Project: A Novel System for the Production of World's First Ultra Fine Ball Grid Array (UFBGA)Spheres the Electronic Industry

There is relentless consumer demand for electronics equipment offering miniaturisation with higher functionality (e.g. cell phones playing music and movies whilst also offering email/SMS/camera functions). The industry is therefore continuously aiming for increases in integrated circuit miniaturization, processor speeds and circuit densities. The resultant increasing numbers of ever finer features on the silicon chip, and the need to electrically connect to them has stretched conventional wired or leaded electronics interconnect technology to its limits. This trend of miniaturisation + higher functionality looks set to continue, requiring fundamental advances in device electrical interconnect and mounting technology._x000D__x000D_Ball Grid Arrays (BGAs) is a key technology that simultaneously addresses the requirements for high density fine feature electrical interconnect and physical attachment of silicon chip devices. BGA is a 2-D array of miniature solder alloy spheres under the silicon chip that provides both electrical connection and mechanical attachment to a mounting socket or circuit board. The small diameter of the solder alloy spheres reduces electrical resistance and capacitance and helps to preserve electrical signal integrity. BGA technology facilitates a reduction in the silicon chip package size, better heat dissipation, and greater module (circuit) densities. A matrix of BGA solder alloy spheres is shown in Figure 1 (see annex A). Typical mobile phones and laptops contain 3,000 and 6,000 BGAs respectively. These BGAs are inside CPU, RAM, DSP, Memory sticks, Consumer electronics (video & digital cameras) etc._x000D__x000D_With increase in electronics miniaturisation and functionality, the sizes of silicon devices are continuing to decrease further and further and the density of connection points (pads) on the silicon chips continues to increase. Therefore, there is an urgent need for smaller and smaller BGA spheres. However, conventional BGA sphere manufacturing technology has reached a size limitation. Using current technology, BGA spheres of diameter greater than 200 µm can be produced satisfactorily but Ultra Fine BGA (UFBGA) spheres of diameter less than 200 µm can not be produced satisfactorily._x000D__x000D_The use of current BGA technology for UFBGA production leads to poor quality product batches due to the following:_x000D_1. Great technical difficulty of producing spheres which possess small diameters (less than 200 µm)._x000D_2. Unacceptable degree of roundness (sphericity). _x000D_3. Unacceptable degree of variation in sizes ie a batch of 200 µm UFBGAs must be within ±2% of diameter._x000D__x000D_Like most manufacturing processes, BGA sphere manufacturing process quality and yield can be measured in terms of the CpK index, which is a statistical measure of central tendency. Commercially viable CpK values are >1.33. The higher the CpK, the higher is the product quality and capability of the manufacturing process. Using current technology, the CpK values for UFBGA spheres production are between 0.66 and 0.9. Therefore, current manufacturing processes are commercially not viable due to high production costs resulting from low yields and the consequent wastage of material._x000D__x000D_Project aims are to prove technical feasibility of producing UFBGA spheres via a commercially viable process (CpK 1.33)._x000D__x000D_Project deliverables are as follows:_x000D_1. New and novel production patentable techniques for producing UFBGAs of less than 150µm._x000D_2. To increase CpK values from the current 0.66 and 0.9 to greater than 1.33._x000D_3. A novel integrated prototype system (UFBGA system) for the production of UFBGAs of less than 150µm._x000D_4. A man-machine interface for the control of the UFBGA prototype._x000D_5. A commercialisation plan. The UFBGA prototype system will be fully commercialised within 1 year of this project’s completion. Full commercialisation will require further work involving comprehensive field-testing and production engineering of the system to satisfy cost, performance and quality criteria in full-scale production. _x000D__x000D_The UFBGA system is targeted at all electronic product producing companies where miniaturisation is a major concern. This includes electronics for aerospace, automotive, mobile phones and laptops. _x000D__x000D_The SME Ps form a supply chain (see figure 2 in annex A), which consists of:_x000D_BizEsp: Solder materials manufacturers (BizEsp)_x000D_KCC: Supplies research in ultrasonic systems. They will further research and develop their current technology to separate the solder flow into exact size UFBGAs._x000D_IKH: They produce man-machine interfaces and will develop their technology for application to the UFBGA prototype system._x000D_ABIS: They are experts in industrial process systems. They will apply their technology for develop the world’s first UFBGA prototype._x000D_

Acronym NEMATIC (Reference Number: 4839)
Duration 01/06/2009 - 01/06/2011
Project Topic The production of UFBGA of less than 150µm involved innovative process_x000D_ using advanced ultrasonic and electrical charges techniques.
Project Results
(after finalisation)
During the NEMATIC project, iKnowHow contributed to the following project results; (1) Real-time industrial vision system for BGA sphere measurement and (2) Man-Machine Interface for the Control of the NEMATIC prototype.
Network Eurostars
Call Eurostars Cut-Off 2

Project partner

Number Name Role Country
5 iKnowHow S.A. Partner Greece
5 BizEsp Limited Partner United Kingdom
5 iKnowHow S.A. Partner Greece
5 Kingston Computer Consulting Limited Coordinator United Kingdom
5 ABIS s.c. Partner Poland