Method for direct chip attach by solder bumps and an underfill layer
    32.
    发明授权
    Method for direct chip attach by solder bumps and an underfill layer 有权
    通过焊料凸块和底部填充层直接贴片的方法

    公开(公告)号:US06341418B1

    公开(公告)日:2002-01-29

    申请号:US09301890

    申请日:1999-04-29

    IPC分类号: H05K334

    摘要: A method for direct chip attach of a semiconductor chip to a circuit board by using solder bumps and an underfill layer is disclosed. In the method, a layer of in-situ polymeric mold material is first screen printed on the top surface of the semiconductor chip exposing a multiplicity of bond pads. The in-situ polymeric mold layer is formed with a multiplicity of apertures which are then filled with solder material in a molten solder screening process to form solder bumps. A thin flux-containing underfill material layer is then placed on top of a circuit board over a plurality of conductive pads which are arranged in a mirror image to the bond pads on the semiconductor chip. The semiconductor chip and the circuit board are then pressed together with the underfill layer inbetween and heated to a reflow temperature of higher than the melting temperature of the solder material until electrical communication is established between the bond pads and the conductive pads. In the bonded assembly, the in-situ polymeric mold layer and the underfill material layer forms a composite underfill to replace a conventional underfill material that must be injected between bonded chip and substrate by a capillary action in a time consuming process.

    摘要翻译: 公开了一种通过使用焊料凸块和底部填充层将半导体芯片直接贴合到电路板的方法。 在该方法中,首先在半导体芯片的顶表面上丝网印刷一层原位聚合物模材料,暴露出多个接合焊盘。 原位聚合物模具层形成有多个孔,然后在熔融焊料筛选过程中用焊料材料填充以形成焊料凸块。 然后将薄的含有焊剂的底层填充材料层放置在电路板的顶部上,该多个导电焊盘以镜像形式布置在半导体芯片上的接合焊盘上。 然后将半导体芯片和电路板与其中的底部填充层一起压在一起,并被加热到高于焊料材料的熔融温度的回流温度,直到在焊盘和导电焊盘之间建立电连通。 在粘合组件中,原位聚合物模层和底部填充材料层形成复合底层填料,以代替在耗时的过程中必须通过毛细管作用在粘合的芯片和衬底之间注入的常规底部填充材料。