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JUNE 2017          TAP TIMES           - 4-

              Fixture development (from 3)                       wire bonder.    Regardless of the automat-
                                                                ed  production  process  solution,  product-
                                                                specific tooling is inevitable.

        duct is tested and proven, and the soft tool-
        ing is already developed.
                                                                Parts-specific fixtures needed
                                                                Both  end  effector  tools  and  parts-specific
        The biggest tooling challenge                           fixtures  are  required  to  securely  hold  the
        The prototype phase presents the biggest                part and properly present it to the process
        challenge for tooling.  For prototype sample            system.
        builds the project schedule is usually com-

        It is important to fabricate part-specific fix-
        tures quickly enough to satisfy the sched-
        ule,  but precisely enough  to validate the
        process and the product.

        Taking advantage of advanced design tools
        like solid modeling and 3D printing can help
        accelerate this step.

        During the proof of concept phase it is often
        best to use as many manual processes as                 Plastic die attach  end-effector  makes  contact  with
        possible.  For example, if parts need wire              the parts being assembled.
        bonding  for  interconnects,  a  manual  wire
        bonder can be used to satisfy that need.                End  effector  tools  are  the  devices  that  fit
                                                                into the process equipment and make phys-
                                                                ical contact with the parts or components
        Use EFD hand dispenser                                  being assembled.
        During such manual processes, fixturing is
        not necessarily required.  If dispense is part          For  example,  the  die  attach  end-effector
        of a required process, the use of a simple              tool (above) is a  small metal  stylus that
        EFD hand dispenser that does not require                matches  the  geometry  of  the  die being
        fixturing is an effective solution.                     picked up and placed.

        The same is true if the product requires die
        attach. If possible, a manual system with-              Keep-out zones
        out custom fixtures may be employed                     End effector tools may have vacuum holes
                                                                that can pick and place a die without dam-
        In  almost  all cases,  once  the  project  is          aging it.  In most MEMS sensor die applica-
        moved into the prototype build phase it be-             tions this tool will also have certain areas
        comes  necessary  to  move  to  highly auto-            known as keep-out zones.
        mated production processes.
                                                                These areas correspond to areas of the die
        Wire bonding processes may be moved to                  that the tool must not contact.
        a gold ball bonder, or fine gauge aluminum                                                   See page 6
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