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A polimer szerkezete termomechanikai grbeparamterek kapcsolata

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A polimer szerkezete termomechanikai grbeparamterek kapcsolata Powered By Docstoc
					IC-tokozás vázlata




                     NP
A
tokozat
funkciói




           NP
                           Tokozószerszám
                          (Transfer molding)
                                   Transfer cylinder




Basic mold holder
     (Upper)
                                   Upper basic
                                     mold                                                        Plunger
  Upper mold
                                      Lead frame with
  Lower mold
                                      device attached                 Pick up arm                Upper Basic Mold

                                   Lower basic
Basic mold holder
                                     mold                                           Lead frame   Upper Mold
     (Lower)
                                                          Pellet
                                   Platen
                                                                                                 Lower Mold

                                                        Pellet Tray                 Pellet
                                                                                    Sensor       Lower Basic Mold

      Clamp                        Ejector                Pellet
                                                           Tray
     cylinder                      cylinder               Table




                    FRONT VIEW                                                      SIDE VIEW




                                 MOLDSET UPPER & LOWER
                                 (96 CAVITY)                                                               NP
                                    Tokozás fázisai


                                               Step 2: Closed mold                Step 3: Placement of pellet
         Step 1: Open mold




    Step 4: Transfer-engaging plunger    Step 5: Transfer-filling the runners   Step 6: Transfer-Filling the mold cavities




Step 7: Open mold after mold compound cure      Step 8: Separating packages from runners & cull                              NP
Szerszám-
kitöltés




            NP
                A tokozóanyag összetétele
                    Catalyst   Hardener   Epoxy resin
                      0%         12%         11%

                                             Release agent,
                                                coloring,
                                             coupling agent
                                                   1%

                                             Flam e retardant
                                                    3%
Silica filler                                Stress relief
    70%                                        additive
                                                  2%

                                            Other
                                             1%




                                                                NP
             A töltőanyag hatása
•   Increase thermal conductivity; Thermal conductivity is higher than
    resinous matrix.
•   Decrease the coefficient of thermal expansion; Thermal
    expansion is less than resinous matrix.
•   Increase both the mechanical strength and modulus; Mechanical
    strength and modulus are higher than resinous matrix.
•   Decrease water absorption and diffusion coefficient; Water is only
    absorbed on the silica surface. As a result, diffusion of water
    through the filler is blocked entirely.
•   Increase melts viscosity; Viscosity is the most important limit on
    amount of filler that can be added.
•   Increase the rate of wear on the cavity surface.
•   Increase alpha particle emission; naturally occurring silica is the
    only significant source of thorium and uranium that are in turn the
    sources of alpha particles.
•   Usually decrease the cost of the composite.

                                                                          NP
       A térhálósodás folyamata
• Most thermosetting molding compounds will crosslink over a wide
  range of temperatures
• In order to be able to transfer the mold compound into the mold
  cavities, it has to be in the liquid low viscosity state.
• The higher the temperature the faster the mold compound cures,
  and therefore the gel time and the time for transfer will decrease.




      Influence of temperature on time-viscosity curve (bath tub curve)
                                                                          NP
  Spirál
szerszám




           NP
                  Flip-chip tokozás
       Áramkör a Si         Forrszem-gömbök                „Flip”
       szeleten




Pozicionálás      Gömbök megolvasztása        Rés kitöltése gyantával




                       (reflow)
                                                  (underfilling)




                                         Pl.: PC alaplapokon a vezérlők

                                                                          NP
Egyéb tokozási technológiák
   (kiöntés, beágyazás)




                              NP

				
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posted:4/28/2011
language:English
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