Backgrinding Wax Adhesive Solutions for SiC, Sapphire, GaN, and GaAs Wafers

Backgrinding Wax Adhesive Solutions
for SiC, Sapphire, GaN and GaAs Wafers

Why is a new backgrinding adhesive solution needed?

Typical wafer backgrinding tape has 200 to 1000 gm/inch peel bond strength. This is adequate for relatively soft, easy to thin silicon wafers. However:

• Hard materials and brittle materials are harder to grind
  • e.g. SiC (silicon carbide), Sapphire, GaN, GaAs and other III-V semiconductors
• Shear bond strength of traditional wafer backgrinding tape is insufficient
• Strong shear bonding wax adhesives are required
• Grinding very hard material generates heat
  • May raise temperature as high as 60ºC
  • Must maintain shear bond strength

BGF Wax Adhesives Films:
Innovated by AIT. Proven by Application.

• Film format wax adhesive
• > 1000 psi shear bonding strength (see graphic below)
  • Hold strong for grinding extremely hard materials like SiC
  • Strength to protect fragile wafers from fracture
    • Materials like GaN and GaAs may fracture with any stress concentration
• Maintain strength at 60ºC
• Different thicknesses available
  • Thin as 3um
  • Thick as 400um
• Film format = Uniformity control
  • Removes skill dependent spin-coating method
    • Even well trained operators still find it difficult to control the uniformity of the wax thickness in spin-coating
• No spin-coating and No drying time ↔ Simplified process and Greater throughput

The patent-pending solution with AIT melt-conformable temporary bonding adhesive wax on disposable carrier is molecular designed for flexibility. It will not induce interfacial stress whether the carrier has 3-7 ppm/ºC of matched CTE to SiC, Sapphire or GaAs wafer or otherwise.  Wax adhesive films are available with thickness of 3µm and up.

BGF novel wax film adhesives, pioneered by AIT, are also available pre-applied on disposable carrier. (hyperlink this). The adhesive provides high shear bonding while the disposable carrier format multiplies wafer throughput. BGF on disposable carrier has TTV of 2um or less.