JP5317753B2 - Bonder device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems wherein a chip position results in changes due to thermal influence, when heating, pressurizing and bonding a semiconductor chip and a circuit board in a chip bonding device, a bump is compressed and wrongly connected to a nearby connection position during heating and the bonded bump peels off during cooling. <P>SOLUTION: By performing thermal influence displacement measurements, preparing thermal displacement amount process, computing cancellation process and canceling chip displacement amount, and by holding a chip at a fixed position, discharge of defective products is prevented. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to a bonder device that adsorbs, picks up, inverts and connects an electronic component that is attached to an adhesive sheet and cut out from a wafer to a substrate.

A wafer is a disk-shaped plate made by thinly slicing an ingot, which is a material for manufacturing a semiconductor element, and in which a crystal of a semiconductor material such as silicon is grown in a cylindrical shape. The thickness of the plate is about 0.03 mm to 1 mm.

  This plate is provided as an electronic component (hereinafter referred to as a chip) in which an integrated circuit is formed in a state where the surface is developed / etched, adhered to an adhesive sheet with the resist removed, and finely diced.

The chip is a square having a side of about 1 mm to 30 mm square, and is sucked and transported by a nozzle or the like and mounted on a substrate or the like.
The present application relates to a device used when a chip is connected to a substrate using a bump, which is also called a flip chip bonder device.

As shown in FIG. 1, the bump 201 refers to a hump-shaped metal formed on the silicon wafer 19 and is formed in a die of the wafer 19 (a region that is cut out as a single block of an integrated circuit to become one semiconductor chip 20). This means a protruding metal terminal connected to an integrated circuit.
The bump 201 formed on the wafer 19 is a part of the wiring of the integrated circuit, and serves as a terminal for connecting the semiconductor chip 20 in which the integrated circuit is configured to the circuit of the circuit board 18. Dozens to thousands of bumps 201 are required for one semiconductor chip 20.

The semiconductor chip 20 on which the bump 201 is formed is inverted and faced down so that the bump 201 is directly connected to the circuit board 18. The bump 201 has a height of 10 to 100 μm and a diameter of 10 to 125 μm. When the bump 201 is heated to 200 ° C. or higher and pressurized for a certain time, the bump 201 is melted and the circuit board 18 and the semiconductor chip 20 are connected.
Therefore, the flip chip bonder must be accurately positioned and mounted with an error within a few μm, and the heated part becomes hot, so accurate positioning with minimal heat countermeasures and displacement due to thermal changes is minimized. It is important to do.

As a countermeasure against heat change, a conventional example as shown in FIG.
In the conventional example, the outer lead 98 of the semiconductor 92 sucked and held by the suction nozzle 91 is pressed by the bonding tool 93 and heated and thermocompression bonded to the lead member 96 by thermocompression.

However, when thermobonding is performed by the bonding tool 93, the height of the stage 94 changes due to thermal expansion, and thus the outer lead 98 may be twisted. Therefore, a height position detecting means 95 is provided on the stage 94 so that the interval W is kept constant by driving the motor 97. The height position detecting means 95 is assumed to use a distance sensor or the like.
In this way, the accuracy of thermocompression bonding of the bonding tool 93 can be improved.

As described above, the height position of the stage 94 that changes due to thermal expansion is detected by the height position detecting means 95, and the pressing position of the bonding tool 93 is controlled according to the output, so that the optimum pressing force to the lead member 96 is achieved. It is said that troubles such as twisting of the outer lead 98 can be prevented by applying a load.
Japanese Patent Application Laid-Open No.7-122596

In the method of making the height of the stage constant by the height position detecting means 95 as in the conventional example, measurement cannot be performed when the bonding tool 93 expands due to a thermal effect.
Further, although not described in the specification of the present application, the semiconductor 92 is sucked and held by the suction nozzle 91, and the outer lead 98 and the lead member 96 are placed on the lower side of the bonding tool 92 and pressed. Therefore, in order to measure the expansion / contraction due to the thermal effect of the bonding tool 93 with a distance measuring device such as a laser, the work must be interrupted and measured. Accordingly, it is impossible to measure the amount of displacement due to the heat effect many times during the work.

The chip 20 used in the present application has a bump 201 attached to the lower surface and is configured to be bonded to the substrate 18. The chip peeled off from the wafer, inverted, and adsorbed to the head is lightly applied to the substrate initially. However, if heating is started, the bumps are dissolved, so if the pressure is kept in the state of being pressed, the melted bumps may spread and be connected to nearby electrodes or bumps.

Further, when the heating is finished and the head is cooled, the vicinity of the head contracts, the chip adsorbed on the head rises and melts, and the bump bonded to the substrate may be peeled off. For this purpose, the chip held by the head must be kept at a certain distance from the substrate during the heating process. As a result, the bumps can be appropriately dissolved and the chip and the substrate can be wired and bonded.

The bumps have the same structure as a general solder ball, and the height is about 10-100 μm, so when the head descends due to thermal expansion, the bumps are crushed and joined to multiple nearby electrodes. When the head rises due to heat shrinkage, the chip adsorbed and held by the head also rises and the joint portion is peeled off.

It is desirable that ideal bonding is performed by bonding the chip and the substrate with the bumps being cylindrical. In order to bond in such a state, the distance between the chip and the substrate must be kept constant by the head suction portion.

In addition, since the heating process varies depending on the type of each chip and each substrate, it must be taken into consideration that the amount of heat-affected displacement varies for each heating process.

  Therefore, in a bonder device in which the chip is sucked and held by the head and moved onto the substrate, and the chip is melted and bonded to a predetermined position of the substrate by a preset heat bonding process, the chip is attached to the upper portion of the head. A force sensor; a head vertical movement means for moving the head up and down; a heating means attached to a lower portion of the head; a chip suction means attached to a lower end of the head; And a control unit that controls the chip to move to the predetermined position on the substrate by melting the bumps by a preset heat bonding process and moving the chip to the predetermined position of the substrate, and the heat bonding process of the chip and the substrate. The head vertical movement means moves the head position to a distance in which the distance between the chip and the substrate is set in advance. And a head position setting unit configured to cancel the thermal displacement by controlling, and when the force sensor detects the contact between the chip adsorbed by the head and the substrate, the head The present invention provides a bonder device characterized in that the vertical position of the head in the heat bonding process is controlled by the vertical movement means of the head based on the setting of the position setting means.

Then, the head and the motor are screwed together by a screw shaft and a bearing so that the vertical movement of the head based on the detection value of the force sensor is detected by a rotational movement of a motor attached to the top of the head. A suction part attached to the lower end of the head, a heating part attached to the upper part of the suction part, and an air intake port attached to the upper part of the heating part. And a force sensor attached to the upper part of the cooling part, and the temperature rise by the heating part is cooled by the cooling part so that the temperature of the heating part is not transmitted to the force sensor and its upper part. A bonder device characterized by
Further, a dummy chip with little thermal deformation during the heat bonding process is sandwiched between the substrate and the head in place of the chip, and the vertical movement means is brought into a free state so that the vicinity of the head due to thermal influence is obtained. The thermal expansion and contraction of the vertical movement means is measured by a motor attached to the upper part of the head and the thermal displacement is set to be canceled by the measured value. Instead of the chip, a dummy chip is sandwiched between the substrate and the head, and when the value of the force sensor increases, the head is raised, and when the value of the force sensor decreases, the When the head is lowered, the thermal expansion and contraction in the vicinity of the head due to the thermal effect is caused by a motor attached to the upper part of the vertical movement means. Thus, a bonder device is provided which is set so as to cancel the thermal displacement according to the measured value.

  In the present invention, the heat-affected displacement measuring means measures in advance the heat-affected displacement according to the parameters of the heating process that differs depending on each chip and each substrate, stores it in the control unit, and keeps the head position at a predetermined distance between the chip and the substrate. It is designed to be controlled.

The amount of heat-affected displacement is detected by the rotation of the servo motor according to the heating process, and the obtained data is output to drive the servo motor according to the heating process. It is configured to be controlled so as to be held at a position.

The thermal influence displacement measuring means is stored in a fixed place, and is automatically taken out during work, and is taken out periodically during work, and it is sucked and held on the head to measure it. Even if it exists, since it can interrupt and measure regularly, it can memorize | store and analyze the data which was efficient and responded to reality, and can be reflected in actual work.

In addition, since the measurement operation can be performed by interrupting periodically, the measurement can be performed in consideration of the change due to the thermal effect of the entire apparatus that changes every moment as the work time elapses.
In such measurement, the heat-affected displacement is measured by converting the amount of heat-affected displacement into the rotation of the motor, and is controlled so as to be driven so as to be canceled by the same motor.

Although the heating process varies depending on the type of chip and varies depending on the situation, the heat-affected displacement can be easily measured without changing the member. Since the head unit of the present invention has a force sensor and analyzes by the control unit so as to keep the applied pressure constant, it can be easily measured at any time with a dummy chip.

While the bumps at the time of mounting are melted, the control unit controls the distance between the chip and the substrate to be kept at a predetermined height set in advance.

As described above, since the position of the chip is held at a predetermined height set by the motor, the bumps are not crushed by the lowering of the head adsorption portion caused by thermal expansion, and the bumps are not erroneously connected. The chip and the substrate can be joined in an ideal cylindrical state, and defective products can be reduced.

The present invention relates to a bonder device for adhering a chip 20 having an error of only a few μm to a substrate 18. By preventing the position of the substrate 18 from changing the position of the substrate 18 due to the expansion caused by heating and the shrinkage caused by cooling, the bonding between the bump 201 disposed on the bonding surface of the chip 20 and the substrate 18 is stabilized. It is intended to make it.
By using an apparatus having this configuration and means, the defect occurrence rate of the chip 20 and the substrate 18 can be reduced.

FIG. 1 is a perspective view of the entire bonder apparatus. Further, the chip 20 and the bump 201 are enlarged and illustrated.
FIG. 2 is a perspective view showing the head portion and its vicinity.
FIG. 3 is a side view of the head portion.
Fig. 4 shows (1) heat-affected displacement process, (2) heating process, (3) cancellation process, and (4) target chip height process in a graph of time and displacement.
FIG. 5 shows an operation flow during thermal change measurement and an operation flow during mounting.
FIG. 6 shows a conventional bonding apparatus.

A control unit 2 is installed in the main body 1 of FIG. 1, and the control unit 2 is a part that transmits, receives, stores, analyzes, and controls data of all motors, operation units, adsorption units, heating units, force sensors, etc. is there.
The chip 20 is placed on the wafer table 16 in the state of the wafer 19 diced while being adhered to the adhesive sheet, and is moved in the X direction by the motor 161.

  The chip 20 is sucked and held by the reversing head 17 and is moved in the Y direction by driving the motor 171. The reversing head 17 is reversed by the motor 172 so that the reversing head 17 is in an upward state at the delivery position, and the chip 20 is reversed to the head unit 30 and delivered to the head unit 30 in a state where the bump 201 is downward.

The chip 20 mounted on the wafer 19 is sequentially attracted and reversed by the reversing head 17 by the movement in the X direction by the reversing head 17 that moves by driving the motor 171 and the movement in the Y direction by the wafer table 16 that moves by driving the motor 161. Then, it is delivered to the head unit 30 at a predetermined position.

The head unit 30 that has received the chip 20 from the reversing head 17 moves in the X direction by driving the motor 29, and is transferred to a predetermined position on the substrate 18.
When the chip 20 sucked and held by the head unit 30 is transferred to a predetermined position, the screw motor 32 is rotated by driving the head motor 31 to move the screw bearing 33 up and down. Similarly, the head portion 30 integrated with the screw bearing 33 moves up and down in the Z direction.

  The substrate 18 is placed at a predetermined position on the stage 40. The stage 40 can be moved in the X direction by the table 401, and can be moved in the Y direction by the table 402. With such a configuration, the substrate 18 placed on the stage 40 can be moved to the working position.

  As shown in FIGS. 2 and 3, the head portion 30 is provided with a suction portion 36 at the lower end portion of the head portion 30, and by suctioning the air from the tip suction air port 361, the tip 20 is sucked below It is configured to hold by suction.

  In addition, since the shape of the chip 20 differs depending on the product type, it is necessary to change the adsorption unit 36 each time, and in order to adsorb and hold the adsorption unit 36 under the heating unit 35, the air is sucked from the adsorption air port 362 and adsorbed. The part 36 is configured to be sucked and held at the lower end part of the head part 30 in a replaceable manner.

A heating unit 35 is attached to the upper portion of the adsorption unit 36, and the heating unit 35 is wired to the control unit 2 by a heating unit wiring 351 so as to generate heat according to a heating process.
A cooling unit 37 is installed at the top of the heating unit 35. Inside the cooling unit 37, a chip adsorption air port 361 and an adsorption unit air port 362 are piped, and cooling air is sent from the cooling air port 371 to the head unit. The temperature of 30 and the adsorbing part 36 can be adjusted according to the heating process (b).

  Further, a second cooling unit 375 is installed on the cooling unit 37, and the heat effect generated by the heating unit 35 passes through the cooling unit 37 and the second cooling unit 375, and the upper force sensor 38 and the shaft thereof. Care is taken not to transmit heat effects to 39.

  The force sensor 38 measures the force applied to the force sensor 38 by the force sensor wiring 381 and transmits it to the control unit 2. A shaft 39 is fixed to the upper part of the force sensor 38, and the shaft 39 is rotated by a head rotating motor 34. With such a configuration, the chip 20 can rotate in the θ direction.

  When the position of the chip 20 transferred from the reversing head 17 to the head unit 30 is shifted or rotated and sucked and held in the θ direction, the image is captured by the imaging unit 8 and processed by the control unit 2 The direction of the rotation is corrected by the head rotation motor 34.

These head portions 30 are fixed to a screw bearing 32, and the screw bearing 32 is screwed into a screw shaft 33 that rotates when the head vertical motor 31 is driven. It is configured to move up and down in the direction.
Accordingly, the head up / down motor 31 is driven to lower the head portion 30, and when the chip 20 comes into contact with the substrate 18, the force sensor 38 senses a delicate pressing force at the time of contact and reaches a predetermined pressing force. The controller 2 is controlled to determine that the motor 31 is stopped and the substrate 18 and the chip 20 are in a predetermined position in contact with each other.

Further, when the head unit 30 extends downward due to thermal expansion or the like, the pressing force detected by the force sensor 38 increases, so that the control unit 2 determines that the pressing force of the chip 20 has increased.
At this time, if a chip that is not thermally deformed, such as a dummy chip, is sucked and held instead of the chip 20, the rise of the screw bearing 32 is converted into a rotation amount by the screw shaft 33 due to thermal expansion and measured by the head vertical motor 31. .
Alternatively, the distance between the chip 20 and the substrate 18 can be kept constant by rotating the head motor 31 so that the pressing force at this time is constant and controlling the head part 30 to rise.

  However, in this measurement, the bump 201 of the chip 20 is dissolved when the actual object is used. Therefore, in the case of mounting work, if the pressing force of the head unit 30 is kept constant, the dissolved bump 20 is crushed and cannot be measured. Therefore, by recording the amount of heat change according to the heating process periodically using a dummy chip between mounting operations, and setting in advance to cancel the movement of the head part 30, it responds quickly to the heating process. Thus, the head unit 30 is moved up and down so that the control unit 2 can control the distance between the chip 20 and the substrate 18 sucked and held by the suction unit 36 to be constant.

The motor used in this apparatus will be described. The head vertical motor 31 will be described as an example. This motor is a servo motor. In the case of a servo motor, a rotary encoder is built in the motor unit.
Such a servo motor generates a rotation pulse from the rotary encoder according to the rotation speed and rotation angle, and transmits it to the control unit 2 for analysis and calculation to determine how much the motor has rotated in which direction. Is done. The same servo motor is used for all other motors used for positioning.
The position of the bearing unit 32 or the head unit 30 is determined by analyzing the rotation pulse transmitted to the control unit 2 by the head vertical motor 31 to determine how much the screw bearing 32 is sent in which direction by such a configuration. The

  The operation of the chip bonder device configured as described above will be described. The wafer 19 transferred from the upstream process is automatically loaded on the wafer table 16. Each position of the chip 20 on the wafer 16 is stored in advance, or is imaged by a camera (not shown) or the like, and each chip position is specified and stored in the control unit 2.

The chips 20 are sucked and held one by one by the reversing head 17 one after another, and the reversing head 17 is rotated upward by the motor 172 so that the chip 20 is reversed 180 degrees and delivered to the head unit 30.
The original chip 20 is affixed to the sheet of the wafer 19 with the bumps 201 facing upward, but the head unit 30 with the bumps 201 facing downward by being sucked and held by the reversing head 17 and reversed. The suction part 36 is transferred so as to be sucked and held.

At this time, the bump 201 of the chip 20 is sucked and held so as to face downward. Thereafter, the head unit 30 moves to the upper part of the substrate 18. The substrate 18 is moved by the stage 40 so that a predetermined position of the substrate 18 is directly below the head unit 30.
Before the head unit 30 is lowered, the imaging unit 8 is inserted between the substrate 18 and the chip 20 attracted to the head unit 30, and images are taken in the vertical direction, and the position of the chip 20 and the position of the substrate 18 coincide with each other. Whether or not the image is captured is analyzed by the control unit 2.

When the head 20 is rotated in the θ direction, the head rotation motor 34 is driven to rotate the head unit 30 in the θ direction, so that the chip 20 changes its rotation.
When the upper and lower images captured by the imaging unit 8 do not match, rotate the head unit 30 in the θ direction or move the stage 40 on which the substrate 18 is mounted to adjust the substrate 18 and the chip 20 to a predetermined position. To do.

Next, the head vertical motor 31 is driven to rotate the screw shaft 33, and the screw bearing 32 screwed with the screw shaft 33 is lowered.
The screw bearing 32, that is, the head portion 30 is lowered to stop the chip 20 at a predetermined position. As an actual action, the head portion 30 is lowered and stops at a position where the bump 201 located on the lower side of the chip 20 contacts the substrate 18.
Whether or not the bump 201 is in contact with the substrate 18 can be determined by the load being changed by the force sensor 38 at the time of contact.

  Then, heating is performed in the heating process (b) in FIG. 4 (2) so that the heating unit 35 has a constant temperature. The heat generated by the heating unit 35 passes through the adsorption unit 36 and is transmitted to the chip 20, and the chip 20 is heated to a predetermined temperature (200 to 300 ° C.) for a predetermined time.

The bump 201 is melted by the heat and connected to the substrate 18. The bump 20 that has become liquid does not spread around due to surface tension so that it becomes a cylinder that connects the chip 20 and the substrate 18, and then air is sent to the cooling unit 37 to rapidly cool the heating unit 35. To do.
Such a heating process (b) is transmitted to the chip 20 through the adsorption portion 36 and is controlled so as to adjust the dissolution state of the bump 201.

  Then, the suction air of the suction part 36 is shut off, and the chip 20 is released in a state where it is welded to the substrate 18, and the mounting of the chip 20 on the substrate 18 is completed.

As described above, whether or not the chip 20 touches the substrate 18 can be determined by the force sensor 38. Further, when the chip 20 is released from the adsorption unit 36, the vacuum pressure is lowered and transmitted to the control unit 2.
As described above, the mounting of the chip 20 on the substrate 18 is completed.

Subsequently, the head unit 30 moves to receive the next chip 20, delivers a new chip 20 from the reversing head 17, sucks and holds it, and transfers it to a predetermined position on the substrate 18.
A plurality of chips 20 are mounted on the substrate 18 by repeating the above method.

  However, the problem here is that if the heating part 35 is heated while the bump 201 of the chip 20 is in contact with the substrate 18 as shown in FIG. 3, the head part 30 is lowered due to the thermal expansion of the suction part 36 and the cooling part 37. That is, the chip 20 is not held in a predetermined space by extending in the direction.

  As described above, the thickness of silicon is about 0.03 to 1 mm, the height of the bump 201 is 10 to 100 μm, and the diameter is 10 to 125 μm. The mounting of the chip 20 and the substrate 18 is completed by heating them to 200 ° C. or higher and going through a certain heating process (b).

  The heating process (b) as shown in (2) of FIG. In the present invention, when the heating process (b) is performed, the dummy chip 202 and the dummy substrate 181 having a small heat change are attached to the suction part 36 of the head unit 30 and the heating process (b) is executed. The reason why the dummy substrate 181 is used is that the substrate 18 is elastic and may be deformed, and further, the product substrate 18 is not damaged.

The dummy chip 202 and the dummy substrate 181 can be made of a material that is not deformed by heat. The pressure change caused by the force sensor 38 during execution of the heating process (b) due to thermal expansion or contraction can be accurately captured.
The force sensor 38 is set based on the load C when the dummy chip 202 comes into contact with the dummy substrate 181, so that the load C increases when the head portion 30 thermally expands.

Therefore, if the head vertical motor 31 is driven so that the value of the force sensor 38 becomes the load C and the head unit 30 is raised, the amount displaced by thermal expansion can be measured by the rotation amount of the head vertical motor 31. . Similarly, when the temperature is lowered, the bed portion 30 is thermally contracted. In this case, if the head vertical motor 31 is driven and the head portion 30 is lowered, the pressure of the force sensor 38 becomes the load C. If the head vertical motor 31 is controlled by the control unit 2 to have a constant load, the heated portion is cooled, and the load C of the contraction force sensor 38 is reduced by the amount of thermal contraction of the head unit 30. However, the head vertical motor 31 is driven to lower the head unit 30 so that the load C does not decrease.
In reality, the load C set by the force sensor 38 has a certain intersection, and is controlled by the control unit 2 so as to move the bed 30 up and down so as not to exceed the upper and lower limits.
Since the dummy chip 202 and the dummy substrate 181 are not deformed, the lower end portion of the suction portion 36 is held at a constant height that does not move up and down due to a heat change. With this method, the heat-affected displacement process (a) in FIG. 4 is measured and stored in the control unit 2.

In the present invention, a method of measuring without using the force sensor 38 in the measurement method of the heat-affected displacement process (a) can also be presented. This method is a method in which the dummy chip 202 and the dummy substrate 181 are sandwiched between the stage 40 and the suction portion 36 of the head unit 30, and the expansion and contraction due to the thermal effect is measured by the rotation pulse generated by the encoder of the head vertical motor 31.
During normal operation when the head vertical motor 31 is stopped, the screw shaft 33 is held by the holding torque so as not to rotate, and the screw bearing 32 functions to prevent vertical movement. Is set between the stage 40 and the suction portion 36 of the head unit 30 and the head vertical motor 31 is set in a free state (no holding torque) before the heating process (b) is performed.
In this state, the heating process (b) is performed. Since the dummy chip 202 and the dummy substrate 181 are not thermally deformed, when the head portion 30 is extended due to thermal influence, the screw bearing 32 is raised, the screw shaft 33 is rotated, and the head vertical motor 31 is rotated. That is, when the screw bearing 32 moves up, the screw shaft 33 rotates and the head up / down motor 31 generates a rotation pulse, so the rotation pulse is measured simultaneously with the time axis of (b) of the heating process, and the heat-affected displacement amount of FIG. In this method, the process (a) is measured and stored in the control unit 2.
If the method is as described above, the head portion 30 that moves up and down due to thermal effects without using the force sensor 38 can be measured by the head up and down motor 31 to create the heat-affected displacement amount process (a). Can do.

With this method, the heat-affected displacement amount process (a) at the lower end of the head unit 30 corresponding to the heating process (b) in (2) of FIG. 4 is created. The above is the thermal expansion displacement measurement method, and a flowchart such as an operation flow at the time of thermal expansion displacement measurement as shown in FIG.

This will be described based on the above flowchart. First, measurement is started in a state where the dummy chip 202 is sucked and held below the sucking portion 36 and the dummy substrate 181 is mounted on the stage 40. This is the F10 step.
Next, in step F2, the head vertical motor 31 is driven to lower the head unit 30.

If the dummy chip 202 is placed at a constant load C (pressing force C) when the dummy chip 202 comes into contact with the dummy substrate 181 (however, if there is no heat change and there is no deformation, it may be the actually used substrate 18). The means detected by the sensor 38 is the step F3.

In step F41, the control unit 2 drives the head vertical motor 31 so that the pressing force C at this time is kept constant, and the pressing unit C controls the pressing force C within a certain tolerance range. Alternatively, as described in paragraph 57, the bed vertical motor 31 is set in a free state so that the applied pressure is constant by the weight of the head unit 30, and the vertical movement due to the thermal expansion of the screw bearing 32 is defined as the rotational movement of the bed vertical motor 31. You may make it measure.
In this way, steps F43 and F42 measure the thermal expansion simultaneously with the execution of the heating process (b) and change the heat.

In step F42, the steps of F41 and F43 are executed and simultaneously the pulse of the head vertical motor 31 is calculated to measure the position displacement of the head unit 30 due to the thermal effect and stored in the control unit 2.
The F4 step is to execute the above F41, F42, and F43 simultaneously.

In step F5, when the heating process (b) is completed as described above, the head unit 30 is raised to complete the measurement, and the measurement value of the heat-affected displacement process (a) is stored in the control unit 2.
After that, the dummy chip 202 and the dummy substrate 181 are removed to complete the heat-affected displacement measurement flow in the step F6.

Next, steps for mounting will be described with reference to the flow (2) in FIG.
The step of E1 is that the chip 20 is delivered from the reversing head 17 and is sucked and held by the head unit 30 and imaged by the imaging unit 8, and the head rotation motor 34 and the stage 40 are driven to determine a predetermined positioning. .

In step E2, the chip 20 attracted and held by the head unit 30 is positioned at a predetermined position on the substrate 18 and the head unit 30 is moved downward.
Next, the force sensor 38 detects that the chip 20 and the substrate 18 are in contact with each other when the pressure is constant, and the control unit 2 determines. This is the E3 step.

Next, a temperature sensor is wired at the same time as the heating wire 351 is wired to the heating unit 35 executed according to the heating process (b), and the temperature is measured at any time and controlled by the control unit 2. The step of E42 is to execute the heating process (b) with the above configuration.

At the same time as the heating process (b) is performed, the suction unit 36 (as shown in the cancellation process (c) of FIG. 4 (3) so that the displacement of the position of the lower end of the suction unit 36 due to thermal deformation becomes zero. Tool) The height adjustment is performed in the same manner as in the heating process (b).

As a result, the distance between the substrate 18 and the chip 20 is performed as in the target chip height process (d) in (4) of FIG. That is, the heat change for h1 written in the heat-affected displacement process (a) in (1) in FIG. 4 is calculated as the heat change for h1 ′ drawn in (3) in FIG. The amount of heat change h1 is canceled by raising the lower end suction part 36 by h1 ', and the lower end part of the suction part 36 is always kept constant at the position of the target chip height process (d) in FIG. . The above is the step of E4.
Here, the height of one scale of the graphs of h1 and h1 ′ represents about 10 to 20 μm, and the horizontal axis of the graph represents the time of about 0.5 to 5 seconds from 0 to p. When the heating process (b) starts when the height at the point p of the heat-affected displacement process (a) and the cancellation process (c) is different from the original height (height at time 0), It is reset to the height of the position.

After the heating process (b) is completed as described above, the adsorption unit 36 moves upward while releasing the adsorption holding of the chip 20 in the step E5.
Then, the head unit 30 starts moving to the delivery position of the reversing head 17 in order to suck and hold the next chip 20. The above is the step of E6.

Then, the suction part 36 at the tip of the head part 30 sucks and holds the chip 20 delivered from the reversing head 17 so that the bump 201 faces downward, and repeats the same process.
By doing as described above, the lower end portion of the suction portion 36 is held at a constant height even when there is a thermal change as shown in FIG. 4 (4), so that the chip 20 is always held at a constant height. Thus, even when the bump 201 is melted without being influenced by the amount of heat change, it is held on the substrate 18 at regular intervals.

In addition, the heat-affected displacement process (a) is performed by repeating the work for a long time, so that the heat effect is conducted to the entire apparatus such as the shaft 39 and the stage 40, thereby causing the heat-affected displacement process (a). Does not necessarily change.

Therefore, during the work, for example, the dummy chip 202 and the dummy substrate 181 are installed at intervals of 30 minutes or 100 cycles, the heating process (b) is performed, the heat-affected displacement process (a) is measured, and the cancellation process (c) is performed. It can be calculated and changed so that the tip 20 is held in the target tip height process (d).

If the time interval is narrowed and the process is changed and the process is changed, the measurement can be performed more accurately. Conventionally, the same work was measured with a laser displacement measuring device, but the work had to be interrupted for a long time.
However, with such a method, measurement can be performed and data can be changed during work, so that the measurement time can be shortened and prompt data can be obtained, thereby preventing the occurrence of defective products.

Using the above method, the distance between the substrate 18 and the chip 20 is obtained by using the force sensor 38 and the encoder of the head up / down motor 31 to obtain displacement data, and the target chip height (d) is made constant. Is accurately performed and the generation of defective products is greatly reduced.

The present invention detects the heat-affected displacement by the rotation of the servo motor according to the heating process, and outputs the obtained data to drive the servo motor according to the heating process, thereby canceling the head position change due to the heat effect. Thus, the control is performed so as to hold it at a fixed position.
If the thermal influence displacement measuring means is automatically controlled so that the dummy substrate and the dummy chip are stored in a fixed place and taken out periodically during the work and sucked and held by the head part, the measurement is automatically performed. Even if it exists, since it can interrupt and measure regularly, it can memorize | store and analyze the data which was efficient and responded to reality, and can be reflected in actual work.
In addition, since the measurement operation can be performed by interrupting periodically, the measurement can be performed in consideration of the change due to the thermal effect of the entire apparatus that changes every moment as the work time elapses. Therefore, it is possible to measure the amount of displacement due to the thermal effect many times during the work.
In such measurement, the heat-affected displacement is measured by converting the amount of heat-affected displacement into the rotation of the motor, and is controlled so as to be driven so as to be canceled by the same motor.
Although the heating process changes depending on the product type and also changes depending on the situation, the heat-affected displacement can be easily measured without changing the members. Since the head portion of the present invention has a force sensor and the control portion analyzes the pressure so as to keep the pressure constant, it can be easily measured at any time with a dummy chip.
As described above, since the position of the chip is held constant by the motor, the bumps are not crushed by thermal expansion and there is no erroneous connection. In addition, the chip and the substrate can be bonded to each other in an ideal state in which the bumps are cylindrical, and defective products can be reduced.

The present invention can be applied not only to a flip chip bonder device but also to a precision component assembling device composed of various heating parts.

It is a perspective view of the whole bonder apparatus. It is the perspective view which displayed the head part and its vicinity. It is a side view of a head part. It is the graph which represented each process with time, the amount of displacement, or temperature. It is the operation | movement flow at the time of a thermal change measurement, and the operation | movement flow at the time of mounting. It is a conventional bonding apparatus.

1
Chip bonder body
2
Control unit
8 Imaging unit
16
Wafer base
161 motor
17
Reversing head
171
motor
172
motor
18
substrate
181 dummy substrate
19
Wafer
20
Chip
201
bump
202
Dummy chip
29
motor
30
Head
31
Head vertical motor
32
Screw bearing
33
Screw shaft
34
Head rotation motor
35
Heating part
351 Heater wiring
36
Adsorption part
361
Chip adsorption air port
362
Adsorption air inlet
37
Cooling unit
371
Cooling unit air inlet
375 Second cooling section
38
Force sensor
381 Force sensor wiring
39 Shaft
40
stage
401
table
402
table
91
Suction nozzle
92
semiconductor
93
Bonding tool
94
stage
95
Height position detection means
96
Lead material
97
motor
98
Outer lead
(a)
Heat-affected displacement process
(b)
Heating process
(c)
Cancellation process
(d)
Target chip height process
P Process end point

Claims (2)

In a bonder device that adsorbs and holds a chip with a head and moves it onto a substrate and melts the bump by a preset heat bonding process and heat-bonds the chip to a predetermined position on the substrate.
A force sensor attached to the top of the head;
Head vertical movement means for moving the head up and down;
Heating means attached to the lower part of the head;
Chip suction means attached to the lower end of the head;
A control unit that controls the head to adsorb and hold the chip, moves it onto the substrate, melts the bump in a preset heat bonding process, and heat-bonds the chip to a predetermined position on the substrate;
A head configured to cancel the thermal displacement by controlling the head position with the head vertical movement means at a predetermined distance between the chip and the substrate in the heat bonding process between the chip and the substrate. And position setting means,
When the force sensor detects the contact between the chip adsorbed by the head and the substrate, the control unit sets the vertical position of the head in the heat bonding process based on the setting of the head position setting means. Controlled by moving means ,
A dummy chip with little thermal deformation is sandwiched between the substrate and the head instead of the chip during the heat bonding process, and the vertical movement means is brought into a free state so that the heat in the vicinity of the head due to thermal influences is obtained. The bonder device is characterized in that expansion and contraction are measured by a motor attached to the upper part of the head of the vertical movement means, and the thermal displacement is set to be canceled by the measured value .
In a bonder device that adsorbs and holds a chip with a head and moves it onto a substrate and melts the bump by a preset heat bonding process and heat-bonds the chip to a predetermined position on the substrate.
A force sensor attached to the top of the head;
Head vertical movement means for moving the head up and down;
Heating means attached to the lower part of the head;
Chip suction means attached to the lower end of the head;
A control unit that controls the head to adsorb and hold the chip, moves it onto the substrate, melts the bump in a preset heat bonding process, and heat-bonds the chip to a predetermined position on the substrate;
A head configured to cancel the thermal displacement by controlling the head position with the head vertical movement means at a predetermined distance between the chip and the substrate in the heat bonding process between the chip and the substrate. And position setting means,
When the force sensor detects the contact between the chip adsorbed by the head and the substrate, the control unit sets the vertical position of the head in the heat bonding process based on the setting of the head position setting means. Controlled by moving means ,
A dummy chip with little thermal deformation is sandwiched between the substrate and the head instead of the chip during the heat bonding process, and when the value of the force sensor rises, the head is raised, and the force sensor When the value decreases, the head is lowered to measure the thermal expansion and contraction in the vicinity of the head due to the thermal effect by the motor attached to the top of the head of the vertical movement means, and the thermal displacement is canceled by the measured value. Bonder device characterized by being set to .

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