Conductive resin-based QFN cutting blade and preparation method thereof

Abstract

The present invention discloses a conductive resin-based QFN cutting blade and a preparation method thereof. A preparation method of a conductive resin-based QFN cutting blade comprises mixing resin powder, silver powder, nickel powder, a dispersant and diamond to obtain a molding material; then hot pressing and curing the molding material to obtain a blade blank; and then machining the blade blank to obtain a conductive resin-based QFN cutting blade. The present invention discloses the application of a conductive resin-based QFN cutting blade in cutting QFN materials, especially in improving the tailing effect. Silver powder has good electrical conductivity and thermal conductivity, but due to its large specific surface area, it is easy to adsorb and agglomerate, which causes the pressed tool to easily form an uneven distribution of fillers and abrasives, thereby resulting in poor quality of the cut product. The present invention mainly uses a dispersant to enhance the uniformity of the distribution of silver powder in the powder material, so that the distribution of the blade filler and the like is more uniform, so that the cut product can be more uniform and better, so that the tailing effect can be improved in the cutting of QFN materials.

Description

Technical Field

[0001] The invention belongs to processing tools, and in particular relates to a resin-based cutting blade with excellent electrical conductivity and a preparation method thereof. Background Art

[0002] At present, resin-based cutting blades are mainly composed of abrasive particles, external fillers, and resin powder. Abrasive particles mainly include diamond and cBN, etc., and resin powder mainly includes phenolic resin, epoxy resin, polyimide resin, etc. CN114472895A discloses a metal sintered diamond ultra-thin cutting blade for QFN, which is obtained by mixing a metal matrix and diamond; the material is successively subjected to cold pressing, sintering, inner hole and outer circle processing, and double end surface thinning processing to obtain a metal sintered diamond ultra-thin cutting blade for QFN; in the metal matrix, the mass percentage of cobalt powder is 70-80%, the mass percentage of copper powder is 10-20%, and the balance is tin powder; a high cobalt content system and small particle size diamond are used, and a small amount of copper powder and tin powder are used to double the life of the QFN knife. CN106378714A discloses an ultra-thin resin dicing knife for high-quality cutting of QFN, the ingredients of which are composed of resin binder, diamond and inorganic filler, wherein the volume fraction of diamond is 12.5-30%, its particle size is 38-104μm, the volume fraction of resin binder is 35-55%, and the inorganic filler is composed of silicon carbide, graphite and chromium oxide, each of which accounts for the volume fraction of the total ingredients: silicon carbide 6-25%, graphite 3-8%, chromium oxide 5-15%. Silicon carbide and chromium oxide in the formula can greatly improve the strength of the dicing knife and extend the life of the dicing knife. A small amount of graphite powder can increase the self-sharpening ability of the blade and maintain the good cutting quality and stability of the blade. From the actual use effect, the existing resin knife has a poor tailing effect when cutting QFN. Summary of the invention

[0003] The invention discloses a resin-based cutting blade with excellent conductivity and a preparation method thereof, which effectively solves the problem of poor tailing effect in cutting QFN with an existing resin knife.

[0004] The present invention adopts the following technical solution:

[0005] A method for preparing a conductive resin-based QFN cutting blade comprises the following steps: mixing resin powder, silver powder, nickel powder, a dispersant and diamond to obtain a molding material; hot pressing and curing the molding material to obtain a blade blank; and machining the blade blank to obtain a conductive resin-based QFN cutting blade.

[0006] In the present invention, by weight: 15-35 parts of diamond, 40-50 parts of resin powder, 10-17 parts of silver powder, 10-16 parts of nickel powder, and 1-5 parts of dispersant; preferably, by weight: 20-25 parts of diamond, 42-48 parts of resin powder, 14-16 parts of silver powder, 13-16 parts of nickel powder, and 3-4 parts of dispersant.

[0007] In the present invention, the resin powder is phenolic resin powder, and the dispersant is T-60701 of Yatu New Materials, both of which are existing products.

[0008] In the present invention, resin powder, silver powder and dispersant are first mixed, then nickel powder is added, and then diamond is added, and the mixture is mixed to obtain a molding material.

[0009] In the present invention, the hot pressing temperature is 180-190°C, the time is 5-10 minutes, and the pressure is 250KN-300KN; the secondary hardening process is a step-by-step temperature increase of 100°C-180°C, and preferably, the temperature difference of each step is 30-50°C; for example, 100°C for 20 minutes + 140°C for 60 minutes + 180°C for 500 minutes.

[0010] The invention discloses the application of a conductive resin-based QFN cutting blade in cutting QFN materials, in particular to improving the tailing effect.

[0011] Silver powder has good electrical and thermal conductivity, but due to its large specific surface area, it is easy to adsorb and agglomerate, which leads to uneven distribution of fillers and abrasives in the pressed cutter, resulting in poor quality of the cut product. The present invention mainly uses a dispersant to enhance the uniformity of the distribution of silver powder in the powder, so that the distribution of the blade filler is more uniform, so that the cut product can be more uniform and better, so that the tailing effect can be improved in the cutting of QFN materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a blade cutting diagram of Example 1;

[0013] Figure 2 This is the blade cutting diagram of Example 2;

[0014] Figure 3 This is a blade cutting diagram for comparative example 1. DETAILED DESCRIPTION

[0015] The present invention adopts conventional raw material products of commercially available grinding wheels and conventional preparation operations, discloses a new resin-based cutting blade with excellent conductivity, and adopts conventional processing tests to find that the product of the present invention solves the problem of poor tailing in the prior art. The phenolic resin powder comes from Shengquan Chemical; the silver powder particle size is 1-5μm; the nickel powder particle size is 1-5μm; the diamond is RVG produced nickel-plated diamond 600#-500#; the dispersant is Yatu New Material T-60701.

[0016] The preparation method of a conductive resin-based QFN cutting blade of the present invention is as follows:

[0017] Mixing: weigh raw materials such as resin powder, silver powder, nickel powder, and dispersant; first mix the resin powder, silver powder, and dispersant, sieve them three times using a sieve to mix the raw materials evenly, then add nickel powder, stir evenly, and sieve, finally add abrasive and sieve to obtain a mixture, place the mixture in a container for three-dimensional mixing for 1.5-2 hours, and obtain a uniformly mixed molding material.

[0018] Molding: First, sieve the molding material, then weigh the molding material and pour it into the mold cavity, use a scraper to level it, press it on a hot press at 185°C for 7 minutes, and cool and demold it to obtain a blade blank.

[0019] Secondary curing: Place the blade blank into the corresponding fixture and cure it in an oven according to a certain process to obtain a blade blank with a certain strength.

[0020] Conventional processing: The solidified blade blank is processed inside and outside to become a finished blade, and then tested and packaged.

[0021] Embodiment 1

[0022] 20.0 parts by weight of diamond, 47.5 parts by weight of phenolic resin powder, 14 parts by weight of silver powder, 3.0 parts by weight of dispersant, and 15.5 parts by weight of nickel powder were weighed, and the raw materials were subjected to a manufacturing method to form a finished blade.

[0023] Cutting QFN (6*6*1mm) for testing, spindle speed 25kRPM, cutting speed 50mm / s, burr within 25 microns. Example 1 Cutting results see Figure 1 It can be seen that the blade of the present invention makes the distance between the cut pieces larger, all exceeding 130 μm.

[0024] Embodiment 2

[0025] 22.5 parts by weight of diamond, 45.0 parts by weight of phenolic resin powder, 15.0 parts by weight of silver powder, 3.0 parts by weight of dispersant, and 14.5 parts by weight of nickel powder were weighed, and the raw materials were subjected to a manufacturing method to form a finished blade.

[0026] Comparative Example 1

[0027] 22.5 parts by weight of diamond, 45.0 parts by weight of phenolic resin powder, 15.0 parts by weight of tin powder, 3.0 parts by weight of dispersant, and 14.5 parts by weight of nickel powder were weighed, and the raw materials were subjected to a manufacturing method to form a finished blade.

[0028] Cutting QFN (6*6*1mm) for testing, spindle speed 25kRPM, cutting speed 50mm / s, cutting results of Example 2 refer to Figure 2 , see the cutting results of comparative example 1 Figure 3 ; The data are shown in Table 1, and the good data are from Example 2.

[0029]

[0030] The product of the invention has a very good tailing effect, which exceeds the limit value of 100 microns currently proposed in the industry, while the cutting effect of the existing resin knife with tin powder added is biased.

[0031] At present, the best QFN cutting knife in production has a tailing of 110-125 μm and a burr of less than 30 μm when cutting QFN of the same specification. In comparison, the cutting knife of the present invention significantly improves the tailing effect.

[0032] Comparative Example 2

[0033] Weigh 22.5 parts by weight of diamond, 48.0 parts by weight of phenolic resin powder, 15.0 parts by weight of silver powder, and 14.5 parts by weight of nickel powder, and form a finished blade after the raw materials are processed by the manufacturing method. When cutting QFN, the burr is too large, exceeding 50 microns, and the service life is low. This shows that the addition of a dispersant can evenly disperse the silver powder in the resin-based powder filler, increase the process stability of the blade after production, and enhance the quality of the product cut by the blade.

[0034] Embodiment 3

[0035] 22.5 parts by weight of diamond, 44.0 parts by weight of phenolic resin powder, 16.0 parts by weight of silver powder, 4.0 parts by weight of dispersant, and 13.5 parts by weight of nickel powder were weighed, and the raw materials were subjected to the above-mentioned manufacturing method to form a finished blade.

[0036] The preparation methods of the above embodiments and comparative examples are as follows:

[0037] Mixing: Weigh raw materials such as resin powder, silver powder, nickel powder, and dispersant (if any); first mix the resin powder, silver powder (or tin powder), and dispersant, sieve them three times with a 200-mesh sieve to mix the raw materials evenly, then add nickel powder, stir evenly, and sieve, finally add abrasive and sieve to obtain a mixture, place the mixture in a container for three-dimensional mixing for 2 hours, and obtain a uniformly mixed molding material.

[0038] Molding: Pass the molding material through a 200-mesh sieve, then pour it into a conventional mold cavity, use a scraper to level it, press it on a hot press at 185°C and 250KN for 7 minutes, and naturally cool and demold it to obtain a blade blank.

[0039] Secondary curing: Place the blade blank into the corresponding fixture and cure it in an oven at 100°C for 20 minutes + 140°C for 60 minutes + 180°C for 500 minutes (heating rate 30°C / minute), and cool it naturally to obtain a blade blank with a certain strength.

[0040] Conventional machining: The solidified blade blank is processed inside and outside to become a finished blade, which is then tested and packaged.

[0041] Since modern cutting machines use electric current to precisely control the cutting depth, high requirements are also placed on the conductivity of the blade. The product of the embodiment of the present invention is connected and spread out for 1 meter, and the resistance is tested with an ohmmeter. The resistance value can be within 1Ω, ensuring the smooth flow of current, thereby ensuring the precise control of the machine processing.

[0042] The present invention is mainly used in the field of resin knife abrasive tool manufacturing, and relates to a resin knife for cutting QFN and having good electrical and thermal conductivity and a preparation process thereof. At present, the resin-based cutting blade is mainly composed of abrasive particles, external fillers, and resin powder. The abrasive particles mainly include diamond and cBN, etc., and the resin powder is mainly phenolic resin, epoxy resin, polyimide resin, etc. The dispersant used in the external filler in the present invention can improve the uniformity of the dispersion of silver powder in the resin matrix powder, thereby improving the overall wear resistance and electrical conductivity of the tool.

Claims

1. A method for preparing a conductive resin-based QFN cutting blade, characterized in that: By weight: 20 parts of diamond, 47.5 parts of phenolic resin powder, 14 parts of silver powder, 15.5 parts of nickel powder, and 3 parts of dispersant; firstly mix the phenolic resin powder, silver powder, and dispersant, then add nickel powder, and then add diamond, and mix to obtain a molding material; then hot press and cure the molding material to obtain a blade blank; then machine the blade blank to obtain a conductive resin-based QFN cutting blade; the hot pressing temperature is 180-190°C, the time is 5-10 minutes, and the pressure is 250kN-300kN; the curing process is a step-by-step heating of 100°C-180°C.

2. A conductive resin-based QFN dicing blade prepared according to the method for preparing a conductive resin-based QFN dicing blade according to claim 1.

3. Use of the conductive resin-based QFN cutting blade according to claim 2 in cutting QFN materials.

4. Application of the conductive resin-based QFN cutting blade according to claim 2 in improving the tailing effect of cutting QFN.

5. A method for processing a QFN material, characterized in that: The QFN material is cut using the conductive resin-based QFN cutting blade described in claim 2 to complete the processing of the QFN material.

6. Use of phenolic resin powder, silver powder, nickel powder, dispersant and diamond in the preparation of the conductive resin-based QFN cutting blade according to claim 2.

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