JP2003315196A - Manufacturing method of pressure sensor, and measuring device for use in the manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sensitivity measuring device for a pressure sensor that can measure sensitivity on a wafer basis. <P>SOLUTION: The measuring device comprises a stage 20 mountable with a wafer 10 in which pressure detection parts for outputting an electrical signal corresponding to pressure are formed in chip units, a stage pressure control part 21, 40 and 51 for applying a controllable pressure to the wafer 10 from the side of the stage 20, a chamber pressure control part 52 and 110 capable of controlling the pressure in a pressure chamber 30, a stage drive part 60 and 70 capable of moving the stage 20 to a desirable position in the pressure chamber 30, and a probe 80 capable of detecting an electrical signal corresponding to the pressure in the pressure chamber 30 output from an individual pressure detection part in the wafer 10. The wafer 10 mounted on the stage 20 is fixed on the stage 20 by a pressure difference between the pressure from the side of the stage 20 and the pressure in the pressure chamber 30. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a pressure sensor which measures the characteristics of the pressure sensor at a wafer level, and a measuring device used in the manufacturing method.

[0002]

2. Description of the Related Art As a pressure sensor formed by cutting from a wafer state, a semiconductor wafer such as a silicon substrate is used, and a pressure sensor function (for example, a diaphragm and a strain gauge) and its characteristic are amplified in one chip. There is a one-chip integrated pressure sensor formed with circuitry for compensation and trimming.

The chips used in this pressure sensor cannot be used as a product if they are cut out from the wafer, because the offset characteristics and the sensitivity characteristics are different for each chip. Here, for example, the offset characteristic is the output at a reference pressure (for example, atmospheric pressure), and the sensitivity characteristic is the slope of the output change when the pressure changes.

Therefore, in the manufacturing process, it is necessary to perform offset measurement and sensitivity measurement and adjustment of each function such as offset characteristic and sensitivity characteristic, that is, trimming.

FIG. 6 shows a manufacturing process of a conventional pressure sensor. First, in the wafer circuit forming step, a pressure detection unit that outputs an electric signal corresponding to the pressure forms a wafer formed for each chip. Here, the pressure detection unit has the above-mentioned pressure sensor function and a circuit for amplifying / compensating and trimming its characteristic.

After this wafer is subjected to an electrical inspection for checking the electrical continuity of each portion and an appearance check,
Dicing cut and cut into chips. Each of the divided chips is subjected to a chip assembling process and a wire bonding process and assembled as an assembly.

The state of this assembly is shown in FIG. In addition,
In FIG. 7, (b) is a schematic sectional view and (a) is a top view of (b). A chip 1 is fixed to a housing 2 having terminals 3, and each electrode pad (not shown) formed on the chip 1 is electrically connected to a terminal 3 by a bonding wire 4.

Although four terminals 3 are shown here,
Of these, three are used for voltage supply (Vcc, GND) and sensor signal output (out), and the remaining one is an adjustment terminal 3a for adjusting characteristics. In this way, with the chip 1 assembled to the assembly, offset measurement, sensitivity measurement, and the respective function adjustments are performed.

That is, in the offset measurement, the measurement is performed using a probe under atmospheric pressure, and in the sensitivity measurement, the measurement is performed by applying a pressure in the range to be measured to this assembly.

At the trimming step, a pseudo signal corresponding to the pressure measured in the previous step is applied from the adjusting terminal 3a to trim the offset characteristic and the sensitivity characteristic in the assy state. This trimming is performed, for example, by adjusting the resistance value by scraping a resistance portion (not shown) formed on the chip 1 with a laser or the like. Then, a final characteristic inspection, that is, an assembly inspection is performed, and the pressure sensor is completed.

[0011]

As described above, conventionally, it takes a lot of time and labor to measure the offset and the sensitivity and further adjust the functions of these characteristics after the assembling of the assembly.

Here, the offset measurement can be performed even in a wafer state by detecting the output under atmospheric pressure using a wafer probe which is an existing device. Sensitivity measurement that requires applying a pressure or a pseudo signal corresponding to the pressure to the sensor must be performed after the assembly of the assembly because there is no apparatus for measuring the wafer.

Further, when the function is adjusted by the assembly, a signal for adjustment is required in addition to the power supply signal and the output signal required for the function of the product, so that the chip 1 is attached as shown in FIG. Adjustment terminal 3a is provided on the housing 2.
It was necessary to attach an extra.

In view of the above circumstances, the present invention focuses on the fact that there is no apparatus for measuring the sensitivity of the wafer as it is in the manufacturing process. It is an object of the present invention to provide a measuring device used for.

[0015]

In order to achieve the above object, the invention according to claim 1 provides a wafer (10) in which a pressure detecting portion for outputting an electric signal according to pressure is formed for each chip. A pressure chamber (30), a stage (20) housed in the pressure chamber and movable in the pressure chamber, and a signal detection unit (80) provided in the pressure chamber and capable of detecting an electric signal from the pressure detection unit. ) And a step of mounting the wafer on the stage,
And a step of measuring an electric signal according to the pressure in the pressure chamber from an arbitrary pressure detection unit on the wafer by the signal detection unit.

According to this, the pressure in the pressure chamber is set to a pressure within the measurement range, and the stage is moved to align the pressure detection part and the signal detection part to be measured of the wafer mounted on the stage. After performing the above, it is possible to detect an electric signal in the pressure detection unit to be measured.

Therefore, since the electric signal from the pressure detecting portion corresponding to the pressure in the pressure chamber, that is, the pressure in the measuring range can be measured, the sensitivity can be measured. Therefore, according to the present invention, it is possible to provide a manufacturing method capable of measuring the sensitivity of a wafer as it is.

If it becomes possible to perform sensitivity measurement on a wafer, which has not been possible in the past, offset measurement, sensitivity measurement, and function adjustment (trimming) of these offset and sensitivity can all be performed in a wafer state. Leads to simplification.

According to the second aspect of the invention, in the step of mounting the wafer (10) on the stage (20),
A pressure is applied to the wafer from the stage side, and the wafer is fixed to the stage by a pressure difference between the pressure from the stage side and the pressure in the pressure chamber (30).

According to this, by appropriately adjusting the pressure from the stage side and the pressure in the pressure chamber, the pressure difference for fixing the wafer to the stage is too large,
It can be prevented from being too small. That is, the fixing force of the wafer to the stage can be adjusted to an appropriate level, and the deformation of the wafer due to the fixing force can be prevented.

When the wafer is fixed to the stage, deformation such as warp of the wafer is liable to occur, and measurement error is likely to occur due to the deformation. However, according to the present invention, such a problem can be avoided. Therefore, the sensitivity can be measured with high accuracy, which is preferable.

Further, in the invention described in claim 3, the probe (80) for detecting an electric signal by contacting the pressure detecting portion is used as the signal detecting portion, and the wafer (10) is used.
After the height of each pressure detection unit in the thickness direction of the wafer is measured with the stage mounted on the stage (20), the position of one of the pressure detection units is set as a reference point, The probe is measured by determining the position coordinates of the other pressure detection units based on the data of the height of each pressure detection unit in the thickness direction of the wafer, and moving the stage based on the determined position coordinates. It is characterized in that the pressure detecting section is brought into contact with it.

In the wafer, a slight warp cannot be avoided. Therefore, when a contact-type probe is used as the signal detection unit, the contact state of the probe varies for each part of the wafer, that is, for each pressure detection unit. As a result, a measurement error is likely to occur in each pressure detection unit.

With respect to this point, in the present invention, one position of each pressure detection unit is used as a reference point, the position coordinates of the other pressure detection units are determined, and the stage is moved based on the determined position coordinates. By doing so, the probe is brought into contact with the pressure detection unit to be measured.

Further, the position coordinates of the other pressure detecting portions are determined based on the height data of each pressure detecting portion measured in advance in the thickness direction of the wafer. That is, even if the wafer warps, the position coordinates in which the amount of the warp is corrected can be obtained by determining the position coordinates in consideration of the height data of each pressure detection unit.

Therefore, by bringing the wafer and the probe into contact with each other on the basis of the obtained position coordinates, it is possible to make the contact state of the probe uniform for each pressure detection unit on the wafer, and as a result, measure for each pressure detection unit. There is virtually no error. Therefore, according to the present invention, more accurate sensitivity measurement can be performed for each pressure detection unit.

Further, in the invention according to claim 4, a stage (2) on which a wafer (10) having a pressure detecting portion for outputting an electric signal according to pressure formed for each chip unit can be mounted.
0) and a pressure chamber (30) housing the stage,
A stage drive unit (60, 70) capable of moving the stage to a desired position in the pressure chamber, and an electric signal corresponding to the pressure in the pressure chamber from each pressure detection unit provided in the wafer are provided in the pressure chamber. Provided is a measuring device comprising a signal detecting section (80) capable of detecting.

According to this, it is possible to provide the measuring apparatus which can appropriately realize the manufacturing method according to the first aspect.

Further, in the invention described in claim 5, in the measuring device according to claim 4, a pressure is applied from the stage side to the wafer (10) mounted on the stage (20) and the pressure is applied. Controllable stage pressure controller (21, 40, 51) and chamber pressure controller (52, 110) capable of controlling the pressure in the pressure chamber (30).
And a wafer mounted on the stage is fixed to the stage by a pressure difference between the pressure from the stage side and the pressure in the pressure chamber.

According to this, it is possible to provide a measuring apparatus which can appropriately realize the manufacturing method according to the second aspect.

According to a sixth aspect of the present invention, in the measuring apparatus according to the fourth or fifth aspect, the signal detecting section is
A probe (80) that detects an electric signal by contacting the pressure detection unit, and uses the probe (80) to move the wafer (10) to the stage (2).
0), the height of each pressure detection unit in the wafer thickness direction is measured, and the pressure of each pressure detection unit is set as a reference point. Based on the height data of the detector in the thickness direction of the wafer, the position coordinates of other pressure detectors are determined, and the stage is moved based on the determined position coordinates to detect the pressure at which the probe should be measured. It is characterized by being brought into contact with the part.

According to this, it is possible to provide the measuring apparatus which can appropriately realize the manufacturing method according to the third aspect.

The reference numerals in parentheses for each means described above are examples showing the correspondence with the specific means described in the embodiments described later.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention shown in the drawings will be described. 1A and 1B are diagrams showing a configuration of a pressure sensor S1 according to an embodiment of the present invention, FIG. 1A is a top view of FIG. 1B, and FIG. 1B is a schematic sectional view.

The chip 1 is a pressure detecting portion for outputting an electric signal according to the pressure, and although not shown in FIG. 1, a silicon substrate and a glass pedestal are joined as shown in FIG. 3 described later. Is.

On the silicon substrate, for example, a diaphragm and a strain gauge are formed, and the diaphragm is strained by applying pressure, and this strain can be output as an electric signal by the strain gauge.

The chip 1 is mounted and fixed on a housing 2 made of resin or the like via the glass pedestal. The terminals 3 are inserted and fixed to the housing 2 by insert molding or the like, and the terminals 3 and the chip 1 are electrically connected to each other by wires 4 such as Au or Al.

Here, on the silicon substrate of the chip 1, at least three electrodes, not shown, are electrode pads for voltage supply (that is, electrode pads for power supply and electrode pads for GND) and electrode pads for signal output. Pads are formed.

The terminal 3 is also connected to the power supply electrode pad (Vcc), connected to the GND electrode pad (GND), and connected to the signal output electrode pad (out). ) Are provided.

In such a pressure sensor S1, when pressure is applied to the chip 1, an electric signal corresponding to the pressure is transmitted from the chip 1 to the terminal 3 via the wire 4 and output from the terminal 3 to the outside. It has become so.

Next, a method for manufacturing the pressure sensor of this embodiment will be described. FIG. 2 is a process diagram showing a manufacturing process of the pressure sensor according to the present embodiment, and FIG. 3 is a schematic configuration diagram of a sensitivity measuring device used in the manufacturing method.

First, in the wafer circuit forming step, the wafer 10 shown in FIG. 3 is formed. In this wafer 10, a silicon wafer 11 and a glass pedestal 12 are bonded together, and the silicon wafer 11 is formed with a pressure detection unit for outputting an electric signal according to the pressure for each chip.

Specifically, the silicon wafer 11 has a strain gauge for functioning as a pressure sensor, amplification, compensation, and trimming (function adjustment) together with the diaphragm.
Several hundred circuits are formed in a grid pattern. When each of the squares is divided in the subsequent process, it becomes the chip 1, that is, the pressure detecting portion. Hereinafter, one chip unit on the wafer 10, that is, one pressure detection unit is referred to as a die.

In this wafer 10, for example, the diaphragm, the circuit including the strain gauge, the electrode pad and the like are formed for each die by using an ordinary semiconductor process, etching technique or the like on the silicon wafer 11. After that, the silicon wafer 11 and the glass pedestal 12 are bonded by anodic bonding or the like.

Next, in this manufacturing method, sensitivity measurement is performed using this wafer 10. First, the sensitivity measuring device used in this sensitivity measuring step will be described with reference to FIG.

As shown in FIG. 3, the wafer 10 to be measured is mounted on the stage 20 on the glass pedestal 12 side. Here, the wafer 10 is warped due to the stress at the time of bonding. In order to alleviate this warp (stress), it is preferable to perform a half-cut, that is, a dicing process with the glass pedestal 12 left a little in the previous step.

The stage 20 is housed and installed in a pressure chamber 30 as an airtight container. Then, the stage 20 fixes the wafer 10 by the force due to the pressure difference from the pressure generation source 40 for the stage and the pressure inside the pressure chamber 30. That is, the pressure inside the stage 20 with the wafer 10 sandwiched therebetween is set to be smaller than the pressure inside the pressure chamber 30.

From the stage pressure generation source 40 to the stage 2
The pressure to 0 can be controlled by a stage switching valve 51 that is set in the middle of a pipe connecting the pressure generating source 40 and the stage 20. Here, the stage switching valve 51 includes the stage pressure generation source 40 and the stage 20 in order to control the pressure inside the stage 20 to a desired pressure.
It is possible to switch between the case of communicating with the inside and the case of communicating with the atmosphere inside the stage 20.

Further, the wafer 10 is mounted on the stage 20.
The grooves 21 are arranged symmetrically with respect to the center of the surface on which is mounted, and the piping from the stage pressure generation source 40 also has a structure in which the pressure is evenly transmitted to the grooves 21. The stage pressure generation source 40 is controllable from a vacuum pressure to a pressure above atmospheric pressure.

In this way, the stage pressure generation source 40,
The switching valve 51 and the groove 21 constitute a stage pressure control unit. The stage pressure control units 21, 4
0 and 51 are capable of applying pressure from the stage 20 side to the wafer 10 mounted on the stage 20 and controlling the pressure.

Below the stage 20, there is a stage drive motor 60, so that the position of the wafer 10 on the X axis, Y axis, Z axis, and θ axis can be controlled by a signal from the stage controller 70. The pressure chamber 30
It is possible to move inside. Here, FIG. 4 is a top view of the wafer 10 in FIG. 3, and the X-axis, Y-axis, Z-axis,
Refer to these FIGS. 3 and 4 for the θ axis.

As described above, the stage drive motor 60 and the stage control device 70 form a stage drive section capable of moving the stage 20 to a desired position in the pressure chamber 30.

A probe 80 is provided inside the pressure chamber 30. Although not shown, the probe 80 is provided with at least two needles for supplying voltage and at least one needle for extracting an output signal. The needles come into contact with the electrode pads on each die of the wafer 10 to supply voltage and take out output signals. Probe 80
Are manufactured so that each needle is aligned with a designated electrode pad.

As described above, the probe 80 is used for the wafer 10
In the pressure chamber 30 from the individual dies (pressure detection unit) in FIG. Also, the probe 80
The voltage is supplied from the power supply 90, and the output signal is the voltmeter 1.
Can be measured at 00.

As described above, the stage 20, the stage drive motor 60, and the probe 80 are mounted in the pressure chamber 30. The pressure chamber 30 has a structure capable of withstanding the pressure when the sensitivity is measured. Wafer 10
It has a structure that can be taken in and out, for example, a structure that can be opened and closed with a lid.

Supplying the pressure for measuring the sensitivity into the pressure chamber 30 is performed by the chamber pressure generating source 1.
It is supposed to be performed by 10. Control of pressure supply at this time is performed by the chamber switching valve 52. Here, the chamber switching valve 52 controls the chamber pressure generation source 1 to control the pressure inside the pressure chamber 30 to a desired pressure.
10 and the inside of the chamber 30 communicate with each other, and the chamber 3
It is possible to switch between the case where 0 is communicated with the atmosphere.

Further, a chamber pressure sensor 120 is attached to the pressure chamber 30, and the pressure in the pressure chamber 30 can be known on the pressure indicator 130. Then, based on the information on the pressure indicator 130, the pressure inside the pressure chamber 30 can be controlled to a desired value by operating the chamber pressure generation source 110 and the chamber switching valve 52.

In this way, the chamber pressure generation source 110
Further, the chamber switching valve 52 constitutes a chamber pressure control unit capable of controlling the pressure in the pressure chamber 30. Then, the wafer 1 mounted on the stage 20
0 is fixed to the stage 20 by the pressure difference between the pressure from the stage 20 side (groove 21 side) and the pressure in the pressure chamber 30.

Further, in the pressure chamber 30, the wafer 10 is
A displacement sensor 140 for measuring the height of the wafer and a displacement indicator 150 are attached, and a camera 160 and a monitor 170 for aligning the wafer 10 are attached.

The displacement sensor 140, the displacement indicator 150, the camera 160 and the monitor 170 monitor the positions of the X-axis, Y-axis, Z-axis and θ-axis of the wafer 10 and the stage control is performed based on the monitor information. Device 7
The position of the wafer 10 can be aligned by controlling the stage drive motor 60 with a signal from 0.

The sensitivity measuring process using the sensitivity measuring device as described above will be described. First, in the sensitivity measuring device shown in FIG. 3, both switching valves 51 and 52 are switched in a direction in which they are connected to the outside air (atmospheric pressure).

Next, the wafer 10 prepared in the wafer circuit forming step is mounted on the stage 20. Here, pressure is applied to the wafer 10 from the stage 20 side, and the pressure from the stage 20 side and the pressure chamber 30 are applied.
The pressure difference from the internal pressure causes the wafer 10 to move to the stage 2
Fixed at 0.

Specifically, in the sensitivity measuring apparatus, the stage pressure generation source 40 is set to a pressure (vacuum pressure) lower by Ps1 than the atmospheric pressure, and the stage switching valve 51 is set.
And the inside of the stage 20 are communicated with each other, and the pressure inside the stage 20, that is, the pressure inside the groove 21 is set to the above vacuum pressure. As a result, the wafer 10 is fixed to the stage 20 by the force of the pressure difference Ps1 between the atmospheric pressure in the pressure chamber 30 and the vacuum pressure.

It is desirable that the pressure difference Ps1 be set so that the wafer 10 is not displaced when the stage 20 is moved, and that the pressure difference Ps1 is set as small as possible (pressure close to atmospheric pressure). This is because the pressure difference Ps1 is reduced to minimize the force for fixing the wafer 10 and reduce the stress transmitted to the wafer 10 that causes an error during sensitivity measurement.

Next, the θ axis is adjusted (parallel alignment) while viewing the image of the wafer 10 with the camera 160 and the monitor 170. X-axis (or Y) of stage drive motor 60
(Axis), and while observing the circuit pattern formed on the wafer 10, the θ axis is moved and adjusted so that the dies are parallel to each other. The stage control device 70 controls the stage drive motor 60.

Next, the displacement sensor 140 measures the height of each die on the wafer 10. The height of each die is the height in the thickness direction (Z-axis direction) of the wafer 10, and is the distance between the surface of each die and the displacement sensor 140. Here, as the displacement sensor 140, a sensor such as a laser displacement meter that can measure a distance without contact is used.

As described above, since the wafer 10 has a slight warp, the height varies depending on the die even within the same wafer 10. Therefore, the displacement sensor 140 is used to measure the height of each die, and the height data is stored in a storage unit (computer or the like) (not shown) in the measuring apparatus.

Next, the XY position of the needle of the probe 80 is adjusted (X-axis and Y-axis adjustment). As described above, each die of the wafer 10 is formed with an electrode pad, and a needle can be pressed against this pad to supply a voltage and take out an output signal.

First, one reference die (reference die) is selected from the wafer 10 and the reference die is aligned. As with the adjustment of the θ axis, the camera 160
While observing the image of the wafer 10 on the monitor 170, the X-axis and the Y-axis are adjusted so that the electrode pad and the needle are aligned with each other.

The X axis and the Y axis can be adjusted by moving the stage drive motor 60 in response to a signal from the stage controller 70. The position of the X-axis and the Y-axis where the adjustment is completed is coordinate value X0, Y
The value 0 is stored in the storage unit.

Next, the height of the needle of the probe 80 is aligned (that is, the Z axis is adjusted). Stage drive motor 6
The Z axis of 0 is raised by a signal from the stage control device 70, and is stopped at a position where all the needles and the electrode pads hit in the reference die.

Whether or not the needle hits the electrode pad can be detected by checking whether the needle has moved in the image on the monitor 170. There is also a method of checking whether or not there is an output signal, and checking using a probe with a contact detection function that has been conventionally used as the probe 80. Adjustment completed Z
The position of the axis is stored in the storage unit as the coordinate value Z0. After the adjustment, the stage 20 is lowered to keep the needle away from the electrode pad.

Next, the movement amount (X1, Y1, Z1) of the stage 20 from the reference die to the other dies to be measured is calculated. The movement amount (X1, Y1, Z1) corresponds to the position coordinate of the die to be measured when the position coordinate (X0, Y0, Z0) of the reference die is used as the reference point.

First, the movement amounts (coordinate values) X1 and Y1 can be calculated based on the coordinate values (X0, Y0) of the reference die from the die intervals and the number of dies to be measured. This utilizes the fact that the intervals between the dies on the wafer 10 and the shapes of the dies are the same.

Regarding the movement amount Z1, first, the height data of each die measured by the displacement sensor 140 is used, and the difference between the height data of the reference die and the height data of other dies to be measured is calculated as Add to the coordinate value Z0 on the Z axis. Thereby, the position where the needle of the probe 80 hits the electrode pad of the die in the height direction (Z-axis direction) can be obtained.

A value obtained by adding the needle pressing amount ΔL to this position is the movement amount of Z1. This needle pressing amount ΔL is
The needle is pushed into the electrode pad so that the needle and the electrode pad can be electrically connected to each other, and it is preset.

When the needle pressing amount ΔL is large, the contact resistance between the needle and the electrode pad is small, but the needle pressing force is large and the wafer 10 may be deformed, that is, the output signal (electrical signal) may fluctuate. There is. On the other hand, when ΔL is small, the contact resistance becomes large and the output signal and the supply voltage vary. Therefore, the optimum ΔL is previously investigated and set.

As described above, the position of one reference die among the respective dies (pressure detecting portions) is set to the reference point (X0, Y0, Z).
0), and the position coordinates (X1, Y1, Z1) of the other dies are determined based on the height data of each die. Here, when there are a plurality of other dies, that is, n dies,
The amount of movement (Xn, Y
n, Zn) is calculated.

By moving the stage 20 based on the determined position coordinates, that is, the amount of movement, even if there is a minute warp existing on the wafer 10,
In the contact between the probe of the probe 80 and the electrode pad of the die to be measured, uniform contact can be realized for each die. That is, the amount of pushing of the needle of the probe 80 can be made the same for each die, so that stable and highly accurate measurement can be performed constantly.

Thus, the position coordinates of each die (X0, Y
0, Z0) and (Xn, Yn, Zn) are determined, and then the measurement at the atmospheric pressure, that is, the offset measurement is started. For the die to be measured, the amount of movement calculated in advance is the X axis, Y
The stage 20 is moved in the axial and Z-axis directions to move the probe 8
Touch the zero needle to the electrode pad on the die to be measured.

A predetermined power supply voltage is supplied from the power supply 90 to the die to be measured via the probe 80, and at that time, the output signal V0 is measured by the voltmeter 100. At the same time, the chamber pressure sensor 120 and the pressure indicator 130 measure the pressure (atmospheric pressure) P0 in the pressure chamber 30. After the measurement, the Z axis of the stage 20 is returned to the initial position Z0. This measurement is performed on a plurality of dies to be measured.

After the atmospheric pressure measurement (offset measurement) is completed, next, preparations are made for measurement at a pressure in the range to be measured. Here, the measurement target is a pressure higher than the atmospheric pressure, but the measurement can be similarly performed even when the pressure is lower than the atmospheric pressure.

First, the chamber switching valve 52 is switched in the direction in which the inside of the stage 20 communicates with the chamber pressure generation source 110, and a preset high pressure Ph that is the object of measurement is supplied into the pressure chamber 30. .

When the pressure in the pressure chamber 30 becomes Ph, the stage pressure generation source 40 becomes Ps1 more than the pressure Ph.
Set to low pressure only. As a result, the force for fixing the wafer 10 (force due to the pressure difference) becomes the same pressure difference Ps1 as in the atmospheric pressure measurement, and the measurement can be performed under the same fixed condition.

Upon completion of the above preparations, measurement at high pressure is started. The procedure is the same as that of the atmospheric pressure measurement. The X axis and Y axis of the stage 20 are moved by a previously calculated movement amount, and further the Z axis is moved to move the needle of the probe 80 to the electrode pad of the die to be measured. Contact.

A predetermined power supply voltage is supplied from the power supply 90 to the die to be measured via the probe 80, and at that time, the output signal V1 is measured by the voltmeter 100. At the same time, the chamber pressure sensor 120 and the pressure indicator 130 measure the pressure P1 in the pressure chamber 30. After the measurement, the Z axis of the stage 20 is returned to the initial position Z0. This measurement is performed on a plurality of dies to be measured.

The atmospheric pressure measurement (offset measurement) data (measurement points) P0 and V0 and the high pressure measurement data (measurement points) P1 and V1 thus obtained have the relationship shown in FIG. From this relationship, sensitivity = (V1-V
0) / (P1-P0) can be obtained. If there are multiple dies measured, the sensitivity is determined for each die.

When the measurement at high pressure is completed, the chamber switching valve 52 is switched to the direction communicating with the outside air (atmospheric pressure) to return the pressure in the pressure chamber 30 to atmospheric pressure. Further, the stage switching valve 51 is switched to a direction in which it communicates with the outside air (atmospheric pressure), the pressure inside the stage 20 is returned to atmospheric pressure, and the wafer 10 is taken out from the pressure chamber 30.
Thus, the sensitivity measurement process including the offset measurement is completed.

Next, the wafer 10 for which the sensitivity measurement has been completed
Is sent to the next wafer trim step. In this wafer trim step, offset adjustment and sensitivity adjustment are performed on the wafer 10.

In the offset adjustment, the offset measurement value data of each die obtained in the sensitivity measurement step is used,
Alternatively, the measurement is performed again using the probe under atmospheric pressure, and the adjustment is performed by trimming the resistance portion formed on each die by a laser or the like.

For sensitivity adjustment, sensitivity measurement value data of each die obtained in the above-mentioned sensitivity measurement step is used, and while applying a pseudo signal to the adjustment electrode pad formed on each die, each die is irradiated with laser or the like. Adjustment is performed by trimming the formed resistance part.

The wafer 10 whose functions have been adjusted at the wafer level is subjected to an electrical inspection for checking electrical continuity of each part and an external appearance check, and then is diced into chips 1 (see FIG. 1). And sent to the assembly process.

In the assembly process, the chip 1 is assembled into the housing 2 and the wire bonding process for connecting the chip 1 to the terminals 3 of the housing 2 is performed to form an assembly, and a final assembly inspection is performed. To do. Thus, the pressure sensor S1 shown in FIG. 1 is completed.

In the manufacturing method of the present embodiment described above, the wafer 10 on which the pressure detection unit for outputting an electric signal according to the pressure is formed for each chip unit (die) is mounted on the stage 20, and The probe 80, which is a detection unit, measures an electric signal corresponding to the pressure in the pressure chamber 30 from an arbitrary die (pressure detection unit) on the wafer 10.

According to this, as described above, the pressure in the pressure chamber 30 is set to a pressure within the measurement range, and the movable stage 20 in the chamber 30 is moved to measure the wafer 10 to be measured. After performing the alignment between the die (pressure detection unit) to be measured and the probe 80, the electric signal in the die to be measured can be detected.

Therefore, since the electric signal from the die corresponding to the pressure in the pressure chamber 30, that is, the pressure in the measurement range can be measured, the sensitivity can be measured. Therefore,
According to the present embodiment, it is possible to provide a manufacturing method capable of measuring the sensitivity of the wafer 10 as it is.

Further, in the above manufacturing method, the wafer 1
In the process of mounting 0 on the stage 20, the stage 2
Pressure is applied to the wafer 10 from the 0 side, and the wafer 10 is fixed to the stage 20 by the pressure difference between the pressure from the stage 20 side and the pressure in the pressure chamber 30.

According to this, by appropriately adjusting the pressure from the stage 20 side and the pressure in the pressure chamber 30, the pressure difference Ps1 for fixing the wafer 10 to the stage 20 becomes too large or too small. Can be prevented. That is, the fixing force of the wafer 10 to the stage 20 can be adjusted to an appropriate level, and the deformation of the wafer 10 due to the fixing force can be prevented.

When the wafer 10 is fixed to the stage 20, deformation such as warpage of the wafer 10 is liable to occur and a measurement error is likely to occur due to the deformation.
Such a problem can be avoided. Therefore,
This is preferable because it enables highly accurate sensitivity measurement.

Further, in the above-mentioned manufacturing method, after measuring the height (height data) of each die (pressure detecting portion) in the wafer 10 in the thickness direction of the wafer 10, one of the dies (pressure data) is Set the position of the reference die to the reference point (X
0, Y0, Z0), and based on the height data of each die, position coordinates (Xn, Yn, Z) of the other dies.
n) is determined, and the stage 20 is moved based on the determined position coordinates, so that the probe 80 is brought into contact with the die to be measured.

According to this, even if there is an inevitable minute warp on the wafer 10, the position coordinates in which the warp amount is corrected are determined by determining the position coordinates in consideration of the height data of each die. be able to.

Therefore, by bringing the electrode pad of the wafer 10 into contact with the needle of the probe 80 based on the obtained position coordinates, the contact state of the probe 80 can be made uniform for each die. The measurement error is virtually eliminated every time. Therefore, more accurate sensitivity measurement can be performed for each die.

As described above, according to the present embodiment, since it is possible to perform the sensitivity measurement on the wafer as it has been conventionally impossible, the offset measurement, the sensitivity measurement, and the function adjustment (trimming) of these offset and sensitivity are performed. All can be done in the wafer state, which leads to simplification of the process.

In this embodiment, since the offset and sensitivity functions are adjusted at the wafer level, the assembly sensitivity measurement and the function adjustment that are conventionally performed in the assembly process are unnecessary. Therefore, as the component cost, the adjustment terminal (see FIG. 7) required for the assembly function adjustment can be eliminated, and the component cost can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a pressure sensor according to an embodiment of the present invention, (a) is a top view of (b), and (b) is a schematic sectional view.

FIG. 2 is a process drawing showing a manufacturing process of the pressure sensor according to the embodiment.

FIG. 3 is a schematic configuration diagram of a sensitivity measuring device used in the manufacturing method of the above embodiment.

FIG. 4 is a top view of the wafer in FIG.

FIG. 5 is a diagram showing a sensitivity relationship in a pressure sensor.

FIG. 6 is a process diagram showing a manufacturing process of a conventional pressure sensor manufacturing method.

7A and 7B are diagrams showing a configuration of a conventional assembled pressure sensor, in which FIG. 7A is a top view of FIG. 7B and FIG.

[Explanation of symbols]

10 ... Wafer, 20 ... Stage, 21 ... Groove, 40 ... Stage pressure generating source, 30 ... Pressure chamber, 51 ... Stage switching valve, 52 ... Chamber switching valve, 60 ...
Stage drive motor, 70 ... Stage control device, 80 ...
Probe, 110 ... Pressure generating source for chamber.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2F055 AA40 BB20 CC02 DD05 EE13                       FF13 FF18 FF43 GG33 GG34                       HH01                 4M106 AA01 AA02 AB20 BA01 CA59                       CA70 DD05 DD13                 4M112 AA01 BA01 CA01 DA16 DA17                       DA18 DA20 EA02 EA11 EA13                       EA14 FA20

Claims (6)

[Claims] 1. A wafer (10) in which a pressure detection unit for outputting an electric signal according to pressure is formed for each chip,
A pressure chamber (30) and a stage (2) housed in the pressure chamber and movable within the pressure chamber.
0) and a signal detecting section (80) provided in the pressure chamber and capable of detecting an electric signal from the pressure detecting section; mounting the wafer on the stage; A step of measuring an electric signal according to the pressure in the pressure chamber from any of the pressure detectors in the wafer by the signal detector, the method of manufacturing a pressure sensor. 2. The wafer (10) is attached to the stage (2).
In the step of mounting on the wafer 0), pressure is applied to the wafer from the stage side, and the wafer is transferred to the wafer by the pressure difference between the pressure from the stage side and the pressure in the pressure chamber (30). The method for manufacturing a pressure sensor according to claim 1, wherein the pressure sensor is fixed to the stage. 3. A probe (80) that detects the electrical signal by contacting the pressure detection unit is used as the signal detection unit, and the wafer (10) is mounted on the stage (20). After measuring the height of each of the pressure detectors in the thickness direction of the wafer, the position of one of the pressure detectors is set as a reference point, and the pressure of each pressure detector is Based on the height data in the thickness direction of the wafer, to determine the position coordinates of the other pressure detection unit, by moving the stage based on the determined position coordinates, to measure the probe The pressure sensor manufacturing method according to claim 2, wherein the pressure sensor is brought into contact with the pressure sensor. 4. A stage (20) on which a wafer (10) having a pressure detection unit for outputting an electric signal according to a pressure is formed for each chip unit can be mounted, and a pressure chamber (30) for accommodating the stage. A stage driving unit (60, 70) capable of moving the stage to a desired position in the pressure chamber, and a stage driving unit (60, 70) provided in the pressure chamber, which is provided in the pressure chamber from the individual pressure detecting units of the wafer. A signal detector (8) capable of detecting an electric signal according to the pressure.
0) and a measuring device. 5. A stage pressure control section (21, 40, 51) capable of applying a pressure to the wafer (10) mounted on the stage (20) from the stage side and controlling the pressure, A chamber pressure control unit (52, 110) capable of controlling the pressure in the pressure chamber (30) is provided, and a wafer mounted on the stage has a pressure from the stage side and a pressure in the pressure chamber. The measuring device according to claim 4, wherein the measuring device is fixed to the stage by a pressure difference. 6. The probe (8) for detecting the electric signal by contacting the pressure detection unit with the signal detection unit.
0), and after measuring the height of each of the pressure detecting portions in the thickness direction of the wafer with the wafer (10) mounted on the stage (20), Using the position of one pressure detection unit as the reference point, the position coordinates of the other pressure detection units are determined based on the height data of each pressure detection unit in the thickness direction of the wafer. The measuring device according to claim 4, wherein the probe is brought into contact with the pressure detection unit to be measured by moving the stage based on the position coordinates.