ClawConnect™ LCD Driver Interconnects

Rapid growth in the global LCD (liquid crystal display) market is being fueled by increasing demands for better resolution and lower cost. PARC’s ClawConnect™ LCD driver interconnects enable the next generation of products by improving the COG (chip-on-glass) technology used to assemble leading-edge small- and medium-sized displays.

Current COG technology uses ACF (anisotropic conducting film) techniques to bond LCD-driver ICs (integrated circuits) to the LCD glass. As displays migrate to finer resolutions, however, ACF is unable to provide reliable interconnects between the fine-pitch contacts on the die and the glass. Using ACF techniques also aggravates other cost and yield issues.

PARC’s ClawConnect™ solution replaces ACF with fine-pitch spring interconnects that are fabricated at the wafer level. This solution reduces the die pitch below current ACF limits and decreases die and assembly costs, while still increasing display resolution.

Fine-pitch ClawConnect™ spring interconnect replaces ACF bumps

Solution Features

• Enables lower cost and better resolution for small- and medium-sized color LCDs
• Replaces ACF techniques currently used in COG, enabling finer pitch and lower display cost
• Reduces interconnect pitch—and hence die-size and cost—by:
  • replacing the ACF Au (gold)-ball matrix with fine-pitch springs
  • redistributing contacts over the die’s active circuitry, now possible because of the low force and low temperature of the ClawConnect™ bonding process
• Eliminates the strict 1-2 µm (micron) bump flatness that ACF requires, thus lowering assembly costs
• Reduces ACFcosts and Au-bump costs by substituting lower-cost springs
• Enables LCD production based on a-Si (amorphous silicon) technology to compete against LTPS (low temperature polysilicon) resolution

Application Areas

• LCD module assembly companies—save money on lower-cost modules, with improved process yield
• LCD driver IC companies—increase die count per wafer for driver ICs, which are currently size-constrained by ACF's large pads
• LCD panel manufacturers using a-Si—extend product range to higher-resolution products, thus better competing against high-resolution, LTPS LCD products
• Handset, PDA, and cell-phone manufacturers—get a lower-cost, higher-resolution product, which impacts image quality and user experience

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