International Business Machines Corporation

Stuart P Lees

Kenneth Skene Murray

William French

Brian L Robertson

Colin David McCall

Alexander Boyd

Noel Patrick Glancy

Briand L Robertson

Solder particles,are deposited onto metallized contacts of a direct chip attach (DCA) site located on a substrate,. The contacts,are coated with a layer of flux,. A pick up head,is positioned in a reservoir,of solder particles,and particles are attracted to the apertures in the end,of the head. The apertures have an arrangement corresponding to the footprint of the metallized contacts on the substrate. The head,is positioned adjacent the substrate,and the particles,released. The particles,stick to the flux,coated on the contacts,. The particles are reflowed, leveled and again coated with flux. An integrated circuit chip is then placed on the leveled reliefs,and the reliefs reflowed again to attach the chip onto the contacts

Solder particle deposition

Inspection apparatus is disclosed for providing a visual indication of the proper merger of the conductive pins of an electrical component in the corresponding openings in a printed circuit board. The apparatus includes an inspection plate which has a plurality of channels defined between first and second opposite faces. In the channels are mounted a plurality of inspection pins which move between a first, rest position (countersunk with respect to the top surface of the inspection plate) and a second, extended position (flush with the plate's top surface). The inspection pins in the plate correspond in number and configuration to the component conductive pins but have a greater cross sectional area than that of the conductive pins. When the component is merged with the printed circuit board, each connector pin passes through the corresponding circuit board opening and pushes against the corresponding inspection pin to cause it to move to the extended position. If the conductive pin is bent or deformed, the inspection pin remains in the rest position such that the apparatus operator is provided with a visual indication of which conductive pins have not merged correctly with the circuit board.

Assembly of electrical components on printed circuit boards

A tool for soldering pin-in-hole electronic circuit components includes a tool plate with a set of via holes corresponding to the holes of a circuit board on which a circuit component is soldered. The board is aligned with the tool plate and hot gas is supplied through the set of plate vias to reflow solder in the board holes. The tool is particularly suitable for use in removing and replacing pinned circuit components. Use of particular gases (e.g., nitrogen) allows soldering to be carried out without the use of flux. Advantages of the tool are that it prevents burning the circuit board and/or unintentionally reflowing other circuit components mounted on the board (by directing hot gas only substantially onto the circuit board's solder-containing holes).

Solder apparatus and method

Solder particles 220 are deposited onto metallized contacts of a direct chip attach (DCA) site located on a substrate 301. The contacts 302 are coated with a layer of flux 303. A pick up head 211 is positioned in a reservoir 201 of solder particles 220 and particles are attracted to the apertures in the end 213 of the head. The apertures have an arrangement corresponding to the footprint of the metallized contacts on the substrate. The head 211 is positioned adjacent the substrate 301 and the particles 220 released. The particles 220 stick to the flux 303 coated on the contacts 302. The particles are reflowed, leveled and again coated with flux. An integrated circuit chip is then placed on the leveled reliefs 501 and the reliefs reflowed again to attach the chip onto the contacts 302.

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Gourock, United Kingdom

Stuart P Lees