JP3449139B2 - Chip crimping equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip crimping device for mounting a chip on a substrate by crimping.

[0002]

2. Description of the Related Art As a method of mounting a chip with bumps such as a flip chip on a substrate, there is a method of pressing the bumps against electrodes of a circuit pattern formed on the surface of the substrate to join them. With this method, it is necessary to strictly manage the load value applied to each bump and the load distribution for each bump. Conventionally, when crimping a chip, the crimp load value was measured and the load was applied while comparing it with the target load value. The way to go is known. A load measuring means such as a load cell is used for measuring the load, and is incorporated in a mechanism for transmitting the crimping load of the chip crimping device.

[0003]

However, in the conventional method, the load measuring means is arranged in series in the load transmitting mechanism, and the crimping tool pressed through the load measuring means is held by a spring or the like. Therefore, there is a problem that it is difficult to accurately measure a minute load.

Therefore, an object of the present invention is to provide a chip crimping device capable of crimping while accurately measuring the crimping load.

[0005]

Crimping device chip of the present invention SUMMARY OF THE INVENTION is a crimping device chip comprising a crimping tool for crimping a chip to a substrate, the substrate positioning means for positioning the substrate, the bonding tool And the adsorption part that adsorbs
A first elevating block mounted with an adsorbing part for performing an elevating operation, a second elevating block performing an elevating operation, and a second elevating block mounted on the second elevating block and applying a predetermined pressing force to the first elevating block. A load applying unit and a load measuring unit interposed between the first elevating block and the second elevating block are provided, and the pressing force of the load applying unit is the load measuring unit via the first elevating block. It is arranged so as to be loaded as the measurement load of.

[0006]

According to the present invention, since the load measuring means can be arranged in the crimping load transmission mechanism without interposing a spring or the like, accurate measurement can be performed even with a minute crimping load. .

An embodiment of the present invention will be described below with reference to the drawings. 1 is a side view of a chip crimping device according to an embodiment of the present invention, FIG. 2 is a partial side view of a chip suction portion of the chip crimping device, and FIG. 3 is an operation time chart of the chip crimping device. FIG. 4 is a partially enlarged view of the operation time chart of the crimping device for the chip.

First, the structure of the chip crimping device will be described.
In FIG. 1, the chip 1 is vacuum-sucked and held on the lower surface of a pressure bonding tool 3 provided below the suction unit 2. The chip 1 has bumps 1a (see FIG. 2) on its lower surface, and the bumps 1a are pressure-bonded to the electrodes on the circuit surface of the substrate.

FIG. 2 shows the structure of the chip suction portion 2 as the chip holding means and the crimping tool 3. In FIG. 2, the crimping tool 3 is a thin plate-shaped component and is in close contact with the upper surface of the chip 1 to vacuum-suck the chip 1. A first suction passage 2a is provided in the center of the suction portion 2. The first suction path 2a communicates with a suction port 3a provided in the pressure bonding tool 3. Therefore, by sucking the suction path 2a, the chip 1 is vacuum-sucked on the lower surface of the crimping tool 3.

The suction portion 2 is provided with a second suction passage 2b. By vacuum suction of the suction path 2b, the crimping tool 3 is detachably vacuum-sucked on the lower surface of the suction section 2, and by releasing the vacuum suction, the crimping tool 3 is detached from the suction section 2. As shown in FIG. 1, a vacuum pipe 4 is connected to the adsorption passage 2a, and the vacuum pipe 4
Is connected to a vacuum source 6 via an on / off valve 5.

In FIG. 1, a heat block 7 is provided immediately above the adsorption section 2. The heat block 7 is electrically controlled by the control unit 60, and heats the chip 1 via the suction unit 2 and the pressure bonding tool 3. The heat block 7 is attached to the shaft 8, and the shaft 8 is attached to the first elevating block 10.

A slider 11 is provided on the back surface of the first elevating block 10, and the slider 11 is slidably fitted to a vertical guide rail 11a provided on the front surface of the first frame 12. Therefore, the first elevating block 10 moves up and down along the guide rail 11a. Further, an inverted L-shaped first projecting portion 13 is provided on the upper portion of the first elevating block 10, and this first protruding portion 13 is provided as will be described later .
The lower surface 14 of the protruding portion 13 of No. 1 comes into contact with a load sensor 33 as a load measuring means described later to transmit the load.

A second elevating block 20 is provided above the first elevating block 10. A slider 21 is provided on the back surface of the second elevating block 20, and the slider 21 is slidably fitted to a vertical guide rail 21a provided on the front surface 22 of the second frame 22. Therefore, the second lifting block 20 moves up and down along the guide rail 21a.

A bracket 26 having a U-shaped cross section is mounted on the upper portion of the second frame 22. Bracket 26
A motor 25 is arranged above. The vertical feed screw 24 driven by the motor 25 is inserted into the nut 23 incorporated in the second lifting block 20. Therefore, when the motor 25 rotates forward and backward, the feed screw 24 rotates forward and backward, the nut 23 moves up and down along the feed screw 24, and the second elevating block 20 and the first elevating block 10 move up and down. That is, the first raising / lowering block 10, the second raising / lowering block 20, the motor 25, the feed screw 24, the nut 23, and the like constitute a lowering means for pushing down the chip 1.

A motor drive unit 29 is connected to the motor 25. The motor drive unit 29 receives a command from the control unit 60 to control the rotation speed of the motor 25, and outputs the rotation speed signal of the motor 25 generated by the encoder 28 to the control unit 6.
Transmit to 0.

Next, a load applying means and a load measuring means for applying a pressing force to the chip 1 via the crimping tool 3 will be described. The cylinder 30, which is a load applying means, is attached to the lower surface of the second elevating block 20. The lower end of the rod 30a of the cylinder 30 is connected to the first projecting portion 13, so that the cylinder 30 exerts a predetermined force by the protrusion of the rod 30a.
Obtaining pressure on the upper surface 15 of first extension portion 13 of the. A regulator 32 is connected to the cylinder 30 and can be set to a predetermined pressing force by adjusting the air pressure of the air supply source 31. The load measuring means is a load sensor 33 such as a load cell, and is arranged on the second protruding portion 35 below the second elevating block 20. First overhang
13 is located above the second overhanging portion 35,
The weight sensor 33 includes a first protrusion 13 and a second protrusion.
It is provided between the parts 35.

The load detecting end 34 of the load sensor 33 is arranged so as to contact the lower surface 14 of the projecting portion 13 of the first elevating block 10 and receive the measured load via the lower surface 14 of the projecting portion 13. With such an arrangement, the sum of the pressing force of the cylinder 30 and the own weight of the first elevating block 10 including the suction portion 2 and the shaft 8 acts on the load sensor 33 as a preload. When the chip 1 is pressure-bonded, the load sensor 3 is used as much as the reaction force from the mounting surface.
The measured value of No. 3 decreases, and the amount of decrease eventually corresponds to the crimping force. Therefore, crimping should be performed while monitoring the decrease value of the load sensor 33.

A movable table 42 is provided below the crimping tool 3.
Is provided. A substrate holder 41 is provided on the movable table 42, and the substrate 40 is provided on the substrate holder 41. The movable table 42 is connected to the control unit 60 via the movable table drive unit 43. By driving the movable table 42, the substrate 40 is horizontally moved in the X direction, the Y direction, and the θ direction, and its position is adjusted.

Next, the means for supplying the chip 1 to the chip crimping device will be described. In FIG. 1, a supply table 70 for the chips 1 is provided below the first frame 12. The supply table 70 is driven by a driving unit (not shown) to move forward and backward to transfer the chip 1 to the crimping tool 3 at the position indicated by the chain line in FIG.

A camera 51 is provided below the first frame 12.
Is provided. This camera 51 is a CCD camera. The camera 51 includes a lens barrel 52 that projects forward. A lens 53 and a lens 54 are provided on the upper and lower surfaces of the tip of the lens barrel 52. The lens barrel 52 is driven by a driving means (not shown) and can move forward and backward, and moves forward between the chip 1 and the substrate 40 which are vacuum-adsorbed by the pressure bonding tool 3 (see the lens barrel 52 indicated by a chain line). ), The position of the chip 1 is recognized through the lens 53, and the position of the substrate 40 is recognized through the lens 54.

An image recognition unit 50 is connected to the camera 51, and the image recognition unit 50 is connected to the control unit 60. The image data captured by the camera 51 is sent to the image recognition unit 50. The image recognition unit 50 recognizes the image data and sends necessary data to the control unit 60.

Next, the control unit 60 will be described. The control unit 60 controls the rotation speed signal of the motor 25 from the lifting motor drive unit 29, the measured value from the load sensor 33, and the image recognition unit 50.
The position data of the board 40 and the position data of the chip 1 are obtained from
5, the chip suction valve 5 is turned on and off, and the heating current of the heat block 7 is controlled. Further, a rigidity value calculation means 61 for calculating a rigidity value (described later) is provided based on the measurement data in the initial stage of crimping.

This chip crimping device has the above-mentioned structure, and its operation will be described below with reference to the drawings. In FIG. 1, the chips 1 are supplied by a supply table 70 located below the first frame 12. Next, the crimping tool 3 that was at the standby level (a) is lowered to vacuum-chuck the chip 1. Then, the crimping tool 3 adsorbs the chip 1 and rises to the standby level (a), and the empty supply table 70 after passing the chip 1 returns to the position indicated by the solid line in FIG. In this state, as described above, the load sensor 33 causes the pressing force A of the cylinder 30, the chip suction portion 2 and the nozzle 8 to be applied.
The sum of the weight B of the first elevating block 10 including the above is applied as a preload F0 = A + B.

The operation of the chip crimping device will be described below with reference to the time charts of FIGS. 1 and 3. In the time chart of FIG. 3, the horizontal axis represents time and the vertical axis represents the height of the bump 1a of the chip 1 held by the pressure bonding tool 3. The solid line a represents the movement of the chip 1 when the crimping tool 3 is driven up and down. However, the chip 1 does not exist at the tip of the crimping tool 3 when the crimping tool 3 is lifted after completion of the crimping. The solid line b represents the measured value of the load sensor 33 that is being measured at the same time. (A) is the standby level, (b) is the primary stop level,
(C) is a secondary stop level before the chip 1 contacts the mounting surface (upper surface of the substrate 40), (D) is a mounting surface level,
(E) shows the first target falling level, and (f) shows the final target falling level. This final target drop level (to) is
It is the descending level corresponding to the target crimp load value.

At timing t0 in FIG. 3, chip 1
The crimping tool 3 that has adsorbed is at the standby level (a). When the crimping operation start command is received, the crimping tool 3 starts descending at high speed, and at the timing t1, the primary stop level (B)
Stop once with. When the camera 51 moves forward during this stop time T1 and its lenses 53 and 54 are located directly under the chip 1, image pickup is started, and image data of the bump 1a surface of the chip 1 and the mounting surface of the substrate 40 below is captured. . This image data is sent to the image recognition unit 50, and the image recognition unit 50
Recognizes the positions of the chip 1 and the substrate 40 based on this image data and transmits the result to the control unit 60. Control unit 60
Transmits a necessary position correction command to the movable table drive unit 43 based on the position information. The movable table drive unit 43 drives the movable table 42 based on the command, and the bump 1a
The electrodes of the substrate 40 are aligned with each other.

After that, when the camera 51 retracts and returns to the original position, the crimping tool 3 starts to descend at a high speed again at the timing t2, and at the timing t3, the secondary stop level slightly above the mounting surface level (d). Stop at (C). When the delay time T2 expires at the timing t4, the crimping tool 3 restarts to descend at the preset low speed contact point search creep speed. During this descent, the bump 1a of the chip 1 contacts the mounting surface (d) of the substrate 40, and then descends while pressing the bump 1a against the mounting surface.

The reaction force of the pressing force W to be pressed is transmitted to the first elevating block 10 via the pressing tool 3, the chip suction portion 2 and the nozzle 8. This reaction force increases as the second elevating block 20 descends, and this increase appears as a decrease in the measurement value of the load sensor 33. Therefore, if the load measurement value is F, the crimping force W is W = F0-F
It is represented by. That is, the lowering operation is controlled while the controller 60 monitors the value of F so that the value of W becomes the target crimping load value.

The descent at the contact point search creep speed is up to a preset first target descent level (e). The measurement value of the load sensor 33 is taken in between the steps from the mounting surface level (d) to the first target lowering level (e), that is, from timing t5 to t6. As described above, since the amount of decrease in the load value corresponds to the crimping force, the control unit 60 determines the load measurement value at the mounting surface level (d) and the load measurement value at the first target lowering level (e). The difference value ΔW / H is calculated, and the rigidity value represented by the ratio ΔW / H with the descending amount H during this stroke is calculated.

Based on this stiffness value, the control unit 60 calculates how much further lowering is required to reach the target final crimping load, and the load is reached before the final target lowering level (f). The command is issued to continuously descend without stopping for measurement.

The continuous lowering of the crimping tool 3 is stopped at a timing t7 at a level slightly higher than the final target lowering level (f) set in advance. After that, during the period T3, stopping and lowering for sampling the load value by the load sensor 33 are alternately repeated until the target crimping load is reached, and the load is gradually lowered (see FIG. 4). When the measured load value reaches the target crimp load value at timing t8, the control unit 60 commands the stop of the descent, and thereafter stops for a predetermined pressurizing and holding time T4.

At the timing t9, the pressure-bonding tool 3 starts rising at a low speed as the pressurizing and holding time T4 increases. At that time, the vacuum breaking valve (not shown) has already been opened, so that the chip 1 is released from the suction state.
After that, the pressure bonding tool 3 is switched from the low speed rising to the high speed rising and returns to the standby level (a) to complete one cycle of the pressure bonding.

The present invention is not limited to the above embodiment.
For example, in the above-described embodiment, in the period T3, the chip is gradually moved down and the chip is gradually and strongly pressed against the substrate 40, but the small-scale descending operation may not necessarily be performed. However, if this small descending operation is performed a little, the chip 1 can be more surely pressure-bonded to the substrate 40 with a desired force without applying an excessive pressure load to the chip 1. In this case, of course, the tact time can be greatly shortened because the descent time in small increments is small.

[0033]

According to the present invention, since the load measuring means can be arranged in the crimping load transmission mechanism without interposing a spring or the like, accurate measurement can be performed even with a minute crimping load.

[Brief description of drawings]

FIG. 1 is a side view of a chip crimping device according to an embodiment of the present invention.

FIG. 2 is a partial side view of a suction portion of a chip of a chip crimping device according to an embodiment of the present invention.

FIG. 3 is an operation time chart of the chip crimping device according to the embodiment of the present invention.

FIG. 4 is a partially enlarged view of an operation time chart of the chip crimping device according to the embodiment of the present invention.

[Explanation of symbols]

1 chip 2 Adsorption part 3 Crimping tool 10 First lifting block 20 Second lifting block (lowering means) 30 cylinders (load applying means) 33 Load sensor (load measuring means) 60 control 61 Stiffness value calculation means

Claims (5)

(57) [Claims] 1. A crimp for crimping a chip to a substratetoolAnd the base
Of the chip with board positioning means for positioning the plate
A crimping device, said crimpingTooladsorptionAdsorption part
And thisAdsorption partA first lifting block fitted with a
Attached to the second lifting block and this second lifting block
A load that applies a predetermined pressing force to the first lifting block.
Applicator, first elevating block and second elevating block
And a load measuring means interposed between
The pressing force of the means is applied to the load cell via the first lifting block.
It is arranged so as to be loaded as the measuring load of the measuring means.
A chip crimping device, characterized in that 2. A crimp for crimping a chip onto a substratetoolAnd the base
Of the chip with board positioning means for positioning the plate
A crimping device, said crimpingTooladsorptionAdsorption part
And thisAdsorption partA first lifting block fitted with a
2 lifting blocks, the first lifting block
A first projecting portion is provided, and the second lifting block is provided.
The lock has a second overhang and the first overhang
The part is located above the second overhang, and
Predetermined on the first projecting portion on the second elevating block
Is provided with a load applying means for applying the force of
Between the overhanging part of the and the second overhanging part
A chip crimping device characterized by having steps. 3. The chip crimping device according to claim 2, wherein the load applying means is a cylinder, and a rod of the load applying means applies a predetermined force to the first projecting portion. . 4. The chip crimping device according to claim 1, wherein the second elevating block is moved up and down by a vertical feed screw driven by a motor. 5. The chip according to claim 1, wherein the first elevating block and the second elevating block have sliders slidably fitted on vertical guide rails. Crimping device.