Modern day information age has seen rapid development of electronic devices industry, leading electronics products such as computers and cellular phones to be increasingly prevalent. People start having constantly increasing demands in phrases of functions and performance of electronics products while constantly decreasing needs in terms of quantity and weight. Up to now, multiple functions, light-weight and miniaturization have become the leading development tendency of modern electronics products. To achieve this goal, feature size of IC (integrated circuit) chips should be downsizing with their complexity degree constantly rising. As a result, I/O count starts uprising and I/O density of packaging starts violent uprising as well. To be appropriate for the development need, some advanced high-density presentation technologies develop among which BGA (ball grid array) is female type because it demonstrates more competent advantages than one other presentation forms on light weight, miniaturization and high performance.
The advent of BGA bundle came as early as the beginning of nineties and contains grown to be a mature high-density presentation technology. BGA packaging technology has been widely applied as packages in COMPUTER chips, microprocessors, ASIC, array, memory, DSP, PDA, PLD etc.
Properties of BGA Packaging
BGA package implements electrical connection between routine I/O conclusion and PCB (printed circuit board) based on array of solder balls under package base. Components with BGA packaging technology are a type of SMDs (Surface Install Devices). Compared with traditional leaded devices such as QFP, PLCC etc., BGA packaging components feature the next properties:
• High Depend of I/O
The number of I/O is identified by device size and solder ball pitch. Because solder balls with BGA packaging are distributed as a possible array at the base of base, BGA package deal can dramatically increase I/O count of components, get smaller package size and save assembly space. Generally communicating, package body volume can save at least thirty percent of space with BGA packaging technology applied in the case of equivalent leads.
• Large Pass Rate of Assembly with Cost Reduced
Leads of traditional QFP and PLCC components are distributed around packages with guide pitch being 1. 27mm, 1. 0mm, 0. 8mm, 0. 65mm or 0. 5mm. As count of I/O goes up, guide pitch has to become definitely downsizing. When pitch is less than 0. 4mm, precision of SMT equipment fails to meet corresponding demands. Furthermore, leads usually become deformed easily, assembly failure rate will therefore rise up.
BGA packaging components, however, organise solder balls in an array at the base of base and can hold higher count of I/O. Standard pitch of solder balls is just one. 5mm, one 27mm and 1. 0mm. Fine frequency BGA features their message to be 0. 8mm, 0. 65mm and 0. 5mm, compatible with SMT equipment.
Other properties of BGA packaging include:
• Make contact with area between BGA solder balls and base is large and short, beneficial for thermal dissipation.
• BGA features shorter leads, shortening signal transmission way, reducing inductance and opposition of leads and customizing circuit performance.
• BGA can obviously improve co-planarity of I/O end, dramatically decreasing loss therefore of bad co-planarity during assembly process.
• BGA works suitable on MCM package deal and can implement high density and high performance of MCM.
• The two BGA and fine frequency BGA are more reliable than fine pitch business lead ICs.