Defect detection method of diamond composite material

Abstract

The invention provides a diamond composite material defect detection method, and belongs to the technical field of diamond composite material detection, and the diamond composite material defect detection method comprises the following steps: S100, arranging a heating sheet on the upper surface of a diamond composite material, and covering the whole upper surface of the diamond composite material with the heating sheet; s200, after the heating sheet is heated, the temperature rises, and heat transfer is generated between the heating sheet and the diamond compound; s300, thermal imaging equipment is adopted to detect the temperature of the heating sheet, and the thermal imaging equipment generates a thermal imaging distribution diagram according to a detection result; and S400, observing the thermal imaging distribution diagram, wherein a hot spot area of the thermal imaging distribution diagram is the defect area of the diamond compound. The invention provides a defect detection method for a diamond composite material, and aims to solve the problem that the detection precision of the diamond composite material is relatively low due to the fact that defects of a bonding surface of the diamond composite material cannot be effectively detected in the prior art.

Description

Technical Field

[0001] The invention belongs to the technical field of diamond composite material detection, and more specifically, relates to a defect detection method for diamond composite material. Background Art

[0002] Electronic materials such as electronic packaging materials, printed circuit board frame materials, and heat sink materials usually require higher thermal conductivity and lower thermal expansion coefficient. Currently, pure copper and its alloys, pure aluminum and its alloys are commonly used in electronic packaging, but the above materials have certain limitations in thermal conductivity and thermal expansion coefficient. Therefore, research on electronic packaging materials with higher thermal conductivity and lower thermal expansion coefficient is an urgent problem to be solved.

[0003] Diamond is the material with the highest thermal conductivity in nature and has a low coefficient of expansion. The composite material formed by combining diamond with other metals can effectively improve the thermal conductivity of the material and reduce its coefficient of expansion. It can be widely used in the electronic packaging industry. For example, the diamond-copper composite material formed by the metallurgical combination of diamond particles and copper alloys has achieved excellent thermal conductivity and helps solve the heat dissipation problem of high-power electronic devices. In addition, the thermal expansion coefficient is extremely low, so that the diamond-copper composite material can still maintain stable size and performance in high-temperature environments, which is suitable for high-precision and high-stability application scenarios.

[0004] However, due to the stability of diamond's own structure and its remarkable chemical inertness, it is extremely difficult to form a good bonding surface when it is composited with a metal matrix, which easily produces defects such as pores, cracks and delamination. The above defects seriously affect the thermal expansion coefficient, mechanical properties, stability and other properties of the composite material. Therefore, defect detection of diamond composite materials is particularly important.

[0005] Most existing technologies use ultrasonic testing to detect defects on the bonding surface of diamond composite materials. However, due to the poor wettability of diamond and metal matrix, complex scattering and refraction phenomena are easily generated on the contact interface between diamond and metal matrix materials, making it impossible to detect reflected waves during ultrasonic scanning, thereby affecting the detection accuracy. Summary of the invention

[0006] The purpose of the present invention is to provide a defect detection method for diamond composite materials, aiming to solve the problem that the defects on the bonding surface of diamond composite materials cannot be effectively detected in the prior art, resulting in low detection accuracy of diamond composite materials.

[0007] To achieve the above object, the technical solution adopted by the present invention is: A defect detection method for a diamond composite material is provided, comprising: S100, disposing a heating sheet on the upper surface of the diamond composite, wherein the heating sheet covers the entire upper surface of the diamond composite; S200, the temperature of the heating sheet increases after heating, and heat transfer occurs with the diamond composite; S300, using a thermal imaging device to detect the temperature of the heating sheet, wherein the thermal imaging device generates a thermal imaging distribution map according to the detection result; S400, observing the thermal imaging distribution map, wherein the hot spot area of ​​the thermal imaging distribution map is the defect area of ​​the diamond composite.

[0008] In a possible implementation, the S100 specifically includes: S110, cleaning the surface of the diamond composite; S120, fixing the heating sheet on the surface of the diamond composite to completely cover the upper surface of the diamond composite; S130, electrically heating the heating plate to increase the temperature of the heating plate and transfer heat to the diamond composite.

[0009] In a possible implementation manner, the S120 specifically includes: S121, coating the heating sheet with a conductive adhesive, wherein the conductive adhesive adheres to the surface of the diamond composite; S122, curing the conductive adhesive to bond and fix the heating sheet to the diamond composite.

[0010] In a possible implementation manner, the S120 further includes: S123, coating thermal grease on the lower surface of the diamond composite; S124, placing the diamond composite coated with thermal grease on a heating platform, and the thermal grease is in full contact with the heating platform; S125, the heating platform and the heating sheet transfer heat to the diamond composite respectively.

[0011] In a possible implementation, the S300 specifically includes: S310, after the heating temperature of the heating platform is stable and the heating sheet obtains a stable current, using a thermal imaging device to detect the temperature of the heating sheet; S320: The thermal imaging device generates a thermal imaging distribution map according to the detection result.

[0012] In a possible implementation, the heating sheet is a chip. In S100, direct current is supplied to the chip to generate heat, and the actual power of the chip is not higher than its maximum power.

[0013] In a possible implementation, in S121, the thickness of the conductive adhesive coated on the heating sheet is 30-50 um.

[0014] In a possible implementation, in S122, the diamond composite and the heating sheet are placed in an oven to cure the conductive adhesive.

[0015] In a possible implementation, in S100, a plurality of the heating sheets are provided, the plurality of heating sheets respectively cover the upper surface of the diamond composite, and outer edges of two adjacent heating sheets are arranged in contact with each other.

[0016] The defect detection method of the diamond composite material provided by the present invention has the beneficial effect that: compared with the prior art, in the defect detection method of the diamond composite material of the present invention, the heating plate is arranged on the upper surface of the diamond composite, and after the temperature of the heating plate rises, heat is transferred to the diamond composite. When defects such as pores, cracks or delamination appear inside the diamond composite, the heat transfer is blocked due to the difference in thermal conductivity between the above-mentioned defect area and the diamond composite, resulting in heat accumulation of the heating plate. The thermal imaging device detects the temperature of the heating plate and generates a thermal imaging distribution map to reflect the temperature distribution of the heating plate. Since the heat transfer of the heating plate corresponding to the defect area is blocked, the heat accumulation causes the temperature to rise, and then a hot spot is displayed on the thermal imaging distribution map. When there are no defects in the diamond composite, its internal structure is uniform, the heating plate continues to transfer heat to the diamond composite, and diffuses to the surrounding area with the contact surface as the highest temperature point, and the temperature of the surrounding area decreases regularly, so the temperature change of the heating plate corresponding to the area should be in a regular gradual state. The present invention detects whether there are defects such as pores, cracks or delamination inside the diamond composite through the heat transfer change of the diamond composite. The detection method is simple, and the problem of ultrasonic detection accuracy being affected due to scattering and refraction easily occurring on the contact surface of the diamond composite is avoided, thereby improving the detection accuracy. In addition, the specific location of the defective area of ​​the diamond composite can also be determined according to the hot spot position in the thermal imaging distribution map. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is a schematic diagram of the structure of the diamond composite and the heating plate used in the embodiment of the present invention.

[0019] In the figure: 1. Heater; 2. Diamond composite. DETAILED DESCRIPTION

[0020] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] In the claims, specification and the above drawings of the present invention, unless otherwise clearly defined, the terms "first", "second" or "third" are used to distinguish different objects, rather than to describe a specific order. Unless otherwise specified, other directional words, such as "vertical", "clockwise", "counterclockwise", etc., indicating directions or positional relationships are based on the directions and positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, so it cannot be understood as limiting the specific protection scope of the present invention. In the claims, specification and the above drawings of the present invention, unless otherwise clearly defined, the terms "fixed connection" or "fixed connection" should be understood in a broad sense, that is, any connection method without a displacement relationship and relative rotation relationship between the two, that is, including non-detachable fixed connection, detachable fixed connection, integrated connection and fixed connection through other devices or elements. In the claims, specification and the above drawings of the present invention, the terms "including", "having" and their variations are used, and the intention is to "include but not limited to".

[0022] It should be noted that diamond composite refers to a diamond composite material formed by combining diamond and metal material, which can be in the form of blocks, sheets or other forms.

[0023] See also Figure 1 , the defect detection method of the diamond composite material provided by the present invention is now described. The defect detection method of the diamond composite material includes S100, setting a heating sheet 1 on the upper surface of the diamond composite 2, and the heating sheet 1 covers the entire upper surface of the diamond composite 2; S200, the temperature of the heating sheet 1 rises after heating, and heat transfer occurs with the diamond composite 2; S300, using a thermal imaging device to detect the temperature of the heating sheet 1, and the thermal imaging device generates a thermal imaging distribution map according to the detection result; S400, observing the thermal imaging distribution map, and the hot spot area of ​​the thermal imaging distribution map is the defect area of ​​the diamond composite 2.

[0024] Compared with the prior art, the defect detection method of the diamond composite material provided by the present invention sets the heating plate 1 on the upper surface of the diamond composite material 2 in the defect detection method of the diamond composite material of the present invention, and after the temperature of the heating plate 1 rises, it transfers heat to the diamond composite material 2. When defects such as pores, cracks or delamination appear inside the diamond composite material 2, the heat transfer is blocked due to the difference in thermal conductivity between the above-mentioned defect area and the diamond composite material 2, resulting in heat accumulation in the heating plate 1. The thermal imaging device detects the temperature of the heating plate 1 and generates a thermal imaging distribution map, which reflects the temperature distribution of the heating plate 1. Since the heat transfer of the heating plate 1 corresponding to the defect area is blocked, the heat accumulation causes the temperature to rise, and then a hot spot is displayed on the thermal imaging distribution map. When there are no defects in the diamond composite material 2, its internal structure is uniform, the heating plate 1 continues to transfer heat to the diamond composite material 2, and diffuses to the surrounding area with the contact surface as the highest temperature point, and the temperature of the surrounding area decreases regularly, so the temperature change of the heating plate 1 corresponding to the area should be in a regular gradual state. The present invention detects whether there are defects such as pores, cracks or delamination inside the diamond composite 2 through the heat transfer change. The detection method is simple, avoiding the problem that the contact surface of the diamond composite 2 is prone to scattering and refraction, which affects the accuracy of ultrasonic detection, and improves the detection accuracy. In addition, according to the position of the hot spot in the thermal imaging distribution map, the specific position of the defect area of ​​the diamond composite 2 can also be determined.

[0025] It should be noted that, since the heating sheet 1 covers the entire upper surface of the diamond composite 2 , defects inside the diamond composite 2 can be fed back to the heating sheet 1 in the corresponding area, thereby enabling defect detection of the entire diamond composite 2 .

[0026] Optionally, the heating sheet 1 may be a heating chip, such as a GaN chip or a SiC chip. After power is turned on, the temperature of the heating sheet 1 increases, thereby achieving heat transfer to the diamond composite 2 .

[0027] Optionally, there may be one or more heating sheets 1 . When there is only one heating sheet 1 , the entire heating sheet 1 covers the surface of the diamond composite 2 .

[0028] It should be noted that in the thermal imaging distribution map, different temperatures are represented by areas of corresponding colors. For example, the higher the temperature, the darker the color. High temperatures are represented by warm colors, and low temperatures are represented by cold colors. When the color of a certain area changes significantly from the surrounding colors (forming a color that is significantly higher than the surrounding temperature), this area is a hot spot. In some embodiments, see Figure 1S100 specifically includes S110, cleaning the surface of the diamond composite 2; S120, fixing the heating sheet 1 on the surface of the diamond composite 2 and completely covering the upper surface of the diamond composite 2; S130, heating the heating sheet 1 by powering on, so that the temperature of the heating sheet 1 increases and heat is transferred to the diamond composite 2.

[0029] First, the surface of the diamond composite 2 is cleaned to prevent the stains on the surface of the diamond composite 2 from affecting the heat transfer of the heating sheet 1 to it, and at the same time, the stains can also prevent the stains from affecting the connection firmness between the heating sheet 1 and the diamond composite 2. The heating sheet 1 is fixed to the cleaned upper surface of the diamond composite 2, so that the entire upper surface of the diamond composite 2 can receive the heat of the heating sheet 1, thereby achieving complete detection of defects in the diamond composite 2 and avoiding detection blind spots.

[0030] In some embodiments, see Figure 1 S120 specifically includes S121, coating the heating sheet 1 with conductive adhesive, and the conductive adhesive adheres to the surface of the diamond composite 2; S122, curing the conductive adhesive, so that the heating sheet 1 and the diamond composite 2 are bonded and fixed.

[0031] Conductive adhesive is an adhesive that has a certain conductivity after curing or drying. It can connect a variety of conductive materials together to form an electrical path between the connected materials. In the electronics industry, conductive adhesive has become an indispensable new material. There are many varieties of conductive adhesives. From the application perspective, conductive adhesives can be divided into two categories: general conductive adhesives and special conductive adhesives. General conductive adhesives only have certain requirements for the conductive properties and bonding strength of the conductive adhesive. In addition to certain requirements for the conductive properties and bonding strength, special conductive adhesives also have certain special requirements. Such as high temperature resistance, ultra-low temperature resistance, instant curing, anisotropy and transparency. In this embodiment, conductive adhesive is used to fix the heating plate 1 to the surface of the diamond composite 2. Not only can the connection between the heating plate 1 and the diamond composite 2 be achieved without damage, but the conductive adhesive has a good thermal conductivity. After the heating plate 1 receives the current and heats up, it can effectively conduct electricity and heat, and accelerate the temperature rise of the diamond composite 2.

[0032] In some embodiments, see Figure 1 , S120 also includes S123, coating thermal grease on the lower surface of the diamond composite 2; S124, placing the diamond composite 2 coated with thermal grease on the heating platform, and the thermal grease is in full contact with the heating platform; S125, the heating platform and the heating sheet 1 transfer heat to the diamond composite 2 respectively.

[0033] Since the diamond composite 2 needs to be placed on a platform to ensure stability during the heating process, the heating platform of this embodiment provides support for the diamond composite 2 while also heating it, providing a bottom temperature for the diamond composite 2. Compared with the solution that only relies on the chip 1 to transfer heat to the diamond composite 2, the overall temperature of the diamond composite 2 can be increased, the sensitivity of detection is improved, and it is beneficial to detect the temperature of the heating sheet 1. Thermal grease can ensure good contact and heat transfer between the diamond composite 2 and the heating platform, and improve detection accuracy.

[0034] In some embodiments, see Figure 1 S300 specifically includes S310, after the heating temperature of the heating platform is stable and the heating sheet 1 obtains a stable current, a thermal imaging device is used to detect the temperature of the heating sheet 1; S320, the thermal imaging device generates a thermal imaging distribution map according to the detection result.

[0035] After the heating platform and the heating plate 1 are stable, the diamond composite 2 can stably receive thermal energy, and the thermal energy has been transmitted in the diamond composite 2 for a certain period of time. At this time, the heating plate 1 is inspected using thermal imaging equipment to detect defects such as pores inside the diamond composite 2.

[0036] In some embodiments, see Figure 1 The heating sheet 1 is a chip. In S100, direct current is supplied to the chip to generate heat. The actual power of the chip is not higher than its maximum power.

[0037] When direct current is applied to the chip, a large amount of heat will be generated inside the chip and accumulate rapidly, causing the temperature of the chip to rise. Diamond composite 2 voltage is not higher than the withstand voltage of the chip to avoid chip damage.

[0038] Specifically, a direct current is passed through the chip. In some embodiments, see Figure 1 In S121, the thickness of the conductive adhesive coated on the heating sheet 1 is 30-50 um.

[0039] If the thickness of the conductive adhesive is too small, it will not be able to effectively bond the heating sheet 1 and the diamond composite 2. However, if the thickness is too large, it will not only cause waste, but also easily lead to the problem of incomplete curing, which also affects the reliability of the connection.

[0040] In some embodiments, see Figure 1 In S122, the diamond composite 2 and the heating sheet 1 are placed in an oven to cure the conductive adhesive.

[0041] The oven heats the diamond composite 2 , the heating sheet 1 and the conductive adhesive as a whole, so that the conductive adhesive is fully cured, thereby improving the firmness of the bonding between the heating sheet 1 and the diamond composite 2 .

[0042] In some embodiments, see Figure 1 In S100, a plurality of heating sheets 1 are provided, and the plurality of heating sheets 1 respectively cover the upper surface of the diamond composite 2, and the outer edges of two adjacent heating sheets 1 are arranged in contact with each other.

[0043] Providing a plurality of heating sheets 1 can not only cover the upper surface of the diamond composite 2 to the maximum extent, but also can flexibly adjust the number of chips for diamond composites 2 of different volumes and shapes, and has a wider applicability.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A defect detection method for diamond composite materials, characterized in that: include: S100, disposing a heating sheet on the upper surface of the diamond composite, wherein the heating sheet covers the entire upper surface of the diamond composite; S200, the temperature of the heating sheet increases after heating, and heat transfer occurs with the diamond composite; S300, using a thermal imaging device to detect the temperature of the heating sheet, wherein the thermal imaging device generates a thermal imaging distribution map according to the detection result; S400, observing the thermal imaging distribution map, wherein the hot spot area of ​​the thermal imaging distribution map is the defect area of ​​the diamond composite.

2. The defect detection method for diamond composite material according to claim 1, characterized in that: The S100 specifically includes: S110, cleaning the surface of the diamond composite; S120, fixing the heating sheet on the surface of the diamond composite to completely cover the upper surface of the diamond composite; S130, electrically heating the heating plate to increase the temperature of the heating plate and transfer heat to the diamond composite.

3. The defect detection method of diamond composite material according to claim 2, characterized in that: The S120 specifically includes: S121, coating the heating sheet with a conductive adhesive, wherein the conductive adhesive adheres to the surface of the diamond composite; S122, curing the conductive adhesive to bond and fix the heating sheet to the diamond composite.

4. The defect detection method for diamond composite material according to claim 3, characterized in that: The S120 further includes: S123, coating thermal grease on the lower surface of the diamond composite; S124, placing the diamond composite coated with thermal grease on a heating platform, and the thermal grease is in full contact with the heating platform; S125, the heating platform and the heating sheet transfer heat to the diamond composite respectively.

5. The defect detection method of diamond composite material according to claim 4, characterized in that: The S300 specifically includes: S310, after the heating temperature of the heating platform is stable and the heating sheet obtains a stable current, using a thermal imaging device to detect the temperature of the heating sheet; S320: The thermal imaging device generates a thermal imaging distribution map according to the detection result.

6. The defect detection method of diamond composite material according to claim 1, characterized in that: The heating sheet is a chip. In S100, direct current is supplied to the chip to generate heat. The actual power of the chip is not higher than its maximum power.

7. The defect detection method for diamond composite material according to claim 3, characterized in that: In S121, the thickness of the conductive adhesive coated on the heating sheet is 30-50 um.

8. The defect detection method for diamond composite material according to claim 3, characterized in that: In the S122, the diamond composite and the heating sheet are placed in an oven to cure the conductive adhesive.

9. The defect detection method for diamond composite material according to claim 1, characterized in that: In the S100, the heating sheets are provided in plurality, the plurality of heating sheets respectively cover the upper surface of the diamond composite, and the outer edges of two adjacent heating sheets are arranged in close contact.

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