BPW128-0830-12CB95 Datasheet, PDF (3/8 Pages) Actel Corporation – SE-CSG128-H, E-Tec lead free prototype socket drawing for CSG128 and CSG128 packages

Socket Mounting Recommendations and Reflow Profile
Purpose
This document is meant to serve as a guide for mounting E-tec surface mount device (SMD)
sockets to the printed circuit board (PCB). The recommendations described here are guidelines
only, and modifications may be needed for your particular socket, PCB, and process.
Application
The sockets this document applies to are as follows: Clam Shell, Knob Lock, Screw Lock, Twist
Lock, Quick Lock and Lever Lock in SMD style. These sockets utilize the E-tec patented spring-
pin technology. This technology allows the pins to be soldered to the PCB while still providing
compliance to the device under test (DUT) via springs located at the other end of the pin. The
pins themselves do not have solder pre-forms as a BGA would with its solder balls. However, the
sockets are designed to mount to the same PCB footprint and pads as required by the BGA, or
any other IC package the socket was designed for (except if locating pegs are used; see ‘Locating
Pegs’ section of this document). When compared to mounting a BGA, an extra volume of solder
paste is required to mount the sockets to the PCB. To effect this, a properly dimensioned stencil
is required. Once the paste has been applied, a standard reflow process is then used to solder the
socket to the PCB. After the socket is verified to have proper electrical connection to the PCB,
the system is then ready to be used.
Locating Pegs
Although designed to mount to the same footprint as the IC, with just a small amount of
additional keep-out area, E-tec sockets can also be offered with locating pegs. The sockets are
typically mounted with two locating pegs, which require two thru-holes drilled into the PCB.
These pegs help to align the socket on the PCB, and hence align the socket’s pins to the PCB’s
pads, during the soldering process. Furthermore, plating the thru-holes allows the locating pegs
to be soldered to the PCB for better mechanical stability during everyday use and handling of the
socket. If the PCB design permits, E-tec recommends the use of these locating pegs. For fine-
pitch, low pin-count sockets without locating pegs, the mechanical strength of the solder joints
may be insufficient. In these cases, it is recommended to epoxy the socket body to the PCB. 3M
Scotch-Weld 2216 B/A is a suitable epoxy. In any case, the proper volume of solder paste is
required to ensure mechanical and electrical integrity. Recommended stencil dimensions are
given in the next section of this document.
E-tec Interconnect Ltd, Industrial Zone C, CH-1072 Forel (Lavaux), Switzerland
1
Phone [phone] · www.e-tec.com · [e-mail]
E-tec Socket Mounting Recommendations
PRELIMINARY