JPH0487344A - Flip-chip bonding apparatus - Google Patents

Abstract

PURPOSE:To uniformly bring the electrode on a substrate into close contact with the bump on a chip by a method wherein an upper-part holder and a lower-part holder form a spherical pair and a gas jet port used to supply a gas is installed at the upper-part holder at a part where the upper-part holder comes into contact with the lower-part holder. CONSTITUTION:A lower-part holder 4 and an upper-part holder 3 which form a spherical pair are energized to a direction in which their mutual contact parts 7a, 7b come into close contact by a holding spring 6. When a gas or the air is supplied to the contact parts 7a, 7b from a gas jet and suction port 8 installed so as to protrude at the upper-part holder 3, an air bearing which uses the gas as a lubricative material is formed. As a result, the lower-part holder 4 can be turned freely in an arbitrary direction with reference to the upper-part holder 3. When the rear surface of a chip 11 is not parallel with the surface of a substrate 12, the lower-part holder 4 is turned properly in an arbitrary direction in such a way that the rear surface of the chip 11 becomes parallel with the surface of the substrate. As a result, a bump 11a on the rear surface of the chip 11 is pressure-bonded uniformly to an electrode 12a on the surface of the substrate 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flip-chip bonding apparatus for directly bonding an electrode of a substrate and a bump of a chip knob in a manufacturing process of a semiconductor device.

[Prior art] Conventionally, LSIs have a large number (hundreds to thousands) of bumps.
When mounting a chip on a substrate such as a liquid crystal display or a main board of a computer, flip chip bonding is used, which eliminates the need for wire bonding.

Flip chip bonding is a method in which electrodes on a substrate and bumps on a chip are accurately aligned and then the electrodes and bumps are directly pressed together. Therefore, during bonding, it is required to make the substrate and the chip parallel to each other, and to uniformly bring the many electrodes of the substrate and the bumps of the chip into close contact with each other.

On the other hand, as a flip chip bonding apparatus, for example, the one shown in FIG. 6 has been devised.

That is, the flip chip bonding device 72 located above the pressure table 70 includes a pressure printer 73, a parallel alignment mechanism section 74, a tool holder 75, a pressure relief material 76, and a bonding tool 77. Further, the bonding tool 77 holds a chip 11, and the bumps 11a of the chip 11 are accurately aligned with the electrodes 12a of the substrate 12 placed on the pressurizing table 70.

In such a configuration, after manually or mechanically ensuring parallelism between the chip 11 and the substrate 12 by the parallel alignment mechanism section 74, the pressurizing cylinder 73 is operated to move the chip 11 into the It is pressed onto the substrate 12.

Further, depending on the warpage of both the chip 11 and the substrate 12, or the difference in parallelism, the substrate 1
2 and the chip 11, but this error is absorbed by the deformation of the pressure relief material 76 during crimping.

[Problems to be Solved by the Invention] However, in such a conventional flip chip bonding device 72, the parallel state between the substrate 12 and the chip 11 is ensured in advance manually or by mechanical means. Before starting the mounting work of the chip 11, it is necessary to make fine adjustments to the bonding tool 77 that holds the chip 11, which is an obstacle to improving productivity.

Furthermore, since the pressure relief material 76 deforms to absorb errors in parallelism between the substrate 12 and the chip 11 during crimping, it is difficult to use the pressure relief material for a long period of time. Therefore, periodic replacement was required, which caused problems in terms of running costs.

The present invention has been made in view of these conventional problems, and it eliminates the need for fine adjustment of the honding tool itself before starting the work, and furthermore, it eliminates the need for fine adjustment of the honding tool itself before starting work, and furthermore, it eliminates the need for fine adjustment of the honding tool itself before starting work, and furthermore, eliminates the need for fine adjustment of the honding tool itself before starting work. The object of the present invention is to provide a flip chip bonding device that enables uniform and close contact between the two.

[Means for Solving the Problems] In order to solve the above problems, in the first aspect of the present invention, a bonding tool holding a chip is pressed into a pressurizing mechanism from above a substrate placed on a substrate mounting table. In the flip chip bonding apparatus, the bonding tool includes an upper holder supported by the pressing mechanism, and a lower part having a tool body that holds the chip. holder, the upper holder and the lower holder form a spherical pair, and the upper holder further includes a gas supplying gas between the abutting portions of the upper holder and the lower holder. It was decided to provide a spout.

The spherical surface portion of the spherical pair may be centered at a center portion of the lower surface of the chip held in the tool body, or at a position that is symmetrical with the center portion of the lower surface of the chip with the spherical portion as the center. Furthermore, in the flip chip bonding apparatus, the upper holder is provided with a gas suction port for adsorbing the upper holder and the lower holder.

In the second invention, a bonding tool holding a chip is pressed by a pressing mechanism section from above the substrate placed on the substrate mounting table, and the bumps of the chip are bonded to the electrodes of the substrate. In the flip chip bonding apparatus, the bonding tool includes an upper holder supported by the pressure mechanism section and a lower holder that holds a tool body that holds the chip, and the upper holder and the lower holder are connected to each other. Both opposing surfaces are spherical surfaces having the same center, and a ball bearing is held between the opposing spherical surfaces.

Further, the centers of both of the spherical surfaces are centered at the center of the lower surface of the chip held by the tool body, or at a position that is symmetrical with the center of the lower surface of the chip with the spherical surface as the center, Furthermore, the flip-chip bonding device is provided with a fixing means for fixing the upper holder and the lower holder as necessary to the upper holder via the ball bearing.

[Function] In the first aspect of the invention having the above configuration, when bonding the chip to the substrate placed on the previous substrate mounting table, the bonding tool holding the chip presses the pressurizing mechanism section. When pressed down by the bonding tool, the chip held by the bonding tool eventually comes into contact with the substrate. At this time, the lower holder and the upper holder forming the honding tool form a spherical pair, and gas is supplied from the gas outlet between the lower holder and the upper holder. Airverine is formed using gas as a lubricant. Therefore, the lower holder is rotatable in any direction relative to the upper holder.

When the chip comes into contact with the substrate, if the lower surface of the chip and the upper surface of the substrate are not parallel, the lower holder is moved as appropriate so that the lower surface of the chip and the upper surface of the substrate are parallel to each other as the bonding tool is pressed. It rotates in the direction of , and spherical learning is performed. Therefore, the bumps on the lower surface of the chip held by the tool body of the lower holder are uniformly pressed against the electrodes on the upper surface of the substrate, and
The chip will be bonded to the substrate.

Further, in the case where the spherical portion of the spherical pair is centered at the center of the lower surface of the chip held by the tool body, or at a position that is symmetrical with the center of the lower surface of the chip with the spherical portion as the center, Even after the chip and the substrate come into contact with each other, the center position of the chip does not shift due to the above-mentioned spherical shape of the lower holder. Therefore, the bumps on the lower surface of the chip and the electrodes on the upper surface of the substrate will not be slightly misaligned during pressure bonding.

Furthermore, when the upper holder is provided with a gas suction port for adsorbing the upper holder and the lower holder, when the bonding between the chip and the substrate is completed, the lower part forming the spherical pair The lower holder is attracted to the upper holder by suctioning gas or air between the spherical parts of the holders through the gas suction port. For this reason, the lower holder that has been subjected to spherical training at the end of honding is maintained in that state. Therefore, the unnecessary spherical shape of the lower holder is prevented during the next bonding.

On the other hand, in the second invention having the above configuration, when bonding the chip to the substrate placed on the substrate mounting table, the bonding tool holding the chip is pressed down by the pressure mechanism section. Eventually, the chip held by the bonding tool comes into contact with the substrate. At this time, both opposing surfaces of the lower holder and the upper holder that constitute the bonding tool are spherical surfaces having the same center, and the ball bearing is sandwiched between the two spherical surfaces. Therefore, the lower holder is rotatable in any direction with respect to the upper holder.

For this reason, when the chip comes into contact with the substrate, if the lower surface of the chip and the upper surface of the substrate are not parallel, the lower holder is moved as appropriate so that the lower surface of the chip and the upper surface of the substrate become parallel as the bonding tool is pressed down. It rotates in the direction of , and spherical learning is performed. Therefore, the bumps on the lower surface of the chip held by the tool body of the lower holder are evenly pressed against the electrodes on the upper surface of the substrate, and the chip is bonded to the substrate.

Further, in the case where the centers of both of the spherical surfaces are centered at the center of the lower surface of the chip held by the tool body, or at a position that is symmetrical with the center of the lower surface of the chip with the spherical surface as the center, Even after the chip and the substrate come into contact with each other, the center position of the tool body that holds the chip does not shift due to the above-described spherical shape of the lower holder. Therefore, the bumps on the lower surface of the chip and the electrodes on the upper surface of the substrate are not slightly misaligned during pressure bonding.

Furthermore, if the upper holder is provided with a fixing means for fixing the upper holder and the lower holder as necessary via the ball bearing, the mounting between the chip and the substrate can be prevented. When finished, the lower holder can be fixed to the upper holder by the fixing means. Therefore, the state of the lower holder which has been subjected to spherical learning at the end of bonding is maintained. Therefore, the unnecessary spherical shape of the lower holder is prevented during the next bonding.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. 1 to 3 show an embodiment according to the first invention, and above the substrate mounting table 1, there is a pressurizing mechanism (not shown) of the flip chip bonding apparatus.
A bonding tool 2 is located. The bonding tool 2 includes an upper holder 3 supported by the pressure mechanism section.
It is composed of the upper holder 3 and a separate lower holder 4.

Hook arms 5a are fixed around the upper holder 3 at an angle of 120 degrees to each other (FIG. 2).
, a hook arm 5b is fixed to the lower holder 4, which is symmetrical to the hook arm 5a (FIG. 3);
A retaining spring 6 is engaged between the footer arms 5a and 5b. The lower holder 4 is brought into close contact with the upper holder 3 by the holding spring 6.

Further, the upper holder 3 and the lower holder 4 form a spherical pair in which both contact portions 7a, 7b are spherical, and the spherical portions 7a, 7b of the spherical pair are the lower surface of the chip (described later). The central part P is its center. In addition, the upper holder 3
A gas ejection suction port 8 is provided in a protruding manner to communicate the outside of the upper holder 3 and the contact portion 7a. The gas jet suction port 8 includes a gas jet port for supplying gas or air between the contact parts 7a and 7b, and a gas suction port for sucking the gas or air between the contact parts 7a and 7b. It also serves as

An air circuit A for supplying the inert gas and sucking gas or air is connected to the gas jet suction port 8 under manual or automatic control.

Further, a tool body 9 having a suction hole 10 for holding a chip is fixed to the lower end of the lower holder 4, and a chip 11 is attracted to the tool body 9. Note that the bumps l formed on the lower surface of the chip 11
la is accurately aligned with the electrode 12a of the substrate 12 placed on the substrate mounting table 1. On the other hand, a heater 14 for heating the lower part holder 4 is provided above the tool body 9, and a heater 14 is provided above the tool body 9.
A gap 13 is provided inside the lower holder 4, where the upper part is located, and the upper holder 3, passing through both.

The operation of the flip chip bonding apparatus having the above configuration will be described below with reference to the timing chart shown in FIG. 4. That is, when bonding the chip 11 to the substrate 12 placed on the substrate mounting table 1, the bonding tool 2 holding the chip 11 is pressed down by the pressure mechanism (not shown). (arrow a) in FIG.
2 (timing A).

At this time, the lower holder 4 and the upper holder 3, which constitute the bonding tool 2 and form a spherical pair, are urged by the holding spring 6 in a direction in which the contact portions 7a and 7b of each other come into close contact with each other, Furthermore, gas and air are supplied between the contact portions 7a and 7b from the gas jet suction port 8 protruding from the upper holder 3, thereby forming an air bell ring using the gas as a lubricant (timing C). ). Therefore, the lower holder 4 is rotatable in any direction (such as the direction of the arrow in FIG. 1) relative to the upper holder 3.

When the chip 11 comes into contact with the substrate 12, the chip 1 adsorbed to the tool body 9 of the lower holder 4
If the bottom surface of the chip 11 and the top surface 12 of the board are not parallel, the lower holder 4 is rotated in an arbitrary direction as the bonding tool 2 is pressed so that the bottom surface of the chi knob 11 and the top surface of the board are parallel. move. That is, the spherical shape of the lower holder 4 is performed, and the lower surface of the chip 11 lands flatly on the upper surface 12 of the substrate. Therefore, the bumps lla on the lower surface of the chip 11 are uniformly pressed against the electrodes 12a on the upper surface of the substrate 12. Therefore, it is possible to bond the chip 11 and the substrate 12 without having to align the bonding tool in parallel before starting the bonding operation, and it is possible to improve work efficiency.

Further, when the above-described spherical learning of the lower holder 4 is performed, since the spherical parts 7a and 7b of the spherical pair are centered on the center part P of the lower surface of the chi knob 11 that is attracted to the tool main body 9, The center position of the chi knob 11 before the spherical learning of the lower holder 4 is performed and the center position after the spherical learning is performed do not change. Therefore, even if the spherical shape of the lower holder 4 is performed, the bumps 1 on the lower surface of the chip 11
2a and the electrode 12a on the upper surface of the substrate 12 are not slightly misaligned.

Further, after the bonding between the chip 11 and the substrate 12 is completed, the tool main body 9 releases the adsorption of the chip 11 (at timing B), the upper holder 3 and the lower holder 4 forming a spherical pair from the gas jet suction port 8 Spherical part 7 with
When the gas or air between a and 7b is sucked (timing D
), the lower holder 4 is fixed to the upper holder 3 by suction. Therefore, as described above, the lower holder 4, which has been subjected to spherical learning at the end of bonding, is maintained in that state.

Therefore, at the next bonding time (timing A), it is only necessary to correct the error in parallelism between the chip 11 and the substrate 12, which is caused by the warping of the chip 11 and the substrate 12 or the difference in parallelism in thickness. As a result, excessive spherical distortion of the lower holder 4 can be prevented, and workability can be improved.

FIG. 5 shows an embodiment according to the second invention. That is, above the substrate mounting table 1, a bonding tool 21 supported by a pressure mechanism (not shown) of the flip chip bonding apparatus is located. The bonding tool 21 is composed of an upper holder 22 and a lower holder 23 supported by the pressure mechanism section.

The lower end surface 22a of the upper holder 22 has a spherical shape, and an opening 24 is provided in the center of the lower end surface 22a, and a spherical seat holder 25 is protruded into the opening 24. The lower end surface 25 of the spherical seat holder 25
a has a spherical shape. The spherical seat holder 25 is fitted into the upper holder 22 so as to be slidable in the vertical direction, and is urged toward the lower holder 23 by a spring 26 provided at the upper part of the spherical seat holder 25. .

Further, above the upper holder 22, a gas suction port 27 is provided.
is provided, and the gas suction port 27 and the center portion of the spherical lower end surface 25a of the spherical seat holder 25 are communicated with each other. Furthermore, the aforementioned air circuit A is connected to the gas suction port 27.

On the other hand, the upper end surface 23a of the lower holder 23 has a spherical shape, and a tool main body 29 having a suction hole 28 for sucking chips is fixed to the lower end of the lower holder 23. The center part of the tool body 29 extends inside the lower holder 23 toward the upper holder 22, and is wrapped with a heater 30 that heats the lower holder 23. It protrudes from the upper end surface 23a.

A spherical seat 31 is screwed onto the upper end surface 29a of the tool main body 29, and the upper end surface 31a has a spherical shape and is slidably in close contact with the lower end surface 25a of the spherical seat holder 25. Further, the upper end surface 29a and the lower end surface 2
Both spherical surfaces of 5a are centered at the center P of the lower surface of the chip 11.

The spherical seat holder 25 and the spherical seat 31 are fixing means for fixing the upper holder 22 and the lower holder 23 as necessary. Then, the lower holder 23
A chip 11 is adsorbed to the protruding lower end of the tool body 29 fixed to the tool body 29, and the bumps 11a formed on the lower surface of the chip 11 are connected to the electrodes of the substrate 12 placed on the substrate mounting table 1. 12a.

On the other hand, a hook arm 32 is provided around the upper holder 22.
a are fixed to each other at an angle of 120 degrees, and
The hook arm 32a is provided around the lower holder 23.
A hook arm 32b is fixed, and a retaining spring 33 is installed between the hook arms 32a and 32b.
is attached. Further, the lower end surface 22a of the upper holder 22 and the upper end surface 23a of the lower holder 23, both of which are spherical, are centered at the center P of the lower surface of the chip 11.

Further, an annular ball bearing 34 is sandwiched between the upper holder 22 and the lower holder 23, and the retaining spring 33 holds the lower holder 23 in place.
is urged toward the external holder 24 side.

A plate 35 is attached between the footer arms 32a and 32b to prevent the ball bearing 34 from falling off.

The operation of the flip chip bonding apparatus having the above configuration will be explained in accordance with the timing chart shown in FIG. 4, similarly to the first invention described above. That is, when bonding the chip 11 to the substrate 12 placed on the substrate mounting table l, the bonding tool 2 holding the chip 11 is pressed down by the pressure mechanism (not shown). 5), the chip 11 that is attracted to the tool body 29 of the bonding tool 2 comes into contact with the substrate 12 (timing A
).

At this time, since the ball bearing 34 is held between the upper holder 22 and the lower holder 23, the lower holder 23 can be rotated in any direction (such as the two directions indicated by the arrows in FIG. 5). Become free.

When the chip 11 comes into contact with the substrate 12, if the lower surface of the chip 11 adsorbed to the tool main body 29 of the lower holder 23 and the upper surface 12 of the substrate are not parallel, the honding tool 21 is pressed down. Accordingly, the lower holder 23 is rotated in an arbitrary direction so that the lower surface of the chip 11 and the upper surface of the substrate are parallel to each other. That is, the lower holder 2
3 spherical learning is performed, and the bottom surface of the chip 11 is the top surface 12 of the substrate.
Land flat on. Therefore, the bump 1 on the bottom surface of the chip 11
1a is uniformly pressed against the electrode 12a on the upper surface of the substrate 12.

Therefore, it is possible to bond the chip 11 and the substrate 12 without having to adjust the parallelism of the bonding tool before starting the bonding operation, and it is possible to improve work efficiency.

Further, when the above-described spherical learning of the lower holder 23 is performed, the lower end surface 22a of the upper holder 22, the upper end surface 23a of the lower holder 23, the lower end surface 25a of the spherical seat holder 25, the upper end surface of the spherical seat 31, Since all of 31a are centered at the center P of the lower surface of the chip 11 adsorbed to the tool body 29, the center position of the chip 11 before the spherical learning of the lower holder 23 and the spherical learning were performed. The center position does not change thereafter. Therefore, even if the spherical shape of the lower holder 23 is performed, the bumps 12a on the lower surface of the chip 11 and the electrodes 12a on the upper surface of the substrate 12 are prevented from being slightly misaligned.

Then, after the bonding between the chip 11 and the substrate 12 is completed, the tool main body 29 releases the adsorption of the chip 11 (at timing B), the gas or air between the spherical seat holder 25 and the spherical seat 31 is sucked into the gas. When sucked from the mouth 27 (timing D), the spherical seat 31 is fixed to the spherical seat holder 25 by suction. Along with this, the lower holder 2
3 is fixed to the upper holder 22 via the ball bearing. Therefore, as described above, the lower holder 23, which has undergone spherical training at the end of bonding, remains in that state.

Therefore, at the next bonding time (timing A), it is only necessary to correct the error in parallelism between the chip 11 and the substrate 12, which is caused by the warping of the chip 11 and the substrate 12 or the difference in parallelism in thickness. Good, lower holder 23
This prevents unnecessary spherical learning, and improves work efficiency.

In addition, in this embodiment, the fixing means for fixing the upper holder 22 and the lower holder 23 as necessary has a spherical shape in the fixing means itself, but the fixing means is not limited to this. Other structures may also be used.

[Effects of the Invention] As explained above, in the flip chip bonding apparatus of the present invention, the bonding tool itself that holds the chip becomes parallel to the board before starting the work of mounting the chip on the top of the board. Even without fine-tuning,
The chip can be automatically landed flat on the substrate. Therefore, since fine adjustment before starting work is unnecessary, productivity can be improved.

Further, when the bumps of the chip and the electrodes of the substrate are pressed together, the bumps of the chip and the electrodes of the substrate can always be uniformly pressed together without using a pressure relief material as in the conventional case. Therefore, there is no need to worry about misalignment between the bumps on the chip and the electrodes on the substrate due to uneven deformation of the pressure relief material, and there is no need to periodically replace the pressure relief material, so the running of the bonding equipment itself is eliminated. It becomes possible to reduce costs.

Furthermore, when crimping the chip and the board, even if the chip itself or the board itself is warped or the parallelism of the thickness is different, the parallelism between the chip and the board is automatically corrected each time the chip and the board are crimped. At the same time, the chip can be landed flat on the substrate. Therefore, since the bumps of the chip and the electrodes of the substrate are always evenly pressed together, it is possible to improve the yield of products.

In addition, since the parallelism between the chip and the substrate that has been corrected by -degrees can be maintained until the next time of crimping, extra correction work is not necessary at the time of the next crimping. Therefore, it is possible to improve the workability of the bonding device itself.

Therefore, it is possible to provide a flip-chip bonding apparatus that does not require fine adjustment of the bonding tool itself and can uniformly bring the bumps of the chip and the electrodes of the substrate into close contact without using a pressure relief material.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment according to the first invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is a sectional view taken along the line ■-■ in FIG. 1. The cross-sectional view, FIG. FIG. 5 is a sectional view showing an embodiment of the flip chip bonding device according to the second invention; FIG. 6 is a diagram showing the flip chip bonding device in the conventional example. FIG. DESCRIPTION OF SYMBOLS 1... Substrate mounting stand, 2, 21... Bonding tool, 3, 22... Upper holder, 4, 23... Lower holder, 7a, 7b... Contact part (spherical part), 8 ... Gas jet suction port (gas jet port, gas suction port), 9.29・
... Tool body, 11... Chip, 11a... Bump, 12... Substrate, 12a... Electrode, 25... Spherical seat holder (fixing means), 27... Gas suction port, 31
... Spherical seat (fixing means), 34... Ball bearing.

Claims (6)

[Claims] (1) In a flip chip bonding apparatus, a bonding tool holding a chip is pressed by a pressure mechanism section from above a substrate placed on a substrate mounting table, and the bumps of the chip are bonded to the electrodes of the substrate. The bonding tool includes an upper holder supported by the pressure mechanism section and a lower holder having a tool body that holds the chip, the upper holder and the lower holder forming a spherical pair, and the upper holder The flip chip bonding apparatus is characterized in that a gas outlet for supplying gas is provided between the abutting portions of the upper holder and the lower holder. (2) The spherical portion of the spherical pair is centered at the center of the lower surface of the chip held in the tool body, or at a position that is symmetrical with the center of the lower surface of the chip with the spherical portion as the center. The flip chip bonding apparatus according to claim 1, characterized in that: (3) The flip chip bonding apparatus according to claim 1, wherein the upper holder is provided with a gas suction port for adsorbing the upper holder and the lower holder. (4) In the flip chip bonding apparatus, a bonding tool holding a chip is pressed by a pressing mechanism section from above a substrate placed on a substrate mounting table, and the bumps of the chip are bonded to the electrodes of the substrate. The bonding tool includes an upper holder supported by the pressure mechanism and a lower holder having a tool body that holds the chip, and both opposing surfaces of the upper holder and the lower holder are the same. A flip chip bonding device characterized in that the flip chip bonding device is a spherical surface formed from the center of , and a ball bearing is sandwiched between the opposing spherical surfaces. (5) The centers of both of the spherical surfaces are centered at the center of the lower surface of the chip held by the tool body, or at a position that is symmetrical with the center of the lower surface of the chip with the spherical surface as the center. 5. The flip chip bonding apparatus according to claim 4. (6) The flip chip according to claim 4, wherein the upper holder is provided with fixing means for fixing the upper holder and the lower holder as necessary via the ball bearing. bonding equipment.