Preparation method of substrate

Abstract

The preparation method of the substrate comprises the steps that graphene slurry is prepared, and the graphene slurry comprises graphene powder particles, a dispersing agent and deionized water; coating the surface of the shielding sheet with the graphene slurry; and curing the graphene slurry to form the graphene heat dissipation layer. The method is simple in process and low in cost, the tightly-attached graphene cooling fins can be formed on the shielding sheet of the substrate in a curing mode, no extra adhesive is needed, and therefore the finally-formed substrate structure is lighter and thinner, and the current light and thin design requirement is met.

Description

Technical Field

[0001] This invention relates to the field of semiconductor substrate processing, and more particularly to a method for preparing a substrate. Background Technology

[0002] With the development of the electronics industry, semiconductor substrates have become an important component. A substrate mainly consists of three parts: a circuit board with circuit coils fabricated using wire-winding / printing / etching processes; a shielding sheet for magnetic field shielding and interference suppression; and a heat sink for heat dissipation. During manufacturing, the circuit board, shielding sheet, and heat sink are sequentially bonded together using adhesives to form a stacked structure. Semiconductor substrates generate a large amount of heat during operation, leading to excessively high device temperatures that affect performance and lifespan. To address this issue, adhesives are currently widely used between the shielding sheet and the heat sink. This method is complex, costly, and the adhesive occupies space in the thickness direction, resulting in a slightly thicker final substrate. This cannot meet the requirements for thinner and lighter electronic devices in the trend towards miniaturization and lightness.

[0003] Therefore, there is an urgent need to provide an improved method for preparing the substrate to overcome the above-mentioned defects. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a substrate. This method is simple, low-cost, and can form a tightly bonded graphene heat sink on the shielding sheet of the substrate without the need for additional adhesives, thereby making the final substrate structure thinner and lighter, meeting the current demand for thinner and lighter designs.

[0005] To achieve the above objectives, the present invention provides a method for preparing a substrate, wherein the substrate includes a shielding sheet, and the method includes the following steps:

[0006] A graphene slurry is prepared, wherein the graphene slurry comprises graphene powder particles, a dispersant, and deionized water;

[0007] The graphene slurry is coated onto the surface of the shielding sheet; and

[0008] The graphene slurry is cured to form a graphene heat dissipation layer.

[0009] Compared with the prior art, the preparation method of the present invention first prepares a graphene slurry, then coats the graphene slurry onto the surface of the shielding sheet, and then cures the graphene slurry to form a graphene heat dissipation layer. Thus, an adhered graphene heat dissipation layer is formed on the surface of the shielding sheet of the substrate. In other words, there is no need to use additional adhesives to bond and assemble the separate shielding sheet and the separate heat dissipation layer together, simplifying the assembly steps and reducing costs. Moreover, the final substrate structure is thinner and lighter, which can meet the design requirements of thin and light electronic devices.

[0010] As one embodiment, the coating step includes: spraying the graphene slurry onto the surface of the shielding sheet using a spray gun.

[0011] As an example, the angle between the spray gun and the surface of the shielding plate is controlled to be 30-60 degrees, and the distance between the spray gun and the surface of the shielding plate is 10-20mm.

[0012] As an example, the spraying speed of the spray gun is controlled to be 30-50 mm / s, and the nozzle diameter of the spray gun is 5.0-10 mm.

[0013] As an example, the spraying pressure of the spray gun is 0.8-1.5 MPa.

[0014] As one embodiment, the curing step includes placing the substrate in an oven to dry and cure it.

[0015] As an example, the baking temperature of the baking oven is controlled at 100-120℃, and the baking time is 2-3 hours.

[0016] As an example, the graphene slurry comprises, by weight, 50-55 parts graphene powder particles, 5-10 parts dispersant, and 35-50 parts deionized water.

[0017] As one example, the dispersant includes sodium polyacrylate and / or sodium hexametaphosphate.

[0018] As one example, the graphene powder particles have at least two particle sizes. Detailed Implementation

[0019] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific implementation methods of this application are described in detail below with reference to some embodiments. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0020] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0021] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0022] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0023] The method for preparing the substrate of the present invention will be further described below with reference to embodiments, but this does not limit the present invention. The method of the present invention aims to provide a method for preparing a substrate that is simple in process, low in cost, and can form a tightly bonded graphene heat sink on the shielding sheet of the substrate without the need for additional adhesives, thereby making the final substrate structure thinner and lighter, meeting the current demand for thinner and lighter designs.

[0024] The substrate of the present invention includes a circuit board and a shielding sheet formed on the circuit board before processing. An embodiment of the method for preparing the substrate of the present invention includes the following steps:

[0025] A graphene slurry is prepared, wherein the graphene slurry comprises graphene powder particles, a dispersant, and deionized water;

[0026] The graphene slurry is coated onto the surface of the shielding sheet; and

[0027] The graphene slurry is cured to form a graphene heat dissipation layer.

[0028] The preparation method of the present invention involves coating the graphene slurry onto the surface of the shielding sheet, and then curing the graphene slurry to form a graphene heat dissipation layer. Thus, an adhered graphene heat dissipation layer is formed on the surface of the shielding sheet of the substrate. In other words, the present invention eliminates the need for additional adhesives to bond and assemble the separate shielding sheet and the separate heat dissipation layer together, simplifying the assembly steps and reducing costs. Moreover, this preparation method results in a thinner and lighter substrate structure, which can meet the design requirements of thin and light electronic devices.

[0029] In one particular embodiment, a graphene slurry is first prepared.

[0030] Prepare graphene powder particles. Preferably, the graphene powder particles are mixed using a powder gradation method, combining multiple types, such as at least two particle sizes. In one embodiment, taking graphene powder particles with particle sizes of 2μm and 5μm as examples, the ratio of 2μm particle size to 5μm particle size graphene powder particles by weight is preferably 2:1-4:1 to obtain better heat dissipation and adhesion effects. Prepare a dispersant. Preferably, the dispersant includes one or both of sodium polyacrylate and sodium hexametaphosphate. Mix the graphene powder particles, dispersant, and deionized water in a specific ratio. As an example, by weight, there are 50-55 parts of graphene powder particles, 5-10 parts of dispersant, and 35-50 parts of deionized water. After stirring and mixing, the viscosity of the graphene slurry is below 1.5 Pa·s.

[0031] Next, graphene slurry is coated onto the surface of the shielding sheet. Specifically, the coating step includes spraying the graphene slurry onto the surface of the shielding sheet using a spray gun. In a preferred embodiment, the angle between the spray gun and the surface of the shielding sheet is controlled to be 30-60 degrees, for example, 45 degrees. The distance between the spray gun and the surface of the shielding sheet is 10-20 mm, for example, 15 mm. More preferably, a spray gun nozzle diameter of 5.0-10 mm is used, the spraying speed is controlled to be 30-50 mm / s, and the spraying pressure is 0.8-1.5 MPa to obtain a more uniform coating effect.

[0032] Finally, the substrate is placed in an oven for drying and curing to solidify the graphene slurry into a graphene heat dissipation layer. Specifically, the oven temperature is controlled at 100-120℃, and the baking time is 2-3 hours.

[0033] After the graphene slurry is cured and molded, a graphene heat dissipation layer is formed on the surface of the shielding sheet. Since the graphene heat dissipation layer can be tightly adhered to the surface of the shielding sheet through curing, compared with the method of bonding the shielding sheet and the heat dissipation sheet with adhesive in related technologies, the present invention does not require additional adhesive to bond and assemble the separate shielding sheet and the separate heat dissipation layer together, so that the final substrate structure is thinner and lighter, thereby meeting the design requirements of thin and light electronic devices.

[0034] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for preparing a substrate, the substrate comprising a shielding sheet, the method comprising the following steps: A graphene slurry is prepared, wherein the graphene slurry comprises graphene powder particles, a dispersant, and deionized water; The graphene slurry is coated onto the surface of the shielding sheet; and The graphene slurry is cured to form a graphene heat dissipation layer.

2. The method for preparing the substrate as described in claim 1, characterized in that, The coating step includes: spraying the graphene slurry onto the surface of the shielding sheet using a spray gun.

3. The method for preparing the substrate as described in claim 2, characterized in that, The angle between the spray gun and the surface of the shielding plate is controlled to be 30-60 degrees, and the distance between the spray gun and the surface of the shielding plate is 10-20mm.

4. The method for preparing the substrate as described in claim 2, characterized in that, The spraying speed of the spray gun is controlled to be 30-50 mm / s, and the nozzle diameter of the spray gun is 5.0-10 mm.

5. The method for preparing the substrate as described in claim 2, characterized in that, The spraying pressure of the spray gun is 0.8-1.5 MPa.

6. The method for preparing the substrate according to claim 1, characterized in that, The curing step includes placing the substrate in an oven to dry and cure it.

7. The method for preparing a substrate as described in claim 6, characterized in that, The baking temperature of the baking oven is controlled at 100-120℃, and the baking time is 2-3 hours.

8. The method for preparing a substrate as described in claim 1, characterized in that, By weight, the graphene slurry comprises 50-55 parts graphene powder particles, 5-10 parts dispersant, and 35-50 parts deionized water.

9. The method for preparing the substrate according to claim 1, characterized in that, The dispersant includes sodium polyacrylate and / or sodium hexametaphosphate.

10. The method for preparing the substrate according to claim 1, characterized in that, The graphene powder particles have at least two particle sizes.