Method for measuring thermal diffusivity of silicon nitride heat dissipation substrate specimen and silicon nitride heat dissipation substrate specimen measured using same

Abstract

Disclosed are: a method for measuring the thermal diffusivity of a silicon nitride heat dissipation substrate specimen; and a silicon nitride heat dissipation substrate specimen measured using the method, wherein the method can improve measurement reliability by limiting thermal diffusivity measurement to horizontal (in-plane) thermal diffusivity measurement, when using a silicon nitride heat dissipation substrate characterized by a small thickness as a specimen, on the basis of having identified differences between thermal diffusivity analysis methods depending on thickness. The method for measuring the thermal diffusivity of a silicon nitride heat dissipation substrate specimen according to the present invention comprises the steps of: (a) preparing a silicon nitride heat dissipation substrate specimen by cutting a silicon nitride heat dissipation substrate; (b) measuring the thickness of the silicon nitride heat dissipation substrate specimen; (c) measuring the thermal diffusion coefficient using the horizontal (in-plane) thermal diffusivity measurement method if the measured silicon nitride heat dissipation substrate specimen is determined to have a thickness that is less than a set thickness; and (d) calculating the thermal conductivity using the measured thermal diffusion coefficient.

Description

Method for measuring thermal diffusivity of silicon nitride heat-dissipating substrate specimens and silicon nitride heat-dissipating substrate specimens measured by the same measuring method

[0001] The present invention relates to a method for measuring thermal diffusivity of a silicon nitride heat-dissipating substrate specimen and a silicon nitride heat-dissipating substrate specimen measured by the measuring method thereof, and more particularly, to a method for measuring thermal diffusivity of a silicon nitride heat-dissipating substrate specimen and a silicon nitride heat-dissipating substrate specimen measured by the measuring method thereof, which can improve the reliability of thermal diffusivity measurement by limiting the method of measuring thermal diffusivity in a horizontal (in-plane) direction when a silicon nitride heat-dissipating substrate having a thin thickness is used as a specimen by confirming the difference in the analysis method of thermal diffusivity according to thickness.

[0002]

[0003] Ceramic materials possess high electrical insulation and thermal conductivity, making them ideal heat carriers for rapidly transferring heat generated by components. Therefore, ceramic materials are used in substrates for transport devices, substrates for highly integrated electronic circuits, heat dissipation components in laser oscillation units, reaction vessel components in semiconductor manufacturing equipment, and precision machinery components.

[0004] In particular, ceramic substrates used in high-power power devices require high insulation, high voltage resistance, high thermal conductivity, high strength, and low dielectric constant. Ceramic substrates that meet these requirements include aluminum nitride heat sinks, alumina heat sinks, and silicon nitride heat sinks.

[0005] Among these, silicon nitride (Si3N4) heat sinks have high strength of 500 to 800 MPa, high toughness of 5 to 8 MPa m, and excellent thermal expansion coefficient compatibility with silicon (Si). In addition, silicon nitride (Si3N4) heat sinks have high thermal conductivity of 70 to 170 W / mK. Therefore, silicon nitride (Si3N4) heat sinks are suitable as materials for next-generation high-output power devices.

[0006]

[0007] In view of the above-described technical problems, the present invention aims to provide a method for measuring thermal diffusivity of a silicon nitride heat-dissipating substrate specimen, which can improve the reliability of thermal diffusivity measurement by limiting the method of measuring thermal diffusivity in the horizontal (in-plane) direction when using a silicon nitride heat-dissipating substrate having a thin thickness as a specimen by confirming the difference in the method of analyzing thermal diffusivity according to thickness, and a silicon nitride heat-dissipating substrate specimen measured by the measurement method.

[0008]

[0009] A method for measuring thermal diffusivity of a silicon nitride heat-dissipating substrate specimen according to an embodiment of the present invention for achieving the above object is characterized by including: (a) a step of cutting a silicon nitride heat-dissipating substrate to prepare a silicon nitride heat-dissipating substrate specimen; (b) a step of measuring a thickness of the silicon nitride heat-dissipating substrate specimen; (c) a step of measuring a thermal diffusivity coefficient in a horizontal (in-plane) direction when the measured silicon nitride heat-dissipating substrate specimen is determined to be thinner than a set thickness; and (d) a step of calculating thermal conductivity using the measured thermal diffusivity.

[0010] In the above step (a), the silicon nitride heat dissipation substrate specimen is cut into a circular shape having a diameter of 1 to 50 mm.

[0011] In the above step (c), if the measured silicon nitride heat dissipation substrate specimen is determined to be thicker than the set thickness, the thermal diffusivity may be measured using either the vertical (out of plane) direction thermal diffusivity measurement method or the horizontal (in plane) direction thermal diffusivity measurement method.

[0012] In the above step (c), it is preferable that the set thickness is 0.5 mm or less.

[0013] It is more preferable that the above setting thickness be 0.25 mm or less.

[0014] In the above step (c), the thermal diffusivity is measured using a laser flash method.

[0015] In the above step (d), the thermal conductivity is calculated according to the following equation 1.

[0016] Equation 1: Thermal conductivity (k) = α × ρ × Cp

[0017] (Here, α represents the thermal diffusivity (㎟ / S), ρ represents the density (g / ㎤), and Cp represents the heat capacity (J / kgK).)

[0018] The above thermal conductivity is measured by measuring the thermal diffusivity coefficient using the in-plane direction thermal diffusivity measurement method, and the measurement deviation of the silicon nitride heat dissipation substrate specimen is 1% or less.

[0019]

[0020] In order to achieve the above object, a silicon nitride heat dissipation substrate specimen measured by a thermal diffusivity measurement method according to an embodiment of the present invention is a silicon nitride heat dissipation substrate specimen measured by a thermal diffusivity measurement method of a silicon nitride heat dissipation substrate specimen, wherein the silicon nitride heat dissipation substrate specimen has a set thickness of 0.5 mm or less, and is characterized in that the thermal diffusivity coefficient is measured by a horizontal (in-plane) direction thermal diffusivity measurement method, and the thermal conductivity is calculated according to the following equation 1.

[0021] Equation 1: Thermal conductivity (k) = α × ρ × Cp

[0022] (Here, α represents the thermal diffusivity (㎟ / S), ρ represents the density (g / ㎤), and Cp represents the heat capacity (J / kgK).)

[0023] It is more preferable that the above setting thickness be 0.25 mm or less.

[0024] The above thermal diffusivity is measured using the laser flash method.

[0025] The above thermal conductivity is measured by measuring the thermal diffusivity coefficient using the in-plane direction thermal diffusivity measurement method, and the measurement deviation of the silicon nitride heat dissipation substrate specimen is 1% or less.

[0026]

[0027] A method for measuring thermal diffusivity of a silicon nitride heat-dissipating substrate specimen according to the present invention and a silicon nitride heat-dissipating substrate specimen measured by the method thereof showed similar tendencies in thermal conductivity values ​​measured by the vertical (out of plane) direction thermal diffusivity measurement method and the horizontal (in plane) direction thermal diffusivity measurement method when the thickness was thick, but it was confirmed that as the thickness became thinner, different thermal conductivity values ​​were shown depending on the thermal diffusivity measurement method even though the substrate was the same.

[0028] Accordingly, the method for measuring thermal diffusivity of a silicon nitride heat-dissipating substrate specimen according to the present invention and the silicon nitride heat-dissipating substrate specimen measured by the method for measuring the same have been found to be limited to measuring the thermal diffusivity of a silicon nitride heat-dissipating substrate specimen having a thickness of 0.5 mm or less by measuring it in a horizontal (in-plane) direction in order to clearly confirm the true value of the thermal diffusivity of the silicon nitride heat-dissipating substrate specimen.

[0029] As a result, the method for measuring thermal diffusivity of a silicon nitride heat-dissipating substrate specimen according to the present invention and the silicon nitride heat-dissipating substrate specimen measured by the method for measuring the same are limited to measuring the thermal diffusivity in the horizontal (in-plane) direction for silicon nitride heat-dissipating substrate specimens having a thickness of 0.5 mm or less, thereby exhibiting an effect capable of responding to international thermal diffusivity and thermal conductivity values, thereby securing the competitiveness of silicon nitride heat-dissipating substrates domestically and internationally.

[0030] In addition to the effects described above, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

[0031]

[0032] Figure 1 is a process flow diagram showing a method for measuring thermal diffusivity of a silicon nitride heat dissipation substrate specimen according to an embodiment of the present invention.

[0033] FIG. 2 is a schematic diagram illustrating a process for measuring a silicon nitride heat dissipation substrate specimen according to an embodiment of the present invention using a vertical (out-of-plane) direction thermal diffusivity measurement method.

[0034] FIG. 3 is a schematic diagram illustrating a process for measuring a silicon nitride heat dissipation substrate specimen according to an embodiment of the present invention using a horizontal (in-plane) direction thermal diffusivity measurement method.

[0035]

[0036] The above-described objects, features, and advantages will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily practice the technical idea of ​​the present invention. In describing the present invention, if it is determined that a detailed description of known technologies related to the present invention may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0037] Any details not described in this specification that can be sufficiently technically inferred by a person skilled in the art will be omitted.

[0038] In this specification, the phrase "any component is disposed "on (or below)" a component or "on (or below)" a component may mean not only that any component is disposed in contact with the upper surface (or lower surface) of said component, but also that another component may be interposed between said component and any component disposed on (or below) said component.

[0039] As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "contains," "has (has)," or "includes" should not necessarily be construed as including all components described in the specification, and should be construed to mean that some of the components may not be included, or that additional components may be included.

[0040] Hereinafter, with reference to the attached drawings, a method for measuring thermal diffusivity of a silicon nitride heat-dissipating substrate specimen according to a preferred embodiment of the present invention and a silicon nitride heat-dissipating substrate specimen measured by the measuring method will be described in detail.

[0041]

[0042] The silicon nitride heat dissipation substrate specimen measured according to the thermal diffusivity measurement method according to the embodiment of the present invention confirms the difference in the analysis method of thermal diffusivity according to thickness, and when a silicon nitride heat dissipation substrate having a thin thickness is used as the specimen, the reliability of the thermal diffusivity measurement can be improved by limiting the method of measuring the thermal diffusivity in the horizontal (in plane) direction.

[0043] To this end, it is preferable that the silicon nitride heat dissipation substrate specimen measured according to the thermal diffusivity measurement method according to the embodiment of the present invention has a thickness of 0.5 mm or less, and the thermal diffusivity coefficient is measured using the in-plane direction thermal diffusivity measurement method, and the thermal conductivity is calculated according to the following equation 1.

[0044]

[0045] Equation 1: Thermal conductivity (k) = α × ρ × Cp

[0046] Here, α represents the thermal diffusivity (㎟ / S), ρ represents the density (g / ㎤), and Cp represents the heat capacity (J / kgK).

[0047] In addition, the thermal conductivity is measured by measuring the thermal diffusivity using the in-plane thermal diffusivity measurement method, and the measurement deviation of the silicon nitride heat sink substrate specimen is less than 1%.

[0048]

[0049] In this regard, a method for measuring thermal diffusivity of a silicon nitride heat dissipation substrate specimen according to an embodiment of the present invention will be described in more detail below.

[0050] FIG. 1 is a process flow diagram showing a method for measuring thermal diffusivity of a silicon nitride heat-dissipating substrate specimen according to an embodiment of the present invention, FIG. 2 is a schematic diagram for explaining a process for measuring a silicon nitride heat-dissipating substrate specimen according to an embodiment of the present invention using a vertical (out of plane) direction thermal diffusivity measurement method, and FIG. 3 is a schematic diagram for explaining a process for measuring a silicon nitride heat-dissipating substrate specimen according to an embodiment of the present invention using a horizontal (in plane) direction thermal diffusivity measurement method.

[0051] Referring to FIG. 1, a method for measuring thermal diffusivity of a silicon nitride heat-dissipating substrate specimen according to an embodiment of the present invention includes a silicon nitride heat-dissipating substrate cutting step (S110), a silicon nitride heat-dissipating substrate specimen thickness measuring step (S120), a thermal diffusivity measuring step (S130), and a thermal conductivity calculating step (S140).

[0052]

[0053] Cutting silicon nitride heat sink substrates

[0054] In the silicon nitride heat sink substrate cutting step (S110), the silicon nitride heat sink substrate is cut to prepare a silicon nitride heat sink substrate specimen.

[0055] These silicon nitride heat-dissipating substrate specimens can be cut into a size suitable for measurement. For example, the silicon nitride heat-dissipating substrate specimens can be cut into a circular shape with a diameter of 1 to 50 mm, but this is not particularly limited. That is, the shape and size of the silicon nitride heat-dissipating substrate specimens can be selectively changed as needed.

[0056] Meanwhile, the thickness of the silicon nitride heat sink substrate specimen may be substantially the same as the thickness of the silicon nitride heat sink substrate.

[0057]

[0058] Measurement of the thickness of silicon nitride heat sink substrate specimens

[0059] In the silicon nitride heat sink substrate specimen thickness measurement step (S120), the thickness of the silicon nitride heat sink substrate specimen is measured.

[0060] The thickness measurement of these silicon nitride heat sink substrate specimens can be performed using, but is not particularly limited to, a thickness measurement gauge, an ultrasonic thickness gauge, a digital thickness gauge, etc.

[0061]

[0062] Thermal diffusivity measurement

[0063] In the thermal diffusivity measurement step (S130), when the measured silicon nitride heat sink substrate specimen is determined to be thinner than the set thickness, the thermal diffusivity is measured using the horizontal (in plane) direction thermal diffusivity measurement method.

[0064] At this stage, the set thickness of the silicon nitride heat sink substrate specimen is preferably 0.5 mm or less, a more preferable set thickness range can be suggested as 0.36 mm or less, and a most preferable set thickness range can be suggested as 0.25 mm or less.

[0065] As illustrated in Fig. 2, the out-of-plane thermal diffusivity measurement method measures the vertical thermal diffusivity coefficient of a silicon nitride heat-dissipating substrate specimen (100) using a laser flash method. To this end, the out-of-plane thermal diffusivity measurement method vertically irradiates a laser from the lower surface of the silicon nitride heat-dissipating substrate specimen (100) and then measures the thermal diffusivity transmitted in the vertical direction.

[0066] Meanwhile, as illustrated in Fig. 3, the in-plane thermal diffusivity measurement method measures the horizontal thermal diffusivity coefficient of a silicon nitride heat-dissipating substrate specimen (100) using a laser flash method. To this end, the in-plane thermal diffusivity measurement method vertically irradiates a laser from the lower surface of the silicon nitride heat-dissipating substrate specimen (100) and then measures the thermal diffusivity transmitted in the horizontal direction.

[0067] In this way, when measuring the thermal diffusivity of a silicon nitride heat dissipation substrate specimen (100), different thermal conductivity values ​​are shown even though the substrate is the same, depending on whether the measurement is made using a vertical (out of plane) direction thermal diffusivity measurement method or a horizontal (in plane) direction thermal diffusivity measurement method. Accordingly, in many cases, the thermal conductivity values ​​of silicon nitride heat dissipation substrates were found to be different from the specifications stated by each manufacturer, which caused confusion. In particular, when each manufacturer measured the thermal conductivity using different methods, it sometimes caused a situation in which false information was provided.

[0068] In particular, when the thickness of the silicon nitride heat dissipation substrate specimen (100) is thick, the thermal conductivity values ​​measured by the vertical (out of plane) direction thermal diffusivity measurement method and the horizontal (in plane) direction thermal diffusivity measurement method show a similar trend, but as the thickness of the silicon nitride heat dissipation substrate specimen (100) becomes thinner, it was confirmed that the same substrate shows different thermal conductivity values ​​depending on the thermal diffusivity measurement method.

[0069] Accordingly, the present invention has confirmed the difference in the analysis method of thermal diffusivity according to the thickness of a silicon nitride heat dissipation substrate specimen (100), and has clarified that when a silicon nitride heat dissipation substrate having a thin thickness of 0.5 mm or less, more preferably 0.25 mm or less, is used as a specimen, it is necessary to measure the thermal diffusivity in a horizontal (in-plane) direction only in order to clearly confirm the true value of the thermal diffusivity of the silicon nitride heat dissipation substrate specimen (100).

[0070]

[0071] Thermal conductivity calculation

[0072] As illustrated in Fig. 1, in the thermal conductivity calculation step (S140), the thermal conductivity is calculated using the measured thermal diffusivity.

[0073] In this step, the thermal conductivity is calculated according to Equation 1 below using the thermal diffusivity measured by the in-plane thermal diffusivity measurement method.

[0074]

[0075] Equation 1: Thermal conductivity (k) = α × ρ × Cp

[0076] Here, α represents the thermal diffusivity (㎟ / S), ρ represents the density (g / ㎤), and Cp represents the heat capacity (J / kgK).

[0077] Accordingly, the thermal conductivity of the silicon nitride heat sink substrate specimen shows a measurement deviation of 1% or less by measuring the thermal diffusivity coefficient using the in-plane thermal diffusivity measurement method.

[0078] With this, the method for measuring thermal diffusivity of a silicon nitride heat dissipation substrate specimen according to an embodiment of the present invention can be concluded.

[0079]

[0080] As examined so far, the method for measuring thermal diffusivity of a silicon nitride heat-dissipating substrate specimen according to an embodiment of the present invention and the silicon nitride heat-dissipating substrate specimen measured by the method for measuring the same show similar tendencies in thermal conductivity values ​​measured by the vertical (out of plane) direction thermal diffusivity measurement method and the horizontal (in plane) direction thermal diffusivity measurement method when the thickness is thick, but as the thickness becomes thinner, it was confirmed that the same substrate shows different thermal conductivity values ​​depending on the thermal diffusivity measurement method.

[0081] Accordingly, it was found that the thermal diffusivity measurement method of a silicon nitride heat-dissipating substrate specimen according to an embodiment of the present invention and the silicon nitride heat-dissipating substrate specimen measured by the measurement method thereof, when measuring the thermal diffusivity of a silicon nitride heat-dissipating substrate specimen having a thin thickness of 0.5 mm or less, should be limited to a horizontal (in-plane) direction thermal diffusivity measurement method in order to clearly confirm the true value of the thermal diffusivity of the silicon nitride heat-dissipating substrate specimen.

[0082] As a result, the method for measuring thermal diffusivity of a silicon nitride heat-dissipating substrate specimen according to an embodiment of the present invention and the silicon nitride heat-dissipating substrate specimen measured by the method for measuring the same are limited to measuring the thermal diffusivity in the horizontal (in-plane) direction for silicon nitride heat-dissipating substrate specimens having a thickness of 0.5 mm or less, thereby exhibiting an effect capable of responding to international thermal diffusivity and thermal conductivity values, thereby securing the competitiveness of silicon nitride heat-dissipating substrates domestically and internationally.

[0083]

[0084] Example

[0085] Hereinafter, the structure and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, these are presented as preferred examples of the present invention and should not be construed as limiting the present invention in any way.

[0086] Anything not described here will be omitted as it is technically feasible for those skilled in this field to infer.

[0087]

[0088] Table 1 shows the measured values ​​of vertical (out of plane) and horizontal (in plane) thermal conductivity by cutting the same silicon nitride heat sink substrate specimens by varying the thickness, and Table 2 shows the measured values ​​of vertical (out of plane) and horizontal (in plane) thermal conductivity by obtaining the same silicon nitride heat sink substrate specimens by varying the thickness.

[0089]

[0090] [Table 1]

[0091]

[0092]

[0093] [Table 2]

[0094]

[0095] As shown in Table 1 and Table 2, for silicon nitride heat sink substrate specimens having a thickness of 0.48 mm and 0.65 mm, it can be confirmed that the thermal conductivity values ​​measured by the vertical (out of plane) direction thermal diffusivity measurement method and the horizontal (in plane) direction thermal diffusivity measurement method are almost the same.

[0096] On the other hand, for silicon nitride heat sink substrate specimens having a very thin thickness of 0.36 mm or less, especially 0.32 mm or less, it can be confirmed that there is a large difference in the thermal conductivity values ​​measured using the vertical (out of plane) direction thermal diffusivity measurement method and the horizontal (in plane) direction thermal diffusivity measurement method.

[0097] That is, in the case of a silicon nitride heat sink substrate specimen having a very thin thickness of 0.32 mm or less, the thermal conductivity value measured using the vertical (out of plane) direction thermal diffusivity measurement method showed a large measurement deviation, but the thermal conductivity value measured using the horizontal (in plane) direction thermal diffusivity measurement method showed a measurement deviation of less than 1%, indicating excellent measurement reliability.

[0098]

[0099] As can be seen from the above experimental results, it was determined that in order to clearly determine the true value of the thermal diffusivity of a silicon nitride heat-dissipating substrate specimen of 0.32 mm or less, the measurement must be limited to the horizontal (in-plane) thermal diffusivity measurement method.

[0100] Therefore, by measuring the thermal diffusivity in the horizontal (in-plane) direction for silicon nitride heat-dissipating substrate specimens having a thickness of 0.32 mm or less, it is possible to secure the competitiveness of silicon nitride heat-dissipating substrates domestically and internationally by demonstrating the effect of being able to correspond to international thermal diffusivity and thermal conductivity values.

[0101]

[0102] While the above description focuses on specific embodiments of the present invention, those skilled in the art will appreciate that various modifications and variations can be made. Such modifications and variations, as long as they do not depart from the scope of the technical concept provided by the present invention, are considered to be within the scope of the present invention. Therefore, the scope of the present invention should be determined by the claims set forth below.

[0103]

[0104] [Explanation of symbols]

[0105] S110: Silicon nitride heat sink substrate cutting step

[0106] S120: Silicon nitride heat sink substrate specimen thickness measurement step

[0107] S130: Thermal diffusivity measurement step

[0108] S140: Thermal Conductivity Calculation Step

Claims

1. (a) A step of preparing a silicon nitride heat dissipation substrate specimen by cutting a silicon nitride heat dissipation substrate; (b) a step of measuring the thickness of the silicon nitride heat-radiating substrate specimen; (c) a step of measuring the thermal diffusivity using the in-plane direction thermal diffusivity measurement method when the measured silicon nitride heat dissipation substrate specimen is determined to be thinner than the set thickness; and (d) a step of calculating thermal conductivity using the measured thermal diffusivity; characterized by including, Method for measuring thermal diffusivity of silicon nitride heat sink substrate specimens.

2. In paragraph 1, In step (a) above, The above silicon nitride heat sink specimen is Characterized in that it is cut into a circular shape with a diameter of 1 to 50 mm. Method for measuring thermal diffusivity of silicon nitride heat sink substrate specimens.

3. In paragraph 1, In step (c) above, When the measured silicon nitride heat sink substrate specimen is determined to be thicker than the set thickness, it is characterized in that the thermal diffusivity may be measured by either the vertical (out of plane) direction thermal diffusivity measurement method or the horizontal (in plane) direction thermal diffusivity measurement method. Method for measuring thermal diffusivity of silicon nitride heat sink substrate specimens.

4. In paragraph 1, In step (c) above, The above setting thickness is Characterized by being less than 0.5mm, Method for measuring thermal diffusivity of silicon nitride heat sink substrate specimens.

5. In paragraph 4, The above setting thickness is Characterized by being less than 0.25mm, Method for measuring thermal diffusivity of silicon nitride heat sink substrate specimens.

6. In paragraph 1, In step (c) above, The above thermal diffusivity is characterized by measuring using a laser flash method, Method for measuring thermal diffusivity of silicon nitride heat sink substrate specimens.

7. In paragraph 1, In step (d) above, The above thermal conductivity is Characterized in that it is calculated according to the following formula 1: Method for measuring thermal diffusivity of silicon nitride heat sink substrate specimens. Equation 1: Thermal conductivity (k) = α × ρ × Cp (Here, α represents the thermal diffusivity (㎟ / S), ρ represents the density (g / ㎤), and Cp represents the heat capacity (J / kgK).) 8. In paragraph 7, The above thermal conductivity is By measuring the thermal diffusivity coefficient using the above-mentioned horizontal (In plane) direction thermal diffusivity measurement method, Characterized in that the measurement deviation of the above silicon nitride heat dissipation substrate specimen is less than 1%. Method for measuring thermal diffusivity of silicon nitride heat sink substrate specimens.

9. A silicon nitride heat-radiating substrate specimen measured by a method for measuring thermal diffusivity of a silicon nitride heat-radiating substrate specimen according to any one of clauses 1 to 8, The above silicon nitride heat dissipation substrate specimen has a set thickness of 0.5 mm or less, and is characterized in that the thermal diffusivity is measured by a horizontal (in-plane) direction thermal diffusivity measurement method, and the thermal conductivity is calculated according to the following equation 1. Silicon nitride heat sink specimens measured according to the thermal diffusivity measurement method. Equation 1: Thermal conductivity (k) = α × ρ × Cp (Here, α represents the thermal diffusivity (㎟ / S), ρ represents the density (g / ㎤), and Cp represents the heat capacity (J / kgK).) 10. In paragraph 9, The above setting thickness is Characterized by being less than 0.25mm, Silicon nitride heat sink specimens measured according to the thermal diffusivity measurement method.

11. In paragraph 9, The above thermal diffusivity is characterized by being measured using a laser flash method, Silicon nitride heat sink specimens measured according to the thermal diffusivity measurement method.

12. In paragraph 9, The above thermal conductivity is By measuring the thermal diffusivity coefficient using the above-mentioned horizontal (In plane) direction thermal diffusivity measurement method, Characterized in that the measurement deviation of the above silicon nitride heat dissipation substrate specimen is less than 1%. Silicon nitride heat sink specimens measured according to the thermal diffusivity measurement method.

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