Cut crystal grain bonding integrated film, its quality management method, and manufacturing method of semiconductor device

Abstract

The present invention discloses a quality management method for a diced die bonding integrated film. The quality management method includes: a first step of preparing a diced die bonding integrated film having a base material layer, a pressure-sensitive adhesive layer, and an adhesive layer, the base material layer having a first surface and a second surface on the side opposite to the first surface, the pressure-sensitive adhesive layer being provided on the second surface of the base material layer and formed of a photocurable pressure-sensitive adhesive, and the adhesive layer being provided on the side of the pressure-sensitive adhesive layer opposite to the base material layer; a second step of calculating a load length ratio tp for the first surface of the base material layer of the diced die bonding integrated film; and a third step of determining whether the quality of the diced die bonding integrated film is good or bad using the load length ratio tp as an index.

Description

Technical Field

[0001] The present disclosure relates to a dicing grain bonding integrated film, a quality management method thereof, and a method for manufacturing a semiconductor device. Background Art

[0002] In the manufacture of semiconductor wafers, it generally includes: a dicing process of singulating a semiconductor wafer into individual semiconductor wafers; a pick-up process of peeling the singulated semiconductor wafers from a pressure-sensitive adhesive layer; and a grain bonding process of bonding the singulated semiconductor wafers to a lead frame, a package substrate, etc. In the manufacture of such semiconductor wafers, a dicing grain bonding integrated film is mainly used, and the dicing grain bonding integrated film includes: a substrate layer; a pressure-sensitive adhesive layer (photo-curable pressure-sensitive adhesive layer) formed of a photo-curable pressure-sensitive adhesive used for fixing the semiconductor wafer in the dicing process; and an adhesive layer for bonding the semiconductor wafer and the lead frame, the package substrate, etc. The dicing grain bonding integrated film can integrate a dicing film including a pressure-sensitive adhesive layer and a grain bonding film including an adhesive layer.

[0003] In recent years, as an example of a method for manufacturing semiconductor wafers by singulating thin semiconductor wafers, so-called stealth dicing has been proposed. In this stealth dicing, the semiconductor wafer is not completely cut, but laser light is irradiated inside the semiconductor wafer on a predetermined cutting line to form a modified layer, and the pressure-sensitive adhesive layer is expanded, thereby cutting the semiconductor wafer (for example, Patent Document 1). From the viewpoint of preventing breakage in the subsequent pick-up process, the semiconductor wafers singulated by stealth dicing are required to peel the pressure-sensitive adhesive layer and the adhesive layer with a small force. Therefore, for the dicing grain bonding integrated film used for the manufacture of thin semiconductor wafers, it is extremely important to improve the success rate of pick-up with a small force.

[0004] In order to improve the success rate of pick-up, the following documents have proposed to improve the dicing film, especially the pressure-sensitive adhesive layer. Patent Document 2 has proposed an optimized composition of the pressure-sensitive adhesive layer. Patent Document 3 has proposed to optimize the substrate layer and the pressure-sensitive adhesive layer together. And, in the substrate layer of the dicing film, in order to improve the success rate of pick-up, excellent uniform extensibility and tensile stress considering the operation process are important. For example, Patent Document 4 describes that the uniform expandability and recovery rate of the film are effective for the expansion process of the semiconductor manufacturing process. And, in Patent Document 5, the gap (cut width) between wafers is controlled by controlling the elongation rate and shrinkage rate of the dicing film to improve the success rate of pick-up.

[0005] On the other hand, in the cutting film, from the viewpoints of improving transportability and suppressing adhesion, various treatments have been studied for the surface of the base material layer on the side opposite to the pressure-sensitive adhesive layer (hereinafter, sometimes referred to as the "back surface of the base material layer" as the case may be). For example, Patent Document 6 describes adjusting the arithmetic surface roughness and treating the back surface of the base material layer with a lubricating material. And, for example, Patent Document 7 describes setting the arithmetic surface roughness of the back surface of the base material layer within a predetermined range from the viewpoints of suppressing adhesion and improving recognition.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2003-338467

[0009] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2015-126217

[0010] Patent Document 3: Japanese Unexamined Patent Application Publication No. 2013-135146

[0011] Patent Document 4: Japanese Unexamined Patent Application Publication No. 2018-065327

[0012] Patent Document 5: Japanese Unexamined Patent Application Publication No. 2017-147293

[0013] Patent Document 6: Japanese Unexamined Patent Application Publication No. 2007-150206

[0014] Patent Document 7: International Publication No. 2017 / 150330 Summary of the Invention

[0015] Technical Problem to be Solved by the Invention

[0016] In the manufacture of semiconductor wafers, light is irradiated onto the pressure-sensitive adhesive layer through the base material layer from the back surface of the base material layer. According to the research of the present inventors, it has been found that the base material layer of the diced die bonding integrated film gradually deteriorates for various reasons, and along with this, the photoreactivity of the pressure-sensitive adhesive layer sometimes also decreases. The decrease in the photoreactivity of the pressure-sensitive adhesive layer leads to a decrease in the success rate of picking up. Therefore, it is important to manage the quality of the diced die bonding integrated film. However, it is impossible to judge whether the quality is maintained by visual observation, and usually it is impossible to know without actual use.

[0017] The present disclosure has been completed in view of such circumstances, and its main object is to provide a new quality management method for a diced die bonding integrated film.

[0018] Means for Solving the Technical Problem

[0019] In the case of a diced die-bonded integrated film, particularly the base material layer of a diced film, it is usually stored in a state where a certain tension is applied to the core before use. Depending on the storage conditions at this time, creep may occur in the base material layer, resulting in uneven deformation on the back surface of the base material layer. Conventionally, in the case of a diced film, a method of controlling the back surface of the base material layer using arithmetic surface roughness (Ra), arithmetic mean height (Sa), coefficient of friction, etc. as indices has been known from the viewpoints of improving transportability, recognizability, and suppressing adhesion (for example, refer to Patent Documents 6 and 7). However, in processes used in recent semiconductor manufacturing steps (for example, a dicing step, etc.), more precise adhesion control is required. In addition, it is considered that the transmittance of light irradiated from the back surface of the base material layer is affected by the unevenness of the back surface of the base material layer, which affects the light reactivity of the pressure-sensitive adhesive layer, and as a result, affects mass productivity. As a result of the present inventors' in-depth study of the state of the back surface of the base material layer, it has been found that the load length ratio tp is excellent as an evaluation index compared to the conventional surface roughness parameters, and the present invention has been completed.

[0020] One aspect of the present disclosure relates to a quality management method for a diced die-bonded integrated film. The quality management method includes: a first step of preparing a diced die-bonded integrated film including a base material layer, a pressure-sensitive adhesive layer, and an adhesive layer, the base material layer having a first surface (corresponding to the "back surface of the base material layer" described above) and a second surface on the side opposite to the first surface, the pressure-sensitive adhesive layer being provided on the second surface of the base material layer and formed of a photocurable pressure-sensitive adhesive, and the adhesive layer being provided on the side of the pressure-sensitive adhesive layer opposite to the base material layer; a second step of calculating the load length ratio tp of the first surface of the base material layer of the diced die-bonded integrated film; and a third step of determining whether the quality of the diced die-bonded integrated film is good or bad using the load length ratio tp as an index.

[0021] The diced die-bonded integrated film thus determined can be a film with excellent pick-up success rate. Therefore, such a quality management method is useful for determining whether the quality of the diced die-bonded integrated film to be used is maintained.

[0022] The load length ratio tp can be the load length ratio tp(50%) at a cutting level of 50%. At this time, the third step can be a step of determining whether the quality is good or bad based on whether the load length ratio tp(50%) satisfies 15% or more.

[0023] Another aspect of the present disclosure relates to a method of manufacturing a semiconductor device. The method of manufacturing the semiconductor device includes: a first step of preparing a diced die bonding integrated film including a substrate layer, a pressure-sensitive adhesive layer, and an adhesive layer, the substrate layer having a first surface and a second surface on the side opposite to the first surface, the pressure-sensitive adhesive layer being provided on the second surface of the substrate layer and formed of a photocurable pressure-sensitive adhesive, and the adhesive layer being provided on the side opposite to the substrate layer with respect to the pressure-sensitive adhesive layer; a second step of calculating a load length ratio tp for the first surface of the substrate layer of the diced die bonding integrated film; a third step of determining whether the quality of the diced die bonding integrated film is good or bad using the load length ratio tp as an index; and a fourth step of manufacturing a semiconductor device using the diced die bonding integrated film determined to be good in the third step.

[0024] The load length ratio tp may be the load length ratio tp(50%) at a cutting level of 50%. At this time, the third step may be a step of determining whether the quality is good or bad based on whether the load length ratio tp(50%) satisfies 15% or more.

[0025] Another aspect of the present disclosure relates to a diced die bonding integrated film. The diced die bonding integrated film includes: a substrate layer having a first surface and a second surface on the side opposite to the first surface; a pressure-sensitive adhesive layer provided on the second surface of the substrate layer and formed of a photocurable pressure-sensitive adhesive; and an adhesive layer provided on the side opposite to the substrate layer with respect to the pressure-sensitive adhesive layer, and the load length ratio tp(50%) at a cutting level of 50% of the first surface of the substrate layer is 15% or more.

[0026] Advantageous Effects of the Invention

[0027] According to the present disclosure, a new quality management method for a diced die bonding integrated film is provided. Further, according to the present disclosure, a diced die bonding integrated film determined to be of good quality by such a method and a method of manufacturing a semiconductor device using such a diced die bonding integrated film are provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic cross-sectional view showing an embodiment of a diced die bonding integrated film.

[0029] Figure 2 is an explanatory diagram for explaining the load length ratio tp.

[0030] Figure 3 is a schematic cross-sectional view for explaining an embodiment of a method of manufacturing a semiconductor device, Figure 3 (a), Figure 3 (b), Figure 3 (c), Figure 3 (d) and Figure 3(e) is a schematic cross-sectional view showing each process.

[0031] Figure 4 is a schematic cross-sectional view for explaining an embodiment of a method for manufacturing a semiconductor device, Figure 4 (f), Figure 4 (g), Figure 4 (h), and Figure 4 (i) are schematic cross-sectional views showing each process.

[0032] Figure 5 is a schematic cross-sectional view showing an embodiment of a semiconductor device. Detailed Embodiments

[0033] Hereinafter, embodiments of the present disclosure will be described with appropriate reference to the accompanying drawings. However, the present disclosure is not limited to the following embodiments. In the following embodiments, unless otherwise specifically stated, its constituent elements (including processes, etc.) are not essential. The sizes of the constituent elements in each figure are conceptual, and the relative size relationships between the constituent elements are not limited to those shown in each figure.

[0034] The same applies to the numerical values and their ranges in this specification, and they do not limit the present disclosure. In this specification, the numerical range represented by "~" means including the numerical values before and after "~" as the minimum value and the maximum value, respectively. Among the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value recorded in one numerical range can be replaced with the upper limit value or the lower limit value of other stepwise described numerical ranges. Moreover, within the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range can be replaced with the value shown in the examples.

[0035] In this specification, (meth)acrylate refers to acrylate or its corresponding methacrylate. The same applies to other similar expressions such as (meth)acryloyl and (meth)acrylic acid copolymer.

[0036] [Quality Management Method for Die-Sliced and Bonded Integrated Film]

[0037] A quality management method for a die-sliced and bonded integrated film according to an embodiment includes: a first process of preparing a die-sliced and bonded integrated film having a base material layer, a pressure-sensitive adhesive layer, and an adhesive layer, the base material layer having a first surface and a second surface on the side opposite to the first surface, the pressure-sensitive adhesive layer being provided on the second surface of the base material layer and formed of a photocurable pressure-sensitive adhesive, and the adhesive layer being provided on the side of the pressure-sensitive adhesive layer opposite to the base material layer; a second process of calculating a load length ratio tp for the first surface of the base material layer of the die-sliced and bonded integrated film; and a third process of determining whether the quality of the die-sliced and bonded integrated film is good or bad using the load length ratio tp as an index.

[0038] <First Process>

[0039] This process is for preparing a diced crystal-bonded integrated film as the object to be managed. Figure 1 It is a schematic cross-sectional view showing an embodiment of the diced crystal-bonded integrated film. The diced crystal-bonded integrated film 1 includes: a base material layer 10 having a first surface 10A and a second surface 10B on the side opposite to the first surface 10A; a pressure-sensitive adhesive layer 20 provided on the second surface 10B of the base material layer 10 and formed of a photocurable pressure-sensitive adhesive; and an adhesive layer 30 provided on the side of the pressure-sensitive adhesive layer 20 opposite to the base material layer 10.

[0040] (Base Material Layer)

[0041] The base material layer 10 can use known polymer sheets or films, and there is no particular limitation as long as it is made of a material that can be expanded in the crystal bonding process. Examples of such materials include: polyolefins such as crystalline polypropylene, amorphous polypropylene, high-density polyethylene, medium-density polyethylene, low-density polyethylene, ultra-low-density polyethylene, low-density linear polyethylene, polybutene, and polymethylpentene; ethylene-vinyl acetate copolymer; ionomer resin; ethylene-(meth)acrylic acid copolymer; ethylene-(meth)acrylate (random, alternating) copolymer; ethylene-propylene copolymer; ethylene-butene copolymer; ethylene-hexene copolymer; polyurethane; polyesters such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate; polyimide; polyetheretherketone; polyimide; polyetherimide; polyamide; wholly aromatic polyamide; polyphenylene sulfide; polyaramide (paper); glass; glass cloth; fluororesin; polyvinyl chloride; polyvinylidene chloride; cellulose-based resin; silicone resin, etc. These materials can be materials mixed with plasticizers, silica, anti-sticking materials, slip agents, antistatic agents, etc.

[0042] Among them, from the viewpoints of properties such as Young's modulus, stress relaxation property, melting point, price, and waste reuse after use, the base material layer 10 can have a surface mainly composed of at least one material selected from polyethylene, polypropylene, polyethylene-propylene random copolymer, and polyethylene-propylene block copolymer, and this surface is in contact with the pressure-sensitive adhesive layer 20. The base material layer 10 can be a single layer or a multi-layer of two or more layers formed of different materials. From the viewpoint of controlling the adhesion to the pressure-sensitive adhesive layer 20 described later, the base material layer 10 can be subjected to surface roughening treatments such as corona discharge treatment and matting treatment as needed.

[0043] The thickness of the base material layer 10 can be 50 to 200 μm, 60 to 150 μm, or 70 to 120 μm. When the thickness of the base material layer 10 is 50 μm or more, it tends to be able to further suppress breakage caused by expansion. When the thickness of the base material layer 10 is 200 μm or less, the stress during picking is likely to reach the adhesive layer, and the pickability tends to be more excellent.

[0044] (Pressure-sensitive adhesive layer)

[0045] The pressure-sensitive adhesive layer 20 is a layer formed of a photocurable pressure-sensitive adhesive. The photocurable pressure-sensitive adhesive is not particularly limited as long as it is a pressure-sensitive adhesive cured by light, and a pressure-sensitive adhesive used in the field of cutting films can be used. The photocurable pressure-sensitive adhesive can be an ultraviolet-curable type photocurable pressure-sensitive adhesive cured by ultraviolet rays.

[0046] The pressure-sensitive adhesive layer 20 is formed on the base material layer 10. As a method for forming the pressure-sensitive adhesive layer 20 on the base material layer 10, for example, there can be mentioned: a method of preparing a varnish for forming a pressure-sensitive adhesive layer, coating the varnish on the base material layer 10, removing the volatile components of the varnish, and forming the pressure-sensitive adhesive layer 20; a method of coating the varnish on a demolded film, removing the volatile components of the varnish, forming the pressure-sensitive adhesive layer 20, and transferring the obtained pressure-sensitive adhesive layer 20 to the base material layer 10, etc.

[0047] The varnish for forming a pressure-sensitive adhesive layer contains, for example, a photocurable pressure-sensitive adhesive and an organic solvent. The organic solvent can dissolve the contained components and can be volatilized by heating. As such an organic solvent, for example, there can be mentioned: aromatic hydrocarbons such as toluene and xylene; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; alcohols such as methanol, ethanol, ethylene glycol, and propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as methyl acetate, ethyl acetate, and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; polyol alkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol dimethyl ether; polyol alkyl ether acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate; amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone, etc. These can be used alone or in combination of two or more. Based on the total mass of the varnish, the solid content concentration of the varnish can be 10 to 60% by mass.

[0048] The thickness of the pressure-sensitive adhesive layer 20 can be, for example, 1 to 200 μm, 3 to 50 μm, or 5 to 30 μm.

[0049] (Adhesive layer)

[0050] The adhesive layer 30 is a layer formed of an adhesive. The adhesive can be an adhesive used in the field of die bonding films. Hereinafter, as one mode, an adhesive containing an epoxy resin, an epoxy resin curing agent, and an (meth)acrylic copolymer having an epoxy group will be described. According to the adhesive layer 30 formed of such an adhesive, the adhesiveness between the wafer and the substrate and between the wafers is excellent, and electrode embeddability, wire embeddability, etc. can be imparted, and bonding can be performed at a low temperature in the die bonding process.

[0051] · Epoxy resin

[0052] Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin, epoxy resin containing a dicyclopentadiene skeleton, stilbene type epoxy resin, epoxy resin containing a triazine skeleton, epoxy resin containing a fluorene skeleton, triphenol phenol methane type epoxy resin, biphenyl type epoxy resin, xylylene type epoxy resin, biphenyl aralkyl type epoxy resin, naphthalene type epoxy resin, polyfunctional phenols, polycyclic aromatic compounds such as anthracene, and diglycidyl ether compounds. These can be used alone or in combination of two or more.

[0053] · Epoxy resin curing agent

[0054] The epoxy resin curing agent can be, for example, a phenolic resin. The phenolic resin can be used without particular limitation as long as it has phenolic hydroxyl groups in the molecule. Examples of the phenolic resin include novolak type phenolic resins obtained by condensing or co-condensing phenols such as phenol, cresol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, aminophenol, and / or naphthols such as α-naphthol, β-naphthol, and dihydroxynaphthalene with compounds having aldehyde groups such as formaldehyde under an acidic catalyst, allylated bisphenol A, phenolic aralkyl resins synthesized from allylated bisphenol F, allylated naphthalene diol, phenol novolak, phenols such as phenol, and / or naphthols and dimethoxy-p-xylene or bis(methoxymethyl)biphenyl, naphthol aralkyl resins, etc. These can be used alone or in combination of two or more.

[0055] · (Meth)acrylic copolymer having an epoxy group

[0056] The (meth)acrylic acid copolymer having an epoxy group may be a copolymer in which glycidyl (meth)acrylate as a raw material is adjusted to an amount of 0.5 to 6% by mass relative to the resulting copolymer. When the amount is 0.5% by mass or more, it tends to be easy to obtain high adhesiveness, and when the amount is 6% by mass or less, it tends to be able to suppress gelation. The remainder of the glycidyl (meth)acrylate may be a mixture of (meth)acrylic acid alkyl esters having an alkyl group with 1 to 8 carbon atoms such as methyl (meth)acrylate, styrene, acrylonitrile, etc. The (meth)acrylic acid alkyl ester may contain ethyl (meth)acrylate and / or butyl (meth)acrylate. The mixing ratio of each component can be adjusted in consideration of the Tg (glass transition point) of the resulting (meth)acrylic acid copolymer having an epoxy group. When the Tg is -10°C or higher, the viscosity of the adhesive layer 30 in the B-stage state tends to become good, and the workability tends to be excellent. The upper limit value of the Tg of the (meth)acrylic acid copolymer having an epoxy group can be, for example, 30°C.

[0057] The weight average molecular weight of the (meth)acrylic acid copolymer having an epoxy group can be 100,000 or more, or can be 300,000 to 3,000,000 or 500,000 to 2,000,000. When the weight average molecular weight is 3,000,000 or less, it tends to be able to suppress the decrease in the filling property between the semiconductor wafer and the support substrate. The weight average molecular weight is a polystyrene conversion value using a calibration curve based on standard polystyrene in gel permeation chromatography (GPC).

[0058] The adhesive may further contain a curing accelerator such as a tertiary amine, imidazoles, quaternary ammonium salts, etc. as needed. As the curing accelerator, for example, 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimesate can be cited. These can be used alone or in combination of two or more.

[0059] The adhesive may further contain an inorganic filler as needed. As the inorganic filler, for example, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whiskers, boron nitride, crystalline silica, amorphous silica, etc. can be cited. These can be used alone or in combination of two or more.

[0060] The adhesive layer 30 is formed on the pressure-sensitive adhesive layer 20. As a method for forming the adhesive layer 30 on the pressure-sensitive adhesive layer 20, for example, a varnish for forming an adhesive layer can be prepared, the varnish is coated on a demolded film to form the adhesive layer 30, and the obtained adhesive layer 30 is transferred to the pressure-sensitive adhesive layer 20. The varnish for forming an adhesive layer contains the components contained therein (for example, epoxy resin, epoxy resin curing agent, (meth)acrylic copolymer having an epoxy group, etc.) and an organic solvent. The organic solvent can be the same as those exemplified in the organic solvents used in the varnish for forming a pressure-sensitive adhesive layer.

[0061] The thickness of the adhesive layer 30 can be, for example, 1 to 300 μm, 5 to 150 μm, or 10 to 100 μm.

[0062] <Second step>

[0063] This step is a step of calculating the load length ratio tp of the first surface of the substrate layer of the diced die bonding integrated film of the object to be managed. Here, the load length ratio tp is a value measured in accordance with JIS B0601:1994. Figure 2 It is an explanatory diagram for explaining the load length ratio tp. As Figure 2 shown, the load length ratio tp (C%) is the percentage with respect to the reference length l at the cutting level C, and is a parameter represented by the following formula. The reference length l is a value determined by surface roughness, surface periodicity, etc. The maximum height Ry is the distance between the highest peak and the lowest valley of the roughness curve. The cutting level C sets the highest peak of the roughness curve to 0% and the lowest valley to 100%. The load length ratio tp (0%) at the maximum cutting level 0% is 0%, and the load length ratio tp (100%) at the cutting level 100% is 100%.

[0064] [Formula 1]

[0065]

[0066] There are various parameters in the surface roughness. For example, the arithmetic mean roughness Ra specified in JIS B0601:1994, etc. are parameters in the height direction of the roughness. On the other hand, the load length ratio tp is a parameter representing the complexity of the unevenness including the width of the peak (width of the valley) of the roughness curve and the information in the height direction of the roughness. The complexity of the unevenness of the surface through which light is transmitted in light transmissivity has a great influence on light scattering, reflection, etc. Therefore, in the diced die bonding integrated film where light transmissivity is important, the load length ratio tp of the surface of the substrate layer can be a more effective evaluation index.

[0067] The load length ratio tp can be measured, for example, by the method described in the embodiments. That is, a sample with a side length of 10 mm can be prepared, and 10 to 30, preferably 20 to 30 samples can be randomly measured with a laser microscope, and thus the load length ratio tp can be calculated. In addition, the median of the predetermined number of samples in the load length ratio tp is more suitable as data than the average value. Here, the median refers to the value located in the middle when a finite number of data are arranged in ascending order. In the case where the number of data is even, it refers to the average value of the values close to the middle. The present inventors believe that in the case of the average value, sometimes a value with a large deviation from other data may be adopted due to local data, and when the absolute value of this data is too large, it will have a great impact on the average value and it cannot be ensured that the data distribution is a normal distribution. Therefore, it is optimal to use the median of the set of data for the load length ratio tp.

[0068] <Third step>

[0069] This step is a step of determining the quality of the cut grain-bonded integral film using the load length ratio tp as an index. The cutting level C% at the load length ratio tp is not particularly limited and can be arbitrarily set. However, since the load curve shows a gentle curve, the load length ratio tp can be the load length ratio tp(50%) at which the cutting level is 50%. At this time, the third step can be a step of determining the quality of the film as good or bad according to whether the load length ratio tp(50%) satisfies 15% or more. When the load length ratio tp(50%) is 15% or more, although there are many convex portions and the surface is relatively complex on the first surface of the base material layer, light is likely to be scattered, refracted or reflected and will not be locally concentrated, so that the light transmittance tends to be uniform. The load length ratio tp(50%) as the determination criterion for the quality of the film can be appropriately set according to the combination of the base material layer and the pressure-sensitive adhesive layer. For example, it can be set to 16% or more, 18% or more, 20% or more, 22% or more, or 25% or more, or it can also be set to 70% or less, 60% or less, or 50% or less.

[0070] The cut grain-bonded integral film determined in this way can be a film with excellent pick-up success rate. And the cut grain-bonded integral film determined in this way can be expected to be able to suppress the decrease in the adhesion during transportation and the detection rate of the inspection device, etc. Thus, the quality management method of the present disclosure is useful for those who judge whether to maintain the quality of the cut grain-bonded integral film to be used.

[0071] [Cut grain-bonded integral film]

[0072] A diced die bonding integrated film according to an embodiment includes: a base material layer having a first surface and a second surface on the side opposite to the first surface; a pressure-sensitive adhesive layer provided on the second surface of the base material layer and formed of a photocurable pressure-sensitive adhesive; and an adhesive layer provided on the side of the pressure-sensitive adhesive layer opposite to the base material layer. The load length ratio tp(50%) at 50% of the cutting level of the first surface of the base material layer in the diced die bonding integrated film is 15% or more. The base material layer, the pressure-sensitive adhesive layer, and the adhesive layer are the same as those exemplified in the quality control method of the above diced die bonding integrated film. Therefore, repeated descriptions are omitted.

[0073] As a method for adjusting the load length ratio tp(50%) at 50% of the cutting level of the first surface of the base material layer, for example, a method of heating the first surface of the base material layer, a method of applying a certain temperature and pressure to a roll with controlled unevenness, etc. can be cited. In the case of heating the first surface of the base material layer, when heating at a temperature above the softening point of the base material layer, the load length ratio tp(50%) tends not to satisfy the predetermined range.

[0074] [Manufacturing method of semiconductor device (semiconductor package)]

[0075] Figure 3 and Figure 4 is a schematic cross-sectional view for explaining an embodiment of the manufacturing method of a semiconductor device. The manufacturing method of the semiconductor device includes: a first step of preparing a diced die bonding integrated film including a base material layer, a pressure-sensitive adhesive layer, and an adhesive layer, the base material layer having a first surface and a second surface on the side opposite to the first surface, the pressure-sensitive adhesive layer being provided on the second surface of the base material layer and formed of a photocurable pressure-sensitive adhesive, and the adhesive layer being provided on the side of the pressure-sensitive adhesive layer opposite to the base material layer; a second step of calculating the load length ratio tp of the first surface of the base material layer of the diced die bonding integrated film; a third step of determining whether the quality of the diced die bonding integrated film is good or bad using the load length ratio tp as an index; and a fourth step of manufacturing a semiconductor device using the diced die bonding integrated film determined to be good in the third step. In addition, the first step, the second step, and the third step are the same as the first step, the second step, and the third step of the above quality control method of the diced die bonding integrated film. Therefore, repeated descriptions are omitted.

[0076] <Fourth step>

[0077] The fourth process is a process of manufacturing a semiconductor device using the diced grain-bonded integrated film determined to be good in the third process. More specifically, the fourth process in the method of manufacturing a semiconductor device includes: a process of attaching the adhesive layer 30 of the diced grain-bonded integrated film 1 to the semiconductor wafer W2 (wafer lamination process); a process of singulating the semiconductor wafer W2, the adhesive layer 30, and the pressure-sensitive adhesive layer 20 (dicing process); a process of irradiating ultraviolet rays to the pressure-sensitive adhesive layer 20 (ultraviolet irradiation process); a process of picking up the semiconductor wafer with an adhesive layer (semiconductor wafer 50 with an adhesive layer) having the adhesive layer 30a attached thereto from the substrate layer 10 (picking process); and a process of bonding the semiconductor wafer 50 with an adhesive layer to the support substrate 60 via the adhesive layer 30a (semiconductor wafer bonding process).

[0078] There is no particular limitation on the dicing in the dicing process. For example, blade dicing, laser dicing, stealth dicing, etc. can be cited. When the thickness of the semiconductor wafer W2 is set to 60 μm or less, stealth dicing can be used for dicing. Hereinafter, a method mainly using stealth dicing for dicing will be described in detail.

[0079] (Modified layer formation process)

[0080] When dicing is performed using stealth dicing, the method of manufacturing a semiconductor device may include a modified layer formation process before the wafer lamination process.

[0081] First, a semiconductor wafer W1 with a thickness H1 is prepared. The thickness H1 of the semiconductor wafer W1 on which the modified layer is formed may exceed 60 μm. Next, a protective film 2 is attached to one main surface of the semiconductor wafer W1 (refer to Figure 3 (a)). The surface to which the protective film 2 is attached is preferably the circuit surface of the semiconductor wafer W1. The protective film 2 may be a backgrind tape for backgrinding of the semiconductor wafer. Next, laser light is irradiated inside the semiconductor wafer W1 to form a modified layer 4 (refer to Figure 3 (b)), and backgrinding and polishing are performed on the side opposite to the surface of the semiconductor wafer W1 to which the protective film 2 is attached (back side), thereby manufacturing a semiconductor wafer W2 having the modified layer 4 (refer to Figure 3 (c)). The resulting thickness H2 of the semiconductor wafer W2 may be 60 μm or less.

[0082] (Wafer lamination process)

[0083] Next, the adhesive layer 30 of the diced grain-bonded integrated film 1 is disposed in a predetermined device. Next, the diced grain-bonded integrated film 1 is attached to the main surface Ws of the semiconductor wafer W2 via the adhesive layer 30 (refer to Figure 3(d)), and strip the protective film 2 of the semiconductor wafer W2 (refer to Figure 3 (e)).

[0084] (Cutting process)

[0085] Next, at least the semiconductor wafer W2 and the adhesive layer 30 are singulated (refer to Figure 4 (f)). When cutting is performed using a dicing saw, singulation can be achieved by performing cooling expansion and heating contraction.

[0086] (UV irradiation process)

[0087] Next, ultraviolet rays are irradiated onto the pressure-sensitive adhesive layer 20 to cure the pressure-sensitive adhesive layer 20, forming a cured pressure-sensitive adhesive layer containing a cured product of a photocurable pressure-sensitive adhesive (refer to Figure 4 (g)). Thereby, the adhesive force between the pressure-sensitive adhesive layer 20 and the adhesive layer 30 can be reduced. During UV irradiation, ultraviolet rays with a wavelength of 200 to 400 nm are preferably used. The UV irradiation conditions are preferably adjusted to an irradiation dose of 200 to 500 mJ / cm 2 at an illuminance of 30 to 240 mW / cm 2 .

[0088] (Pickup process)

[0089] Next, the substrate layer 10 is expanded to separate the semiconductor wafers 50 with the adhesive layer from each other. At the same time, the semiconductor wafers 50 with the adhesive layer pushed up from the substrate layer 10 side by the ejector pins 42 are adsorbed by the suction chuck 44, and picked up from the cured pressure-sensitive adhesive layer 20ac (refer to Figure 4 (h)). In addition, the semiconductor wafer 50 with the adhesive layer has a semiconductor wafer Wa and an adhesive layer 30a. The semiconductor wafer Wa is formed by dicing the semiconductor wafer W2, and the adhesive layer 30a is formed by dicing the adhesive layer 30. The cured pressure-sensitive adhesive layer 20ac is formed by dicing the cured pressure-sensitive adhesive layer containing a cured product of a photocurable pressure-sensitive adhesive. The cured pressure-sensitive adhesive layer 20ac can remain on the substrate layer 10 when picking up the semiconductor wafer 50 with the adhesive layer. In the pickup process, expansion is not necessarily required, but by performing expansion, the pickability can be further improved.

[0090] The upward push amount of the ejector pins 42 can be set appropriately. Furthermore, from the viewpoint of ensuring sufficient pickability even for extremely thin wafers, for example, two-stage or three-stage pickup can be performed. Also, the semiconductor wafer 50 with the adhesive layer can be picked up by a method other than using the suction chuck 44.

[0091] (Semiconductor wafer bonding process)

[0092] After picking up the semiconductor wafer 50 with the adhesive layer, the semiconductor wafer 50 with the adhesive layer is bonded to the support substrate 60 via the adhesive layer 30a by thermocompression bonding (refer to Figure 4 (i)). A plurality of semiconductor wafers 50 with adhesive layers can be bonded to the support substrate 60.

[0093] Figure 5 It is a cross-sectional view schematically showing an embodiment of the semiconductor device. Figure 5 The semiconductor device 100 shown includes: a semiconductor wafer Wa; a support substrate 60 mounted on the semiconductor wafer Wa; and an adhesive layer 30a provided between the semiconductor wafer Wa and the support substrate 60 to bond the semiconductor wafer Wa and the support substrate 60. The adhesive layer 30a can be a cured product of an adhesive (die bonding film). The semiconductor device 100 can electrically connect the semiconductor wafer Wa and the support substrate 60 by wire bond 70. The semiconductor device 100 can resin-seal the semiconductor wafer Wa on the surface 60a of the support substrate 60 with a resin sealing material 80. The semiconductor device 100 can form solder balls 90 on the surface of the support substrate 60 opposite to the surface 60a for electrical connection with an external substrate (mother board).

[0094] Figure 5 The semiconductor device 100 shown can be manufactured by a manufacturing method that includes, in addition to the above processes, a process of electrically connecting the semiconductor wafer Wa and the support substrate 60 by wire bond 70 and a process of resin-sealing the semiconductor wafer Wa on the surface 60a of the support substrate 60 using a resin sealing material 80.

[0095] Examples

[0096] Hereinafter, the present disclosure will be further specifically described by examples, but the present disclosure is not limited to these examples. In addition, unless otherwise specified, commercially available reagents were used for the compounds.

[0097] [Preparation of Cut Die Bonding Integrated Film]

[0098] <Manufacturing Example 1>

[0099] (Fabrication of Die Bonding Film)

[0100] An adhesive containing a thermosetting epoxy resin (trade name “FH-D2-10”, manufactured by Hitachi Kasei Co., Ltd.) was coated on a release substrate (polyethylene terephthalate film, thickness 38 μm) to form an adhesive layer with a thickness of 10 μm, and a die bonding film having the adhesive layer was produced.

[0101] (Fabrication of Cut Film)

[0102] A photocurable pressure-sensitive adhesive of the ultraviolet-curable type was coated on a base film (an ionic bond polymer-based single-layer film, trade name “HM-1855”, thickness 100 μm, softening point 56 °C, manufactured by DOW-MITSUI POLYCHEMICALS CO., LTD.) serving as a base material layer to form a pressure-sensitive adhesive layer with a thickness of 10 μm, and a cut film having the pressure-sensitive adhesive layer was produced. In addition, the softening point temperature is a value measured in accordance with JIS K6760.

[0103] (Production of a cut die-bonded integrated film)

[0104] The adhesive layer of the die-bonded film produced above and the pressure-sensitive adhesive layer of the cut film produced above were bonded. The bonding was performed using a laminating device at a temperature of 23 °C and a laminating speed of 12.5 mm / s.

[0105] <Manufacturing Example 2>

[0106] The base film in the produced cut film was brought into contact with a roll set at 40 °C, which is below the softening point of the base film, for 1 second, and in other respects, a cut die-bonded integrated film of Manufacturing Example 2 was produced in the same manner as in Manufacturing Example 1.

[0107] <Manufacturing Example 3>

[0108] The base film of the produced cut film was brought into contact with a hot plate set at 70 °C, which is above the softening point of the base film, for 1 second, and heat dissipation was immediately performed, and in other respects, a cut die-bonded integrated film of Manufacturing Example 3 was produced in the same manner as in Manufacturing Example 1.

[0109] <Manufacturing Example 4>

[0110] The base material layer of the produced cut film was brought into contact with a hot plate set at 70 °C, which is above the softening point of the base film, for 3 seconds, and heat dissipation was immediately performed, and in other respects, a cut die-bonded integrated film of Manufacturing Example 4 was produced in the same manner as in Manufacturing Example 1.

[0111] [Calculation of arithmetic mean roughness Ra, ten-point mean roughness Rz, and load length ratio tp(50%)]

[0112] The base material layer of the obtained cut die-bonded integrated films of Manufacturing Examples 1 to 4 was cut out in a square of 10 mm on a side. The first surface of the cut-out base material layer was observed using a laser microscope, and the arithmetic mean roughness Ra, ten-point mean roughness Rz, and load length ratio tp(50%) were calculated. In addition, the reference length l was set to 800 μm based on the calculated arithmetic mean roughness Ra in accordance with JIS B0601:1994. The results are shown in Table 1.

[0113] Device: Shape Measurement Laser Microscope VK-X100 (manufactured by KEYENCE CORPORATION)

[0114] Field of view: Using a 20x lens

[0115] Pitch: 0.75 μm

[0116] Condition: Room temperature (23 °C)

[0117] Analysis method: According to JIS B0601:1994

[0118] Observation application: VK-H1V2 (manufactured by KEYENCE CORPORATION)

[0119] Monitor: Arithmetic mean roughness Ra, ten-point mean roughness Rz, load length ratio tp (50%)

[0120] N number: 20 - 30

[0121] [Evaluation of the pick-up success rate]

[0122] The pick-up success rates of the obtained diced grain-bonded integrated films of Production Examples 1 to 4 were evaluated.

[0123] <Fabrication of evaluation samples>

[0124] (Formation of a modified layer)

[0125] A back grinding tape was attached to one side of a semiconductor wafer (silicon wafer (thickness 750 μm, outer diameter 12 inches)) to obtain a semiconductor wafer with a back grinding tape. Laser light was irradiated onto the surface of the semiconductor wafer on the side opposite to the side with the attached back grinding tape, and a modified layer was formed inside the semiconductor wafer. The laser irradiation conditions are as follows.

[0126] Laser oscillator model: Semiconductor laser-pumped Q-switched solid laser

[0127] Wavelength: 1342 nm

[0128] Oscillation mode: Pulse

[0129] Frequency: 90 kHz

[0130] Output power: 1.7 W

[0131] Moving speed of the semiconductor wafer stage: 700 mm / second

[0132] Next, back grinding and polishing were performed on the surface of the semiconductor wafer on the side opposite to the side with the attached back grinding tape, thereby obtaining a semiconductor wafer with a thickness of 30 μm.

[0133] (Wafer lamination)

[0134] Peel the PET film of the diced and bonded integrated film, and attach the adhesive layer to the surface of the semiconductor wafer on the side opposite to the side where the back grinding tape is attached.

[0135] (Cutting)

[0136] Next, fix the semiconductor wafer with the diced and bonded integrated film having a modified layer to the expanding device. Next, expand the cut film under the following conditions to singulate the semiconductor wafer, the adhesive layer, and the pressure-sensitive adhesive layer.

[0137] Device: Manufactured by DISCO CORPORATION, trade name “DDS2300 Fully Automatic Die Separator”

[0138] Cooling and expanding conditions:

[0139] Temperature: -15°C, height: 9 mm, cooling time: 90 seconds, speed: 300 mm / second, standby time: 0 second

[0140] Heating and shrinking conditions:

[0141] Temperature: 220°C, height: 7 mm, holding time: 15 seconds, speed: 30 mm / second, heating rate: 7°C / second

[0142] (Ultraviolet irradiation)

[0143] Irradiate the pressure-sensitive adhesive layer of the singulated semiconductor wafer with ultraviolet light having a central wavelength of 365 nm at an irradiation intensity of 70 mW / cm 2 and an accumulated light quantity of 150 mJ / cm 2 to form a cured pressure-sensitive adhesive layer containing a cured product of a photocurable pressure-sensitive adhesive, thereby obtaining an evaluation sample of the pick-up property described later.

[0144] <Evaluation of pick-up property>

[0145] Using a die bonder DB-830P (manufactured by FASFORD TECHNOLOGY CO., LTD. (formerly manufactured by Hitachi High-Technologies Corporation)), a pick-up test was conducted with 9 needles. The pick-up chuck used was RUBBER TIP13-087E-33 (manufactured by MICRONICS JAPAN CO., LTD., product name, size: 10×10 mm). The ejector pin used was EJECTOR NEEDLE SEN2-83-05 (manufactured by MICRONICS JAPAN CO., LTD., product name, diameter: 0.7 mm, tip shape: semi-circle with a diameter of 350 μm). Nine ejector pins were arranged at equal intervals starting from the center of the needle.

[0146] (Success rate of pick-up)

[0147] In the above pick-up test, those with a pick-up success rate of 99.5% or more were evaluated as "A", and those below 99.5% were evaluated as "B". The results are shown in Table 1.

[0148] [Table 1]

[0149] Manufacturing Example 1 Manufacturing Example 2 Manufacturing Example 3 Manufacturing Example 4 Ra (average value) (μm) 1.39 1.31 1.36 1.27 Rz (average value) (μm) 22.11 23.62 24.22 20.23 tp (50%) (median value) (%) 16.0 25.6 14.8 12.0 Pickup success rate A A B B

[0150] As shown in Table 1, the diced grain-bonded integrated films of Production Examples 1 to 4 have the same degree of arithmetic mean roughness Ra and ten-point mean roughness Rz. Among them, it was found that the diced grain-bonded integrated films of Production Examples 1 and 2 satisfy the condition that the load length ratio tp(50%) is 15% or more, and the evaluation of the pick-up success rate is extremely excellent. In contrast, it was found that the pick-up success rate of the diced grain-bonded integrated films of Production Examples 3 and 4 with a load length ratio tp(50%) less than 15% is insufficient. From these results, it was confirmed that the quality management method of the present disclosure is useful for determining whether the quality of the diced grain-bonded integrated film to be used is maintained.

[0151] Symbol description

[0152] 1 - Diced grain-bonded integrated film, 2 - Protective film, 4 - Modified layer, 10 - Substrate layer, 10A - First surface, 10B - Second surface, 20 - Pressure-sensitive adhesive layer, 20ac - Cured pressure-sensitive adhesive layer, 30, 30a - Adhesive layer, 42 - Ejector pin, 44 - Adsorption chuck, 50 - Semiconductor wafer with adhesive layer, 60 - Support substrate, 70 - Bonding wire, 80 - Resin sealing material, 90 - Solder ball, W1, W2 - Semiconductor wafers, H1 - Thickness of semiconductor wafer W1, H2 - Thickness of semiconductor wafer W2, 100 - Semiconductor device.

Claims

1. A quality management method for a diced die-bonded integrated film, comprising: A first step of preparing a diced die-bonded integrated film having a substrate layer, a pressure-sensitive adhesive layer, and an adhesive layer, wherein the substrate layer has a first surface and a second surface on the side opposite to the first surface, the pressure-sensitive adhesive layer is provided on the second surface of the substrate layer and is formed of a photocurable pressure-sensitive adhesive, and the adhesive layer is provided on the side of the pressure-sensitive adhesive layer opposite to the substrate layer; A second step of calculating a load length ratio tp for the first surface of the substrate layer of the diced die-bonded integrated film; and A third step of determining whether the quality of the diced die-bonded integrated film is good or bad using the load length ratio tp as an index, wherein the load length ratio tp is the load length ratio tp(50%) at a cutting level of 50%, and the third step is a step of determining whether the quality is good or bad based on whether the load length ratio tp(50%) satisfies 15% or more.

2. A method for manufacturing a semiconductor device, comprising: A first step of preparing a diced die-bonded integrated film having a substrate layer, a pressure-sensitive adhesive layer, and an adhesive layer, wherein the substrate layer has a first surface and a second surface on the side opposite to the first surface, the pressure-sensitive adhesive layer is provided on the second surface of the substrate layer and is formed of a photocurable pressure-sensitive adhesive, and the adhesive layer is provided on the side of the pressure-sensitive adhesive layer opposite to the substrate layer; A second step of calculating a load length ratio tp for the first surface of the substrate layer of the diced die-bonded integrated film; A third step of determining whether the quality of the diced die-bonded integrated film is good or bad using the load length ratio tp as an index; and A fourth step of manufacturing a semiconductor device using the diced die-bonded integrated film determined to be good in the third step, wherein the load length ratio tp is the load length ratio tp(50%) at a cutting level of 50%, and the third step is a step of determining whether the quality is good or bad based on whether the load length ratio tp(50%) satisfies 15% or more.

3. A diced die-bonded integrated film, comprising: A substrate layer having a first surface and a second surface on the side opposite to the first surface; A pressure-sensitive adhesive layer provided on the second surface of the substrate layer and formed of a photocurable pressure-sensitive adhesive; and An adhesive layer provided on the side of the pressure-sensitive adhesive layer opposite to the substrate layer, wherein the load length ratio tp(50%) at a cutting level of 50% for the first surface of the substrate layer is 15% or more.

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