JP2007129016A - Adhesive sheet for manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive sheet for manufacturing semiconductor devices which will not have contamination due to silicone components, can maintain a sufficient tensile storage elasticity even at a high temperature, and can be peeled off lightly and will less likely cause problems of residual glue. <P>SOLUTION: The adhesive sheet 1 for manufacturing semiconductor devices is used for manufacturing a semiconductor device having a leadless structure, wherein at least a semiconductor element and a conductive portion are sealed with sealing resin, and the protrusion of the conductive portion is exposed on the rear face side. The adhesive sheet 1 for manufacturing semiconductor devices consists of a base material layer 3 and at least an adhesive layer 2, formed on the base material layer 3. The adhesive layer 2 consists of a first adhesive layer 2a, having a tensile storage elasticity of 1 MPa or higher at 200&deg;C on the base material layer 3 side, and a second adhesive layer 2b, containing a rubber component and an epoxy resin component on the adhesion face side which is opposite from the base material side. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to an adhesive sheet for manufacturing a semiconductor device, and more particularly to an adhesive sheet for manufacturing a semiconductor device used for manufacturing a semiconductor device having a leadless structure in which semiconductor elements are sealed with a sealing resin.

  In general, a semiconductor device uses a metal lead frame as one of its constituent members. However, in order to realize a large number of pins, it is required to reduce the lead pitch in the lead frame. . However, if the width of the lead itself is reduced along with miniaturization, the strength of the lead is reduced, and a short circuit phenomenon due to bending of the lead occurs. Therefore, the package must be enlarged in order to ensure the lead pitch. As described above, in a semiconductor device using a lead frame, since the package size is large and thick, a surface mount type semiconductor device having a so-called leadless structure without the influence of the lead frame has been proposed. (For example, refer to Patent Document 1 below).

  The semiconductor device described in Patent Document 1 is shown in FIG. In this method of manufacturing a semiconductor device, first, a metal foil is attached to the base material 101, the metal foil is etched so that the metal foil remains in a predetermined portion, and then the size equivalent to that of the semiconductor element 102 is obtained. The semiconductor element 102 is fixed onto the metal foil 103a (die pad) having the adhesive 104 using an adhesive 104. Next, the semiconductor element 102 and the metal foil 103b are electrically connected by a wire 105, and transfer molded with a sealing resin 106 using a mold (FIG. 7A). Finally, the molded sealing resin is molded. The semiconductor element is completed as a package by peeling 106 from the substrate 101 (FIG. 7B) However, the semiconductor device obtained by this manufacturing method has the adhesive 104 and the metal foil 103a (die pad) on the semiconductor element 102. However, there is still a problem from the standpoint of demanding a small and thin semiconductor device.

  Regarding the problem of thinning the semiconductor device as described above, for example, Patent Document 2 below discloses a surface-mounted semiconductor device having a leadless structure that is excellent in strength and can be thinned at low cost, and a method for manufacturing the same. Has been.

  On the other hand, in a method for manufacturing a semiconductor device having a leadless structure, a silicone-based adhesive tape is generally used as a heat-resistant adhesive tape. However, if silicone adhesive tape is used, it will contaminate the affixed surface during peeling after the series of steps, resulting in poor wettability when soldering the semiconductor device to the mounting substrate, resulting in a decrease in mounting yield. The problem of doing. Also, in the wire bonding process, in order to obtain a good metal bond between the wire and the lead pad, it may be heated close to 200 ° C. However, when a silicone adhesive tape is used, the lead pad surface is generated due to the generation of siloxane gas. There is a problem that wire bonding property is deteriorated due to contamination and a decrease in tensile storage elastic modulus.

  Further, as shown in Patent Document 1, when used for manufacturing a semiconductor device having a leadless structure, the silicone adhesive is exposed to a chemical solution in a wet process in an etching process and a plating process, and eluted silicone components. However, there is a problem that the surface is contaminated and the wire bonding property is deteriorated.

  In order to solve such a problem, Patent Document 3 discloses a method for manufacturing a semiconductor device in which a rubber / epoxy adhesive tape is used instead of a silicone adhesive tape, and the adhesive tape can be peeled off without generation of siloxane gas during heating. It is disclosed.

Japanese Patent Laid-Open No. 9-252014 JP 2001-210743 A JP 2005-72343 A

  However, in recent years, the number of wire bonds has increased due to an increase in the number of elements due to lamination, and the heating time for wire bonds has become longer. For this reason, it has been found that the rubber / epoxy adhesive tape cannot withstand the heat treatment in the wire bonding process and causes adhesive residue at the time of peeling. In particular, as shown in FIG. 8, when a rubber / epoxy adhesive tape 112 composed of a base material 110 and an adhesive layer 111 described in Patent Document 3 is applied to manufacture of a semiconductor device described in Patent Document 1, the adhesion When the tape 112 is peeled off, there is a problem that an adhesive residue 113 is generated in a portion shaded by the metal stay 103b in the peeling direction. Moreover, since the tensile storage elastic modulus at the time of a heating is low, there exists a problem that favorable wire bond property cannot be ensured.

  The present invention has been made in consideration of the above-mentioned problems, and its purpose is not to be contaminated by a silicone component, to maintain a sufficient tensile storage elastic modulus even at high temperatures, to allow light peeling, and a problem of adhesive residue. Another object of the present invention is to provide an adhesive sheet for manufacturing a semiconductor device that is less likely to occur.

  The inventors of the present application have studied an adhesive sheet for manufacturing a semiconductor device in order to solve the conventional problems. As a result, it has been found that the above problems can be solved by adopting the following configuration, and the present invention has been completed.

  That is, in order to solve the above-described problem, the adhesive sheet for manufacturing a semiconductor device according to the present invention has a part of the conductive portion on the lower surface of the sealing body in which at least the semiconductor element and the conductive portion are sealed with a sealing resin. An adhesive sheet for manufacturing a semiconductor device used for manufacturing a semiconductor device, wherein the adhesive sheet for manufacturing a semiconductor device has at least an adhesive layer on a substrate, and the adhesive layer Has a first adhesive layer having a tensile storage modulus at 200 ° C. of 1 MPa or more on the substrate side, and a second adhesive layer containing a rubber component and an epoxy resin component on the substrate side. It has in the opposite sticking surface side, It is characterized by the above-mentioned.

  In the said structure, the 2nd adhesive bond layer contains the rubber component, The softness | flexibility by the side of the sticking surface in an adhesive bond layer is improved, for example, the fall of the tensile strength at the time of a heating is prevented. As a result, for example, when the adhesive sheet is peeled off after sealing with a sealing resin, adhesive residue in the shadowed part of the conductive part is partially prevented with respect to the peeling direction of the adhesive sheet. can do. Moreover, when a 2nd adhesive bond layer contains an epoxy resin component, the fall of a tensile storage elastic modulus can be prevented and wire bondability can be made favorable.

  In addition, in the above configuration, by providing the first adhesive layer having a tensile storage elastic modulus at 200 ° C. of 1 MPa or more, sufficient tensile storage elastic modulus can be more reliably maintained even at high temperatures, and wire bonding properties can be improved. This can be further improved and the yield can be improved. Further, by providing the first adhesive layer, the first adhesive layer improves the anchoring force (physical bonding force) between the base material and the base material when peeling the adhesive sheet. Throwing destruction between the first adhesive layer and the first adhesive layer can be suppressed, and it is possible to prevent only the base material from peeling off and generating adhesive residue.

  In the above configuration, the first adhesive layer preferably includes an alkoxy-containing silane-modified epoxy resin, a curing agent, and a rubber component as essential components. In the alkoxy-containing silane-modified epoxy resin contained in the first adhesive layer, for example, when a carbonyl group is generated by oxidation, the carbonyl group and the hydroxyl group on the surface of the substrate form a hydrogen bond. Thereby, a chemical bond force can be increased between the first adhesive layer and the base material, and the anchoring force can be further increased.

  In the above configuration, the epoxy resin component in the second adhesive layer preferably has an epoxy equivalent of 1000 g / eq or less. As a result, the crosslink density becomes appropriate, and it is possible to more reliably prevent the problem of adhesive residue at the time of peeling.

  In the above configuration, it is preferable that the tensile storage elastic modulus at 200 ° C. of the substrate is 1 GPa or more. Thereby, for example, even when a wire bonding step is performed and the adhesive sheet of the present invention is placed under a high temperature condition, heat resistance that can sufficiently withstand the condition can be exhibited.

  In the above configuration, it is preferable that the anchoring force between the base material and the first adhesive layer is equal to or greater than the peeling force between the sealing resin after sealing and the second adhesive layer. Thereby, when peeling an adhesive sheet, since throwing destruction between a base material and a 1st adhesive bond layer is suppressed, it can prevent that only a base material peels and a paste residue generate | occur | produces.

  The present invention has the following effects by the means described above.

  That is, according to the present invention, in manufacturing a semiconductor device in which a part of the conductive portion is exposed on the lower surface of a sealing body in which a semiconductor element or the like is sealed with a sealing resin, Generation of adhesive residue can be prevented even in the surroundings. Furthermore, since sufficient tensile storage elastic modulus is reliably maintained even under high temperature conditions, wire bonding properties are excellent. As a result, according to the present invention, it is possible to provide an adhesive sheet for manufacturing a semiconductor device capable of manufacturing a semiconductor device with a high yield.

  Embodiments of an adhesive sheet for manufacturing a semiconductor device and a semiconductor device according to the present invention will be specifically described below with reference to the drawings.

  First, the adhesive sheet for manufacturing a semiconductor device of the present invention (hereinafter simply referred to as an adhesive sheet) will be described. FIG. 1 is a cross-sectional view showing an adhesive sheet according to the present embodiment. As shown in the figure, the adhesive sheet 1 of the present invention has a configuration in which an adhesive layer 2 is laminated on a base material layer (base material) 3. The adhesive layer 2 has a structure in which a second adhesive layer 2b located on the sticking surface side and a first adhesive layer 2a located on the base material layer 3 side are laminated. The thickness of the adhesive layer 2 is usually 1 to 50 μm, the first adhesive layer 2 a is 1 to 15 μm, and the second adhesive layer 2 b is 1 to 35 μm. In addition, the adhesive sheet 1 of this invention contains a tape form, a label form, etc. other than a sheet form.

  The second adhesive layer 2b is a highly elastic layer containing a rubber component and an epoxy resin component as constituent materials. By including a rubber component, the flexibility of the adhesive surface side in the adhesive layer 2 is improved, and for example, a decrease in tensile strength during heating is prevented. As a result, when the adhesive sheet 1 is peeled off, it is possible to prevent the adhesive residue from being shadowed by the protruding portion of the conductive portion in the peeling direction. Moreover, by including an epoxy resin component, it is possible to prevent a decrease in tensile storage elastic modulus and improve wire bonding properties.

  The rubber component is not particularly limited, and examples thereof include those conventionally used for epoxy adhesives such as NBR (acrylonitrile butadiene rubber), acrylic rubber, acid-terminated nitrile rubber, and thermoplastic elastomer. Nipol 1072 (trade name, manufactured by Nippon Zeon Co., Ltd.), Nipol-AR51 (trade name, manufactured by Nippon Zeon Co., Ltd.) and the like. Of these, NBR is preferably used from the viewpoint of compatibility with the epoxy resin, and the amount of acrylonitrile is particularly preferably 30 to 70%.

  The rubber component is added to give flexibility to the adhesive, but the heat resistance decreases as the content increases. In this respect, the proportion of the rubber component in the organic material of the second adhesive layer 2b is preferably 30 to 60% by weight, and more preferably 35 to 50% by weight. When the proportion of the rubber component is less than 30% by weight, the flexibility of the adhesive layer 2 is lowered, the tensile strength during heat treatment is lowered, and the connection terminal (conductive portion) of the semiconductor package is removed when the adhesive sheet 1 is peeled off. ), And adhesive residue is likely to occur on the mold resin surface. When it exceeds 60% by weight, the tensile storage elastic modulus is lowered and the wire bonding property is lowered.

  The epoxy resin component is a compound containing two or more epoxy groups in the molecule, such as glycidylamine type epoxy resin, bisphenol F type epoxy resin, bisphenol A type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy. Examples include resins, biphenyl type epoxy resins, naphthalene type epoxy resins, aliphatic engineering epoxy resins, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, halogenated epoxy resins and the like. These resin components can be used alone or in admixture of two or more. Especially, it is preferable to use a bisphenol A type epoxy resin from the point of peelability with respect to the sealing resin after a sealing process.

  The use ratio of the epoxy resin component is preferably 40 to 70 parts by weight, more preferably 50 to 65 parts by weight, with respect to 100 parts by weight of the organic substance in the second adhesive layer 2b. When the amount is less than 40 parts by weight, the second adhesive layer 2b is not sufficiently cured and the heat resistance tends to be insufficient. Moreover, when it exceeds 70 weight part, a softness | flexibility will fall and workability will fall. The epoxy equivalent of the epoxy resin in the second adhesive layer 2b of the adhesive layer 2 is 1000 g / eq or less, preferably 500 g / eq or less. When the epoxy equivalent exceeds 1000 g / eq, the crosslink density is reduced, and thus the adhesive strength after curing is increased, and adhesive residue is liable to occur at the time of peeling after the sealing step.

  Moreover, in the 2nd adhesive bond layer 2b, it is preferable to add the hardening | curing agent for hardening the epoxy resin which is a hardening component. As the curing agent, phenol resins, various imidazole compounds and derivatives thereof, hydrazide compounds, dicyandiamide, or those obtained by microencapsulating them can be used. In particular, when a phenol resin is used as a curing agent, a phosphorus compound such as triphenylphosphine can be used as a curing accelerator.

  When the phenol resin is selected as the curing agent, a part of the addition amount of the epoxy resin can be replaced with the phenol resin so that the use ratio of such a curing agent is substantially equal to the epoxy resin. The use ratio of the other curing agent and curing accelerator is 0.5 to 5 parts by weight, preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of the organic matter.

  The first adhesive layer 2a is a release layer having a tensile storage elastic modulus at 200 ° C. of 1 MPa or more. By providing the first adhesive layer 2a, a sufficient tensile storage elastic modulus can be maintained even in a high temperature condition during the wire bonding process, and the wire bonding property can be further improved and the yield can be further improved. I can plan.

  The constituent material of the first adhesive layer 2a is not particularly limited as long as it is thermosetting. Specifically, for example, epoxy thermosetting resin, polyester thermosetting resin, polyurethane thermosetting resin, polyimide thermosetting resin, polybenzimidazole thermosetting resin, urea resin, melamine type Resins, phenolic resins, resorcinol resins and the like can be mentioned. Of these thermosetting resins, alkoxy group-containing silane-modified epoxy resins are particularly preferred in the present invention.

  The alkoxy group-containing silane-modified epoxy resin used as the constituent material of the first adhesive layer 2a can be produced by subjecting a bisphenol A type epoxy resin and a hydrolyzable alkoxysilane to dealcoholization and esterification. As the hydrolyzable alkoxysilane, those generally used in the sol-gel method can be used.

  Specific examples of hydrolyzable alkoxysilanes include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, and tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, and methyltrimethoxysilane. Alkyltrialkoxysilanes such as propoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, phenyl Examples include freel trialkoxysilanes such as trimethoxysilane and phenyltriethoxysilane, or condensates thereof.

  As these hydrolyzable alkoxysilanes, it is preferable to use at least one selected from tetraalkoxysilanes, alkyltrialkoxysilanes, and condensates thereof. This is because these hydrolyzable alkoxysilanes have a slow condensation reaction. In particular, methoxysilane-based ones form siloxane bonds (Si—O—Si) without hydrolysis when heated, so that it is not necessary to add water during condensation, and the remaining water makes the resin cloudy There is nothing. Therefore, it is excellent in handleability.

  The ratio of the bisphenol A type epoxy resin and hydrolyzable alkoxysilane used in the production of the silane-modified epoxy resin used in the present invention is not particularly limited, but the weight of hydrolyzable alkoxysilane in terms of silica / bisphenol A type epoxy. The weight (weight ratio) of the resin is preferably in the range of 0.01 to 1.2.

  However, if the alkoxy group equivalent of the hydrolyzable alkoxysilane / hydroxyl equivalent of the bisphenol A type epoxy resin is around 1 (stoichiometrically equivalent), the viscosity of the solution increases due to the progress of the dealcoholization reaction. Since gelation is likely to occur, the equivalence ratio is adjusted to less than 0.8 or 1.2 or more so as to increase either the hydroxyl equivalent of the bisphenol A type epoxy resin or the alkoxy equivalent of the hydrolyzable alkoxysilane. Is preferred.

  In the present invention, in order to eliminate the adhesive residue after peeling, the anchoring force between the base material layer 3 and the first adhesive layer 2a is such that the peeling force for the sealing resin after sealing with the sealing resin is It is preferable that it is equivalent or more. Thereby, throwing destruction can be prevented and generation | occurrence | production of adhesive residue can be prevented.

  In addition, the second adhesive layer 2b and the first adhesive layer 2a have an inorganic filler, an organic filler, a pigment, an anti-aging agent, a silane coupling agent, within a range that does not deteriorate the properties of the adhesive sheet 1. Various known additives such as a tackifier can be added as necessary. In particular, the addition of an anti-aging agent is effective in preventing deterioration at high temperatures.

  The base material layer 3 is preferably a heat-resistant base material, for example, a plastic base material such as polyester, polyamide, polyphenylene sulfide, polyetherimide, polyimide or the like, and a porous base material, a paper base material such as glassine paper, fine paper, or Japanese paper. Nonwoven fabric base materials such as cellulose, polyamide, polyester, and aramid, and metal film base materials such as aluminum foil, SUS foil, and Ni foil are included.

  As thickness of the base material layer 3, it is 10-200 micrometers normally, Preferably it is 25-100 micrometers. When the thickness is less than 10 μm, the handleability is lowered, and when it exceeds 200 μm, the cost may increase.

  In the mounting process of the semiconductor element subjected to wire bonding or the like, the adhesive sheet 1 is placed under a high temperature condition of about 150 ° C. to 200 ° C. Therefore, the base material layer 3 and the adhesive layer 2 of the adhesive sheet 1 are required to have heat resistance that can withstand this. From such a viewpoint, as the base material layer 3, one having a tensile storage elastic modulus at 200 ° C. of 1 GPa or more, preferably 10 GPa or more is suitably used. As the second adhesive layer 2b of the adhesive layer 2, one having a tensile storage elastic modulus at 200 ° C. of 0.5 MPa or more, preferably 1 MPa or more is suitably used. As the first adhesive layer 2a, a layer having a tensile storage modulus at 200 ° C. of 1 MPa or more, preferably 2 MPa or more is suitably used. Such an adhesive layer 2 is less likely to soften and flow in a semiconductor element mounting process or the like, and enables more stable connection. In addition, the measuring method of a tensile storage elastic modulus is mentioned later.

  Further, in the present embodiment, the amount of generated siloxane-based gas when the adhesive sheet 1 is heated at 200 ° C. is 1000 ng / g or less, preferably 500 ng / g or less, more preferably 100 ng / g or less. Is preferred. If the amount of generated gas exceeds 1000 ng / g, silicone contamination on the surface of the adherend, transfer of the silicone component to the outer pad side, etc. may occur, resulting in poor metal bonding during wire bonding and soldering. large.

  The adhesive sheet 1 of this Embodiment can be manufactured with a general manufacturing method. That is, the constituent material of the first adhesive layer 2a is dissolved in a predetermined solvent to prepare a coating solution, and this coating solution is applied onto the base material layer 3, and then the coating layer is heated and dried under predetermined conditions. To do. Further, for the second adhesive layer, the constituent material of the second adhesive layer 2b is dissolved in a predetermined solvent to prepare a coating solution, which is applied onto the first adhesive layer 2a, and then heated and dried. Thus, the second adhesive layer 2b is formed. Thereby, the adhesive sheet 1 of this Embodiment can be formed. Here, the solvent is not particularly limited, but considering the good solubility of each constituent material of the first adhesive layer 2a and the second adhesive layer 2b, a ketone solvent such as methyl ethyl ketone is preferably used. It is done. Further, the first adhesive layer 2a and the second adhesive layer 2b are sequentially laminated by repeating the steps of applying the constituent material as an aqueous dispersion solution, applying the solution onto the base material layer 3, and drying by heating. In addition, a method of forming the adhesive sheet 1 is also exemplified.

  As described above, the adhesive sheet 1 according to the present embodiment is excellent in heat resistance, has a good releasability from the sealing resin and the metal, and does not contain a silicone component in the adhesive sheet 1. It is possible to suppress surface contamination of the adherend due to components, poor wettability during soldering due to the contamination, poor bonding during the wire bonding process, and the like. Further, the adhesive sheet 1 of the present embodiment is a sealed body in which at least a semiconductor element and a conductive part are sealed with a sealing resin, and a part of the conductive part is displayed as an overhanging part on the lower surface side. The present invention can be particularly suitably used for manufacturing a semiconductor device having a leadless structure. Specifically, it can be used as follows.

  First, as shown to Fig.2 (a), the adhesive sheet 1 which has the base material layer 3 and the adhesive bond layer 2 is prepared. Next, as shown in FIG. 2 (b), a plurality of conductive portions 20 and a die pad portion 21 for placing semiconductor elements are formed at predetermined positions on the adhesive layer 2 in the adhesive sheet 1. To make a substrate. As shown in the drawing, the conductive portion 20 and the die pad portion 21 have protruding portions 20a and 21a in the upper and lower portions, respectively, and a substrate forming process for forming the conductive portion 20 and the die pad portion 21 will be described later.

  FIG. 3 schematically shows a plan view of the adhesive sheet 1, that is, the substrate when the conductive portion 20 and the like are formed. A plurality of conductive portions 20 corresponding to the number of electrodes of the semiconductor element 10 are formed on the adhesive sheet 1, but the plurality of conductive portions 20 are all electrically independent. A plurality of die pad portions 21 are also formed corresponding to the semiconductor elements 10 and are electrically independent from each other.

  Next, as shown in FIG. 2C, the adhesive layer 2 is formed on the die pad portion 21 on the substrate so that the semiconductor element 10 on which the electrode 11 is formed becomes the substrate side. The plurality of conductive portions 20 and the electrodes 11 of the semiconductor element 10 are electrically connected by wires 30. In addition, when the chip size is small and the fixing force by the adhesive sheet 1 is insufficient, the semiconductor element may be securely fixed on the adhesive sheet with a commercially available die attach material such as a silver paste or a die attach film. I do not care. Even in this case, since the die pad is unnecessary, the thickness can be reduced to 100 to 200 μm as compared with the conventional semiconductor device.

  Next, as illustrated in FIG. 2D, the semiconductor element 10, the wire 30, and the conductive portion 20 are sealed with a sealing resin 40 to form a sealing body 41 on the adhesive sheet 1. Sealing with the sealing resin 40 is performed using a mold by a normal transfer molding method. Examples of the sealing resin 40 include an epoxy-based sealing resin. After molding, post-curing heating of the sealing resin 40 is performed as necessary. The post-curing heating may be before or after separation of the adhesive sheet 1 described later. Subsequently, as illustrated in FIG. 4, the adhesive sheet 1 is peeled from the sealing body 41, and the semiconductor device 43 in which the protruding portion 20 a of the conductive portion 20 is exposed from the lower surface 42 of the sealing body 41 is obtained.

  FIG. 5 shows a procedure for forming the conductive portion 20 on the adhesive layer 2 in the adhesive sheet 1 in the above-described substrate creation process. This process is described as follows.

  A metal foil made of copper or a copper alloy is prepared as a material for the conductive portion 20. As this metal foil, one having a thickness of 0.01 to 0.1 mm is used from the viewpoint of strength. First, rye film resist is pasted on both sides of the metal foil, and as shown in FIG. 5A, the dry film resist 61 on both sides of the metal foil 60 is formed in a pattern opposite to the shape of the conductive part 20 by photolithography. Pattern each.

  Next, as shown in FIG. 5 (b), using the dry film resist 61 as a mask, a nickel plating layer 62 as a copper diffusion barrier layer and a noble metal plating layer 63 are partially plated in the shape of a conductive portion, and then FIG. As shown in c), the dry film resist 61 is removed. Here, the thickness of the nickel plating layer 62 is preferably in the range of 3 to 30 μm, for example. Moreover, as thickness of the noble metal plating layer 63, it is preferable to exist in the range of 0.05-0.5 micrometer, for example. Further, the noble metal used for the noble metal plating layer 63 is preferably at least one of Au, Ag, and Pt.

  Subsequently, as shown in FIG. 5 (d), the metal foil 60 formed with the nickel plating layer 62 and the noble metal plating layer 63 is attached to the adhesive layer 2 side of the adhesive sheet 1, and in this attached state, As shown in FIG. 5E, the metal foil 60 is etched using the noble metal plating layer 63 as a resist to make the conductive portion 20 independent, and the outer shape of the adhesive sheet 1 is further processed by pressing. Then, the side surface of the metal foil 60 is also etched in the step of etching the metal foil 60 using the noble metal plating layer 63 as a resist to make the conductive portion 20 independent. As a result, overhanging portions 20 a composed of the nickel plating layer 62 and the noble metal plating layer 63 are formed above and below the metal foil 60.

  As described above, the process diagram of FIG. 5 shows the case where a conductive portion of a type having protruding portions on both upper and lower surfaces is formed, but only on the functional surface (upper surface) of the metal foil as in a semiconductor device. When forming a conductive part with an overhang, apply a diffusion barrier layer and a noble metal plating layer only to the functional surface of the metal foil, and attach the metal foil to the adhesive sheet on the non-plated side. In this state, the metal foil is etched. Thereby, the electroconductive part which has an overhang | projection part only in a functional surface can be made independent.

  Note that it is practical to manufacture a plurality of semiconductor devices together in the method for manufacturing a semiconductor device of the present invention. An example is shown in FIG. FIG. 6A is an explanatory view schematically showing a plan view of the adhesive sheet 1. On the upper surface of the adhesive sheet 1, a region where one semiconductor element is fixed and a conductive portion formed around the region are 1. It is represented as one block 70, and a large number of the blocks 70 are formed in a grid shape. On the other hand, FIG. 6B is an enlarged view of one block 70, and the necessary number of conductive portions 20 are formed around the semiconductor element fixing region 71.

  In FIG. 6A, for example, the width (W) of the adhesive sheet 1 is 500 mm, and a plurality of blocks 70 are formed on the adhesive sheet 1 through a predetermined process. A rolled substrate is produced. The adhesive sheet 1 having a width of 500 mm obtained in this manner is appropriately cut and used so as to have the number of blocks necessary for the next semiconductor element mounting step and resin sealing step. In this way, when a plurality of semiconductor elements are encapsulated in a resin, the adhesive sheet is separated after the resin is encapsulated, and then cut into a predetermined size by dicer cutting or punching. A semiconductor device is obtained.

  Hereinafter, preferred embodiments of the present invention will be described in detail by way of example. However, the materials, blending amounts, and the like described in the examples are not intended to limit the scope of the present invention only to them, but are merely illustrative examples, unless otherwise specified. Further, “parts” means “parts by weight”.

Example 1
[Preparation of adhesive sheet]
60 parts of alkoxy-containing silane-modified epoxy resin (trade name; Composeran E103, manufactured by Arakawa Chemical Co., Ltd.), 5 parts of imidazole (trade name; C11Z (manufactured by Shikoku Kasei Kogyo Co., Ltd.)), acrylonitrile butadiene rubber (Nippon Zeon Corporation) ), Trade name: Nipol 1072J) An adhesive solution A containing 35 parts was prepared.

  Furthermore, with respect to the adhesive solution A, 44 parts of acrylonitrile butadiene rubber (manufactured by Nippon Zeon Co., Ltd., trade name: Nipol 1072J), bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., trade name: Epicoat 1002; epoxy) Equivalent 650 g / eq) 35 parts, phenol resin (Arakawa Chemical Co., Ltd., trade name; P-180) 20 parts, triphenylphosphine (Hokukosei Co., Ltd., trade name; TPP) 1 part Then, it was dissolved in MEK solvent so as to have a concentration of 35% by weight to prepare an adhesive solution A1.

  Next, the adhesive solution A was applied as a base material on a copper foil having a thickness of 35 μm, and then dried at 140 ° C. for 3 minutes, thereby forming a first adhesive layer having a thickness of 5 μm.

  Then, after apply | coating adhesive solution A1 on a 1st adhesive bond layer, the 2nd adhesive bond layer whose thickness after drying is 10 micrometers is formed by making it dry at 130 degreeC for 3 minutes, Thereby, thickness A 15 μm thermosetting adhesive sheet was prepared.

[Production of substrate]
First, a dry film resist (trade name: Odile AR330, manufactured by Tokyo Ohka Co., Ltd.) was laminated on both sides of a 40 μm thick copper foil (trade name; Olin 7025). And the dry film resist was patterned by the pattern opposite to the electroconductive part by the photolithographic method. Next, using the patterned dry film resist as a mask, nickel plating and Au plating were sequentially performed on both sides of the copper foil, and then the dry film resist was removed. Subsequently, a copper foil in which a laminate of a nickel plating layer and an Au plating layer was partially disposed was attached to an adhesive sheet via an adhesive layer. Then, in this attached state, the copper foil was etched using the Au plating layer as a resist to make the conductive portion independent. During this etching process, the side surfaces of the copper foil were also etched to provide overhang portions made of Au and nickel above and below the copper foil. Finally, the outer shape of the adhesive sheet was processed by pressing.

And the electroconductive part was formed on the adhesive sheet with the pattern as shown in the example of FIG. 6A (W is 500 mm). Sixteen conductive portions were formed on each side of the square in one block 70, for a total of 64 conductive portions.

[Installation of semiconductor elements]
An aluminum vapor-deposited silicon chip for test (6 mm × 6 mm) was fixed to the adhesive layer surface (corresponding to 71 in FIG. 6B) of the adhesive sheet. Specifically, after pasting under conditions of 175 ° C., 0.3 MPa, and 1 second, it was dried and fixed at 150 ° C. for 1 hour. Next, bonding between the electrode of the silicon chip and the conductive portion was performed using a gold wire having a diameter of 25 μm. The number of wire bonds is 64 points per chip.

  Wire bonding was performed on 10 units of the 1 unit (4 × 4), that is, 160 aluminum vapor-deposited chips. The success rate of wire bonding was 100%. Subsequently, a sealing resin (trade name: HC-100, manufactured by Nitto Denko Corporation) was molded by transfer molding. After the resin molding, the adhesive sheet was peeled off at room temperature. Further, post-curing was performed in a dryer at 175 ° C. for 5 hours. Then, it cut | disconnected by 1 block unit with the dicer, and the semiconductor device was obtained.

  The wire bonding conditions, transfer mold conditions, tensile storage modulus measurement method, adhesive force measurement method, and wire bond success rate are as follows.

(Comparative Example 1)
In this comparative example, the adhesive solution A1 of Example 1 was applied onto a copper foil and dried under the same conditions as in Example 1 to form an adhesive layer having a thickness of 15 μm. Adhesive sheet was prepared. Other than that was carried out similarly to the said Example 1, and produced the semiconductor device.

(Comparative Example 2)
In this comparative example, the same procedure as in Example 1 was conducted except that 70 parts of acrylonitrile butadiene rubber (manufactured by Nippon Zeon Co., Ltd., Nipol DN1072J) contained in the adhesive solution A used in Example 1 was used. A thermosetting adhesive sheet was prepared. Other than that was carried out similarly to the said Example 1, and produced the semiconductor device.

(Transfer mold conditions)
The transfer mold is an epoxy-based encapsulating resin (trade name: HC-300, manufactured by Nitto Denko Corporation) using a mold machine (Model-Y-series manufactured by TOWA) at 175 ° C., preheating for 40 seconds, injection. The test was carried out under conditions of a time of 11.5 seconds and a curing time of 120 seconds.

(Wire bond success rate)
The pull strength of the wire bond was measured using a bonding tester “PTR-30” manufactured by Reska Co., Ltd., with a measurement mode: pull test and a measurement speed: 0.5 mm / sec. The case where the pull strength was 0.04N or higher was regarded as success, and the case where it was smaller than 0.04N was regarded as failure. The wire bond success rate is a value obtained by calculating the success rate from these measurement results. The wire bonding conditions were as follows.

Device: “UTC-300BI SUPER” manufactured by Shinkawa Co., Ltd.
Ultrasonic frequency: 115KHz
Ultrasonic output time: 15 ms Ultrasonic output: 120 mW
Bond load: 1018N
Search load: 1037N

(Tensile storage modulus)
Adhesive layers (thickness: 100 μm) were formed on the release liner subjected to the release treatment by the same method as in Example 1 and Comparative Examples 1 and 2, respectively. Next, the sample was cut so that the sample size was 30.0 mm long × 5.0 mm wide × 0.1 mm thick to prepare a sample. Subsequently, after each sample was placed in an oven at 150 ° C. for 1 hr, the adhesive layer was tension-stored at 200 ° C. using a viscoelasticity measuring device (Rheometrics, model: RSA-II). The elastic modulus was measured. The results are shown in Table 1 below. The tensile storage elastic modulus is measured by setting the sample on a film tension measuring jig, having a frequency of 1.0 Hz, a strain of 0.025%, and a heating rate of 10 ° C./min in a temperature range of 50 ° C. to 250 ° C. Performed under conditions. Moreover, the tensile storage elastic modulus was measured also about the copper foil of thickness 35 micrometers as a base material on the same conditions. The copper foil was 80 GPa.

(Peelability)
After heating at 180 ° C. × 3 hr and leaving at 25 ° C. for 60 minutes, the peel force when the adhesive sheet was peeled from the semiconductor device at a peel rate of 50 mm / min at 90 ° peel was measured.

(Throwing power)
Each adhesive sheet bonded on both sides with a linear pressure of 2 kg / cm was measured by peeling it off at a speed of 50 mm / min with a Tensilon type tensile tester.

(Adhesive residue)
The presence or absence of adhesive residue on the sealing resin surface when the adhesive sheet was peeled was confirmed.

(result)
About the adhesive sheet of the said Example 1 and Comparative Examples 1-2, the tensile storage elastic modulus, anchoring force, wire bond property, peelability, and adhesive residue property were evaluated by the said method. These results are shown in Table 1 below.

  As is apparent from Table 1, the adhesive sheet of Example 1 was excellent in releasability from the sealing resin and the lead frame surface, and no adhesive residue was observed. Moreover, wire bondability was also favorable. On the other hand, when the adhesive sheet shown in Comparative Example 1 was used, adhesive residue was generated on the sealing resin and the lead frame surface after peeling, resulting in throwing damage. Moreover, when the rubber component shown in Comparative Example 2 was 60% by weight or more, no adhesive residue was generated, but the wire bondability deteriorated and the success rate decreased.

It is a cross-sectional schematic diagram which shows the adhesive sheet for semiconductor device manufacture which concerns on one Embodiment of this invention. It is process drawing for demonstrating the manufacturing method of the semiconductor device using the said adhesive sheet for semiconductor device manufacture. In the manufacturing method of the said semiconductor device, it is explanatory drawing which showed typically the top view of the adhesive sheet (board | substrate) at the time of forming an electroconductive part. It is a cross-sectional schematic diagram which shows the semiconductor device obtained by the said manufacturing method. It is process drawing which shows the procedure of the board | substrate preparation in the manufacturing method of the said semiconductor device. It is a top view of the state which formed the electroconductive part in the said adhesive sheet at the board | substrate preparation process in the manufacturing method of the said semiconductor device. It is explanatory drawing which shows an example of the conventional semiconductor device which has a leadless structure. It is a schematic diagram which shows a mode that the conventional adhesive tape is peeled in manufacture of the said semiconductor device.

Explanation of symbols

1 Semiconductor device manufacturing adhesive sheet (adhesive sheet)
2 Adhesive Layer 2a First Adhesive Layer 2b Second Adhesive Layer 3 Base Material Layer (Base Material)
DESCRIPTION OF SYMBOLS 10 Semiconductor element 11 Electrode 20 Conductive part 20a Overhang part 21 Die pad part 30 Wire 40 Sealing resin 41 Sealing body 42 Lower surface 43 Semiconductor device 60 Metal foil 61 Dry film resist 62 Nickel plating layer 63 Noble metal plating layer 70 Block 71 Semiconductor element Fastening area

Claims (5)

A semiconductor device manufacturing adhesive sheet used for manufacturing a semiconductor device in which a part of the conductive portion is exposed on the lower surface of a sealing body in which at least a semiconductor element and a conductive portion are sealed with a sealing resin,
The adhesive sheet for manufacturing a semiconductor device is configured to have at least an adhesive layer on a substrate,
The adhesive layer has a first adhesive layer on the substrate side having a tensile storage modulus at 200 ° C. of 1 MPa or more,
And the adhesive sheet for semiconductor device manufacture which has the 2nd adhesive bond layer containing a rubber component and an epoxy resin component on the sticking surface side opposite to the said base material side.   The adhesive sheet for manufacturing a semiconductor device according to claim 1, wherein the first adhesive layer contains an alkoxy-containing silane-modified epoxy resin, a curing agent, and a rubber component as essential components.   The adhesive sheet for manufacturing a semiconductor device according to claim 1, wherein the epoxy resin component in the second adhesive layer has an epoxy equivalent of 1000 g / eq or less.   The adhesive sheet for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the base material has a tensile storage modulus at 200 ° C of 1 GPa or more.   The anchoring force between the base material and the first adhesive layer is equal to or greater than the peeling force between the sealing resin after sealing and the second adhesive layer. The adhesive sheet for manufacturing a semiconductor device according to any one of the above.

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