JP2602045B2 - Sample header for thermal diffusivity measurement - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sample header for holding a test sample in a thermal diffusivity measuring apparatus for a highly heat conductive thin plate.

[Conventional technology]

The thermal diffusivity measurement method using a laser flash method or the like is a method of irradiating uniform light energy to an object held at a predetermined temperature with a constant thickness, instantaneously converting the heat into heat, and measuring the back surface temperature of the object due to the absorbed heat. The change is measured by an infrared detector or the like, and the thermal diffusivity α is calculated from the half time t1 / 2 of the temperature rise curve according to the following equation.

α = 0.1388 · L ² / t1 / 2 In the above equation, L is the thickness of the test sample.

However, this method cannot be applied to a thin plate having a sample thickness of 1 mm or less.

In the measurement of the thermal diffusivity of a thin plate, a half time t1 / 2 is measured according to an equation similar to the above equation, and the thermal conductivity is obtained from the reciprocal thereof using α as an intermediate function.

The half-time measurement method includes an optical path shielding jig for irradiating the flash light only to the target irradiation area of the subject and a shielding jig for the temperature detector to detect the temperature of only the target detection area of the subject. And by properly fixing the subject.

In addition, since the heat radiation characteristics of the substrate cannot be determined by measuring one substrate at one point, the method of loading the test object into the measurement device when measuring multiple locations on one substrate is limited by the measurement cost and data reliability. Bounces immediately.

Since this thermal diffusivity measurement depends on the detection of a minute value of the detector, the suitability of the loading of the subject into the apparatus is directly linked to the reliability of the data, and the measurement still includes many instability factors.

[Problems to be solved by the invention]

According to the above conventional method, a jig assembly for holding the sample between the optical path shielding jig and the temperature detector system is performed, when the subject itself is replaced, and when the measurement site of the subject is changed, Each time, it was necessary to repeat the operation of separating the optical path shielding jig and the detector system and setting the subject at a predetermined position.

In addition, since it is difficult to make the alignment with respect to the measurement fixed point during measurement and to keep the subject holding pressure constant, the reliability of the obtained data may be impaired.

Further, when the subject is small, the subject may slip down and be damaged due to negligence during the operation.

[Means for solving the problem]

In the present invention, in order to solve the above problem, a metal or ceramic sample holding spacer is sandwiched between the flash light source side jig and the temperature sensor side jig, and the jig is covered in the blank space of the spacer. We have developed a sample header for measuring the thermal diffusivity of a highly thermally conductive thin plate that can measure the thermal diffusivity of any part of the specimen by inserting and holding the specimen or sliding the specimen along the spacer.

That is, FIG. 1 shows that the spacer (4) has an inverted triangular cut (4 ') at an angle of 90 ° and is held between the light source side jig (1) and the detector side jig (5). A square specimen (2) is formed in a sample space on a spacer (4) by forming a header.
Is inserted.

By changing the insertion site of the subject (2), the four corners (ad) of the sample (2) can be continuously measured at fixed points without disassembling the apparatus.

In order to classify the heat dissipation characteristics of the rectangular substrate, the thermal diffusivity at four corners is measured.

Measurement at predetermined four measurement points (ad) is efficiently and accurately performed.

FIG. 3 shows a case where the invention is applied to a circular sample (2 '). The sample (2) is placed within the included angle (e) given to the spacer (4), and the light source side jig (1) and the detector side jig are used. (5) The case where the measurement is performed while the temperature is held stably during the period is shown.

The center of the measurement point of the circular sample (2 ') is suitable, and the narrow spacer (4) can measure not only a rectangle but also a circular sample (2') with high efficiency and accuracy.

FIG. 4 shows that the upper and lower edges of the light source side jig (1) have projections (9) parallel to the horizontal plane to enable a fixed point measurement of the sample, and a square sample is inserted between the projections. The predetermined points of the subject can be measured by sliding the sample.

The measurement of an arbitrary point is also appropriately performed using the guide-type projection (9).

In addition, as an application example, when measuring a rectangular sample whose vertical width is smaller than the space between protrusions, a blank is provided at the upper part, and the rectangular spacer is bitten along the lower edge protrusion (9) (particularly, (Not shown), a rectangular sample piece is carried on the spacer and held on the optical path, and is slid left and right to measure a predetermined point.

The header may be made of a metal such as stainless steel, aluminum, tantalum or the like, or a ceramic such as alumina, zirconia or silicon nitride.

In the case of stainless steel and aluminum, it is preferable to apply a surface finish to reduce thermal contact with the sample.

If you want to reduce the weight of the header, use aluminum.

When performing high temperature measurement, it is preferable to use a high melting point metal such as tantalum or ceramics.

Regardless of which material is used, in order to suppress the scattering of light, the surface is blackened with a material having low thermal conductivity and which is not easily deformed.

[Operation and Examples]

Hereinafter, the operation and examples of the sample header for measuring the thermal diffusivity of the high thermal conductive thin plate of the present invention will be described in detail, and the material, shape, size, thickness, cut shape, depth, etc. It is a matter of course that the present invention is not limited to the embodiments.

FIG. 2 is a sectional view of a jig constituting a sample header of the thermal diffusivity measuring apparatus, and FIG. 2A shows a state in which a subject (2) is inserted in a spacer (4) of the present invention. Fig. (B) shows the detector-side jig (5), Fig. (D) shows the light-source-side jig (1), and Fig. (C) shows a partial cross-sectional side view of a sample header obtained by combining them.

The cut angle (e) of the spacer (4) in FIG.

An AIN substrate is selected as an object to be a 10 mmφ disc-shaped thin plate (2 ′).

The light source side jig (1) and the optical path shielding cylinder (8) are integrated and subjected to precision processing after welding.

The jig (1) on the light source side, the jig (5) on the detector side, and the spacer (4) are accurately aligned by pins inserted into the centering holes (6), and assembled by bolting the bolt holes (7). It does not need to be disassembled unless the blackening of the inner surface of the jig is deteriorated.

The circular thin plate (2 ′) is supported in a 10.5 mmφ circular hole at one corner of the square circular sample holding plate (4 ″) in FIG. 4 ') on which a holding plate (4 ") is carried.

The object (2 ') is irradiated with a laser beam through a small circular hole of the light path shielding cylinder (8), while a predetermined part of the specimen is irradiated by an infrared detector through a three-part circular hole (3) of the detector side jig. The actual measurement is performed by detecting the temperature of the area.

FIG. 5 shows the results obtained by measuring the thermal diffusivity at the four corners of a square aluminum nitride substrate using the sample header for measuring the thermal diffusivity of a highly thermally conductive thin plate of the present invention, and calculating the thermal conductivity. It can be seen that the measured values of the four corners of each piece show good convergence of data, and that the variability of each measurement operation has been eliminated and the reliability of the data has been improved.

〔The invention's effect〕

The sample header for measuring the thermal diffusivity of the high thermal conductive thin plate of the present invention enables continuous measurement for a predetermined measurement point by repeatedly attaching and detaching the sample to and from the spacer without disassembling the device for each measurement. As a result, data with higher accuracy than before can be obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a main part of a device including a sample header for measuring the thermal diffusivity of a highly thermally conductive thin plate according to the present invention, FIG. 2 is a cross-sectional view thereof, and FIG. The figure shows a cross-sectional view of the main part when a square sample is used, and FIG. 5 shows the data of the thermal conductivity obtained using the header of the present invention. (1) Light source side jig (2) Subject sample (3) Detector insertion hole (4) Header (5) Detector side jig (6) Centering hole (7) Bolt hole (8) Optical path shielding cylinder (9) Projection (ad) Square sample measurement point (e) Spacer cut angle

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Koji Izuma, 30 Soya, Hadano-shi, Kanagawa Toshiba Ceramics, Inc. Central Research Laboratory (56) References JP-A-62-133345 (JP, A) JP-A-58 -52553 (JP, A) JP-A-58-80548 (JP, A)

Claims (1)

(57) [Claims] In a thermal diffusivity measuring apparatus for a thin plate having high thermal conductivity, a metal or ceramic spacer for holding a sample is sandwiched between a jig on a flash light source side and a jig on a temperature sensor side. The thickness and width of the spacer correspond to the subject, the subject is inserted and held in the space provided by the spacer, and is stably held by the fixed point assigning function of the space of the spacer. A sample header for measuring thermal diffusivity, which measures thermal diffusivity.