Leadless chip carrier

Thermal Expansion Coefficients of Leadless Chip Carrier Compatible Printed Wiring Boards... 

Eccobond D125F/Henkel Stencil application for surface-mount devices (capacitors, resistors, small outline ICs, and plastic leadless chip carriers) N/A N/A N/A... 

The number of dots that can be dispensed per unit of time also depends on viscosity. The use of low-viscosity adhesives increases the number of dots that can be dispensed. However, there is a tradeoff between the speed at which the adhesive can be dispensed and the speed of device placement. Most automated component-placement equipment operate faster than adhesive-dispensing equipment. A comparison of the effect of viscosity on dispensing and placement times is shown in Table 4.19 for an 86-lead plastic-encapsulated leadless chip carrier (PLCC). ... 

Hermetic packages, such as the older flat pack design or ceramic leadless chip carriers (CLCCs), are used in harsh applications (such as military and space applications) where water vapor and contaminants can shorten the life of the device. Thus they are used in mission critical communication, and navigation and avionic systems. The reliability of CLCC package connections can be further improved by the attachment of leads to the connection pads, to eliminate differences in the thermal coefficient of expansion between the parts and the circuit board material. 

Ceramic leadless chip carrier [CLCC (or CLLCC)], see LCCC. 

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. 

LEADLESS CHIP CARRIER A chip carrier (usually ceramic) with integral metallized terminations and no compliant external leads. 

Polyimides are also being used in conjunction with silica fabric (which has a coefficient of expansion approximately one tenth that of E-glass) to produce laminates with expansion coefficients in the XY plane which are as low as 6-7 ppm, i.e. close to that of a ceramic chip carrier. This composite satisfies the requirement for a substrate material for direct attachment of the larger ( to 1 in dimension) leadless chip carriers which are used for mounting LSI and VLSI chips. ... 

DFR design for reliability PLCC plastic leadless chip carrier... 

Mounting of FPAs was discussed in a general way in Section 8.6 - but we reiterate here the need for a good thermal interface. This is usually done with a thin sheet of indium (0.005 in.) between the leadless chip carrier and the dewar cold-plate, and a springed-type clamp. Make it a habit to examine the indium whenever you mount an FPA. If LCCCs are loaded and unloaded many times, some of the indium sheet may stick to the backs of removed LCCCs, or the sheet may simply become too thin. The sheet can be refreshed a few times by dimpling the surface with a probe, but it should eventually be replaced. 

Engelmaier, W. Eatigrre life of leadless chip carrier solder joints during power cycling. IEEE Trans. Components Hybrids Manuf. TechnoL, CHMT 1983, 6 (3), 232 237. 

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