公开(公告)号：GB2354636A

公开(公告)日：2001-03-28

申请号：GB9922637

申请日：1999-09-25

Applicant: IBM

Inventor： MONOPOLI MICHELE ,  ZAMBON FRANCO ,  SIRTORI VITTORIO ,  GIUSSANI LUIGI ,  LOMBARDI LORENZA

IPC: H01L21/60 ,  H05K3/00 ,  H05K3/34 ,  C09D5/00

Abstract: A method of mounting a chip 105 on a substrate 101 provided with gold pads 201 comprises applying a protective paste over the pads, the paste consisting of a solution of a citrate salt dissolved in water with the addition of glycerol. After mounting, soldering and adhesively securing the chip to the substrate, the protective paste is washed away followed by UV cleaning and wire bonding.

公开(公告)号：GB2352030A

公开(公告)日：2001-01-17

申请号：GB9916485

申请日：1999-07-14

Applicant: IBM

Inventor： SIRTORI VITTORIO ,  LOMBARDI LORENZA ,  MONOPOLI MICHELE ,  ZAMBON FRANCO

IPC: G01B11/06 ,  G01B11/30 ,  G01B13/02 ,  G01N21/21 ,  G01N21/88 ,  G01Q60/00

Abstract: To measure surface roughness . d. and contaminant thickness T of a surface using ellipsometry, tables of values of . C. and . W. are compiled for known values of surface roughness and contaminant thickness where ```. C. is the ratio between the amplitudes of the two polarisation planes of a beam incident on the surface multiplied by the ratio of the amplitudes of the two planes of the reflected beam and ```. W. is the difference between the phases on the two polarisation planes of the of the incident beam and reflected beam. The values of . C. and . W. are then measured for the surface under investigation, and the tables used to determine the values of surface roughness . d. and contaminant thickness T of that surface.

公开(公告)号：GB2336122A

公开(公告)日：1999-10-13

申请号：GB9807407

申请日：1998-04-08

Applicant: IBM

Inventor： BASSI LUIGI ,  MONOPOLI MICHELE ,  SPINZI PAOLO ,  VILLA DANILO

IPC: B23K1/018 ,  H05K3/34

Abstract: In a method for reworking a Ball Grid Array electronic module 201, 203, 205, by removing the solder balls from the substrate surface after one or more of the connections have been detected to be damaged. The module is immersed in a water soluble oil bath and heated to the melting point. Then a rotating brush 241, with the rotating axis perpendicular to the substrate plan, removes the solder balls and the solder material particles while the module is still immersed in the fluid.