Ball grid array

Electroless deposition can successfully be used in the production of various composite materials useful for the electronics applications. The examples include silver-coated copper or nickel particles, used in screen printing,43 gold-coated nickel powders, silver and/or palladium-coated polymers or glass powders used in ball grid array, etc. 

Fig. 14.1 Schematic diagram of a microprocessor assembly showing different levels of packaging and thermal management solution using a heat sink. TIM thermal interface material, BGA ball grid array...

Lau, J. H. (1993), Ball Grid Array Technology, McGraw-Hill, New York. 

Figure 1.9 Ball-grid-array package. Source Amkor.

Figure 1.10 High-density multichip packaging flip-chip-attached die on ball-grid-array...

Lastly, adhesives are used to dissipate stresses that may be generated from thermal excursions, mechanical shock, vibration, or moisture. Specially formulated adhesives are effectively used as underfills for flip-chip devices and ball-grid-array packages to compensate for mismatches of expansion coefficients among the solder, the silicon chip, and the ceramic or plastic-laminate substrate. Low-stress adhesives are also used to attach fragile devices such glass diodes and to dampen stresses due to vibration. 

Rework of underfill flip-chip devices and ball-grid-array packages 212 References 212... 

Land grid array and fine-pitch ball-grid array (National)... 

Chip Array Ball Grid Array (Amkor)... 

Ball-grid array, land-grid Flash memory and ASIC... 

The absorption of moisture in underfill adhesives induces a tensile hygrothermal stress on the solder-ball connections causing electrical opens in the connections and cracking in the adhesive. These tensile stresses offset the compressive stresses that underfill adhesives provide in improving the reliability of flip-chip and ball-grid-array devices. 

Computed Tomography, Fig. 5 Quality control of solder points and bonding wires of a ball grid array (BGA) used for microchips (Courtesy of Volume Graphics GmbH)... 

Underfill for ball-grid-array (BGA) packages. After attaching the BGA packages to a PWB and reflowing the solder, an underfill adhesive similar to that used for flip chips may be dispensed and allowed to fill the spaces between the solder balls, thus reinforcing the connections and relieving stress in the entire structure. 

Rework of Underfill Flip-Chip Devices and Ball-Grid Array Packages... 

Figure 12.9 Acoustic image of solder bumps in a ceramic ball grid array package. Comparing this image with the results of X-ray microscopy indicated that some of the solder bumps had separated from the die surface.

We have developed 11.5ppm/°C material [5]. Ikemizu et al. [6] reported that by using this material the ceramic hne pitched ball grid array package and... 

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