tape

Abstract

To provide a tape having conformability and heat resistance. [Solution] A tape (10) having a pressure-sensitive adhesive layer (11) on one side of a base layer (12), which has a breaking elongation of 100% or more and an elastic modulus of 2 GPa or less, and after heating at 230°C for 80 seconds, maintains a breaking elongation of 100% or more and an elastic modulus of 2 GPa or less.

Description

Technical Field

[0001] The present invention relates to a tape.

Background Art

[0002] In the manufacturing process of semiconductor components, as described in Patent Documents 1 to 4, a tape having an adhesive layer is used to attach the semiconductor to be processed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the semiconductor fixed to the tape is a chip, the tape's followability to the chip is required. Further, when mounting the semiconductor chip fixed to the tape on a substrate such as an interposer, heat resistance of the tape to withstand the melting temperature of the solder is required in the reflow process.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a tape having followability and heat resistance.

Means for Solving the Problems

[0006] To solve the aforementioned problems, the present invention provides a tape having an adhesive layer on one side of a base layer, having a breaking elongation of 100% or more and an elastic modulus of 2 GPa or less, and maintaining a breaking elongation of 100% or more and an elastic modulus of 2 GPa or less after heating at 230°C for 80 seconds.

[0007] The tape may have a reduced adhesive strength due to the hardening of the adhesive layer. The tape may have an adhesive strength of 0.5 N / 25 mm or less to polybenzoxazole (PBO) after heating at 230°C for 80 seconds, or after the adhesive strength has been reduced by curing the adhesive layer.

[0008] The tape may have a release film on the adhesive surface of the adhesive layer opposite to the substrate layer. The aforementioned tape may be a protective tape for a semiconductor chip. [Effects of the Invention]

[0009] According to the present invention, the tape has a breaking elongation of 100% or more and an elastic modulus of 2 GPa or less, and maintains a breaking elongation of 100% or more and an elastic modulus of 2 GPa or less after heating at 230°C for 80 seconds, thereby providing conformability and heat resistance even when the tape holds a semiconductor chip. [Brief explanation of the drawing]

[0010] [Figure 1] This is a cross-sectional view showing an example of tape. [Modes for carrying out the invention]

[0011] The present invention will be described below based on preferred embodiments. Figure 1 shows an example of a tape according to the embodiment. The tape 10 of the embodiment is a tape having an adhesive layer 11 on one side of a base layer 12, and has a break elongation of 100% or more and an elastic modulus of 2 GPa or less. Furthermore, the tape 10 maintains a break elongation of 100% or more and an elastic modulus of 2 GPa or less even after heating at 230°C for 80 seconds.

[0012] The adhesive layer 11 can fix adherends such as semiconductor wafers and semiconductor chips with a predetermined adhesive strength. The adherends are fixed to the adhesive surface 11a of the adhesive layer 11. In this specification, the adhesive layer refers to either an adhesive layer, an adhesive layer, or a material that combines the properties of both an adhesive layer and an adhesive layer. The adhesive layer 11 can be formed from an adhesive. The adhesive refers to either an adhesive, an adhesive, or a material that combines the properties of both an adhesive and an adhesive. Adhesive strength refers to peel strength, and for example, adhesive strength or bonding strength. The adhesive surface 11a is the surface on which the adhesive layer 11 has adhesive strength, and for example, refers to an adhesive surface or bonding surface. Specific examples of adhesives include acrylic adhesives, silicone adhesives, urethane adhesives, epoxy adhesives, olefin heat sealants, etc. The adhesive layer 11 is not limited to pressure-sensitive adhesives (adhesives), and may be formed using curing adhesives, reactive adhesives, solvent-based adhesives, etc. A tape 10 using an adhesive in the adhesive layer 11 may be an adhesive tape. A tape 10 using an adhesive in the adhesive layer 11 may be an adhesive tape.

[0013] Until the adherend is fixed to the adhesive layer 11, the adhesive surface 11a of the adhesive layer 11 may have a release film 14. To improve the bonding strength between the adhesive layer 11 and the base layer 12, the base layer 12 may have an anchoring agent layer between it and the adhesive layer 11. If the tape 10 has a release film 14, the release film 14 is removed before the tape 10 is attached to the adherend. The tape body 13, which has the adhesive layer 11 on one side of the base layer 12, is bonded to the adherend.

[0014] The base layer 12 is not particularly limited, but examples include polyolefin resins such as polyethylene (PE) resin and polypropylene (PP) resin; polyester resins such as polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin and polyethylene naphthalate (PEN) resin; and at least one resin film such as nylon polyamide (PA) resin, polyimide (PI) resin, polyetherimide (PEI) resin, polyamideimide (PAI) resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyphenylene sulfide (PPS) resin, polyetheretherketone (PEEK) resin, and fluororesin.

[0015] The optical properties of the base layer 12 are not particularly limited and can be transparent, translucent, or opaque. The base layer 12 may be a resin film with coloring or printing. The thickness of the base layer 12 is not particularly limited, but for example, it may be 5 to 500 μm, and in the case of a thin layer, it may be about 15 to 30 μm. The base layer 12 may be a single layer or a laminate of two or more layers.

[0016] From the viewpoint of conformability to the adherend, it is preferable that the elongation at break of the tape 10 is 100% or more and the elastic modulus of the tape 10 is 2 GPa or less. If the tape 10 has a release film 14, the elongation at break and elastic modulus of the tape body 13, which has an adhesive layer 11 on one side of the base layer 12 and excludes the release film 14, are measured as the elongation at break and elastic modulus of the embodiment.

[0017] Elongation at break is a value expressed as a percentage of the elongation of a sample, such as a film, at the point of breakage under constant-speed tensile stress. Specifically, if the length of the sample before the tensile test is Lo and the length of the sample at break is L, the elongation at break is expressed as (L-Lo) / Lo × 100 (%). The higher the elongation at break, the more flexible the film is against tensile force.

[0018] The elastic modulus is, for example, the proportionality constant between stress and strain when a sample such as a film undergoes elastic deformation. Examples of the elastic modulus include tensile elastic modulus, compressive elastic modulus, flexural elastic modulus, shear elastic modulus, torsional elastic modulus, etc. The elastic modulus in the tensile direction is called Young's modulus. The apparatus and sample used for the Young's modulus test may be the same as those used for the elongation at break test. The elastic modulus of the tape 10 is not particularly limited as long as it is 2 GPa or less, but it may be 0.5 GPa or more, and for example, it may be about 1.0 GPa.

[0019] The base material layer 12 preferably has heat resistance for heat treatment at a heating temperature of 200°C to 260°C, for example, as a resin with high heat resistance. Specific examples of the heat-resistant resin include, for example, at least one of polyimide (PI) resin, polyetherimide (PEI) resin, polyamideimide (PAI) resin, polyethersulfone (PES) resin, polyphenylene sulfide (PPS) resin, polyetheretherketone (PEEK) resin, polyethylene naphthalate (PEN) resin, fluororesin, etc.

[0020] When the tape 10 is used for applications that require heat treatment, it is preferable that the above-mentioned elongation at break and elastic modulus are maintained even after the heat treatment. For example, it is preferable that the tape 10 maintains an elongation at break of 100% or more and an elastic modulus of 2 GPa or less even after heating at 230°C for 80 seconds.

[0021] In at least one of the base material layers 12, it is preferable to use, for example, a highly stretchable polyimide resin having an aliphatic unit with 3 or more carbon atoms between aromatic units as a resin having both heat resistance and flexibility. Further, the aliphatic unit preferably contains a polyalkyleneoxy group having an alkylene group with about 1 to 10 carbon atoms. As a material for forming the polyimide resin layer, a solvent-soluble polyimide varnish may be used. The polyimide resin may be a copolymer having an imide group in the molecule, and may be a polyetherimide (PEI) resin, a polyamideimide (PAI) resin, etc.

[0022] Preferably, the adhesive layer 11 can reduce its adhesive strength to the adherend so that the adherend, such as a semiconductor wafer or semiconductor chip, can be easily removed if necessary. For example, by adding a photosensitive material such as a photocurable resin or a photopolymerization initiator to the adhesive layer 11, the adhesive layer 11 can harden when irradiated with energy rays such as ultraviolet rays or electron beams, thereby reducing its adhesive strength. In this case, it is preferable that the substrate layer transmits the energy rays necessary to harden the adhesive layer 11. For example, it is preferable that the transmittance of the substrate layer 12 is 15% or more at wavelengths of 365 nm, 405 nm, or in between these wavelengths.

[0023] The release film 14 is not particularly limited as long as it is a film that covers and protects the adhesive layer 11 when the tape 10 is not in use, and can be peeled off before fixing the adherend. The release film 14 may be a resin film having a release agent layer on its surface, such as a silicone-based release agent, a fluorine-based release agent, or a long-chain alkyl-based release agent, or it may be a resin film without a release agent layer on its surface. The release film 14 does not need to have excellent heat resistance, high stretchability, or energy ray transmittance, but it may be transparent to facilitate visual inspection of the adhesive layer 11.

[0024] The method for manufacturing the tape 10 is not particularly limited, but the tape 10 may be manufactured by forming an adhesive layer 11 on a base layer 12. The tape 10 may also be manufactured by forming an adhesive layer 11 on a release film 14 and then compounding it with the base layer 12. The tape 10 may also be manufactured by sequentially forming the adhesive layer 11 and the base layer 12 on the release film 14 by coating or the like.

[0025] When winding the tape 10 into a roll, the laminate having the tape body 13 and the release film 14 may be formed into a roll. Alternatively, the release film 14 may be omitted, and the tape body 13 may be wound so that the adhesive layer 11 overlaps with the base layer 12. If the release film 14 is omitted, the base layer 12 may also perform the function of the release film 14, or a release agent layer may be provided on the back surface 12a of the base layer 12.

[0026] The method for manufacturing semiconductor components using the tape 10 is not particularly limited, but the tape 10 may be attached to a semiconductor wafer or attached to a semiconductor chip. When the tape 10 is used during semiconductor wafer processing, a manufacturing method can be described that includes a fixing step of fixing the semiconductor wafer to the adhesive layer 11 of the tape 10, a dicing step of cutting the semiconductor wafer to which the tape 10 is attached to obtain a semiconductor chip on the adhesive layer 11, and a pickup step of peeling the semiconductor chip off the tape 10. When the tape 10 is used to protect a semiconductor chip, the semiconductor chip obtained by cutting the semiconductor wafer may be fixed to the adhesive layer 11 of the tape 10, and processing of the semiconductor chip may be performed on the tape 10.

[0027] Each process related to the manufacturing of semiconductor components may be carried out under conditions different from those of the fixed process, such as the main body or location. When removing the adherend from the adhesive layer 11, the adhesive layer 11 may be irradiated with energy rays to reduce its adhesive strength. A reflow process may be performed in which the semiconductor chip is soldered to other components such as an interposer or lead frame while the semiconductor chip remains fixed on the adhesive layer 11. When the tape 10 is applied to the reflow process, it is preferable that the tape 10 has heat resistance that can withstand the reflow process. The solder used for reflow is not particularly limited, but may be in the form of a plate, paste, cream, etc. The tape 10 may be used to temporarily fix the semiconductor chip to the interposer, etc., before reflow. The surrounding area may be vacuumed to ensure that the tape 10 adheres tightly to the semiconductor chip, etc.

[0028] Although the present invention has been described above based on preferred embodiments, the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention.

[0029] The adherend is not limited to semiconductor wafers and semiconductor chips such as silicon (Si), but can also include glass substrates, metal substrates, resin substrates, laminates containing one or more of these, and electronic devices. Even with these adherends, a process similar to the semiconductor component manufacturing method described above can be performed to process and treat the adherend with the tape attached, followed by a step to peel the adherend off the tape 10. The tape's applications are not particularly limited, but include protective tape, cover tape, dicing tape, die bonding tape, masking tape, polishing tape, sealing tape, transport tape, insulating tape, and process tape. [Examples]

[0030] The present invention will be specifically described below with reference to examples.

[0031] (Preparation of tapes in Examples 1 and 2) Tapes of Examples 1 and 2 were prepared by forming a 20 μm thick adhesive layer using a heat-resistant, low-tack adhesive, and then forming a base layer using a solvent-soluble polyimide varnish (product name MP17A) manufactured by Mitsui Chemicals, Inc. In the tape of Example 1, the thickness of the base layer was 12.5 μm. In the tape of Example 2, the thickness of the base layer was 25 μm.

[0032] (Preparation of the tape for Comparative Example 1) Comparative Example 1 tape was prepared by forming a 20 μm thick adhesive layer using the same materials as in Examples 1 and 2, and then forming a base layer using a polyether ether ketone film (product name EXPEEK®, 25 μm thick) manufactured by Kurabo Industries Ltd.

[0033] (Preparation of the tape for Comparative Example 2) Comparative Example 2 tape was prepared by forming a 20 μm thick adhesive layer using the same materials as in Examples 1 and 2, and then forming a base layer using a polyimide film from Toray DuPont (product name Kapton® 50H, thickness 12.5 μm).

[0034] (Evaluation of responsiveness) Tape was applied to an interposer on which chips with a height of 50-60 μm were placed at intervals of 500-600 μm using a vacuum tape mounter. The tape was applied to the surface of the interposer and the outer surface of each chip so as to cover the periphery of the multiple chips placed on the interposer. (○) was evaluated when the tape deformed to follow each chip, and (×) was evaluated when the tape did not deform to follow each chip.

[0035] (Evaluation of tensile properties) Three tensile properties were measured: Young's modulus, breaking strength, and elongation at breaking. A Shimadzu AGS-X 500N measuring instrument was used. The sample size was 15 mm wide x 120 mm long. The ambient temperature was room temperature (23°C). The sample was gripped 10 mm from both ends along its length, and measurements were taken three times repeatedly at a tensile speed of 50 mm / min. The average value was used. Young's modulus (GPa) was calculated from the initial slope of the chart. Breaking strength was measured as the strength (MPa) at which the sample broke. The elongation at break was calculated as 100 × (L - Lo) / Lo, where Lo is the length of the sample before testing and L is the length of the sample at break.

[0036] (Heat resistance) For heat resistance, a sample of the same type as the tensile properties described above was placed in an oven and heated at 230°C for 80 seconds. Three types of tensile properties were then measured: Young's modulus, breaking strength, and elongation at breaking.

[0037] (adhesive strength) Adhesion strength was measured using an EZ Graph manufactured by Shimadzu Corporation. The sample size was 25 mm wide x 100 mm long, the temperature was 23°C (room temperature), the adherend was a PBO-treated silicon wafer, the bonding method was a 2 kg roller, the bonding area was 25 mm wide x 90 mm long, the tensile speed was 300 mm / min, and the peeling angle was 180°. Three measurements were repeated, and the average value was adopted. Two types of adhesion strength were measured: "initial adhesion strength" and "adhesion strength after heating." "Initial adhesion strength" is the adhesion strength measured before heating. "Adhesion strength after heating" is the adhesion strength measured after heating at 230°C for 80 seconds. The PBO-treated silicon wafer used as the adherend is a silicon wafer with a PBO film on its surface, and by using this adherend, the adhesion strength to PBO can be measured.

[0038] The evaluation results are shown in Table 1.

[0039] [Table 1]

[0040] The tapes of Examples 1 and 2 possessed heat resistance sufficient to withstand the reflow process, as well as excellent conformability to the chip and strong adhesive properties. Due to the high elongation at break and low modulus of elasticity of the tapes, it was found that they could achieve excellent conformability to the surface, including the areas around the irregularities, even on substrates with circuit components such as semiconductor chips. The tapes in Comparative Examples 1 and 2 had a break elongation of less than 100% and an elastic modulus exceeding 2 GPa, resulting in poor conformability to the chip. The tapes in Comparative Examples 1 and 2 also possessed heat resistance, as there was little difference between their tensile properties before heating and their tensile properties after heating at 230°C for 80 seconds. Despite the heat resistance of the tapes, the poor conformability to the chip is thought to be due to the low break elongation and high elastic modulus (Young's modulus), which resulted in low deformability of the tapes. [Explanation of symbols]

[0041] 10...Tape, 11...Adhesive layer, 11a...Adhesive surface, 12...Base layer, 12a...Back, 13...Tape body, 14...Release film.

Claims

1. A tape having an adhesive layer on one side of a substrate layer formed using a solvent-soluble polyimide varnish, The aforementioned tape is a protective tape that protects a semiconductor wafer or semiconductor chip as an adherend. The tape has a breaking elongation of 100% or more and an elastic modulus of 2 GPa or less, and maintains a breaking elongation of 100% or more and an elastic modulus of 2 GPa or less after heating at 230°C for 80 seconds.

2. The tape according to claim 1, wherein the adhesive layer can reduce its adhesive strength by hardening.

3. The tape according to claim 1 or 2, wherein, after heating at 230°C for 80 seconds, or after the adhesive strength is reduced by hardening of the adhesive layer, the adhesive strength to polybenzoxazole (PBO) is 0.5 N / 25 mm or less.

4. The tape according to any one of claims 1 to 3, wherein the adhesive layer has a release film on the adhesive surface opposite to the base material layer.

5. A protective tape for protecting a semiconductor chip as an adherend, according to any one of claims 1 to 4.

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