Leadless sockets

Note that these cost a couple of hundred dollars a piece usually and are mountable on standard PCB eval boards. They are actually much cheaper than the near-permanent leadless sockets some test engineers use on special boards. 

MISMATCH OF THERMAL EXPANSION. The thermal expansion mismatch of organic substrates and leadless ceramic chip carriers has been widely reported, and a great deal of development work was carried out. However, the actual number of these packages used worldwide is small, and many of those overcome the problem by using clips and sockets. 

Leadless ceramic chip carrier (LCCC), or ceramic leadless chip carrier. JEDEC registered type A must be socketed when on a printed circuit board or a ceramic substrate board, and type B must be soldered. The LCC minipack must be soldered onto printed circuit boards. 

Often, detector arrays are adhesively mounted in leadless ceramic chip carriers (LCCs). Electrical leads are plated on the surface of the LCC and mate with matching spring-loaded, gold-plated contacts in a socket that can be mounted in a dewar, while allowing the flat back of the LCC to be pressed against the dewar s cold surface. In this case, a 3-5 mil (0.003-0.005 in.) thick sheet of indium is placed between the... 

FPAs are commonly mounted on a leadless ceramic chip carrier (LCCC - but sometimes seen as LCC) for wire-bonding before test, and for the test itself. The common LCCCs sizes have 68, 84, 100, and 124 pins. These typically have bottom contacts for interfacing to a standard test socket. 

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