Cover tape and electronic component packaging assembly

Abstract

The utility model provides a cover tape. The cover tape comprises a first polymer substrate layer, an adhesive layer, a gum coating and a static dissipative film structural layer, the first polymer substrate layer has a first major surface and a second major surface; the adhesive layer is arranged on the first main surface of the first polymer substrate layer; the gum coating is arranged on the second main surface of the first polymer substrate layer; the static dissipative film construction layer is disposed on a middle portion of the adhesive layer such that both end portions of the adhesive layer remain exposed. The static dissipative film structural layer comprises a second polymer substrate layer and a conductive coating; the second polymeric substrate layer has a first major surface and a second major surface, the second major surface being adhered to the adhesive layer, and the conductive coating disposed on the first major surface of the second polymeric substrate layer. The conductive coating is a coating comprising a dielectric polymer binder and carbon nanotubes dispersed in the dielectric polymer binder. The utility model further provides an electronic component packaging assembly comprising the cover tape.

Description

Technical Field

[0001] The utility model relates to a cover tape, in particular to a cover tape which is matched with a carrier tape to carry electronic components. The utility model also relates to an electronic component packaging assembly comprising the cover tape. Background Art

[0002] In the field of electronic circuit assembly technology, it is often necessary to transfer electronic components from a component supply source to a specific location on a circuit board to be attached. Electronic components may be of many different types, including surface mount components, such as memory chips, integrated circuit chips, and other chips.

[0003] The electronics industry continues to move toward smaller devices, and these smaller electronic components in turn require the ability to more precisely and accurately remove these components from the electronic component packaging assembly that includes a carrier tape and a cover tape. Most known cover tapes use a heat activated adhesive (HAA) or a pressure sensitive adhesive (PSA) to adhere the cover tape to the carrier tape. To remove the component, the cover tape must first be carefully peeled or loosened from the carrier tape to expose the electronic component to a vacuum nozzle or other component handling equipment used to safely remove the electronic component.

[0004] One technical problem with carrier and cover tapes is providing an appropriate cover tape that seals the pocket structure on the carrier tape that holds the electronic components. The carrier or cover tape must also provide some protection against the generation of static electricity that can damage such delicate electronic components, to avoid electrostatic discharge that can damage the electronic components. Moreover, the winding and unwinding of the cover tape can exacerbate such problems by generating static charges. In addition, the industry requires that the electronic components located within the pocket structure of the carrier tape be inspected without peeling the cover tape off the carrier tape, so cover tape transparency becomes an important requirement.

[0005] Therefore, it is necessary to develop a cover tape and an electronic component packaging assembly that have both sufficient static dissipation performance and certain light transmittance. Utility Model Content

[0006] One of the purposes of the utility model is to provide a cover tape which has both sufficient static dissipation performance and certain light transmittance.

[0007] Another object of the present invention is to provide an electronic component packaging assembly which has sufficient static dissipation performance and a certain light transmittance to facilitate observation of the electronic components therein.

[0008] According to one aspect of the utility model, a cover tape is provided, which includes: a first polymer substrate layer, an adhesive layer, a back adhesive coating, and an electrostatic dissipative film structural layer. The first polymer substrate layer has a first main surface and a second main surface; the adhesive layer is arranged on the first main surface of the first polymer substrate layer; the back adhesive coating is arranged on the second main surface of the first polymer substrate layer; the electrostatic dissipative film structural layer is arranged on the middle part of the adhesive layer so that the two end parts of the adhesive layer remain exposed. The electrostatic dissipative film structural layer includes a second polymer substrate layer and a conductive coating; the second polymer substrate layer has a first main surface and a second main surface, the second main surface is adhered to the adhesive layer, and the conductive coating is arranged on the first main surface of the second polymer substrate layer. The conductive coating is a coating containing a dielectric polymer binder and carbon nanotubes dispersed in the dielectric polymer binder. The conductive coating has a thickness of 0.1 to 2 microns.

[0009] According to another aspect of the utility model, an electronic component packaging assembly is provided, which includes: a carrier tape, the carrier tape includes a film body, the film body has at least one recess that can accommodate electronic components; and a cover tape as provided in an embodiment of the utility model, the cover tape seals the recess of the carrier tape in a peelable manner.

[0010] The utility model has the following beneficial effects: the cover tape of the utility model has sufficient static dissipation performance and also has a light transmittance of 80%-90%, so that the electronic components in the electronic component packaging assembly can be easily observed, and the cover tape of the structure is easy to manufacture. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the following drawings are only exemplary of some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Moreover, these drawings should not be understood as any limitation on the present utility model.

[0012] Figure 1 This is a schematic diagram of the cover tape structure of an embodiment of the utility model;

[0013] Figure 2 It is a schematic diagram of the structure of an electronic component packaging assembly according to an embodiment of the utility model. DETAILED DESCRIPTION

[0014] It should be noted that the following embodiments are exemplary descriptions of the present invention, and the features in different embodiments can be combined with each other without conflict. The present invention will be described in detail below with reference to the accompanying drawings and in combination with specific embodiments.

[0015] like Figure 1 The cover tape 100 of one embodiment of the utility model is shown as a schematic diagram of the structure. The cover tape 100 includes: a first polymer base layer 110, an adhesive layer 130, a back adhesive coating 150, and a static dissipative film structural layer 120. The first polymer base layer 110 has a first main surface and a second main surface, the adhesive layer 130 is arranged on the first main surface of the first polymer base layer 110, and the back adhesive coating 150 is arranged on the second main surface of the first polymer base layer 110. The static dissipative film structural layer 120 is arranged on the middle part of the adhesive layer 130 so that the two end parts 130a and 130b of the adhesive layer 130 remain exposed. The static dissipative film structural layer 120 includes a second polymer base layer 140 and a conductive coating 160; the second polymer base layer 140 has a first main surface and a second main surface, the second main surface is adhered to the adhesive layer 130, and the conductive coating 160 is arranged on the first main surface of the second polymer base layer 140. The conductive coating 160 is a coating including a dielectric polymer binder and carbon nanotubes dispersed in the dielectric polymer binder. The conductive coating 160 has a thickness of 0.1 to 2 micrometers.

[0016] The first polymer substrate layer 110 and the second polymer substrate layer 140 are generally films made of polymer materials. To ensure the light transmittance of the cover tape, the first polymer substrate layer 110 and the second polymer substrate layer 140 are optically transparent. The first polymer substrate layer 110 and the second polymer substrate layer 140 can be made of the same polymer material or different polymer materials. Suitable polymer materials illustratively include: polyesters, such as polyethylene terephthalate (PET) and polyester copolymers; polyolefins, such as polyethylene (PE, including many grades of polyethylene, such as low-density polyethylene LDPE) and polyethylene copolymers, polypropylene (PP, including biaxially oriented polypropylene BOPP) and polyolefin copolymers.

[0017] The first polymer substrate layer 110 and the second polymer substrate layer 140 may have suitable thicknesses according to specific needs, typically in the range of about 5 microns to about 100 microns, more typically in the range of about 6 microns to about 32 microns, or even 13 microns to 25 microns.

[0018] The adhesive layer 130 of the cover tape 100 of the present embodiment of the utility model is selected as a pressure-sensitive adhesive layer. It is well known to those skilled in the art that pressure-sensitive adhesives have the following characteristics, including: (1) strong and permanent adhesion, (2) adhesion with pressure not exceeding finger pressure, (3) sufficient ability to remain on the adherend, and (4) sufficient adhesive strength and the ability to be cleanly removed from the adherend. Many pressure-sensitive adhesive layers are suitable for the adhesive layer 130 in the cover tape 100 structure of the utility model, which are easy to seal at room temperature without heating and can provide stable peeling force. Generally, a pressure-sensitive adhesive layer with a peeling force greater than 20 grams at room temperature is selected.

[0019] The pressure-sensitive adhesive layer can be selected from the adhesive layer formed by a pressure-sensitive adhesive, such as block copolymers, natural rubber, acrylic adhesives, etc. However, silicone adhesives are not preferred because they may be contaminated. Block copolymer adhesives include ethylene-propylene adhesives, styrene-ethylene-butylene-styrene adhesives, etc. Particularly preferred are acrylate adhesives, including (meth) alkyl acrylates, etc. The pressure-sensitive adhesive layer can further include tackifiers, defoamers, antioxidants, etc., as long as they do not interfere with the adhesive properties or clarity of the adhesive. How to select the appropriate pressure-sensitive adhesive and additives for the pressure-sensitive adhesive layer is well known to the general technicians in the industry and will not be repeated.

[0020] The static dissipative film structural layer 120 is arranged on the middle part of the adhesive layer 130 so that the two end parts 130a and 130b of the adhesive layer 130 remain exposed, and then the exposed parts 130a and 130b of the adhesive layer 130 adhere the cover tape to the corresponding edge positions of the carrier tape to seal the recessed portion, i.e., the pocket, on the carrier tape, and are arranged so that the exposed parts 130a and 130b of the adhesive layer 130 do not directly contact the electronic components in the recessed portion on the carrier tape.

[0021] Conductive coating 160 is essential for preventing electronic components from discharging due to the release of triboelectric charges. In an embodiment of the present invention, conductive coating 160 is selected as a coating formed by coating a mixture of a dielectric polymer binder and carbon nanotubes dispersed in the dielectric polymer binder. Carbon nanotubes can be single-walled or multi-walled. Carbon nanotubes are easily available from commercial sources. Examples of suitable carbon nanotubes include those obtained from AQUACYL AQ0101 multi-walled carbon nanotube dispersions from Nanocyl USA (Sambreville, Belgium). Based on the total weight of conductive coating 160, carbon nanotubes are typically present in conductive coating 160 in an amount of 0.5% to 5% (e.g., in the range of 1% to 3%), but smaller and larger amounts can also be used. Suitable dielectric polymer binders include, for example, non-conductive acrylic polymers, polyurethanes, polyvinyl chloride plastisols, and ethylene-vinyl acetate copolymers. The conductive coating 160 formed by coating a mixture including carbon nanotubes dispersed in a dielectric polymer binder is known to the skilled person in the industry, such as disclosed in CN103404249A. In some embodiments, the dielectric polymer binder is formed by coalescing and optionally thermally curing a corresponding latex dispersion (e.g., an aqueous dispersion of corresponding polymer binder particles). This method is particularly advantageous if a dispersion of carbon nanotubes containing a dispersion medium compatible with the liquid phase of the polymer latex dispersion is used.

[0022] The conductive coating 160 of the present invention preferably has a thickness of 0.1 to 2.0 microns, more preferably 0.1 to 1.0 microns. 5 Ohm to 10 10 The surface resistance of the coating is in the ohm range.

[0023] The conductive coating 160 is disposed on the first main surface of the second polymer substrate layer 140 of the static dissipative film structural layer 120. Compared with CN103404249A, the static dissipative film structural layer 120 of such a structure has the characteristics of reliable structure, uniform adhesive layer thickness, simple processing technology, etc.

[0024] Preferably, a first primer layer 170 is disposed between the adhesive layer 130 and the first major surface of the first polymer substrate layer 110. A second primer layer 180 is disposed between the conductive coating layer 160 and the first major surface of the second polymer substrate layer 140. The first primer layer 170 and the second primer layer 180 may be well-known coatings suitable for increasing the adhesion between layers, respectively increasing the adhesion between the polymer substrate layer and the adhesive layer, and the adhesion between the conductive coating layer 160 and the second polymer substrate layer 140. The primer layer may be formed by coating a suitable composition on the substrate layer, and suitable compositions include, for example, acrylic polymers, such as polyacrylamide, aminated acrylic polymers (such as 50% solid content, available from Nippon Shokubai Co., Osaka, Japan), and polyurethanes, such as NK350 (a polyurethane primer coating solution available from Nippon Shokubai Co., Ltd., Osaka, Japan).

[0025] A low-adhesion adhesive coating 150 is provided on the second major surface of the first polymer substrate 110. The adhesive coating 150 can be coated on the second major surface of the first polymer substrate 110 using a gravure roller to allow the cover tape to be rolled up and kept intact, and then unwound for use. The adhesive coating 150 is sometimes also referred to as a backing, which is generally a low-adhesion backing. The "low adhesion" generally refers to a peeling force of less than 100g, particularly less than 50g, under specified test tapes and conditions.

[0026] The cover tape of the utility model has sufficient electrostatic dissipation performance and also has a light transmittance of 80% to 90% in at least a part of the visible light spectrum (about 400nm to about 700nm), and a more typical light transmittance of 85% to 90%. 4 Ohm to 10 11 ohm range, with a more typical surface resistance of 10 5 Ohm to 10 10 The surface resistance is preferably within the range of 10 5 Ohm to 10 7 The ohm range has sufficient electrostatic dissipation performance and sufficient light transmittance, which makes it easy to observe the electronic components in the electronic component packaging assembly.

[0027] Specific Examples

[0028] Unless otherwise indicated, percentages, ratios, etc. in the examples and the rest of the specification are by weight.

[0029] The light transmittance is measured using a BYK Gardner HazeGard Plus Transmittance Meter, Model 4725, in accordance with ASTM D1003 "Standard Test Method for Haze and Light Transmittance of Transparent Plastics".

[0030] The surface resistance was measured according to the ANSI / STM 11.13 method using a Trek Model 152 resistance meter from Trek Japan (Tokyo, Japan) in contact with the surface of the item to be measured using a two-point probe and a voltage of 10V or 100V.

[0031] Static dissipative film construction layer example 1

[0032] A primer coating (NK350, a primer coating solution from Nippon Shokubai Co. (Osaka, Japan)) was gravure-roll coated onto a 12 μm PET film, and the primer-coated film was heated and dried in an oven to obtain a 0.3 μm dry coating, i.e., a composite layer of the second primer coating and the second polymer substrate layer.

[0033] 11.70kg deionized water, 3.233kg N-methyl pyrrolidone and 0.351kg triethylamine are mixed to prepare solvent mixture. Then, 1.0kg 1 weight % carbon nanotube (CNT) dispersion obtained from Nanocyl USA (Sambreville, Belgium) in the form of AQUACYL AQ0101 carbon nanotube dispersion is added, 1.5kg polyurethane (PU) emulsion obtained from Covestro in the form of NeoRez R-3986 is added, and then a total of 15.284kg of the above-mentioned solvent mixture is added under stirring. The obtained coating mixture is stirred evenly. Next, the solution containing carbon nanotubes prepared above is applied to the composite layer of the second primer and the second polymer substrate layer prepared above using a gravure roller. Then the resulting film is heated in an oven to dry the wet coating, thereby obtaining a static dissipative film structural layer.

[0034] Static dissipative film construction layer example 2

[0035] The primer coating solution (NK100PM, from Nippon Shokubai Co. (Osaka, Japan)) was gravure roll coated onto a 15 μm PET film (PET-1), and the primer-coated film was heated and dried in an oven to obtain a 0.3 μm dry coating, i.e., a composite layer of the second primer layer and the second polymer substrate layer.

[0036] A solvent mixture was prepared by mixing 9.0 kg of deionized water, 3.233 kg of N-methylpyrrolidone and 0.351 kg of triethylamine. Then, 1.0 kg of 1 wt % carbon nanotube (CNT) dispersion obtained from Nanocyl USA (Sambreville, Belgium) in the form of AQUACYL AQ0101 carbon nanotube dispersion was added to 2.7 kg of 1.0 wt % sodium dodecylbenzene sulfonate solution (in deionized water) and then stirred. Then 1.5 kg of polyurethane (PU) emulsion obtained from DSM NV (Heerlen, The Netherlands) in the form of NeoRez R-960 was added and stirred evenly. Finally, a total amount of 12.584 kg of the above-prepared solvent mixture was added under stirring. According to the same method as described in Example 1, the above-prepared solution containing carbon nanotubes was applied to the composite layer of the second primer layer and the second polymer substrate layer prepared above, thereby preparing an electrostatic dissipative film construction layer.

[0037] Preparation of adhesive structure layer

[0038] The adhesive structure layer refers to a composite layer structure including a first polymer substrate layer, an adhesive layer and a low adhesion backsize coating.

[0039] By way of example, the adhesive structural layer can be prepared by using a PET film as the first polymer base layer, a sample of the adhesive structural layer is prepared, one side of the PET film is coated with a polyurethane low-adhesion backing glue, an acrylate-based primer is used to form a first primer layer, and then a 25-micron-thick acrylate-based pressure-sensitive adhesive is coated on the opposite side of the PET film to form an adhesive layer.

[0040] The adhesive structure layer can also directly use 3M 2656 pressure-sensitive tape.

[0041] The aforementioned adhesive structure layer is laminated to the above-prepared static dissipative film structure layer to form a Figure 1 Cover tape sample of the structure shown.

[0042] Cover tape example E-1

[0043] Cover tape Example E-1 can be formed by laminating Static Dissipative Film Construction Layer Example 1 as described above to 3M Company's 2656 Pressure Sensitive Tape (ie, the aforementioned Adhesive Construction Layer).

[0044] Cover tape example E-2

[0045] Cover tape Example E-2 can be formed by laminating Static Dissipative Film Construction Layer Example 2 as described above to 3M Company's 2656 Pressure Sensitive Tape (ie, the aforementioned Adhesive Construction Layer).

[0046] Cover tape comparison example

[0047] The commercially available cover tape was tested, and the performance was compared with the cover tape of the embodiment of the utility model.

[0048] A comparative cover tape example (CE-3) was formed by laminating a clear and uncoated 0.5 mil thick PET film material to a 3M non-conductive 2656 pressure sensitive adhesive structural layer.

[0049] The cover tape comparative example (CE-4) is a metal conductive film (equivalent to the static dissipative film construction layer) prepared by sputtering nickel and chromium on a 0.5 mil thick PET film material. The cover tape is formed by laminating the metal conductive film with the adhesive construction layer 2656.

[0050] Cover tape comparative example CE-5, a coated graphite conductive film (ie, equivalent to a static dissipative film structural layer) was prepared by polishing and coating nanographite particles on a 0.5 mil PET film material. The cover tape was formed by laminating the graphite conductive film with an adhesive structural layer.

[0051] Performance comparison table of the utility model cover tape example and comparative example

[0052]

[0053] From the above performance parameters, the cover tape of the embodiment of the utility model has better light transmittance (greater than 85%), haze within 5% and good surface resistivity. In addition, from the perspective of preparation, the cover tape of such structure provided by the utility model has the advantages of reliable structure, preparing the adhesive structure layer and the static dissipative film structure layer separately, and then compounding the adhesive structure layer and the static dissipative film structure layer together, uniform thickness of the adhesive layer, the back adhesive layer and the conductive coating layer, and simple processing technology.

[0054] According to another embodiment of the present invention, an electronic component packaging assembly 300 is provided, comprising: a carrier tape 200 and a cover tape 100 as provided in an embodiment of the present invention. The carrier tape 200 comprises a film body 210, and the film body 210 has at least one recess 220 (also referred to as a "pocket" in the industry) that can accommodate an electronic component; the cover tape 100 seals the recess 220 of the carrier tape 200 in a peelable manner.

[0055] Since those skilled in the art are very familiar with how to prepare the carrier tape of the electronic component packaging assembly, which is not the focus of the present invention, it will not be described in detail.

[0056] It is understood that the embodiments described above are only used to describe and not to limit the present invention. It is understood by those skilled in the art that the present invention can be modified and deformed as long as it does not deviate from the spirit and scope of the present invention. The above modifications and deformations are considered to be within the scope of the present invention and the appended claims. The scope of protection of the present invention is defined by the appended claims. In addition, any figure marks in the claims should not be understood as limitations on the present invention. The verb "comprise" and its variations do not exclude the presence of other elements or steps other than those stated in the claims. The indefinite article "a" before an element or step does not exclude the presence of multiple such elements or steps.

Claims

1. A cover tape comprising: a first polymeric substrate layer having a first major surface and a second major surface; an adhesive layer disposed on the first major surface of the first polymer substrate layer; A back adhesive coating, the back adhesive coating being disposed on the second major surface of the first polymer substrate layer; The static dissipative film structural layer is characterized in that the static dissipative film structural layer is arranged on the middle part of the adhesive layer so that the two end parts of the adhesive layer remain exposed, and the static dissipative film structural layer includes a second polymer base layer and a conductive coating; the second polymeric substrate layer having a first major surface and a second major surface, the second major surface being adhered to the adhesive layer; The conductive coating is disposed on the first major surface of the second polymer substrate layer; The conductive coating is a coating formed by coating a mixture comprising a dielectric polymer binder and carbon nanotubes dispersed in the dielectric polymer binder. The conductive coating has a thickness of 0.1 to 2 microns.

2. The cover tape according to claim 1, characterized in that A first primer layer is disposed between the adhesive layer and the first major surface of the first polymeric substrate layer.

3. The cover tape according to claim 1, characterized in that A second primer layer is disposed between the conductive coating and the first major surface of the second polymeric substrate layer.

4. The cover tape according to claim 1, characterized in that The adhesive layer is a pressure-sensitive adhesive layer.

5. The cover tape according to claim 1, characterized in that The conductive coating has a thickness of 0.1 to 1.0 micrometer.

6. The cover tape according to claim 1, characterized in that The conductive coating has 10 5 Ohm to 10 10 The surface resistance of the coating is in the ohm range.

7. The cover tape according to claim 1, characterized in that The first polymeric substrate layer and the second polymeric substrate layer are optically clear.

8. An electronic component packaging assembly, comprising: A carrier tape, the carrier tape comprising a film body having at least one recessed portion capable of accommodating an electronic component; It is characterized in that it also includes a cover tape as described in any one of claims 1 to 7, wherein the cover tape seals the recessed portion of the carrier tape in a peelable manner.

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