A cover tape for electronic component packaging and a method of manufacturing the same

Abstract

The present application belongs to the technical field of electronic component packaging, and relates to a cover tape for electronic component packaging and a preparation method thereof. The cover tape comprises a substrate layer and a heat-sealing layer, and particles are arranged on the side of the substrate layer away from the heat-sealing layer, and the number of the surface particles protruding and distributed on the layer is 1200-2000 per 0.1 mm 2 , so that the problem of adhesion after winding and reverse winding when unwinding is inhibited, and the heat-sealing performance of the cover tape is not affected.

Description

Technical Field

[0001] This invention belongs to the field of electronic component packaging technology, and relates to a cover tape for electronic component packaging and its preparation method, wherein the cover tape has anti-adhesion properties. Background Technology

[0002] In recent years, with the rapid development of surface mount technology (SMT) for electronic components, SMT technology has also made significant progress. To better preserve and transport small electronic chip components, carrier tapes are typically used for encapsulation. Electronic components are stored in various pockets of the carrier tape, which are then sealed with cap tape. Before use, the cap tape is stored in a wound form, with the front and back overlapping. During storage, factors such as the storage environment may cause the cap tape to stick or become entangled. Furthermore, after being sealed onto the carrier tape, the cap tape is stored as a coil. During this coil storage, the cap tape comes into contact with both the electronic components and the carrier tape. Sometimes, the cap tape and electronic components may stick together, affecting the smooth removal of the electronic components and even subsequent use. Therefore, developing a cap tape that does not stick is urgently needed in the market.

[0003] In the prior art, the cover tape has at least a substrate layer and a heat-sealing layer. The anti-adhesion of the cover tape is usually improved by containing an anti-blocking agent in the heat-sealing layer or adding a functional layer with anti-adhesion properties.

[0004] For example, Japanese Patent JP4615984B2 discloses a laminated film having at least a substrate layer and a heat-sealing layer. The heat-sealing layer is a thermoplastic resin composed of a styrene copolymer and an ethylene polymer. The thermoplastic resin cover tape, at 100% by weight, is composed of a resin composition containing 1-15 parts by weight of cross-linked microparticles of a styrene resin relative to that portion, with a thickness of 4-30 μm. This provides the cover tape with good transparency and heat-sealing properties, preventing the adhesive layers of electronic components from sticking together during long-term storage. However, in actual production, the cover tape formed in this way still cannot completely avoid the problem of sticking. Furthermore, the added anti-sticking components must be evenly dispersed in the heat-sealing layer; otherwise, the heat-sealing performance between the heat-sealing layer and the carrier tape will be affected, requiring high-quality anti-sticking agents.

[0005] In other cases, such as JP1997207988A and JP2004001876A, when adding particulate matter to the heat-sealing layer, it is necessary to consider the uniform dispersion of the particulate matter. Otherwise, it will affect the heat-sealing performance of the heat-sealing layer and the carrier tape, resulting in a decrease in the heat-sealing performance of the cover tape and the carrier tape.

[0006] Another example is the heat-sealing cover tape structure disclosed in Chinese Utility Model Patent 201721113998.1, which includes several silica particles on the outer surface of the heat-sealing layer, with some of the silica particles protruding outward from the outer surface of the heat-sealing layer. Based on this design, particles can also be provided on the outer surface of the substrate layer. While this solution can solve the adhesion problem to some extent, the presence of particles on the heat-sealing layer affects the heat-sealing performance with the carrier tape. Summary of the Invention

[0007] To solve the adhesion problem during the winding of the cover tape, the present invention provides a cover tape in which particles are arranged on the surface of the substrate layer away from the heat-sealing layer to achieve the purpose of anti-adhesion, and the heat-sealing layer does not contain anti-adhesion components.

[0008] The present invention adopts the following technical solution:

[0009] A first aspect of the present invention provides a cover strip for packaging electronic components, comprising a substrate layer consisting of at least three layers A, B, and C, and a heat-sealing layer, wherein layer A is adjacent to the heat-sealing layer, and layer C is away from the heat-sealing layer, characterized in that 1200-2000 protrusions of 0.1 mm are distributed on the surface of layer C of the substrate layer. 2 Particle a, and does not contain anti-blocking components within the heat seal layer.

[0010] In the present invention, the apparent structure of the substrate layer C is adjusted so that the number of protruding particles a on its surface is 1200~2000 per 0.1 mm. 2 Within a certain range, even without adding anti-blocking components to the heat-sealing layer, the purpose of anti-blocking can be achieved.

[0011] Compared with the prior art of adding anti-adhesion components to the heat-sealing layer, the anti-adhesion method of the present invention is simpler to process, easier to control processing conditions, has excellent anti-adhesion effect, and stable product performance.

[0012] The anti-adhesion method of the present invention is achieved by adjusting the apparent structure of the C layer of the substrate layer, so that the number of protruding particles a on its surface is 1200~2000 per 0.1mm. 2 Within a certain range, it achieves the purpose of anti-adhesion. Compared with adding anti-adhesion components to the heat-sealing layer, the present invention improves the surface roughness of the C layer by adding particles a to the C layer of the substrate layer and making the particles a protrude from the surface of the C layer, thereby improving the anti-adhesion effect and replacing the solution of adding anti-adhesion components to the heat-sealing layer, thereby reducing the impact on the heat-sealing performance of the heat-sealing layer.

[0013] In this invention, when the number of protruding particles a on the surface of the substrate layer C is greater than 1200 per 0.1 mm... 2At this time, after the C layer with protruding particles a is laminated with the heat-sealing layer, there are a large number of gaps, so that the final cover tape does not have the problem of reverse winding during unwinding. If the number of protruding particles a is greater than 2000 / 0.1mm 2 On the one hand, this will greatly increase costs, and on the other hand, it will make the C layer too slippery, causing the cover tape to be unable to be wound and rolled into a finished product.

[0014] In this invention, the type of particle 'a' is not limited; any particle that can be used in the cover tape is acceptable. For example, commonly used silica particles, calcium carbonate particles, etc.

[0015] In one embodiment of the present invention, the particle a is preferably an irregular particle to increase the anti-adhesion of the cover tape, such as amorphous silica particles, amorphous calcium carbonate particles, etc.

[0016] In one embodiment of the present invention, the particle size of particle a is 1~12 μm, and the thickness of layer C is 0.5~2 μm, in order to maximize the number of protrusions of particle a on the surface of layer C. If the particle size of particle a is greater than 12 μm or the thickness of layer C is less than 0.5 μm, the number of protrusions of particle a on the surface of layer C will be greater than 2000 per 0.1 mm. 2 This makes the C layer too slippery, preventing the cover tape from being wound into the finished product. If the particle size of particle a is less than 1 μm or the C layer thickness is greater than 2 μm, the number of protrusions of particle a on the C layer surface will be less than 1200 per 0.1 mm. 2 This cannot achieve the purpose of preventing adhesion.

[0017] In one embodiment of the present invention, the thickness of the heat-sealing layer is 20~40μm. Since the thickness of the heat-sealing layer is much larger than the diameter of particles a contained in layer C, the requirement for the uniformity of the protruding distribution of particles a in layer C is not high, and the protruding distribution of particles a will not affect the heat-sealing performance of the heat-sealing layer.

[0018] In one embodiment of the present invention, the thickness of layer A is 2~5μm and the thickness of layer B is 15~20μm.

[0019] In one embodiment of the present invention, the C layer includes a PET masterbatch containing particles a, wherein the content of particles a in the PET masterbatch is 500ppm to 6000ppm.

[0020] In one embodiment of the present invention, layer A is made of PET and PET masterbatch containing particles b, wherein the PET masterbatch content is 30-70% by mass, and the particle b content in the PET masterbatch is 500ppm-6000ppm. Particle b may be the same as or different from particle a. Since the processing of the substrate layer and the heat-sealing layer of the cover tape is relatively separate, after the substrate layer is formed and wound up, layer A and layer C are in contact in the wound state. Adding particles b to layer A can prevent adhesion between layer A and layer C during the winding process of the film formed by the substrate layer (commonly referred to as the base film).

[0021] In one embodiment of the present invention, the B layer is made of PET and recycled material, wherein the recycled material is waste material after the substrate film is cut off, and its proportion is 10% to 40%.

[0022] In one embodiment of the present invention, the main component of the heat-sealing layer is a heat-sealing resin, and the heat-sealing layer does not contain anti-adhesion components. The heat-sealing resin may be one or more of the following: polyethylene copolymer, ethylene vinyl acetate copolymer, ethylene methacrylate copolymer, ethylene butyl copolymer, styrene butadiene copolymer, styrene isoprene copolymer, hydride of styrene butadiene copolymer, and hydride of styrene isoprene.

[0023] A second aspect of the present invention provides a method for preparing the above-mentioned cover strip, comprising the following steps:

[0024] (S-1) Using multi-layer co-extrusion technology, the raw materials of the three layers A, B and C of the substrate layer are fed into different extruders. After melt extrusion, they are stretched longitudinally and transversely, then heat-set at 230-245℃, and stress is released at a relaxation rate of 1%~7% to form the substrate layer.

[0025] (S-2) After corona treatment of the surface of layer A of the substrate layer obtained above, a heat-sealing layer is formed on it to obtain a cover strip having a substrate layer and a heat-sealing layer.

[0026] (S-3) The prepared cover tape is wound with a tension of 20~30 kgf and then stored. If the winding tension is less than 20 kgf, the tension is too small and the cover tape will automatically unwind during storage. If the winding tension is greater than 30 kgf, the tension is too large and there is still a possibility of adhesion.

[0027] By implementing the above technical solution, the present invention has the following advantages:

[0028] This invention involves distributing particles on the surface of layer C, on the side of the substrate layer away from the heat-sealing layer, such that the number of protruding particles is 1200-2000 per 0.1 mm. 2 This achieves the goal of suppressing adhesion after the cover tape is wound and the problem of reverse winding during unwinding, without affecting the heat-sealing performance of the cover tape. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to specific embodiments.

[0030] It should be noted that the following embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

[0031] Methods for detecting the number of particle protrusions on the membrane surface:

[0032] By removing the PET from the particle surface to completely expose the particles, the detection accuracy is improved. Specifically, the prepared cover strip is made into 100mm x 100mm samples, placed in a plasma cleaner for 10 minutes, and 20 0.1mm particles are randomly selected using SEM. 2 Photographs of the back of the cover were taken, and the particle count was counted using Particle Metric software. The average value was taken as the particle count.

[0033] This detection method uses a plasma cleaner to clean the surface of the cover tape to remove PET from the surface of the protruding particles, making the particles completely exposed. This enhances the clarity of the particle signal captured by the SEM, thereby improving the detection accuracy of the number of protruding particles.

[0034] Method for determining heat seal layer transfer amount:

[0035] The cover tape sample was unwound, and the residual adhesive content on the surface of layer A of the cover tape was compared using an optical microscope at 200x magnification. This section primarily explains an evaluation method. When there is no residual adhesive on the surface of layer A of the cover tape, it is marked as OK.

[0036] Methods for determining anti-adhesion properties:

[0037] After the wrapped cover tape sample is left to stand for 1 day, it is suspended and subjected to a free fall unwinding test. The unwinding time of the cover tape is recorded. The shorter the free fall unwinding time, the better. An unwinding time of less than or equal to 3 hours is excellent, greater than 3 hours and less than or equal to 6 hours is good, and greater than 6 hours is NG.

[0038] Example 1

[0039] This embodiment provides a cover strap for packaging electronic components, which is heat-sealed with a paper or plastic carrier tape to seal the electronic components inside the carrier tape pocket.

[0040] The cover strip in this embodiment includes a substrate layer and a heat-sealing layer.

[0041] Substrate layer

[0042] It adopts a three-layer structure, specifically layer A, layer B, and layer C. Layer A is adjacent to the heat-sealing layer, layer B is located in the middle, and layer C is on the side away from the heat-sealing layer. The thickness of layer A is 2μm, the thickness of layer B is 21.5μm, and the thickness of layer C is 1.5μm.

[0043] The components of each layer are as follows:

[0044] Layer A: It is made by mixing and melting 70% ultra-bright PET chips with 30% PET masterbatch containing particles b. Particles b are silica particles with a particle size of 1~12μm and a particle content of 4000ppm.

[0045] Layer B: Made of ultra-bright PET chips and recycled materials, wherein the recycled materials are waste materials after the substrate film is cut off, accounting for 35%.

[0046] Layer C: Made by melting and mixing 20% ​​ultra-bright PET chips with 80% masterbatch containing particle b. Particle a is amorphous silica particles with a particle size of 1-12 μm, and particle b content is 4000 ppm. The number of particle b protrusions on the surface of layer C is 1600 per 0.1 mm. 2 .

[0047] heat seal layer

[0048] The heat-sealing layer is 30 μm thick. The main component of the heat-sealing layer is heat-sealing resin, and the heat-sealing layer does not contain anti-blocking components. The heat-sealing layer is a mixture of heat-sealing ethylene-vinyl acetate copolymer and low-density polyethylene.

[0049] The cover strip in this embodiment is prepared by the following method:

[0050] Step 1: Ingredient Preparation: Prepare the raw materials for each layer according to the above ingredients and proportions;

[0051] Step 2: Using multi-layer co-extrusion technology, the raw materials of the three layers A, B, and C of the substrate layer are fed into different extruders. After melt extrusion, they are stretched longitudinally and laterally, and then heat-set at 230-245℃ (240℃ is selected in this embodiment). Stress is released at a relaxation rate of 1% to 7% (5% is selected in this embodiment) to form the substrate layer.

[0052] Step 3: After corona treatment of the surface of layer A of the substrate layer obtained above, a heat-sealing layer composed of heat-sealing resin without anti-adhesion components is set to form a cover strip with a substrate layer and a heat-sealing layer.

[0053] Step 4: After winding the prepared cover strip with a tension of 20~30 kgf, store it.

[0054] Example 2

[0055] This embodiment provides an anti-adhesion cover for packaging electronic components, which heat-seals the electronic components inside the carrier bag with a paper or plastic carrier tape.

[0056] The cover strip in this embodiment includes a substrate layer and a heat-sealing layer.

[0057] Substrate layer

[0058] It adopts a three-layer structure, specifically layer A, layer B, and layer C. Layer A is adjacent to the heat-sealing layer, layer B is located in the middle, and layer C is on the side away from the heat-sealing layer. The thickness of layer A is 2μm, the thickness of layer B is 21μm, and the thickness of layer C is 2μm.

[0059] The components of each layer are as follows:

[0060] Layer A: It is made by mixing and melting 70% ultra-bright PET chips with 30% PET masterbatch containing particles b. Particles b are silica particles with a particle size of 1~12μm and a particle content of 4000ppm.

[0061] Layer B: Made of PET and recycled materials, wherein the recycled materials are waste materials from the trimming of the substrate film, accounting for 35%.

[0062] Layer C: This layer is made by melting and mixing 55% high-gloss PET chips with 45% PET masterbatch containing particle a. Particle a is amorphous silica particles with a particle size of 1-12 μm and a particle content of 4000 ppm. The number of particle a protrusions on the surface of layer C is 1200 per 0.1 mm. 2 .

[0063] heat seal layer

[0064] The heat-sealing layer has a thickness of 20 μm. The main component of the heat-sealing layer is heat-sealing resin, and the heat-sealing layer does not contain anti-blocking components. The heat-sealing layer is an ethylene methacrylate copolymer with heat-sealing properties.

[0065] The preparation method of the cover strip is the same as in Example 1.

[0066] Comparative Example 1:

[0067] The difference from Example 1 is that the proportion of PET masterbatch containing particle a is 30%, and the number of protrusions of particle a on the surface of layer C is 800 per 0.1 mm. 2 .

[0068] Comparative Example 2:

[0069] The difference from Example 1 is that the PET masterbatch containing particle a is added at a 100% ratio, and the number of particle a protrusions on the surface of layer C is 3000 per 0.1 mm. 2 .

[0070] Comparative Example 3:

[0071] The difference from Example 1 is that the particle size of particle a in layer C is 15~20μm.

[0072] Comparative Example 4:

[0073] The difference from Example 1 is that the particle size of particle a in layer C is 0.5~1.0 μm.

[0074] Comparative Example 5:

[0075] The difference from Example 1 is that the C layer is 4 μm thick.

[0076] Comparative Example 6:

[0077] The difference from Example 1 is that the C layer is 0.4 μm thick.

[0078] Comparative Example 7:

[0079] The difference from Example 1 is that silica particles, with a particle size of 3-12 μm and a particle content of 4000 ppm, were added to the heat-sealing layer as an anti-blocking component. Although the anti-blocking performance of this comparative example is slightly better than that of Example 1, there is a problem of poor peel strength stability after the cover tape is subsequently heat-sealed to the surface of the plastic / paper carrier tape, indicating that adding particles to the heat-sealing layer affects the heat-sealing performance of the cover tape.

[0080] The performance of the cover tape in each embodiment and comparative example was tested, and the results are shown in Table 1 below.

[0081]

Claims

1. A cover strip for packaging electronic components, comprising a substrate layer consisting of at least three layers A, B, and C, and a heat-sealing layer, wherein layer A is adjacent to the heat-sealing layer, and layer C is distant from the heat-sealing layer, characterized in that, The surface of the substrate layer C has 1200~2000 protrusions per 0.1mm. 2 Particle a, and does not contain anti-blocking components within the heat seal layer.

2. The cover tape for packaging electronic components according to claim 1, characterized in that, The particle a is an irregular particle.

3. A cover strip for packaging electronic components according to claim 1, characterized in that, The particle a has a particle size of 1~12μm, and the C layer thickness is 0.5~2μm.

4. A cover strip for packaging electronic components according to claim 1, characterized in that... The thickness of the heat-sealing layer is 20~40μm.

5. A cover strip for packaging electronic components according to claim 1, characterized in that, The C layer includes a PET masterbatch containing the particle a, wherein the content of particle a in the PET masterbatch is 500ppm to 6000ppm.

6. A cover strip for packaging electronic components according to claim 1, characterized in that, Layer A has a thickness of 2~5μm and layer B has a thickness of 15~20μm.

7. A cover strip for packaging electronic components according to claim 1, characterized in that, The A layer is made of PET and PET masterbatch containing particles b, wherein the PET masterbatch content is 30-70% by mass and the particle b content is 500ppm-6000ppm.

8. A cover strip for packaging electronic components according to claim 1, characterized in that, The main component of the heat-sealing layer is a heat-sealing resin, which may be one or more of the following: polyethylene copolymer, ethylene vinyl acetate copolymer, ethylene methacrylate copolymer, ethylene butyl copolymer, styrene butadiene copolymer, styrene isoprene copolymer, hydride of styrene butadiene copolymer, and hydride of styrene isoprene.

9. A cover strip for packaging electronic components according to claim 1, characterized in that, The B layer is made of PET and recycled materials, which are waste materials after the substrate film is cut off, accounting for 10% to 40%.

10. A method for preparing a cover strip for packaging electronic components according to any one of claims 1-9, comprising the steps of preparing a substrate layer and forming a heat-sealing layer, characterized in that, The prepared cover tape is wound with a tension of 20~30 kgf and then stored.

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