Device for coating heat-conducting silicone grease on sinking surface and coating method thereof

Abstract

The invention discloses a device for coating a sinking surface with heat-conducting silicone grease and a coating method thereof, and belongs to the technical field of heat-conducting silicone grease coating, the device comprises a mesh plate, the mesh plate is made of a frameless steel sheet, a plurality of mesh holes are formed in the mesh plate, and a plurality of positioning pieces are arranged on the side wall of the mesh plate; when the mesh plate is placed in the sinking surface, the width of a unilateral gap formed between the side face of the mesh plate and the inner side face of the side wall of the sinking surface is 0.3 mm-0. 7mm. The problem that an existing heat-conducting silicone grease device cannot penetrate into the sinking surface and form a tight attaching position relation with the sinking surface is solved. And therefore, the technical problem that the heat-conducting silicone grease cannot be printed on the coating area of the sinking surface is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of coating thermal grease, and particularly relates to a device for coating thermal grease on a sunken surface and a coating method thereof. Background Art

[0002] The sunken surface refers to the recessed coating area formed by mechanical processing on the heat dissipation substrate of the electronic device. For the coating of the sunken surface, ordinary mesh plate printing technology cannot be implemented because the coating area sinks to form a depression. The existing technology uses manual coating, which is inconvenient to operate, low in efficiency, and cannot guarantee the coating quality requirements, affecting the life of the IGBT (insulated gate bipolar transistor). The ordinary mesh plate is composed of a metal frame on all sides and a steel sheet in the middle, with corresponding holes cut on the steel sheet. The size of this structure is often relatively large, and the sunken surface is often a relatively narrow groove area. Therefore, the ordinary mesh plate cannot penetrate into the sunken surface and form a close fitting position relationship, and thus cannot print the thermal grease to the sunken surface coating area through the mesh.

[0003] Chinese patent CN102120207A discloses a device and related coating method for applying thermal grease to the heat dissipation surface of an IGBT module. The device utilizes a mesh plate and a mesh filling tool. The mesh plate fits tightly against the heat dissipation surface of the IGBT module, and the mesh filling tool is used to fill the thermal grease, ensuring uniform distribution and reducing air entrainment. This achieves a uniform, thin layer of thermal grease, improving the heat dissipation effect of the IGBT module, extending its service life, reducing thermal grease waste, and improving operational efficiency. However, this device only addresses the coating problem of planar heat dissipation surfaces. The sunken surface is a concave three-dimensional structure with sidewalls and depth. The flat mesh plate of the device cannot be embedded in the bottom of the groove, and mechanical pressing structures such as uprights and connecting blocks cannot be lowered into place due to obstruction by the sidewalls of the groove. Summary of the Invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a device for applying thermal grease to a sunken surface and a coating method thereof, so as to solve the technical problem that the existing thermal grease device cannot penetrate into the sunken surface and form a close fitting position relationship with it, resulting in the inability to print thermal grease on the coating area of the sunken surface.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a device for applying thermal grease to a sunken surface, comprising a mesh plate, wherein the mesh plate is made of a frameless steel sheet, a plurality of grid holes are provided on the mesh plate, and a plurality of positioning members are provided on the side wall of the mesh plate; when the mesh plate is placed in the sunken surface, the width of a single-sided gap formed between the side surface of the mesh plate and the inner side surface of the side wall of the sunken surface is 0.3 mm to 0.7 mm.

[0007] Preferably, the thickness of the steel sheet is 0.2 mm to 0.3 mm.

[0008] Preferably, the positioning members are anti-deformation notches, and the anti-deformation notches are distributed in a linear array with a spacing of 3 mm.

[0009] Preferably, the size of the anti-deformation notch is 0.3mm*4mm.

[0010] Preferably, it also includes a mesh filling tool used in conjunction with the mesh plate.

[0011] Preferably, the mesh filling tool is a scraper.

[0012] Preferably, the size of the scraper is 0.8 mm to 1.2 mm smaller than the inner size of the grid holes.

[0013] Preferably, the plurality of grid holes are distributed in an array.

[0014] The present invention also provides a method for applying thermal grease to the sunken surface using the device, comprising the following steps:

[0015] S1: embedding the bottom surface of the mesh plate into the groove of the sunken surface;

[0016] S2: After taking the thermal grease with a scraper, press the scraper downward at an angle with the scraper plane and the sunken surface to fill the thermal grease through the grid holes to the sunken surface;

[0017] S3: Move the scraper in a single direction to scrape off the thermal grease overflowing from the grid holes to form a uniform coating.

[0018] Preferably, the inclination angle is 45°.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention discloses a device for applying thermal grease to a sunken surface. The device adopts a mesh plate made of a frameless steel sheet, so that the size of the mesh plate is more compatible with the size of the sunken surface. The mesh plate of the frameless steel sheet is designed with a single-side gap of 0.3mm-0.7mm, so that the mesh plate can be installed and smoothly penetrate into the sunken surface, and ensure that a precise gap is formed with the side wall when the mesh plate is embedded in the sunken surface. The tightly fitting setting eliminates the assembly tolerance of the traditional mesh plate and the sunken surface, avoiding leakage of the grease or incomplete coating; the positioning piece fixes the position of the mesh plate, and realizes the limitation of the mesh plate to avoid deviation caused by operation within the sunken surface. In addition, the device does not require additional flipping, locking or limiting mechanisms, has a simple structure, low device cost, and is easy to operate. At the same time, it reduces the waste of thermal grease and has high operating efficiency.

[0021] Furthermore, the 0.2mm-0.3mm thick steel sheet can adapt to the tiny shape tolerance of the sunken surface, achieve dead angle-free fitting, and reduce the influence of the mesh plate's own weight on positioning.

[0022] Furthermore, the anti-deformation notches are distributed in a linear array with a spacing of 3mm, ensuring uniform contact between the mesh plate and the entire area of the sunken surface, eliminating uneven thickness of the silicone grease coating.

[0023] Furthermore, the size of the anti-deformation notch is set to 0.3mm x 4mm, which offsets the internal stress of the steel sheet when it is under pressure and avoids bonding failure caused by bending of the mesh.

[0024] Furthermore, a scraper is used as a mesh filling tool to make the application of thermal grease more convenient.

[0025] Furthermore, a plurality of grid holes are distributed in an array, so that the coating of the thermal grease is more uniform.

[0026] Furthermore, the scraper size is smaller than the mesh hole size by 0.8mm-1.2mm, so as to avoid the scraper getting stuck in the mesh hole and damaging the structure, while also scraping off the overflowed silicone grease to form a uniform coating.

[0027] The present invention also provides a method for applying thermal grease to the sunken surface using the device. When the scraper is tilted and pressed down, shear force is generated to force the grease to penetrate the grid holes. The scraper is moved horizontally in a single direction to avoid repeated scraping and disturbing the distribution of the grease, thereby achieving thickness consistency.

[0028] Furthermore, the flow direction of the thermal grease is controlled at an inclination angle of 45° to enhance the mesh filling rate and solve the problem of bubbles in the holes caused by traditional vertical pressing. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A diagram of a device for coating a sunken surface with thermal grease according to the present invention;

[0030] Figure 2 This is a partial enlarged view of the device for applying thermal grease to the sunken surface of the present invention;

[0031] Among them: 1-grid hole; 2-anti-deformation notch; 3-mesh plate;

[0032] Figure 3 This is a 3D rendering of the device for coating the sunken surface with thermal grease according to the present invention. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0034] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0035] The present invention is described in further detail below with reference to the accompanying drawings:

[0036] See also Figures 1 to 3 The present invention provides a device for applying thermal grease to a sunken surface, comprising a mesh plate 3 made of a frameless steel sheet, provided with a plurality of grid holes 1, and a plurality of positioning members provided on the sidewall of the mesh plate 3. When the mesh plate 3 is placed in the sunken surface, the width of the single-sided gap formed between the side surface of the mesh plate 3 and the inner side surface of the sidewall of the sunken surface is 0.3mm-0.7mm. If the width of the single-sided gap is less than 0.3mm, the installation resistance increases dramatically and the risk of scratching the groove wall increases. If it is greater than 0.7mm, the leakage of thermal grease will increase.

[0037] Preferably, the thickness of the steel sheet is 0.2 mm to 0.3 mm.

[0038] Preferably, the positioning members are anti-deformation notches 2 , and the anti-deformation notches 2 are distributed in a linear array with a spacing of 3 mm.

[0039] Preferably, the size of the anti-deformation notch 2 is 0.3 mm*4 mm.

[0040] Preferably, a mesh filling tool used in conjunction with the mesh plate 3 is also included.

[0041] Preferably, the mesh filling tool is a scraper.

[0042] Preferably, the size of the scraper is 0.8 mm to 1.2 mm smaller than the inner size of the grid hole 1 .

[0043] Preferably, a plurality of grid holes 1 are distributed in an array.

[0044] The present invention also provides a method for applying thermal grease to the sunken surface using the device, comprising the following steps:

[0045] S1: embedding the bottom surface of the mesh plate 3 into the groove of the sunken surface;

[0046] S2: After taking the thermal grease with a scraper, press the scraper downward at an angle with the scraper plane and the sunken surface, and fill the thermal grease through the grid hole 1 to the sunken surface;

[0047] S3: Move the scraper in a single direction to scrape off the thermal grease overflowing from the grid hole 1 to form a uniform coating.

[0048] Preferably, the inclination angle is 45°.

[0049] The present invention also provides a method for manufacturing the device for coating the sunken surface with thermal grease, comprising the following steps:

[0050] 1) Based on the inner side dimensions of the side wall of the sunken surface to be coated, shrink the steel sheet inward by 1mm to obtain the rectangular dimensions of the bottom surface of the steel sheet, and then make the four sides of the rectangular bottom surface of the steel sheet outward to form a common rectangular shape. Then, set a linear array of anti-deformation notches 2 outside the contour line of the bottom surface of the steel sheet. The size of the anti-deformation notches 2 is 0.3mm*4mm, and the spacing is 3mm; then set the following on the bottom surface area of the steel sheet: Figure 1 Several grid holes 3 shown;

[0051] 2) The common-side rectangles around the steel sheet are bent 90 degrees by a bending process to form surrounding walls, thereby obtaining a special mesh plate coated with thermal grease on the sunken surface; the height of the surrounding wall is 25mm-35mm.

[0052] Further preferably, in the bending process, the anti-deformation notch 2 is parallel to the center line of the side wall of the mesh plate as the bending line, the bending angle is 0.5mm, and the 3D effect is as follows Figure 2 Do not drill holes on the surrounding walls of the steel sheet to install enclosures and protective strips.

[0053] A further preferred method is to use a stainless steel sheet (SUS304) with a thickness of 0.2mm–0.3mm, photochemically etched to form a frameless, independent mesh plate. This reduces weight by 70% compared to traditional mesh plates and can accommodate narrow grooves with a depth of ≤5mm. When the thickness is less than 0.2mm, the steel sheet lacks rigidity (deformation >50μm); when it exceeds 0.3mm, it loses flexibility and cannot compensate for unevenness of the groove bottom surface (measured tolerance ±20μm).

[0054] Further preferably, the depth of the notch is controlled to be 1.5 times the thickness of the steel sheet (0.45 mm) to ensure that the stress is concentrated at the bottom of the notch during bending.

[0055] In order to ensure that the thermal grease coating on the sunken surface meets the quality requirements (accurate dosage and uniform distribution), the mesh plate of the present invention is specially used to accurately control the thermal grease coating.

[0056] Example 2

[0057] Small IGBT module: For the Infineon FF900R12ME4 module used in automotive inverters, its sunken surface is a narrow and deep groove with dimensions of 42mm×28mm×1.8mm. Traditional manual coating results in a thickness deviation of up to ±35% due to space limitations. This invention solves this problem by using a customized mesh plate.

[0058] Customization of mesh plate: The steel sheet material is SUS304 stainless steel with a thickness of 0.25mm. The bottom rectangle is generated by shrinking the sunken surface by 1mm. The size of the rectangle is 41mm×27mm.

[0059] Anti-deformation slot linear array distribution: size 0.3mm × 4mm, spacing 3mm, 14 slots are set along each of the four sides of the mesh plate (56 in total) to offset bending stress.

[0060] Grid hole array design: The size of the square hole is 0.5mm×0.5mm, the bridge interval is 0.1mm, the opening rate is 62%, and it covers the entire bottom area of the mesh plate.

[0061] Micro-gap control: The single-side gap between the side wall of the mesh plate and the inner side of the groove is set to 0.5mm, and the tolerance is ensured to be ±0.05mm by calibration with a plug gauge.

[0062] Scraper selection: width 4.0mm, material is polyurethane, hardness 80ShoreA.

[0063] Method for applying thermal grease using the above mesh plate:

[0064] 1) Manually press the mesh plate lightly to fit into the groove on the sunken surface. Align the notch with the corner of the groove for self-positioning. This takes ≤ 3 seconds.

[0065] 2) Apply high-thermal conductive silicone grease (brand: Shin-Etsu 7921, viscosity 250,000 cP) and apply downward pressure with a scraper at a 45° angle and a speed of 0.2 m / s. The grease should penetrate the mesh due to shear thinning, achieving a fill rate >98%.

[0066] 3) Apply the grease uniformly at a speed of 0.15 m / s in the direction parallel to the IGBT terminal, and smooth out the overflowed grease to form a uniform layer.

[0067] Example 3

[0068] Large industrial inverter modules (for industrial equipment applications): For the Mitsubishi CM600HA-24A module, the sunken surface features a wide, shallow groove measuring 120mm x 80mm x 1.5mm. Traditional mesh panels, due to their large size, are prone to deformation, leading to silicone grease accumulation (thickness deviation ±40%).

[0069] Mesh plate reinforcement:

[0070] The thickness of the steel sheet is increased to 0.3mm, the material is SUS316L corrosion-resistant, and the bottom surface size of the steel sheet is reduced by 1mm to 119mm×79mm.

[0071] Anti-deformation notches are optimized: the size is 0.3mm×4mm, the spacing is 3mm, but a double-row staggered array (30 notches on each side) is used to increase the bending stiffness by 1.5 times.

[0072] Grid hole layout: rectangular holes with a size of 0.6mm×0.4mm, and an array density increased to 200 holes / cm 2 , suitable for large area coating.

[0073] Gap and tool: Single-side gap 0.7mm (compensation for thermal expansion), scraper size is customized to width 6.0mm (smaller than the inner diameter of the hole 1.2mm).

[0074] Method for applying thermal grease using the above mesh plate:

[0075] 1) An automated robotic arm performs the insertion, and a force sensor provides feedback on the fit (resistance < 0.1Ω confirms full contact).

[0076] 2) Use Dow Corning TC-5022 silicone grease, preheat it to 40°C to reduce the viscosity, press the scraper at a 45° angle, and fill at a speed of 0.3m / s;

[0077] 3) Apply along a single long side at a speed of 0.1 m / s to avoid backflow.

[0078] Example 4

[0079] Consumer electronics chip packaging: For mobile phone processor heat dissipation grooves, the groove dimensions are 10mm×8mm×0.5mm, requiring ultra-thin coating (thickness 0.1mm±0.005mm). Traditional methods, due to insufficient precision, result in excessive thickness (thermal efficiency drops by 30%).

[0080] Micro mesh plate: The steel sheet thickness is 0.2mm (ultra-thin design), and the bottom surface size is 9mm×7mm.

[0081] Anti-deformation notch 2 is miniaturized: the size is 0.3mm×3mm (maintaining the width-to-depth ratio), the spacing is 2mm, and there are 10 notches on each side to compensate for micro-bending stress.

[0082] Optimization of grid hole 1: circular holes with a diameter of 0.3 mm, an array spacing of 0.2 mm, and an opening rate of 55% to avoid silicone grease drawing.

[0083] Precision gap control: single-side gap 0.3mm, scraper width 2.0mm (smaller than the hole inner diameter 0.8mm).

[0084] Method for applying thermal grease using the above mesh plate:

[0085] 1) Vacuum pen assisted placement, microscope calibration gap (tolerance ± 0.02mm);

[0086] 2) Use Hongfucheng HF-300 brand low-viscosity silicone grease, press the scraper at a 45° angle, and control the pressure to 0.2N;

[0087] 3) Apply at a speed of 0.05m / s in a single pass.

[0088] The above content is only for explaining the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A device for coating a sunken surface with thermal grease, characterized in that: The invention comprises a mesh plate (3), wherein the mesh plate is made of a frameless steel sheet, a plurality of grid holes (1) are provided on the mesh plate (3), and a plurality of positioning members are provided on the side wall of the mesh plate (3); when the mesh plate (3) is placed in the sunken surface, the width of the single-side gap formed between the side surface of the mesh plate (3) and the inner side surface of the side wall of the sunken surface is 0.3 mm to 0.7 mm.

2. The device for coating a sunken surface with thermal grease according to claim 1, characterized in that: The thickness of the steel sheet is 0.2mm-0.3mm.

3. The device for coating a sunken surface with thermal grease according to claim 1, characterized in that: The positioning members are anti-deformation notches (2), and the anti-deformation notches (2) are distributed in a linear array with a spacing of 3 mm.

4. The device for coating a sunken surface with thermal grease according to claim 3, characterized in that: The size of the anti-deformation notch (2) is 0.3mm*4mm.

5. The device for coating a sunken surface with thermal grease according to claim 1, characterized in that: Also included is a mesh filling tool used in conjunction with the mesh plate (3).

6. The device for coating a sunken surface with thermal grease according to claim 5, characterized in that: The mesh filling tool is a scraper.

7. The device for coating a sunken surface with thermal grease according to claim 6, characterized in that: The size of the scraper is 0.8 mm to 1.2 mm smaller than the inner size of the grid hole (1).

8. The device for coating a sunken surface with thermal grease according to claim 1, characterized in that: A plurality of grid holes (1) are distributed in an array.

9. A method for coating a sunken surface with a device for coating thermal grease according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: embedding the bottom surface of the mesh plate (3) into the groove of the sunken surface; S2: After taking the thermal grease with a scraper, press the scraper downward at an angle with the scraper plane and the sinking surface, so that the thermal grease passes through the grid holes (1) and fills the sinking surface; S3: Move the scraper in a single direction to scrape off the thermal grease overflowing from the grid holes (1) to form a uniform coating.

10. The method for coating a sunken surface with a device for coating thermal grease according to claim 9, characterized in that: The inclination angle is 45°.

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