BGA General Info   Ball Matrix: (see examples on right) Full Grid Perimeter Rows With Center Thermo Via Staggered Array Substrate Material: BT (Bismaleimide Triazine) -- PBGA and SBGA. Polyimide -- µBGA, flexBGA and TBGA Ceramic -- CBGA, CLGA (Land Grid Array) and CCGA (Column Grid Array) FR4 -- LBGA Ball Material: Eutectic - Sn63/Pb37 - PBGA, CSP, flexBGA Near Eutectic - Sn62/Pb36/Ag2 - LBGA High Temperature - Sn10/Pb90 - CBGA Lead Free - Sn96.5/Ag3.0/Cu0.5 - Sn95.5/Ag4.0/Cu0.5 - Sn96.5/Ag3.5 Ball Pitch: Fine Pitch and CSP: 0.5mm, 0.75mm and 0.8mm PBGA types 1.0mm, 1.27mm and 1.5mm Thermal Pads: Center balls to dissipate heat. "Pop Corn" Phenomena: Prior to assembly, it is recommended to bake BGA at 125°C for 24 hours to remove moisture and prevent delamination and cracking. Thermal Mismatch: Thermal mismatch occurs when mounting large ceramic CBGA (>31mm) onto laminate substrates, such as FR-4. Conversely, thermal mismatch occurs when mounting large Plastic PBGA (>31mm) onto ceramic substrates. During repeated temperature cycling, the solder balls on non-compatibly matched large PBGA and CBGA will tear away from the substrates. Why BT is Used: BT (Bismaleimide Triazine) is the popular material of choice for PBGA because its TCE (Temperature Coefficient Expansion) is mid-range between the TCE of FR-4 PC boards, copper and the silicon die which is attached inside the PBGA with adhesive. Daisy Chain (See example right): Used on dummy BGAs to perform continuity testing after mounting to the substrate (PC Board).   Top of Page    Back To Products    Back To BGA    TopLine Home Visit the TopLine Document Center for thousands of component outline drawings. TopLine Catalogs in PDF format Dummy Components(4Mb) and Practice Kits (5Mb). TopLine Corporation 95 Highway 22 W Milledgeville, GA 31061, USA Toll Free USA/Canada (800) 776-9888 International: 1-478-451-5000  •  Fax: 1-478-451-3000 Email: Info