Elastic brush wheel for precise packaging carrier plate and preparation method

Abstract

The invention belongs to the technical field of grinding materials, and particularly discloses an elastic brush wheel for a precise packaging carrier plate and a preparation method, and the elastic brush wheel comprises a supporting pipe, a sponge coating the surface of the supporting pipe, rubber coating the surface of the sponge, and a grinding sheet coating the surface of the rubber. The grinding sheet is prepared from the following raw materials in parts by weight: 1-5 parts of polyvinyl alcohol, 12-21 parts of distilled water, 5-20 parts of phenolic resin, 7-10 parts of hydroformylation agent, 5-6 parts of catalyst and 40-70 parts of grinding material, so that the grinding sheet can be better attached to the surface of a packaging carrier plate, and the elastic brush wheel can improve the grinding efficiency on the basis of carrying out continuous line production on the packaging carrier plate. And the grinding precision and the grinding uniformity of the packaging carrier plate are greatly improved, so that the machined packaging carrier plate has the precision requirement for surface roughness.

Description

Technical Field

[0001] The invention relates to the technical field of grinding materials, and in particular to an elastic brush wheel for a precision sealing loading plate and a preparation method thereof. Background Art

[0002] In the field of grinding, there are many types of products. Different types of grinding tools need to be selected according to the shape of the grinding tool and the requirements for grinding precision. According to the shape and function of the mold, it can be roughly divided into dispersed free abrasives (grinding stones, etc.), coated molds (sand belts, gauze, etc.) and consolidated molds (grinding wheels, brush wheels, etc.). Among them, grinding wheels are suitable for grinding and polishing cylindrical devices, while cylindrical brush wheels are more suitable for cutting and grinding two-dimensional planar devices. For the surface cleaning and polishing of the package carrier, the cylindrical brush wheel has a more significant advantage in continuous grinding.

[0003] Commonly used brush wheels are non-woven brush wheels and ceramic brush wheels. Based on the existing non-woven brush wheels and ceramic brush wheels, it is difficult to obtain products that can achieve ultra-high precision grinding by adjusting the raw material ratio. The non-woven brush wheel uses a non-woven process to bond the abrasive with resin on the elastic fiber as a reinforcing material to form an abrasive distribution system with a three-dimensional mesh structure. It has the characteristics of good grinding conformability and is suitable for grinding electronic devices with complex shapes. However, it has the disadvantages of easy chip drop and hole clogging, low grinding efficiency, and large surface roughness difference when grinding the package carrier board surface, and limited grinding capacity. The ceramic brush wheel is pressed into a ceramic brush wheel grinding sheet by phenolic resin powder and silicon carbide abrasive, and then cut and processed to form; or the epoxy resin physical / chemical foaming method is used to add the abrasive and stir evenly, and then cast to form a ceramic brush wheel grinding sheet. Although the grinding efficiency and grinding accuracy have been greatly improved compared with traditional grinding wheels, the mesh count of the outer surface of the ground product can reach 320#-1500#. However, conventional ceramic brush wheels, like non-woven brush wheels, are only suitable for continuous de-resining process grinding of traditional HDI (printed circuit boards) or multi-layer circuit boards. In the current precision grinding of package carriers, the roughness Ra value after grinding needs to be within 100 nanometers, and the above two series of ceramic brush wheels cannot meet the relevant process requirements; Although the above-mentioned non-woven brush wheel and ceramic brush wheel have high cutting force and can be used for removing resin and burrs, their high hardness will reduce the overall conformity and cause uneven grinding. Summary of the invention

[0004] In order to overcome the defects of the prior art, the present invention provides an elastic brush wheel for a precision-sealed loading plate and a preparation method thereof.

[0005] The technical solution adopted by the present invention to solve the technical problem is: The first scheme of the present invention is to provide an elastic brush wheel for fine sealing loading plate, comprising a support tube, a sponge coated on the surface of the support tube, a rubber coated on the surface of the sponge, and an abrasive sheet coated on the surface of the rubber. The raw materials for making the abrasive sheet include the following components by weight: 1-5 parts of polyvinyl alcohol, 12-21 parts of distilled water, 5-20 parts of phenolic resin, 7-10 parts of formaldehyde agent, 5-6 parts of catalyst and 40-70 parts of abrasive.

[0006] The idea of ​​solving the technical problem of the present invention is: in terms of structure, the sponge of the brush wheel of the present invention makes the grinding sheet have a certain buffering force in the process of contacting the packaging carrier, thereby forming elastic contact, which makes the brush wheel have the advantage of continuous processing; in terms of materials, the sponge-like three-dimensional structure of polyvinyl alcohol and the rigid structure of phenolic resin complement each other, so as to prepare a polymer material that is elastic but not soft, rigid but not brittle, and can simultaneously achieve good self-sharpening and conformability, so that the grinding sheet can better fit the surface of the packaging carrier, so that the elastic brush wheel can greatly improve the grinding accuracy and grinding uniformity of the packaging carrier on the basis of being able to perform continuous flow operation on the packaging carrier, so that the processed packaging carrier has the precision requirements of surface roughness.

[0007] The grinding accuracy and grinding efficiency of traditional disc grinding wheels are far inferior to those of cylindrical brush wheels, so polyvinyl alcohol has not yet been used in precision grinding of packaging substrates.

[0008] Specifically, polyvinyl alcohol has excellent adhesion, chemical stability, thermal stability and wear resistance, but due to its water solubility, it is necessary to avoid using aqueous grinding fluid during grinding and cutting. Therefore, polyvinyl alcohol is hydroformylated with a hydroformylating agent, and the hydroformylation time is shortened by a catalyst, so that polyvinyl alcohol has water resistance, thereby reducing the dissolution of polyvinyl alcohol in water, greatly enhancing the stability of the brush wheel while maintaining the grinding performance, and can adapt to both dry and wet grinding applications.

[0009] In addition, the sponge-like three-dimensional structure of polyvinyl alcohol can provide micro-bubbles for the grinding sheet, which can alleviate the heat dissipation and chip removal problems of the brush wheel during the grinding process, and avoid the problems of overheating of the packaging carrier and chip blocking of the holes.

[0010] As a further embodiment, the hydroformylating agent is one or more of formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, and n-valeraldehyde.

[0011] As a further embodiment, the catalyst is one or more of hydrochloric acid, nitric acid, phosphoric acid, formic acid, acetic acid, propionic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid.

[0012] As a further solution, the abrasive is one or more of diamond, silicon carbide, boron carbide, brown corundum, white corundum, and chrome corundum.

[0013] As a further solution, the mesh number of the abrasive is 3000#~4000#, which meets the requirements of grinding accuracy and roughness of the surface of the high-precision packaging carrier.

[0014] As a further solution, the elastic brush wheel is columnar, and the columnar brush wheel can effectively improve the working efficiency compared with the flat grinding wheel.

[0015] The second solution of the present invention is to provide a method for preparing an elastic brush wheel for a precision seal loading plate, the method for preparing the elastic brush wheel for a precision seal loading plate comprises the following steps: 1) Put polyvinyl alcohol and distilled water into a container, then place the container in a water bath, and stir with a stirrer at a speed of 150-240r / min for 30-60min to obtain a polyvinyl alcohol aqueous solution; 2) Keep the speed at 150-240r / min, control the temperature of the polyvinyl alcohol aqueous solution at 20-30℃, then add the abrasive and stir for 3-5min, and continue to add the phenolic resin and stir for 3-5min; 3) Adding the formaldehyde agent to the system of step 2) and stirring for 3-5 minutes, and then adding the catalyst and stirring for 3-5 minutes to obtain a uniformly mixed slurry; 4) pouring the slurry obtained in step 3) into a mold, leaving it to stand for 3 hours and then curing it in a low temperature environment for 20 hours to obtain an abrasive sheet; 5) Bond the abrasive sheet obtained in 4) to the rubber after brushing with glue. After the glue is cured, cut the abrasive sheet horizontally and vertically into square particles by a grinding and cutting machine; wind the sponge on the outer surface of the support tube, brush glue on the outer surface of the sponge, and wind and bond the rubber cured with the abrasive sheet on the outer surface of the sponge. After the glue is cured, trim the entire brush wheel to obtain an elastic brush wheel for precision sealing loading plate.

[0016] Specifically, in step 2), phenolic resin is added to the polyvinyl alcohol aqueous solution and mixed evenly to improve the stability of the abrasive sheet and the overall wettability of the abrasive sheet, so that the abrasive can be better dispersed in the polyvinyl alcohol aqueous solution.

[0017] As a further embodiment, the temperature of the water bath in step 1) is 60-90°C.

[0018] As a further embodiment, the low temperature in step 4) is 55-75°C.

[0019] The present invention has at least one of the following beneficial effects: (1) In terms of structure, the sponge of the brush wheel of the present invention enables the abrasive sheet to have a certain buffering force when contacting the packaging carrier, thereby forming an elastic contact, which enables the brush wheel to have the advantage of continuous processing; in terms of materials, the sponge-like three-dimensional structure of polyvinyl alcohol and the rigid structure of phenolic resin complement each other, thereby constructing a polymer material frame that is elastic but not soft, rigid but not brittle, and can simultaneously achieve good self-sharpening and conformability, so that the abrasive sheet can better fit the surface of the packaging carrier, so that the elastic brush wheel can greatly improve the grinding accuracy and grinding uniformity of the packaging carrier on the basis of being able to perform continuous flow operations on the packaging carrier, so that the processed packaging carrier can meet the surface roughness accuracy requirements.

[0020] (2) Polyvinyl alcohol is hydroformylated with a hydroformylating agent, and the hydroformylation time is shortened by a catalyst, so that the hydroformylated polyvinyl alcohol has water resistance, thereby reducing the dissolution of polyvinyl alcohol in water during the use of aqueous grinding fluid. The water resistance and stability of the brush wheel are greatly enhanced while maintaining the grinding performance, and can adapt to various application scenarios such as dry grinding and wet grinding.

[0021] (3) The sponge-like three-dimensional structure of polyvinyl alcohol can provide micro-bubbles for the grinding sheet, which can alleviate the heat dissipation and chip removal problems of the brush wheel during the grinding process, and avoid the problems of overheating of the packaging carrier and chip blocking of the holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of an embodiment of the present invention; Figure 2 This is a microscopic morphology of the surface of the packaging carrier after grinding in Example 1 of the present invention; Figure 3 This is a scanning electron microscope image of the grinding sheet of the elastic brush wheel in Example 1 of the present invention.

[0023] In the figure, 1-support tube, 2-sponge, 3-rubber, 4-abrasive sheet. DETAILED DESCRIPTION

[0024] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] It should be noted that in the following embodiments and comparative examples, Figure 1 As shown, the elastic brush wheel for fine sealing the loading plate is columnar, and includes a support tube, a sponge 2 coated on the surface of the support tube 1, a rubber 3 coated on the surface of the sponge 2, and a grinding sheet 4 coated on the surface of the rubber 3.

[0026] Example 1 The raw materials for making the abrasive sheet of the elastic brush wheel include the following components by weight: 1 part of polyvinyl alcohol, 21 parts of distilled water, 5 parts of phenolic resin, 7 parts of formaldehyde agent, 5 parts of catalyst and 40 parts of abrasive.

[0027] A method for preparing an elastic brush wheel for a precision sealing loading plate comprises the following steps: 1) Put polyvinyl alcohol and distilled water into a container, then place the container in a water bath at 60°C, adjust the stirrer and stir at a speed of 150 r / min for 60 min to obtain a polyvinyl alcohol aqueous solution; 2) Keep the rotation speed at 150r / min, control the temperature of the polyvinyl alcohol aqueous solution at 25°C, then add a 3000# mesh abrasive and stir for 4 minutes, continue to add phenolic resin and stir for 4 minutes; the abrasive is silicon carbide; 3) Add a formaldehyde to the system of step 2) and stir for 4 minutes, then add a catalyst and stir for 4 minutes to obtain a uniformly mixed slurry; wherein the formaldehyde is selected as the formaldehyde and the catalyst is selected as hydrochloric acid.

[0028] 4) pouring the slurry obtained in step 3) into a PP mold of 1100×70×25 mm and letting it stand for 3 hours; then sending the mold into an oven and curing it at a temperature of 55° C. for 20 hours to obtain a grinding sheet; 5) Bond the abrasive sheet obtained in 4) to the rubber after brushing with glue. After the glue is cured, cut the abrasive sheet horizontally and vertically into square particles (square particles are distributed in a matrix, and the particle size is 13×13 mm) by a grinding and cutting machine; wind the sponge on the outer surface of the support tube, and brush glue on the outer surface of the sponge. Wind and bond the rubber cured with the abrasive sheet on the outer surface of the sponge. After the glue is cured, trim the entire brush wheel to obtain an elastic brush wheel for precision sealing loading plates.

[0029] Example 2 The raw materials for making the abrasive sheet of the elastic brush wheel include the following components by weight: 5 parts of polyvinyl alcohol, 12 parts of distilled water, 20 parts of phenolic resin, 10 parts of formaldehyde agent, 6 parts of catalyst and 70 parts of abrasive.

[0030] A method for preparing an elastic brush wheel for a precision sealing loading plate comprises the following steps: 1) Put polyvinyl alcohol and distilled water into a container, then place the container in a 90°C water bath, adjust the stirrer and stir at a speed of 240 r / min for 30 minutes to obtain a polyvinyl alcohol aqueous solution; 2) Keep the rotation speed at 240r / min, control the temperature of the polyvinyl alcohol aqueous solution at 25°C, then add a 4000# mesh abrasive and stir for 4 minutes, continue to add phenolic resin and stir for 4 minutes; the abrasive is diamond; 3) Add a formaldehyde to the system of step 2) and stir for 4 minutes, then add a catalyst and stir for 4 minutes to obtain a uniformly mixed slurry; wherein the formaldehyde is acetaldehyde and the catalyst is nitric acid.

[0031] 4) pouring the slurry obtained in step 3) into a PP mold of 1100×70×25 mm and letting it stand for 3 hours; then sending the mold into an oven and curing it at a temperature of 75° C. for 20 hours to obtain an abrasive sheet; 5) Bond the abrasive sheet obtained in 4) to the rubber after brushing with glue. After the glue is cured, cut the abrasive sheet horizontally and vertically into square particles (square particles are distributed in a matrix, and the particle size is 13×13 mm) by a grinding and cutting machine; wind the sponge on the outer surface of the support tube, and brush glue on the outer surface of the sponge. Wind and bond the rubber cured with the abrasive sheet on the outer surface of the sponge. After the glue is cured, trim the entire brush wheel to obtain an elastic brush wheel for precision sealing loading plates.

[0032] Example 3 The raw materials for making the abrasive sheet of the elastic brush wheel include the following components by weight: 3 parts of polyvinyl alcohol, 13 parts of distilled water, 15 parts of phenolic resin, 9 parts of formaldehyde agent, 6 parts of catalyst and 63 parts of abrasive.

[0033] A method for preparing an elastic brush wheel for a precision sealing loading plate comprises the following steps: 1) Put polyvinyl alcohol and distilled water into a container, then place the container in a water bath at 60°C, adjust the stirrer and stir at a speed of 150 r / min for 60 min to obtain a polyvinyl alcohol aqueous solution; 2) Keep the rotation speed at 150r / min, control the temperature of the polyvinyl alcohol aqueous solution at 25°C, then add abrasive with a mesh size of 3600# and stir for 4 minutes, continue to add phenolic resin and stir for 4 minutes; the abrasive is boron carbide; 3) Add a formaldehyde to the system of step 2) and stir for 4 minutes, then add a catalyst and stir for 4 minutes to obtain a uniformly mixed slurry; wherein the formaldehyde is propionaldehyde and the catalyst is acetic acid.

[0034] 4) pouring the slurry obtained in step 3) into a PP mold of 1100×70×25 mm and letting it stand for 3 hours; then sending the mold into an oven and curing it at a temperature of 55° C. for 20 hours to obtain a grinding sheet; 5) Bond the abrasive sheet obtained in 4) to the rubber after brushing with glue. After the glue is cured, cut the abrasive sheet horizontally and vertically into square particles (square particles are distributed in a matrix, and the particle size is 13×13 mm) by a grinding and cutting machine; wind the sponge on the outer surface of the support tube, and brush glue on the outer surface of the sponge. Wind and bond the rubber cured with the abrasive sheet on the outer surface of the sponge. After the glue is cured, trim the entire brush wheel to obtain an elastic brush wheel for precision sealing loading plates.

[0035] Comparative Example 1 Compared with Example 1, the only difference is that no formaldehyde agent and catalyst are added to the raw materials of the abrasive sheet for making the elastic brush wheel, and the rest is the same as Example 1.

[0036] Comparative Example 2 This comparative example provides an epoxy resin-based ceramic brush wheel. The raw materials for making the grinding sheet of the ceramic brush wheel include the following components: 75 parts of silicon carbide, 9 parts of modified epoxy resin, 3 parts of liquid phenolic resin, 2 parts of aluminum borate whiskers and 10 parts of hollow microspheres.

[0037] The preparation method is similar to that of Example 1, except that the slurry obtained in step 4) needs to be hot-pressed after being put into a mold, and demolded after cooling to obtain an abrasive sheet.

[0038] The brush wheels obtained in Examples 1-3 and Comparative Examples 1-2 were subjected to performance tests, and the test items and test results are shown in Table 1 below: Figure 2 The microscopic morphology of the surface of the package carrier after grinding in Example 1 shows that the package carrier is ground relatively evenly. Combined with Table 1, compared with Comparative Example 2, the surface roughness of the package carrier after grinding by the elastic brush wheel of the present invention is much smaller than the surface roughness of the package carrier after grinding by the conventional epoxy resin-based ceramic brush wheel, which can meet the precision requirements of the package carrier.

[0039] Figure 3 This is a scanning electron microscope image of the grinding sheet of the elastic brush wheel of Example 1. It can be seen that there are a large number of micro-bubbles in the internal structure of the grinding sheet. Combined with Table 1, the density of the elastic brush wheel cast using water-based polyvinyl alcohol is lower than that of Comparative Example 2, that is, the porosity is higher, the overall air permeability and heat dissipation are better, and its overall appearance structure is more uniform, thereby greatly improving the grinding accuracy and grinding uniformity of the packaging carrier. At the same time, the lower density can make it have better water absorption and chip removal performance, which is beneficial to improving the overall grinding performance and brush life of the brush wheel.

[0040] Combined with Table 1, the life of the grinding sheet of the elastic brush wheel of Example 1 is longer than that of the comparative example 1. The brush wheel of the present invention has higher stability. After the addition of the hydroformylating agent, the hydrocarbon groups of the polyvinyl alcohol are consumed, the proportion of hydrocarbon groups in the structure is reduced, and the water resistance and stability of the brush wheel during the grinding process in an aqueous environment are improved. This shows that the hydroformylation of polyvinyl alcohol by the hydroformylating agent can improve the water resistance of the hydroformylated polyvinyl alcohol.

[0041] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. An elastic brush wheel for fine sealing loading plate, characterized in that: The invention comprises a support tube, a sponge coated on the surface of the support tube, a rubber coated on the surface of the sponge, and an abrasive sheet coated on the surface of the rubber. The raw materials for making the abrasive sheet include the following components in parts by weight: 1-5 parts of polyvinyl alcohol, 12-21 parts of distilled water, 5-20 parts of phenolic resin, 7-10 parts of formaldehyde agent, 5-6 parts of catalyst and 40-70 parts of abrasive.

2. The elastic brush wheel for fine sealing loading plate according to claim 1, characterized in that: The hydroformylating agent is one or more of formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde and n-valeraldehyde.

3. The elastic brush wheel for fine sealing loading plate according to claim 1, characterized in that: The catalyst is one or more of hydrochloric acid, nitric acid, phosphoric acid, formic acid, acetic acid, propionic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid.

4. The elastic brush wheel for fine sealing loading plate according to claim 1, characterized in that: The abrasive is one or more of diamond, silicon carbide, boron carbide, brown corundum, white corundum, and chrome corundum.

5. The elastic brush wheel for fine sealing loading plate according to claim 4, characterized in that: The mesh number of the abrasive is 3000#~4000#.

6. The elastic brush wheel for fine sealing loading plate according to claim 1, characterized in that: The elastic brush wheel is columnar.

7. A method for preparing an elastic brush wheel for a precision seal loading plate, the method being used to prepare an elastic brush wheel for a precision seal loading plate as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: 1) Put polyvinyl alcohol and distilled water into a container, then place the container in a water bath, and stir with a stirrer at a speed of 150-240r / min for 30-60min to obtain a polyvinyl alcohol aqueous solution; 2) Keep the speed at 150-240r / min, control the temperature of the polyvinyl alcohol aqueous solution at 20-30℃, then add the abrasive and stir for 3-5min, and continue to add the phenolic resin and stir for 3-5min; 3) Adding the formaldehyde agent to the system of step 2) and stirring for 3-5 minutes, and then adding the catalyst and stirring for 3-5 minutes to obtain a uniformly mixed slurry; 4) pouring the slurry obtained in step 3) into a mold, leaving it to stand for 3 hours and then curing it in a low temperature environment for 20 hours to obtain an abrasive sheet; 5) Bond the abrasive sheet obtained in 4) to the rubber after brushing with glue. After the glue is cured, cut the abrasive sheet horizontally and vertically into square particles by a grinding and cutting machine; wind the sponge on the outer surface of the support tube, brush glue on the outer surface of the sponge, and wind and bond the rubber cured with the abrasive sheet on the outer surface of the sponge. After the glue is cured, trim the entire brush wheel to obtain an elastic brush wheel for precision sealing loading plate.

8. The method for preparing an elastic brush wheel for a precision seal loading plate according to claim 7, characterized in that: The temperature of the water bath in step 1) is 60-90°C.

9. The method for preparing an elastic brush wheel for a precision seal loading plate according to claim 7, characterized in that: The temperature of the low temperature in step 4) is 55-75°C.

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