JP2974192B2 - Bonding equipment for wafer and mounting plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus suitable for heating a wafer, in which a thermoplastic resin is interposed, and a mounting plate such as a glass substrate, and then pressing and bonding the mounting plate.

[0002]

2. Description of the Related Art In general, a wafer (made of a material such as silicon or gallium arsenide) is polished on a top surface with a grindstone while being adhered on a mounting plate and fixed via the mounting plate. Conventionally, the bonding between the wafer and the mounting plate is performed by placing the wafer on a mounting plate with a thermoplastic resin interposed between them, preheating them, placing them in a non-breathable pack, and suction-reducing the inside of the pack to fix them together. Then, while heating the wafers and the like contained in the pack to dissolve the thermoplastic resin, pressurize them through a diaphragm on which hydraulic pressure acts.After the completion of the pressurization, the wafers and the like are cooled and the thermoplastic resin is cooled. Is solidified, and thereafter, the wafer or the like is taken out of the pack, whereby the wafer is attached to a mounting plate with a thermoplastic resin.

[0003]

However, in such a conventional bonding method, the entire wafer or the like is uniformly applied because the thickness of the diaphragm is not uniform or the diaphragm is weak to heat. As a result, the wafer bonded to the mounting plate may be warped or may be bonded to the mounting plate in a state of being inclined, and as a result, the wafer may be polished to a predetermined state. This takes time and labor, and the wafer is polished so as to have a non-uniform thickness, making the wafer unusable. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a bonding facility capable of sticking a wafer and a mounting plate so that upper and lower surfaces of the mutually bonded wafer and mounting plate are as parallel as possible. The purpose is to provide.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the bonding equipment of the present invention is an equipment for heating a wafer and a mounting plate with a thermoplastic resin interposed therebetween, and then pressurizing to bond the wafer and the mounting plate. And a pressure plate mechanism; a pressure receiving plate mechanism that presses the wafer and the mounting plate with the thermoplastic resin interposed in cooperation with the pressure plate mechanism; and is located at each vertex of one triangle in a plan view. Load cells arranged so as to support one of the pressure plate mechanism and the pressure receiving plate mechanism; heating means for heating the vicinity of the surfaces of the pressure plate mechanism and the pressure receiving plate mechanism to a predetermined temperature; A cooling mechanism for cooling the pressure plate mechanism and the pressure receiving plate mechanism, wherein the pressure plate mechanism and the pressure receiving plate mechanism press the wafer and the mounting plate with the thermoplastic resin interposed therebetween. The load cell and detecting the parallelism of the wafer and the mounting plate.

[0005]

The operation of the bonding apparatus constructed as described above will be described. The wafer and the mounting plate with the thermoplastic resin interposed therebetween are set between the pressing plate mechanism and the pressure receiving plate mechanism. The vicinity of the surface of the plate mechanism is heated to a predetermined temperature by heating means to melt the thermoplastic resin, and the wafer and the like are connected to the pressure plate mechanism while detecting the parallelism of the wafer and the mounting plate through three load cells. Pressure is applied by the pressure receiving plate mechanism, and after completion of the pressurization, the thermoplastic resin is cooled by the cooling means and solidified. Thereby, the silicon wafer and the mounting plate can be bonded via the thermoplastic resin.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described in detail with reference to FIGS. As shown in FIG. 1 which is a partial cross-sectional front view showing one embodiment of the present invention, an elevating device 2 for elevating and lowering an elevating frame 17 to be described later is installed at the center of a base plate 1 having a platen shape. I have. In this elevating device 2, as shown in FIG. 2 which is a partial cross-sectional front view, a hollow rotary shaft 3 which is vertically oriented is rotatably mounted on a casing 5 via a bearing 4, and a hollow rotary shaft 3 is provided. A nut 6 with a ball interior is fitted on the nut 6. A screw shaft 7 is screwed into the nut 6. On the right side of the hollow rotary shaft 3 or the like, a servo motor 12 with a downward speed reducer 11 is provided so as to be supported by the casing 5, and an output shaft of the servo motor 12 Belt pulley 13
Also, the screw shaft 7 is connected to the belt pulley 8 via an endless belt 14 so that the screw shaft 7 moves up and down by forward and reverse rotations of the servo motor 12.

As shown in FIG. 1, guide rods 15 are erected at the four corners of the base 1, and a ceiling frame 16 is installed between the upper ends of the guide rods 15. . Further, the guide rods 15 and 15 have
The lifting frame 17 has linear bearings 1 at the four corners.
It is pierced and mounted slidably up and down via 8, 18,
The connecting member 10 of the lifting device 2 is fixed to the center of the lower surface of the lifting frame 17. The lifting frame 1
7, three load cells 19, 19, 19 are arranged and mounted so as to be located at respective vertices of one equilateral triangle in a plan view, and these three load cells 19, 19, 19 are arranged. Reference numeral 19 denotes a controller 20 comprising a microcomputer, an amplifier 21 and an A / D converter 22.
The controller 20 converts the analog signals of the loads acting on the three load cells 19, 19, 19 into digital signals via the A / D converter 22 and inputs the analog signals. Then, the loads applied to the three points are respectively measured, and the difference between the maximum value and the minimum value of the loads at the three points is calculated. When the calculated difference is larger than a preset value, Means that the parallelism between the wafer and the mounting plate is not at a predetermined level.

Further, these three load cells 19, 1
A pressing plate mechanism 23 is provided between the upper ends of the plates 9 and 19. In the pressing plate mechanism 23, as shown in FIG. 1, a rectangular ceramic pressing plate main body 24 and a rectangular supporting plate 25 are provided. A heating unit 27 and a cooling pipe 28 with a built-in refrigerant as a cooling unit are provided between the pressing plate main body 24 and the support plate 25 at predetermined intervals vertically and opposed to each other via an intermediate member 26. And a heat insulating member 40, and the cooling pipe 28 is connected to a refrigerant circulation device (not shown).

In the heating means 27, as shown in FIG. 3, which is a schematic diagram, a thermocouple 29 buried near the surface of the pressing plate body 24 to detect the temperature near the surface.
And an electric heater plate 3 for heating the pressing plate body 24
0 is provided, and a thermocouple 32 for detecting the temperature of the electric heater plate 30 near the electric heater 31 is embedded in the electric heater plate 30.
Reference numerals 9 and 32 are electrically connected to the input terminal of the temperature controller 33 for the pressure plate main body and the input terminal of the temperature controller 34 for the electric heater plate, respectively. The input terminal of the heater plate temperature controller 34 is electrically connected, and the output terminal of the electric heater plate temperature controller 34 is electrically connected to the current switching means 35. Reference numeral 35 is opened and closed by a signal from the electric heater plate temperature controller 34. The electric heater 31 is electrically connected to a power supply 38 via a power regulator 36 and a current switching means 35.

Therefore, in the pressing plate mechanism 23,
By the supply of electric power to the electric heater 31, the pressing plate body 24 is heated via the electric heater plate 30, and as shown in FIG. The temperature of the plate 30 is measured by the thermocouple 29 and the temperature controller 33 for the pressure plate is measured.
In the pressure plate temperature controller 33, the PID is calculated from the difference between the measured value and a preset value.
An operation is performed to calculate a value for heating the pressing plate body 24 to a required temperature in the form of a percentage.
The calculated value is input to the electric heater plate temperature controller 34, and a value for heating the electric heater plate 30 to a target value is calculated by a preset calculation formula. For example, the calculated value of the PID calculation is 0. 180%
⁰ C, 200 at the time of 190 ⁰ C, 100% at the time of 50%
Calculated as ⁰ C.

Next, a PID calculation is performed from the second calculated value and the difference between the temperature of the electric heater plate 30 and the temperature measured by the thermocouple 32.
The value for heating 0 to the required temperature is similarly calculated in the form of percentage, and based on the third calculated value, the current switching means 35
Is opened and closed. As a result, electric power is supplied to the electric heater 31 for the required time, and the electric heater plate 30 can heat the vicinity of the surface of the pressing plate body 24 to a desired temperature. As shown in FIG. 1, a pressure receiving plate mechanism 37 is mounted on the lower surface of the ceiling frame 16 so as to face the pressure plate mechanism 23. The pressure plate mechanism 37 turns the pressure plate mechanism 23 upside down. And a control device similar to that of the pressure plate mechanism 23 is provided.

Next, the operation of bonding the mounting plate and the wafer using the above-configured equipment will be described.
As shown in FIG. 1, with the elevating frame 17 lowered, a mounting plate and a wafer to be bonded to each other are placed on the pressing plate main body 24 of the pressing plate mechanism 23, and heat is applied between the mounting plate and the wafer. After setting with a plastic resin interposed, the equipment is started. Then, the servo motor 12 is driven to rotate forward, and electric power is supplied to the electric heaters 31, 31, and the pressurizing plate mechanism 2 is driven by the electric heater plates 30, 30.
The pressure plate body 24 and the pressure receiving plate body of the pressure receiving plate mechanism 37 are heated, whereby the thermoplastic resin is melted by the heat from the pressure plate body 24 and the pressure receiving plate body. At the same time, the mounting plate, the thermoplastic resin and the wafer are detected while the pressing force of the pressing plate main body 24 and the pressure receiving plate main body and the parallelism between the wafer and the mounting plate are detected by the three load cells 19, 19, and 19. Is pressurized.

The pressurized load cells 19, 1
When 9 and 19 detect the target value, the drive of the servo motor 12 is stopped. If the load cells 19, 19, 19 do not detect the target value even after pressurizing for a predetermined time, the wafer or the like is processed as a defective product, and then the supply of power to the electric heaters 30, 30 is stopped. Subsequently, a refrigerant is circulated through the cooling pipes 28, 28 to cool and solidify the thermoplastic resin. Thereafter, the servo motor 12 is driven to rotate in the reverse direction, and the pressure plate mechanism 23 is lowered via the lifting frame 17. As a result, it is possible to take out the bonded body between the mounting plate and the wafer, the upper and lower surfaces of which are bonded by the thermoplastic resin and the upper and lower surfaces of which have a predetermined degree of parallelism, from the pressing plate main body 24.

In the above embodiment, the pressing plate mechanism 23
Is provided below, but the arrangement of the pressure plate mechanism 23 and the pressure receiving plate mechanism 37 is reversed so that the pressure plate mechanism 23 is provided above and the pressure receiving plate mechanism 37 is provided below. A similar effect can be obtained even with a structure in which the plate mechanism 37 and the like are rotated by 90 degrees. In the above embodiment, the pressure plate mechanism 23 is connected to the load cells 19, 19, 19.
However, the pressure receiving plate mechanism 37 may be supported. Further, in the above embodiment, the three load cells 19, 19, 19 are arranged so as to be located at the respective vertices of one equilateral triangle in a plan view, but this equilateral triangle may be an appropriate triangle. . Further, in the above embodiment, the lifting device 2 uses the ball screw mechanism driven by the servo motor 11, but is not limited to the device having this structure, and various pressing devices such as a hydraulic cylinder may be used. Of course. Further, the heating means 27 may have any mechanism as long as it can heat the pressing plate main body 24 and the pressure receiving plate main body to a predetermined temperature. Furthermore, a resistance temperature detector may be used instead of the thermocouples 29 and 32 as the temperature sensor.

[0015]

As is clear from the above description, according to the present invention, since the heating means is provided in the pressing plate mechanism and the pressure receiving plate mechanism, the thermoplastic resin interposed between the mounting plate and the wafer is heated and melted. Can be used as an adhesive,
Furthermore, since one of the pressure plate mechanism and the pressure receiving plate mechanism is supported by a load cell arranged so as to be located at each vertex of one triangle in a plan view, the mounting plate and the wafer are parallelized on both upper and lower surfaces thereof. Can be applied to increase the pressure as much as possible. As a result, when the wafer is polished by fixing it through the mounting plate, the entire wafer can be easily and reliably polished to a uniform thickness. It has an excellent effect.

[Brief description of the drawings]

FIG. 1 is a partially sectional front view showing an embodiment of the present invention.

FIG. 2 is an enlarged front view of a main part of FIG.

FIG. 3 is a schematic view showing an embodiment of a heating means which is one of the components of the present invention.

FIG. 4 is a block diagram showing an electrical configuration of an embodiment of a heating unit which is one of the components of the present invention.

[Explanation of symbols]

 Reference Signs List 19 load cell 23 pressure plate mechanism 27 heating means 28 cooling pipe 37 pressure receiving plate mechanism

Claims (1)

(57) [Claims] 1. A facility for heating a wafer and a mounting plate with a thermoplastic resin interposed therebetween and then applying pressure to bond the wafer to the mounting plate, comprising a pressing plate mechanism 23; and a wafer with a thermoplastic resin interposed therebetween. A pressure receiving plate mechanism 37 for pressing a mounting plate in cooperation with the pressure plate mechanism 23; and a pressure receiving plate mechanism 37 and the pressure receiving plate mechanism 37 which are arranged at respective vertices of one triangle in a plan view. And heating means 27, 27 for heating the vicinity of the surfaces of the pressure plate mechanism 23 and the pressure receiving plate mechanism 37 to a predetermined temperature; and the pressure plate mechanism 23, Cooling means 28, 28 for cooling the pressure receiving plate mechanism 37, wherein the pressure plate mechanism 23 and the pressure receiving plate mechanism 37 are mounted on a wafer with the thermoplastic resin interposed therebetween. The apparatus for bonding a wafer and a mounting plate, wherein the load cells 19, 19, 19 detect the parallelism between the wafer and the mounting plate when the plate is pressed.