JPH07176569A - Flip chip bonder - Google Patents

Abstract

PURPOSE:To reduce mounting defects caused by the variation of the heights of bumps formed on a flip chip by a method wherein the flip chip is mounted on a board for connection after the board is inclined with an angle so as to have the variation of the distances between the tips of the bumps and the board pads minimum. CONSTITUTION:The two-dimensional positions of all the bumps of a flip chip 1 are aligned beforehand with the two-dimensional positions of the pads of a board 2 which correspond to the bumps. The heights of all the bumps of the flip chip 1 which is attracted and held by a mounting head 4 are measured by a non-contact shape measurement unit 6 by driving an X-Y stage 7. An inclination angle calculating unit 8 calculates the optimum board inclination angle of the board 2 which makes the variation of the distances between the tips of the bumps and the board 2 minimum from the height data of all the bumps. The board 2 is inclined to have the optimum board inclination angle by a biaxial goniotable 9. Then a Z-stage 5 is made to descend and the flip chip 1 is mounted on the board 2 for connection. With this constitution, a chip having defective bumps can be detected before mounting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flip chip bonder, and more particularly to a flip chip bonder for mounting a flip chip on a substrate after tilting the substrate so that all bumps of the flip chip are optimally connected to the substrate pad.

[0002]

2. Description of the Related Art A conventional flip chip bonder (Shokai Sho6)
2-118435) has a structure in which the mounting head surface or the substrate stage surface can be freely tilted to cope with variations in bump shape.

[0003]

In the conventional flip chip bonder described above, when there is a bump having a shape extremely different from that of the surrounding bumps, there is a drawback that the bump or the surrounding bumps are not connected to the substrate pad. there were.

[0004]

The present invention provides a flip chip bonder for mounting a flip chip on a substrate under pressure,
A substrate stage that fixes the substrate, a mounting head that sucks and holds the flip chip, a Z stage that lowers the mounting bed from directly above the substrate and presses the flip chip onto the substrate, and a flip chip formed on the flip chip The non-contact shape measuring unit for measuring the height of all the bumps, and the tilt angle calculation for calculating the optimum substrate tilt angle such that all the bumps are uniformly connected to the substrate from the height data of all the bumps of the flip chip. And a biaxial goniometer stage which is installed below the substrate stage and tilts the substrate to the optimum substrate tilt angle calculated by the tilt angle calculation unit.

[0005]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

The flip chip bonder shown in FIG. 1 includes a flip chip 1, a substrate 2 for mounting and connecting the flip chip 1, a substrate stage 3 for fixing the substrate 2, and a mounting head 4 for sucking and holding the flip chip 1. The Z stage 5 that lowers the mounting head 4 from directly above the substrate to press the flip chip 1 against the substrate 2, the non-contact shape measuring unit 6 that measures the height of the bumps formed on the flip chip 1, and all the bumps. An XY stage 7 that moves the non-contact shape measuring unit 6 to measure the height, and an inclination angle calculation unit that calculates an optimum substrate inclination angle such that all the bumps are uniformly connected to the substrate 2 based on the height data of all the bumps. 8 and a biaxial goniometer stage 9 which is installed below the substrate stage 3 and tilts the substrate 2 to the optimum substrate tilt angle calculated by the tilt angle calculator 8.

The flip chip bonder of this embodiment mounts and connects the flip chip 1 on the substrate 2 by performing the following operations. The positions of all the bumps of the flip chip 1 and the corresponding pads of the substrate 2 on the plane are previously aligned.
The height of all the bumps of the flip chip 1 sucked and held by the mounting head 4 is measured by the non-contact shape measuring unit 6 on the XY stage 7.
Drive and measure. The inclination angle calculator 8 calculates the optimum substrate inclination angle of the substrate 2 from the height data of all the bumps so that the variation in the distance between the tip of the bump and the substrate 2 is minimized.
If the variation in bump height is large and the calculated optimum substrate inclination angle is large, mounting of the chip is stopped. The biaxial goniometer table 9 tilts the substrate 2 to the optimum substrate tilt angle, then lowers the Z stage 5 to mount and connect the flip chip 1 to the substrate 2.

[0009]

According to the flip chip bonder of the present invention, the flip chip is mounted on and connected to the board after the board is tilted at such an angle that the distance between the bump tip and the board pad is minimized. There is an effect of improving. In addition, defective bump chips are detected before mounting, which also has the effect of improving yield.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

[Explanation of symbols]

 1 Flip chip 2 Substrate 3 Substrate stage 4 Mounting head 5 Z stage 6 Non-contact shape measuring unit 7 XY stage 8 Tilt angle calculation unit 9 Biaxial goniometer stage

Claims (1)

[Claims] 1. In a flip chip bonder for mounting a flip chip on a substrate under pressure, a substrate stage for fixing the substrate, a mounting head for sucking and gripping the flip chip, and a mounting bed descending from directly above the substrate. The Z stage for pressing the flip chip onto the substrate, the non-contact shape measuring unit for measuring the height of all bumps formed on the flip chip, and the height data of all bumps of the flip chip show that all bumps are A tilt angle calculation unit that calculates an optimum substrate tilt angle for uniformly connecting to the substrate, and a tilt angle calculation unit that is installed under the substrate stage and tilts the substrate to the optimum substrate tilt angle calculated by the tilt angle calculation unit. A flip chip bonder including an axial goniometer stage.