JPH02181447A - Die bonding device - Google Patents

Abstract

PURPOSE:To prevent the mixing of bubbles in the interface of an IC chip and adhesives by bringing the IC chip into contact on a printed wiring board under a previously inclined state and mounting the IC chip so as to run parallel finally thereto. CONSTITUTION:When a bonding pad 2 sucks an IC chip 7, the chip 7 and the pad 2 are at stand-by under the state, in which they are inclined at approximately 20-30 deg., by the theta-axis of rotation. A circuit board 8 is set at a desired position under the pad 2. A head body begins to be lowered, and is lowered until the underside of one end section of the chip 7 reaches the printed wiring board 8. The theta-axis of rotation and a Z-axis drive system begin to be moved simultaneously, and are operated until the chip 7 runs parallel with the printed wiring board. Adhesives 10 are shifted and pushed by the chip 7 at that time, and no bubble is mixed on the interface of the chip 7 and adhesives 10 finally and the chip 7 is mounted to the board 8.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a die bonding device for IC chips necessary for circuits of radio receivers, television receivers, video tape recorders, communication equipment, electronic computers, and the like.

2. Description of the Related Art Conventionally, when an IC is mounted on a substrate surface, an IC is used which has been subjected to a die bonding process and a wire bonding process, and then is packaged with a sealant containing an epoxy resin as a main component. In the adhesive bonding process, an adhesive is applied in advance onto a metal frame called a lead frame, which serves as a base material. At the same time, the semiconductor wafer is sliced, the divided IC chips are prepared, and after being taken out individually with a bonding head, the IC chips are mounted on the desired position on the lead frame coated with adhesive and hardened by heat. . In addition, in the wire bonding process, a wire wire with a wire diameter of 20 μm to 50 μm, with a ball formed at the tip using a spark current, is passed through a needle-like head with a thin hole called a capillary, and an IC called a bonding pad is passed through a needle-like head with a thin hole called a capillary. The ball portion at the tip of the Au wire S is crimped onto the A/vapor deposition surface. Further, the same action is repeated on the base material to press it to the conductor portion, thereby establishing electrical continuity between the base material and the IC.

In addition, in recent years, a method has been adopted for Hipuri, Tsudoe C, etc. that involves die bonding IC chips directly onto the substrate surface without packaging, and directly wire bonding the conductors on the substrate surface and the IC chips. Efforts are being made to reduce costs.

Problems to be Solved by the Invention When attaching an IC to a base material using the conventional die bonding method described above, adhesive or cream solder is first applied to the base material. Application methods include a printing method, a transfer method, and a dispenser method. Since the printing method requires a printing device and is a separate process, a transfer method and a dispenser method are often used.

In the transfer method, a jig called a transfer pin, which has been processed in advance to match the IC chip, is brought into contact with adhesive spread on a flat surface, and after the adhesive is transferred to the transfer pin, it is then brought into contact with the substrate to perform the transfer. It is something to do. At this time, the surface of the transferred adhesive is unstable in shape, and in some cases, when the IC chip is attached, air bubbles may be mixed in at the interface between the IC chip and the adhesive, and when it hardens, it may expand and destroy the IC chip. ,
It may cause delamination at the interface. The same thing can be said for the dispenser method.

Means for Solving the Problems In order to solve the above problems, the present invention provides a die bonding apparatus that applies an adhesive onto a circuit board and mounts a pair of ICs thereon. This method prevents air bubbles from entering the interface between the IC chip and the adhesive by bringing the IC chip into contact with the substrate surface in a suspended state and finally mounting the IC chip horizontally to the substrate surface.

Function In the present invention, the die bonding head initially
It is perpendicular to the chip, and a suction pad is attached to the tip. When an IC mounted on an expandable sheet is taken out by a bonding head, the suction pad is kept in a vacuum state, and the head moves up and down to approach the IC chip and attach it to the bonding head. After that, the bonding head rises and performs a θ rotation about the center of the tip of the bonding pad. The bonding head descends again, this time approaching the board to be attached. When the lower end of one end of the tilted IC chip reaches the surface of the circuit board, the head starts rotating θ again and mounts the IC chip so that it is parallel to the board. At this time, the θ rotation of the IC chip occurs, causing an action to push the pre-applied adhesive. At the same time, it removes air bubbles that are mixed in at the interface between the adhesive and the IC chip, and prevents cracks in the IC chip that occur during curing. This prevents peeling.

Example Next, an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

First, FIG. 1 is a diagram showing the configuration of a bonding head section of a die bonding apparatus. Reference numeral 1 denotes the head body, and a pounding pad 2.3 is attached to the tip of the head body.

The head body 1 is attached to the apparatus body by a zero-rotation shaft 6. Further, the head main body 1 is configured to be able to perform vertical movement using a two-axis drive system 4, and x-axis movement using an X-axis drive system 5. First, under the head body 1,
IC chips, which are obtained by slicing and dividing a wafer, are arranged on a sheet called an expanded sheet.
The head body 1 begins to descend by the shaft drive system 4. next,
At the time when the bonding pad 2 reaches the IC chip 7, suction starts, and the head main body 1 starts to rise again by the two-axis drive system 4 to pick up the IC chip 7. Next, 0 rotation axis 6
The angle between the IC chip and the head body 1 is approximately 20° to 30°.
The IC on the expandable sheet under the head body 1 was placed on the XY table 9.
The circuit board 8 is then replaced by the circuit board 8, and the circuit board 8 is set under the bonding pad 2 in a desired position on the circuit board 2 (FIG. 2a). Immediately thereafter, the head body 1 begins to descend by the two-axis drive system 4 until the bottom surface of one end of the IC chip 7 reaches the printed wiring board 8 (FIG. 2b).

After that, the θ rotation axis 6 and the two-axis drive system 4 start moving simultaneously,
It operates until the IC chip is parallel to the printed wiring board.

At this time, the adhesive 1o is pushed and moved by the IC chip 7, and the IC chip 7 is finally attached to the printed wiring board 8 without any air bubbles being mixed in at the interface between the IC chip 7 and the adhesive 10 ( Figure 2C1d). The suction of the suction pad 2 stops, and the head body 1 is raised by the two-axis drive system 4, completing die bonding.

As described in detail, the present invention provides an interface between the adhesive and the IC chip by bringing the IC chip into contact with the printed wiring board in a pre-tilted state and finally mounting the chip so that the chip is parallel to the printed circuit board. There are no air bubbles mixed in, and the C-chip does not break or peel off during curing, allowing highly reliable die bonding of paired ICs.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a bonding head portion of a die bonding apparatus according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram from an inclined state to mounting an IC chip parallel to a substrate. 1... Head body, 2... Ponding pad (for small chips), 3... Ponding pad (for large chips), 4... 2 axes Drive system, 6.
...X-axis drive system, 6...θ rotation axis, 7.
...IOf, b, 8... circuit board, 9.
...x, y table, 1o...adhesive. Name of agent: Patent attorney Shigetaka Awano and 1 other person −
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Claims (1)

[Claims] In a die bonding machine that applies adhesive to a circuit board and mounts a pair of ICs, the IC chip is taken out by the bonding head, and then brought into contact with the board surface in a pre-tilted state, and finally leveled with the board surface. Die bonding equipment equipped with a mechanism for attaching IC chips.