imide layer, a resist layer, a diamond-like carbon layer and a graphite layer; and removed by dry etching, plasma etching or wet etching method, by laser ablation or by treatment with an oxygen plasma. A patterned mask layer is partially removed from the first connecting member by the dry etching, plasma etching or wet etching method. The protective layer is provided as a positive photoresist layer or a negative photoresist layer, or is patterned by photolithography after the production of the material connection such that the protected surface portion is exposed. The first connecting member is formed as a substrate (6). The second connecting member is formed as a semiconductor chip (5) having an upper chip metallization and a lower chip metallization. The upper chip metallization is arranged facing away from the semiconductor chip after the formation of the bonded connection. The lower chip metallization is arranged facing a side of the chip after formation of the bonded connection. The first connection surface is formed by a surface portion of the lower chip metallization. The protected surface portion is formed by a surface portion of the metallic surface of the substrate. The protective layer is applied at a time when the semiconductor chip is located in a wafer composite with a further semiconductor chip. An independent claim is included for a method for forming an electrical connection.