Handling and Use of Die Products

Die Products have been singulated and assembled into individual packages for over 35 years. During this time standardized and formalized processes have been developed to insure that highly reliable product was assembled. The use of die products in applications previously populated by packaged product requires that consideration be given to the die product since its format is different than the typical packaged product. While die products are robust in the proper assembly environment, improper handling can result in unreliable assemblies. In utilizing die products consideration must be given to:

• Foreign Material: among the most common are skin, hair, spittle, cosmetics, dust, dirt, fingerprints, airborne particles, machine oils and friction by-products
  • Impact of foreign material: among the effects observed are electrical leakage, electrical shorts, latent failures, visual defects and corrosion.
  • Techniques for control during processing include: air filtration, cleanroom smocks, face masks, gloves, hairnets, work area hoods, equipment maintenance, housekeeping and employee training.
    
• ESD: electrostatic discharge can have the same effects on die products as those experienced with packaged devices.
  • Typical failure modes: state or level upset effects, immediate device breakdown, cumulative degradation from repeated exposure and latent damage causing subsequent failure.
  • Techniques for control during processing: humidity of 30% to 60%, use of conductive or static dissipative materials, use of ionizers, conductive paths to ground for personnel and work surfaces, and employee training.
    
• Die Product Packaging: The various packaging options utilized are based on their ability to protect die during transit.
  • The consideration that should be given when selecting from the various shipping mediums include: cost of use, level of automation, die orientation requirements, contamination potential, processing ease, multiple supplier commonality, equipment interface capability, inventory and storage control, resealibility and mechanical protection.
    
• Specific Product Related Information: this information is available from individual Die Product datasheets.

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Die Tape on Reel Format 

The continued growth of the bare die market has included an increasing segment of high volume applications (e.g. telecommunications, automotive, computers). Because of tape on reel's proven characteristics of low cost and high-speed manufacturing, National Semiconductor's Die Products customers in these markets are increasingly requesting die products to be packed in tape on reel.

Customers are given a competitive advantage through the speed and efficiency that tape on reel provides. Carrier tape offers the electrical and mechanical protection of our other shipping media and additionally provides the customer with large die quantities on a single reel for greater efficiency. In fact, a single 7 inch reel may hold up to 7,000 die. Tape on reel also offers the advantage of quickly presenting to the assembly machine a die that is always oriented and in position. No need for the machine to waste time searching for the part or determining proper orientation. Reels, when used in a cassette format, may be plugged into or removed from an assembly machine in banks allowing quick reconfigurations.

Die products are available in Surftape® carrier tape on 7 inch diameter reels. Surftape® (figure 1) is an adhesive assisted tape. Tape is available in 8mm and 12mm widths (the tape width used is determined by die size). The adhesive assisted carrier tape utilizes a punched cavity opening with pressure sensitive adhesive at the bottom to hold the die in place. The pressure sensitive adhesive is actually a strip on each side of the cavity bottom, which provides a gap for push pin removal of the die. Go to Top
Glossary of Terms & Abbreviations		References
AOI automated optical inspection   Ag silver   Al aluminum   Au gold   BGA ball grid array   C capacitance   COB chip-on-board   Cu copper   CSP chip scale package   CTE coefficient of thermal expansion   DCA direct chip attach   DIP dual inline package   EMI electromagnetic interference   ESD electrostatic discharge   FCP few-chip package   HDI high density interconnect   IC integrated circuit   I/O input/output   L inductance   MCP multichip package   Ni nickel   PBGA plastic ball grid array   Pd palladium   PWB printed wiring board   QFP quad flat pack   R resistance   RF radio frequency   RGA residual gas analysis   SIP system in package   SMD surface mount device   SOC system on chip   Tg glass transition temperature   µBGA micro ball grid array		"Thin Film Multichip Modules", Messner, Turlick, Balde & Garrou, ISM Technical Monograph, 1992   "Electronic Packaging and Interconnection Handbook", Charles Harper, McGraw-Hill, 2000   "Wire Bonding in Microelectronics: Materials, Processes, Reliability and Yields", George Harman, McGraw-Hill, 1997   JESD 49, ES59008

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