Ironwood Electronics SBT User Manual - Manual (Page 4)

3 | P a g e S B T
. d o c , R e v . C , 6 / 2 8 / 2 0 1 2 , V P
Tel: (800) 404-0204
www.ironwoodelectronics.com
3. Maximum solder ball diameter of IC should be less than or equal to that shown in the table.
4. Maximum and minimum solder ball height should fall within the range shown in the table.
If any of the above parameters do not match, please call Ironwood Tech Support @1-800-404-0204 to help
select a socket (which may currently be in development).
PCB Requirements
Please refer to page 2 of the socket drawing for all PCB recommendations.
For IC body sizes of 30mm or below, the socket requires 4 mounting holes.
For IC body sizes of 31mm or above, the socket requires 8 mounting holes.
Two alignment holes are used in all sockets.
The BGA pattern is not symmetrical with respect to the
mounting holes . The BGA pattern is same as the one used for the elastomer socket. It is shifted due to the fact
that the wire filaments in the elastomer are at an angle (the shift is half the elastomer thickness in the positive x-
direction). The same footprint used by elastomer socket is recommended for stamped pin socket for
interchangeability. Again, please refer to page 2 of the drawing for recommended footprint.
Thickness
1.5mm minimum. This will change per customer application, environment and usage.
Finish
SnPb plating or Immersion Au or Immersion Ag. Other plating may be used but testing may be required.
Typical Solder mask clearance over pad surface is acceptable.
Cleanliness
Isopropyl Alcohol or equivalent should be used to clean the board surface prior to attaching socket.
IC and PCB Reflow Requirement
If the same IC is used for number of cycles, crown tip on stamped pin damages the Sn63Pb37 solder balls on IC
and conical tip damages HASL(hot air solder level) pads on PCB. From our test results, we recommend
reflowing IC solder balls every 10 cycles and HASL PCB every 30 cycles. Gold plated PCBs will not need any
reflows.
Socket Assembly
Refer to figure 4 for graphical illustrations.
1. Install the socket base assembly onto the target PCB with the hardware (socket base screws) provided.
Because of asymmetrical tooling holes, the socket can be assembled with only one orientation.
2. Place BGA package (solder ball side down) into the socket. NOTE: BGA orientation on target PCB is
critical. If an IC frame (optional) is supplied, place it over the BGA package. This IC frame may be
necessary for packages in which the encapsulate around the die does not extend to the edge of the IC’s
substrate.
3. Place compression plate on top of the BGA package.
4. Install the socket top assembly on to the socket base assembly and swivel to lock into the position.