What is a TCP/COF Package?

The TCP/COF is a package technology which employs a flexible printed circuit film (with sprocket holes for transportation that is similar to photographic films) bonded with gold bumps on chip to make the electrical input and output connections between the circuit board and the display panel for driver function.

TCP film is comprised of 3 layers: PI, adhesive and copper foil. It has a punched device hole in the chip area so that the cantilevered inner leads can absorb direct thermal conduction from the bonding tool during the gang bonding process to the gold bumps. Additionally, the TCP package utilizes a liquid adhesive compound to attach the hanging chip and protect the chip surface.

COF film is comprised of 2 layers: PI and copper foil. The gold bumped chip is bonded onto the inner leads of the printed circuit film using a flip chip process. As COF film is thinner than TCP film, it is capable of a finer circuit pitch and has greater flexibility. The COF package requires an underfill material to fill and fix the gap between the film and chip.

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Why use TCP/COF Package?
TCP/COF are widely used in panel (LCD, OLED, PDP...) driver packages for a long time. The assembly type is gang bond technique with reel-to-reel carrier method. It is intended to replace the wire bonding technique with improved reliability and high throughput manufacturing capability. These package types allow high-density circuits pattern for high I/O pin count driver IC.
1.Description :
TCP/COF stands for the "Tape Carrier Package" and "Chip On Film", these packages are widely used for the packaging IC drivers for LCD, OLED, PDP...etc. Siliconware's TCP/COF family includes TCP, COF and IJTCP (ink jet printer driver).
2.Feature :
2.1. Advantage :
High I/O pin count for high image resolution and large size panel. Thin, light and flexible for compact products. High freedom of pin count design.
2.2. Package compositions
	2.2.1 Chip with gold plating bumps:
		(1) Chip size: Length: 24 mm (Maximum) Width: 0.7 mm (Minimum) Thickness: 300~736 um
		(2) Gold bumps: Bump height: 18+/- 3 um Hardness: 55 +/- 15 Hv. Bump pitch: 40 um (for TCP package); 30 um (for COF package)
	2.2.2 Tape film:
		(1) Tape width: 35W / 35SW / 48W / 48SW / 70W / 70SW(for COF package). (2) Copper foil: FQ-VLP...etc.Thickness: 15 / 18 / 25 / 35 um (for TCP package); 8 um (for COF package) (3) Copper foil plating: Gold or Tin plating (4) Base film: PI (Kapton EN...etc.)      Thickness: 50 / 75 um (for TCP package); 25 / 38 um (for COF package) (5) Solder resistance (AE-70-M11...etc.) (6) Adhesive (for TCP package) (7) Flex coating (for TCP package)
	2.2.3 Encapsulation: Liquid compound (for TCP package); Underfill (for COF package)
3. Application :
Driver IC for LCD panel ( TFT , STN , CSTN...etc ) Driver IC for OLED , PDP...etc. Driver IC for Ink jet printer (IJTCP )
4. Process flow & BOM.
Process Flow BOM Wafer Sort & Inking Ink Lapping Lapping tape Wafer Mount UV tape Dicing Saw Sawing blade Inner Lead Bonding Chip , Tape Encapsulation Liquid compound Post Cure NA Marking NA ( laser marking) Function Test NA Final Visual Inspection NA Packing Antistatic reel , Aluminum bag
5.Reliability :
• Temp. Cycle Test -65 ~ +150°C, 100 cycles • Pressure Cooker Test 121°C, 100% RH, 2 ATM, 96 hours • High Temp. Storage Test 125°C, 1000 hours • Low Temp. Storage Test -65°C, 1000 hours • Temperature & Humidity Test 85°C, 85% RH, 1000 hours

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