JP3608241B2 - Thermal deformation measuring device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an apparatus for measuring an out-of-plane thermal deformation of an object, and more particularly to an apparatus for measuring a thermal deformation suitable for measuring a two-dimensional distribution of out-of-plane thermal deformation of an object. Particularly suitable for measuring deformation.
[0002]
[Prior art]
Electronic parts such as semiconductor devices basically have a structure in which plate-like members having different linear expansion coefficients are laminated. For this reason, when such a temperature change of the electronic component is applied, the component is deformed out of plane due to the bimetal effect, and warpage occurs. As a result, stress may be applied to the constituent members and joints of the electronic component, causing destruction. Thus, in the development of electronic components, consideration for thermal deformation is important, and a thermal deformation measuring device is required in order to select materials to be used and to evaluate prototype electronic components.
[0003]
As a method for measuring the thermal deformation of an electronic component, JP-A-1-237476 discloses a method for measuring the thermal deformation of a material by applying a needle to a sample to be measured and heating it, and measuring the displacement of the opposite needle. It is disclosed in the publication.
[0004]
As another method of measuring the thermal deformation of electronic components, the measurement method by the moire method is the 41st Electronic Components and Technology Conference Proceedings (1991), pages 382 to 387 (Processings of 41st Electronic Components Technology). Conference, (1991), pp 382-387).
[0005]
[Problems to be solved by the invention]
Of the above-described conventional techniques, the contact-type method using a needle can basically measure only one point. If the number of needles is increased, the displacement of a plurality of points can be measured, but the number of the points is naturally limited, and the disadvantage is that the displacement of a plurality of dense points cannot be measured. In particular, as described above, the thermal deformation of an electronic component often causes a problem of warping, so it is necessary to know the displacement of a plurality of consecutive points, and this method is not suitable for this purpose.
[0006]
The thermal deformation measurement method by the moire method can measure an arbitrary displacement of the surface to be measured and can obtain two-dimensional information, and therefore meets the above purpose. However, since this method uses interference fringes of light, a special technique is required for data processing for digitizing displacement, and there is a problem in measurement accuracy. Furthermore, the range of displacement that can be measured is small.
[0007]
An object of the present invention is to provide an apparatus that easily and accurately measures a two-dimensional distribution of out-of-plane thermal deformation of an object centered on an electronic component.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the thermal deformation assumption apparatus comprises a thermostatic chamber for changing the temperature of the sample, means for measuring the deformation of the sample, and a control device for controlling the deformation measurement and the thermostatic chamber temperature, The upper surface of the thermostat is covered with a transparent plate, an optical non-contact displacement meter is provided above the transparent plate, the displacement meter is scanned in a two-dimensional plane, and the sample provided in the thermostat and the displacement meter This is achieved by sequentially measuring the distance between them and recording the measurement results in a storage device provided in the control device.
[0009]
As means for scanning the displacement meter, it is effective to use a screw-type stage driven by a pulse motor, and to perform positioning control of the stage by a digital control system using a control device. As a method for measuring the displacement, when measuring the distance between the sample and the displacement meter, the scanning of the displacement meter is stopped and allowed to stand for a certain time, and then the distance between the sample and the displacement meter is measured. It is effective to perform screw rotation control to cancel backlash of the screw of the screw type stage as needed, and to move the displacement meter by one turn along the circumference of the measurement range prior to displacement measurement. is there.
[0010]
Furthermore, a hole is made in the bottom of the thermostatic chamber, a support member made of a material having a linear expansion coefficient of 1 ppm / ° C. or less is passed through this hole, the lower end of the support member is fixed to the surface plate, and the sample is formed at the upper end of the support member. By supporting the measurement accuracy can be improved. It is desirable that the support member is composed of three quartz rods, a quartz plate is placed on the upper ends of the three support members, and a sample is placed on the quartz plate.
[0011]
In addition, as a method for heating the sample, it is preferable to set the temperature of the sample by sending high-temperature air heated (temperature adjusted) by a hot air generator (heating / cooling device) into a constant temperature bath. Cooling is preferably performed by sending air cooled by a refrigerator into a thermostatic chamber.
[0012]
In the thermal deformation measuring device according to the present invention, data on the distance between the sample and the displacement meter in the scan of the same specification performed twice or more is stored in the storage device, and the difference between any two sets of the data is calculated. Thus, the amount of displacement of the sample can be obtained, and by performing each scan while changing the temperature (that is, scanning the same specification is performed twice or more by changing the sample temperature, the difference between any two sets of the data) ) To obtain the amount of thermal deformation. The principle of the optical displacement meter is to measure the distance between the sample and the displacement meter by reflecting the laser beam generated by the semiconductor laser generating element to the sample and detecting the position of the reflected light by the semiconductor position sensor. desirable. Further, it is an object of the present invention to add a function for displaying the displacement amount of the sample on the display device to the control device.
[0013]
[Action]
The thermal deformation measuring apparatus according to the present invention covers the top surface of a thermostatic chamber with a transparent plate, and an optical non-contact displacement meter is provided above the transparent plate, and the thermometer is scanned in a two-dimensional plane. The distance between the sample provided inside and the displacement meter can be sequentially measured, and the measurement result can be recorded in the storage device provided in the control device, so that the two-dimensional distribution of the out-of-plane thermal deformation of the sample can be increased. The accuracy can be obtained.
[0014]
As a means for scanning the displacement meter, a screw-type stage driven by a pulse motor is used, and the positioning of the stage is controlled by a digital control system using a control device, and the screw backlash of the screw-type stage is canceled. Since the rotation control is performed at any time, the positioning accuracy of the displacement meter is high. Furthermore, a hole is made in the bottom of the thermostatic chamber, a support member made of a material having a linear expansion coefficient of 1 ppm / ° C. or less is passed through this hole, the lower end of the support member is fixed to the surface plate, and the sample is placed at the upper end of the support member. Therefore, it is not affected by thermal deformation or vibration of the thermostatic chamber. In addition, since the temperature of the sample is adjusted by sending air temperature-adjusted by the heating / cooling device to the thermostat, the heating / cooling rate of the sample is fast and the temperature distribution is small.
[0015]
In the thermal deformation measuring device according to the present invention, data on the distance between the sample and the displacement meter in the scan of the same specification performed twice or more is stored in the storage device, and the difference between any two sets of the data is calculated. Thus, since the amount of displacement of the sample is obtained, thermal deformation with respect to an arbitrary temperature change can be easily obtained.
[0016]
The principle of the optical displacement meter is to measure the distance between the sample and the displacement meter by reflecting the laser light generated by the semiconductor laser generator to the sample and detecting the position of the reflected light by the semiconductor position sensor. Used during measurement, scanning of the displacement meter is stopped and allowed to stand for a certain period of time, and then the distance between the sample and the displacement meter is measured, so that measurement accuracy is high and data processing is easy. . And since the function which displays the displacement amount of a sample on a display apparatus is added to this control apparatus, the measurer can understand the two-dimensional distribution of the out-of-plane displacement of a sample easily.
[0017]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. ◆
FIG. 1 is a perspective view showing an outline of an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing an outline of the embodiment of the present invention. The thermostat 2 is installed on the surface plate 9 via a support column 10. The upper surface of the thermostat 2 is covered with a transparent plate 3. For example, heat-resistant glass is used as the material of the transparent plate 3. Moreover, the heat insulation efficiency of a thermostat can be improved by making this glass into a double glass structure. Three holes are formed in the bottom surface of the thermostatic chamber 2, and support members 4a, 4b, and 4c are passed through the holes. As the material of the support members 4a, 4b, and 4c, it is necessary to use a material having a small linear expansion coefficient, for example, quartz. The shape of the support member is a columnar shape or a pipe shape.
[0018]
A sample placement plate 5 is placed on the upper ends of the support members 4a, 4b, 4c. The sample mounting plate 5 is also made of quartz. Further, a sample 11 is placed on the sample setting plate 5. A stage 7b for moving in the y direction is fixed on the surface plate 9, and a stage 7a for moving in the x direction is further fixed thereon. These stages use a pulse motor driven screw stage. The displacement meter 1 is fixed to the stage 7a via a displacement meter support jig 6. The displacement meter support jig 6 is adjusted so that the displacement meter 1 is positioned above the sample 11.
[0019]
In this embodiment, a displacement meter is formed by reflecting the visible laser beam generated by the semiconductor laser generating element to the sample and detecting the position of the reflected light by the semiconductor position sensor to measure the distance between the sample and the displacement meter. Using. Therefore, since the laser beam hitting the sample can be visually observed, the measurement position can be easily known. A duct 8a for supplying hot air and a duct 8b for exhausting air are connected to the side surface of the thermostatic chamber 2, and although not shown in the figure, the duct 8a is connected to the hot air generator by a heat insulating pipe. .
[0020]
In FIG. 2, the air flow is indicated by arrows. In FIG. 1 and FIG. 2, the electrical wiring connected to the displacement meter 1 and the stages 7a and 7b is omitted.
[0021]
FIG. 3 shows a control diagram in the embodiment of the present invention. In this embodiment, a control device is constituted by a computer, a display, a stage controller, a displacement meter controller, and a temperature controller.
[0022]
Data input / output is performed using a computer, and a stage controller, a displacement meter controller, and a temperature controller are operated according to commands from the computer, and control the stage, displacement meter, and hot air generator, respectively. Data measured by the displacement meter is transferred to a computer and recorded in a storage device built in the computer. The measurement data is subjected to appropriate data processing by a computer and displayed on a display.
[0023]
FIG. 4 is a flowchart showing the operation of the thermal deformation measuring apparatus of the present embodiment. The measurement procedure will be described below using this figure. In this embodiment, in order to measure the two-dimensional out-of-plane thermal deformation distribution of the sample, the displacement meter is moved to each lattice point in the rectangular area. Therefore, first, the measurement interval and the number of measurement points in both the x and y directions are input.
[0024]
Next, the number of measurements (the number of temperature steps) and the set temperature at each step are input. Prior to the measurement, the displacement meter is rotated once along the circumference of the measurement area. The measurement area can be confirmed by the measurement person visually observing the laser beam from the displacement meter that hits the sample.
[0025]
If the measurement area is wrong at this time, the process returns to the beginning (this function is omitted in FIG. 4). Then go into measurement. First, the displacement meter is moved to the origin of the coordinates, and the temperature of the thermostatic chamber is controlled to the set value in step 1. When the temperature is stabilized, the displacement meter is moved by dx in the x direction. After the displacement meter is stopped, the distance between the sample and the displacement meter is measured, and the measured value is transferred to a computer and recorded. After measuring Nx times dx in the x direction, this time, it moves by dy in the y direction and again measures Nx times dx in the x direction. This operation is performed Ny times in the y direction to complete the temperature step 1 measurement.
[0026]
Although omitted in the flowchart, when measuring the displacement, always stop the screw with the same rotation direction. This is to prevent a decrease in positioning accuracy due to screw backlash. Next, the temperature is controlled to the set value in Step 2, and the same displacement measurement is performed. When the measurement is completed up to the last temperature step, the measurement conditions and measurement results are recorded as one data set.
[0027]
The measurement result is displayed by causing the computer to read the data set. Calculation of predetermined data is performed and the result is displayed on the display. The predetermined calculation mentioned here is, for example, calculating the difference between the displacement of an arbitrary step and the displacement of another step, and the thermal deformation generated between these steps can be obtained by this calculation.
[0028]
Since the thermal deformation measuring apparatus according to the present embodiment performs measurement by scanning the displacement meter in a two-dimensional plane, the two-dimensional distribution of the out-of-plane thermal deformation of the sample can be obtained with high accuracy. As a means of scanning the displacement meter, a digitally controlled pulse motor-driven screw-type stage is used, and screw rotation control that cancels backlash of the screw of the screw-type stage is performed at any time. Is extremely high.
[0029]
Furthermore, since the sample is directly supported by the surface plate via a quartz support member having a small linear expansion coefficient, the sample is not in contact with the thermostat and is not affected by thermal deformation or vibration of the thermostat. In addition, since the sample is heated by sending high-temperature air heated by the hot air generator into the thermostatic chamber, the temperature increase rate of the sample is high and the temperature distribution is small.
[0030]
The principle of the optical displacement meter is to measure the distance between the sample and the displacement meter by reflecting the laser beam generated by the semiconductor laser generator to the sample and detecting the position of the reflected light with a semiconductor position sensor. Since it is used, measurement accuracy is high and data processing is easy.
[0031]
Furthermore, during the measurement, the scanning of the displacement meter is stopped and allowed to stand for a certain period of time, and then the distance between the sample and the displacement meter is measured, thereby eliminating measurement errors due to vibration of the displacement meter support jig, etc. be able to. Since the measurement data is processed by a computer and displayed on a display device, the measurer can easily understand the two-dimensional distribution of the out-of-plane displacement of the sample.
[0032]
FIG. 5 shows an example of the out-of-plane thermal deformation measurement of the electronic device measured by the thermal deformation measurement device according to the present embodiment, which was prototyped by the inventors. It can be seen that the shape of the thermal deformation is measured with very high accuracy and easy to understand.
[0033]
【The invention's effect】
As described above, the thermal deformation measuring apparatus according to the present invention can easily and accurately measure the two-dimensional out-of-plane thermal deformation of an object. Useful.
[Brief description of the drawings]
FIG. 1 is a perspective view of an embodiment of the present invention.
FIG. 2 is a cross-sectional view of an embodiment of the present invention.
FIG. 3 is a control diagram of the embodiment of the present invention.
FIG. 4 is a flowchart showing the operation of the embodiment of the present invention.
FIG. 5 is a thermal deformation of an electronic component measured by a thermal deformation measuring apparatus according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Displacement meter, 2 ... Constant temperature bath, 3 ... Transparent plate, 4a, 4b, 4c ... Support member, 5 ... Sample installation board, 6 ... Displacement meter support jig, 7a, 7b ... Stage, 8a, 8b ... Duct, 9 ... Surface plate, 10 ... Constant temperature bath support column, 11 ... Sample.

Claims (8)

In a thermal deformation measuring apparatus comprising a thermostatic chamber for changing the temperature of the sample, means for measuring deformation of the sample, and a control device for controlling the deformation measurement and the temperature of the thermostatic chamber, the upper surface of the thermostatic chamber is covered with a transparent plate. An optical non-contact displacement meter is provided above the transparent plate, the displacement meter is scanned in a two-dimensional plane, the measurement position of the sample provided in the thermostat is scanned, and the scanned measurement position of the sample And sequentially measuring the distance between the displacement meter and recording the measurement result in a storage device provided in the control device ,
A thermal deformation measuring apparatus , wherein the sample is supported by an upper end of a support member arranged so as to pass through a hole in the bottom of the thermostatic chamber .   2. The thermal deformation measuring apparatus according to claim 1, wherein a hole is made in the bottom surface of the thermostatic chamber, a support member made of a material having a linear expansion coefficient of 1 ppm / ° C. or less is passed through the hole, and the lower end of the support member is inserted. A thermal deformation measuring apparatus, which is fixed to a surface plate and supports a sample at the upper end of the support member.   2. The thermal deformation measuring device according to claim 1, wherein measurement data of a distance between the sample and the displacement meter in the same specification scan performed twice or more is stored in the storage device, and two arbitrary sets of the data are stored. A thermal deformation measuring apparatus characterized in that a displacement amount of a sample is obtained by calculating a difference between the two.   2. The thermal deformation measuring apparatus according to claim 1, wherein the distance between the sample and the displacement meter is measured by reflecting the laser beam generated by the semiconductor laser generating element to the sample and detecting the position of the reflected light by the semiconductor position sensor. A thermal deformation measuring device using a displacement meter according to the method.   2. The thermal deformation measuring apparatus according to claim 1, wherein when measuring the distance between the sample and the displacement meter, the scanning of the displacement meter is stopped and allowed to stand for a certain period of time, and then between the sample and the displacement meter. A thermal deformation measuring apparatus for measuring a distance.   2. The thermal deformation measuring apparatus according to claim 1, wherein the displacement gauge is moved once along the circumference of the measurement range prior to the displacement measurement.   3. The thermal deformation measuring apparatus according to claim 2, wherein the support member is composed of three quartz rods, a quartz plate is placed on the upper ends of the three support members, and a sample is placed on the quartz plate. A thermal deformation measuring device characterized in that:   2. The thermal deformation measuring apparatus according to claim 1, wherein the sample is scanned at least twice at different temperatures, and the difference between the two sets of measured data is calculated to obtain the amount of thermal deformation of the sample. A thermal deformation measuring device characterized by the above.

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