CHOICE OF ATTACHMENT PROCESS
- THERMOCOMPRESSION
WELD – for
LCC’s with gold plated finish
- THERMOCOMPRESSION
TIN-LEAD BOND(5/95) – for
pre-tinned LCC’s .350" square or larger
Spec
Sheet(Adobe PDF 774Kb)
Round lead ceramic chip carriers were developed
in response to the need for a family of low cost leaded chip
carriers, capable
of meeting the requirements of MIL-M-38510 and MIL-STD-883, while
providing the compliance between the ceramic chip carrier and
the PWB. The round lead was chosen for its ability to locate
itself into the castellation of the leadless chip
carrier and be attached by thermocompression welding of gold plated
finished
LCC's or tin-lead soldering of pretinned
LCC's. Since the attachment processes are
achieved with heat and pressure in |
 |
milliseconds, the leads can
be attached after the complete assembly
of
the
electronic device. Thus, the semiconductor manufacturer
can utilize one process to provide LCC’s or leaded chip carriers.
Previously, each type of package required a specific production
line with
distinct tooling and processes to provide “J”, “Gullwing”,
and the various other lead forms. Now all chip carriers can
be processed through end of line as LCC’s. The final
lead form is selected and the leads attached, formed, and
hot solder
dipped in eutectic solder, just prior to shipment or board
mounting. The advantages of the single processing are reflected
in higher
quality and lower costs. Users of chip carriers can significantly
increase the reliability of the PWB assembly by adding leads
to readily available LCC’s. Lead forms are available
to meet every design and operations requirement. |
