Process for transferring material to semiconductor chip conductive pads using a transfer substrate
August 2, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3621564 3645392 3719981 Method of manufacturing thick-film circuit devices Method of screening paste solder onto leaded hybrid substrates Method and transfer plate for applying solder to component leads Method and apparatus for solder bumping of printed circuit boards Microbeam laser machine for acting on objects having thin layers of material Process of fabricating a circuit package Method of making high density solder bumps and a substrate socket for high density solder bumps InventorsApplicationNo. 510401 filed on 08/02/1995US Classes:438/616, By transcription from auxiliary substrate228/180.22, Lead-less (or "bumped") device257/E21.503, Encapsulation of active face of flip chip device, e.g., under filling or under encapsulation of flip-chip, encapsulation perform on chip or mounting substrate (EPO)257/E21.508, Forming solder bumps (EPO)257/E21.511, Mounting on insulating member provided with metallic leads, e.g., flip-chip mounting, conductive die mounting (EPO)257/E23.021, Bump or ball contacts (EPO)257/E23.061, Leads being also applied on sidewalls or bottom of substrate, e.g., leadless packages for surface mounting (EPO)257/E23.067, Via connections through substrates, e.g., pins going through substrate, coaxial cables (EPO)257/E23.068Additional leads joined to metallizations on insulating substrate, e.g., pins, bumps, wires, flat leads (EPO)ExaminersPrimary: Graybill, David E.Attorney, Agent or FirmForeign Patent References
International ClassesH01L 021/288H01L 021/58 H01L 021/60 AbstractA process within substrate is provided with vias communicating with surface contacts or bumps. Joining material paste is forced through holes in a screen onto an area array of the contacts on the substrate then the screen is biased against the substrate as the paste is heated and cooled to transfer the joining material onto the contacts. Alternately, joining material paste is forced into the screen and then a substrate is placed onto the screen with an area array of bump contacts of the substrate in contact with the solder paste, and then the paste is heated and cooled to transfer the material onto the bumps. The joining material may be a solder paste, conductive adhesive paste, or transient liquid bond paste. The substrate may be a semiconductor chip substrate, flexible or rigid organic substrate, or a metal substrate coated to form a dielectric surface. Also, the substrate may be a computer chip, chip carrier substrate or a circuit board substrate. The process may be used to produce flip chips, ball grid array modules, column grid array modules, circuit boards, and attachment structures of the preceding components including information handling systems.Other References
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