SHINKAWA – STB-FA-IL-20 First run : 2000

Technical Specification
Fully automatic wire automatic bonding machine
Range : Adjustment 1mm vertical / strong 10 mm X & Y / strong X = 100 mm Y = 100 mm
Bonding force : 1.0 30KgF (100 gF) – steps
Automatic lapping : X = 120 mm Y = 100 Z = 100 mm

The TAB (Tape Automated Bonding) technology is a usual micro-electronic industrial process.  TAB involves bonding a gold bumped die to a circuit built on a flexible material, such as polyimide. The TAB is used primarily in the flat panel display industry to mount driver chips between the glass of the display and the input circuitry behind the display. It is also used in optical applications such as the sensors of  stepper motors.

The flexible circuit used in TAB allows for the package to be bent by up to 180°. TAB is also utilized as a package format for Multi Chip Modules (MCM). In this format, the die and some of the leads are punched from the tape, the leads are formed, and the package is mounted similar to a J-Lead package. In some cases, the leads are not formed, but are soldered directly to the board.

TAB is typically a single sided polyimide based circuit, although two-metal tape is available (but more expensive). Copper is either electro-deposited to the tape or rolled copper is attached to the tape using an adhesive. The circuitry is then imaged using a photolithography process. The main advantage of TAB is the tight pitch of the circuit. Currently, line pitches of 45 microns are achievable (22.5 micron lines/spaces). This allows for high-density circuits for high pin count devices.

There are two methods of achieving the connexion between the die and the circuit. 

- The first one is a single point thermosonic bond. Single point bonding requires that each bond pad position be individually bonded using heat, time, force and ultrasonic applied to the TAB lead which is directly over its unique gold bumped bond pad. This process doesn't require specific tools but on the other hand, it takes more times.

- The second one, the Gang bonding uses thermocompression bonding to create a diffusion bond between all leads and bumps at the same time. A specially designed tool bonds all the leads to the die using force, temperature and time. It has the highest throughput.  This is the principle on which the Shinkawa operates.

Then, the devices can be encapsulated, delivered in a reel-to-reel or singular format. 

An another advantage of this process is the minimized size of the circuits: the resulting height is the sum thickness of the die, the bumps and the copper track.

The TAB tape, on to which the silicon die is bonded by the Shinkawa, is fed from reels in widths whose standards are those applying to component supply (and also the photographic industry) and are 44mm, 56mm 72mm and 88mm.  The tape has square sprocket holes similar to photographic film which the machine uses to index it forward for each bond set.

Figure 1: Attachment points for wires and bumps


Figure 2: Detail of wire bonds


Figure 3: Typical lead layout for gang bonding as on a Shinkawa


Figure 4:  Typical complete device soldered to PCB.  Inside this encapsulation would be the chip and leads as shown in Figure 3, above