This technology can substantially reduce ic size and have the advantages such as high density, low sensitivity, low cost and effective heat dissipation. Eutectic snpb finepitch solder bumping and assembly for radhard pixel detectors alan huffman, richard labennett, salvatore bonafede, and chad statler. They are driven by the desire to pack more and more functionality and enhanced value into the same size handheld device, and often at lower costs. Design, manufacturing, and handling guidelines for cypress.
Characterization of a thick copper pillar bump process. Flip chip, also known as controlled collapse chip connection or its abbreviation, c4, is a method for interconnecting semiconductor devices, such as ic chips and microelectromechanical systems. The compa tibility of electroless nickel bumping to be implem ented in wafer manufacturing with in the next millennium sho ws that this is a key technology, not only for wafe r technologies in use. Stencil printing technology for 100m flip chip bumping citeseerx. Whether you have a need to process a single wafer or are. Wafer probe card solutions feinmetall viprobe is a buckling beam technology for contacting pads. Wafer bumping is often separated into two different categories. Adjustments were made to the printer parameters, namely. The bonding process needs to be compatible with the properties of the device wafer. Screen and stencil printing processes for wafer backside. Then it is going to melt the bumping by heat in assembly. Predominantly leadfree solders are used to create these bump. Am18x5bwam18x5cw wafer datasheet wire bond and gold bump wafers ambiq micro inc. Understanding wafer bumping packaging technology anysilicon.
Bump formation for flip chip and csp by solder paste printing. Most wafers are made of silicon extracted from sand. Effects of printing process parameters were also considered. Phoenix, az 85044 abstract as pin counts and interconnection densities increase there is growing interest in copper pillar bumps for flip chip and wafer. Eutectic snpb finepitch solder bumping and assembly for. For this aim, it is essential to use low cost bumping techniques. Once the ubm is deposited, a thick photoresist is applied to the wafer and patterned to create. Eight major steps to semiconductor fabrication, part 1. Semiprobe wafer inspection system wis examines, locates and identifies defects created during wafer manufacturing, probing, bumping,dicing or general handling. The photoresist is spincoated on the wafer and distributed evenly on the wafer surface. Figure 3 wafer bumping by ecd or electroplating method for c4 and c2 bumps status and outlooks of flip chip technology figure 3 wafer bumping by ecd or electroplating method for c4 and c2 bumps status and outlooks of flip chip technology. Coating thickness planarity across a wafer is the key metric for a successful coating process. Wafer bumping is an essential to flipchip or board level semiconductor packaging. Predominantly leadfree solders are used to create those bump.
The wafer bumping process can be classified according to its bump materials. A typical wafer bumping process flow involves two coating process steps. Figures 7 and 8 show the results of whole wafer scans reporting the corrected lt measurements of bump height and coplanarity for all bumps on the wafer. This categorization and affiliated nomenclature is partially based on the solder bump size and the type of equipment used to create the bump. Wafer processing bumping and meol at k4 and assembly at k1.
Ubm materials include al, ti, ni,ag,au, cu, niv and tiw while wb materials include sn, pb, and low alpha pb and sn. In order to fulfill the specific requirements for wafer bumping a new modular electroless ni wafer bumping line has been developed. Such processing is a key to the extremely high throughput. Bumping fine pitch u bump niau pad multilayer rdl low temp. This paper shows a low cost wafer level bumping process based on a electroless nickelgold. Each module can take batches of 50 wafers 8 or 10 wafers 12. Solder bumping and wafer level chip scale packaging. Design, manufacturing, and handling guidelines for cypress wafer level chip scale packages. Micross ait provides full inhouse stateoftheart wafer bumping and wlcsp solutions. Experience with bump bonding atlas particle physics. Flip chip refers to bumps on semiconductor wafers which are in the range of 50 to. Pdf in this paper solder paste printing is reported at sub 100mum pitch using.
Stencil printing remains the technology route of choice for flip chip bumping because of its economical. Tamarack successfully performed wafer debonding, including wafer edge deactivation in ap278b, they debonded the wafers in two steps. Bumping, ubm and mpw bumping of mpw and single chips difficult mpw. Characterization of a thick copper pillar bump process warren w. Assembly cow chip attach wafer underfill and mold csp or fcbga w lid.
Consumer electronics markets, the mobile phone market in particular, are extremely demanding. One advantage is the batch processing, where all components on a large wafer. Aug 01, 2009 nero 9 is a suite of optical disc authoring software program from nero ag, formerly ahead software, with its core principal product of nero burning rom. Basic unit silicon wafers basic processing unit 150, 200, 300 mm disk, 0. Wafer level packaging having bump onpolymer structure john j. The first photoresist is applied to prevent the ubm layer from being etched. A common feature of the joined structures is that the chip is lying face down to the. Flip chip refers to bumps on semiconductor wafers which. Stencil printing technology for wafer level bumping at sub100 micron pitch using pbfree alloys. Wafer bumping wafer level packaging chip scale packaging. This provides microelectronic device manufacturers with accurate, timely quality assurance and process information. The wafer solder bump process is to produce the solder bumping of the wafer pad. Pdf stencil printing technology for wafer level bumping at sub. Design for flipchip and chipsize package technology.
Figure 3 from status and outlooks of flip chip technology. Gold bump has been the most popular for tab technology since its introduction in 1970 triggs and byrns 1971. Understanding and mitigating chippackage board interactions. Ubm deposition, solder bumping, wafer thinning, and dicing. The results of wafer bumping by solder paste printing after reflow are shown in fig. All bumps of the wafer were measured to determine the bump height distribution. The second photoresist coat is applied to create the opening for solder deposition. These facilities are uniquely situated adjacent to major foundries to provide reduced timetomarket with integrated factory logistics and enables amkor to provide. Mike pinelis is the ceo and editor of mems investor journal, an independent publication he. Wafer level systeminpackage wlsip and bumped wafer packageonpackage pop wafer level packaging applies similar processes as used in frontend wafer processing. San jose, ca 95126 elliott capsuto, craig mcewen shinetsu microsi, inc. A wafer, also called a disc, is a thin, glossy slice of a silicon rod that is cut using specific diameters. In the sempictures the high homogeneity of bumps can be seen.
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