JP4140963B2 - Manufacturing method of semiconductor device, adhesive tape used in the method, and semiconductor device manufactured by the method - Google Patents

Description

  The present invention belongs to the technical field of surface-mount semiconductor devices, and in particular, relates to a method for manufacturing a surface-mount semiconductor device having a leadless structure, and to an adhesive tape for manufacturing a semiconductor device used in the method, Further, the present invention relates to a semiconductor device obtained by the method.

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 accordingly, the strength of the lead is lowered, and a short circuit phenomenon due to bending of the lead occurs. Therefore, the package has to be enlarged in order to ensure the lead pitch. Thus, a semiconductor device using a lead frame has a large package size and a large thickness. For this reason, a surface-mount type semiconductor device having a so-called leadless structure without the influence of a lead frame has been proposed (see, for example, Patent Document 1 and Patent Document 2).
Japanese Patent Laid-Open No. 9-252014 JP 2001-210743 A

  The semiconductor device described in Patent Document 1 is shown in FIG. In this semiconductor device manufacturing method, first, a metal foil as a base substrate is attached to the base material 101, the metal foil is etched so as to leave the metal foil in a predetermined portion, and then the size equivalent to that of the semiconductor element 102 is obtained. The semiconductor element 102 is fixed on the metal foil 103a (die pad) having a thickness by using an adhesive 104, and the semiconductor element 102 and the metal foil 103b are electrically connected by a wire 105, and a mold is used. Transfer molding is performed with the sealing resin 106 (FIG. 7A). Finally, the molded sealing resin 106 is separated from the base material 101 to complete the semiconductor element 102 as a package (FIG. 7B). However, when the metal foil is used for the base substrate in this manner, the separation from the base material is mechanically performed. However, since the metal foil is difficult to bend, the semiconductor device after sealing is mechanically separated during the separation. It will add a load.

  Moreover, in the manufacturing method described in Patent Document 1, it is required that the base material and the metal foil are sufficiently adhered in the etching process of the metal foil and the molding process of the sealing resin. The sealing resin, the base material and the metal foil are required to be easily separated. Thus, the base material and the metal foil are required to have contradictory properties in adhesion properties. In other words, durability against chemicals used for etching is required, and durability is required so that the semiconductor element does not shift under high temperature in the molding process and pressure applied when the sealing resin flows in the mold. However, it is required that the base material and the sealing resin, and the base material and the metal foil can be easily separated after molding. However, the Teflon (registered trademark) material, the silicone material, the Teflon (registered trademark) coated metal, and the like exemplified as the base material cannot satisfy such adhesion characteristics.

  A semiconductor device described in Patent Document 2 is shown in FIG. This semiconductor device is manufactured by the following method. First, a metal plate 201 in which a grid-like concave groove 201a is formed on a metal plate to be a base material is obtained. Next, the semiconductor element 202 is fixed to the metal plate 201 with an adhesive 203, and then wire bonding is performed at a place necessary for design to form a wire 204, and transfer molding is performed with a sealing resin 205 (FIG. 8A). ). Next, the back surface side of the metal plate 201 is polished to a thickness of at least 1/2 or more, and the metal plate 201 is cut together with the sealing resin 205 to a size according to the design to obtain a semiconductor device (FIG. 8B). )). However, in this manufacturing method, it is necessary to remove the metal plate by a mechanical polishing method or a chemical polishing method such as etching. Therefore, from the viewpoint of damage to the product in terms of environment and cost. However, it is not a very good method.

The adhesive tape of the present invention is an adhesive tape used in the above manufacturing method, and a first adhesive layer, a resin base layer, and a second adhesive layer are sequentially laminated on the metal base layer. a multilayer structure, together with the first adhesive layer of which is perforated the property of losing the adhesive force by heating, the second adhesive layer consists of thermosetting adhesive, elastic modulus before curing at 100 to 150 ° C. is 0 .1MPa below, the elastic modulus after curing at 200 ° C. is characterized der Rukoto least 0.1 MPa.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a method for manufacturing a surface-mount type semiconductor device having a leadless structure capable of being thinned and excellent in strength. In addition, an adhesive tape for manufacturing a semiconductor device used in the method is provided, and a semiconductor device obtained by the method is provided.

In order to achieve the above object, a method for manufacturing a semiconductor device according to the present invention includes a substrate forming step in which at least a plurality of conductive portions are partially formed on an adhesive surface of an adhesive tape, and at least one semiconductor in which electrodes are formed. A semiconductor element mounting step in which the element is fixed on the substrate so that the side on which no electrode is formed is the substrate side, and the upper side of the plurality of conductive portions and the electrode on the upper side of the semiconductor element are electrically connected by wires; The semiconductor element, the wire, and the conductive part are sealed with a sealing resin to form a semiconductor device on the adhesive tape, the adhesive tape is removed from the semiconductor device, the adhesive tape is removed, and the individual is cut by punching or punching. A method for manufacturing a semiconductor device comprising a cutting step for singulation,
The adhesive tape has a multilayer structure in which a first adhesive layer, a resin base layer, and a second adhesive layer are sequentially laminated on a metal base layer, and the first adhesive layer of which has an adhesive force by heating. Use adhesive tape with the property of losing,
In the adhesive tape removing step, by heating to a predetermined temperature, the adhesive strength of the first adhesive layer in the adhesive tape is lost and the metal base material layer is peeled off, and then the resin base material layer is first bonded. The adhesive layer and the second adhesive layer are folded back and peeled off.

  The adhesive tape of the present invention is an adhesive tape used in the above manufacturing method, and a first adhesive layer, a resin base layer, and a second adhesive layer are sequentially laminated on the metal base layer. The first adhesive layer has a property of losing adhesive force by heating in a multilayer structure.

  And the said adhesive tape can take the form which a 1st adhesive bond layer has a heating foam peeling function as a property which loses adhesive force by heating.

In the adhesive tape, both the metal base material layer and the resin base material layer have an elastic modulus at 200 ° C. of 1.0 GPa or more, and the first adhesive layer and the second adhesive layer have an elastic modulus at 200 ° C. It is preferably 0.1 MPa or more.

In the adhesive tape, it is preferable that the thermosetting adhesive of the second adhesive layer contains an epoxy resin, an epoxy curing agent, and an elastic body as essential components.

  Further, in the semiconductor device of the present invention, the electrode on the upper side of the semiconductor element and the upper side of the plurality of conductive portions are electrically connected by wires, respectively, and the lower side where the electrode of the semiconductor element is not formed and the wire of the conductive portion A semiconductor device having a leadless structure in which a semiconductor element, a wire, and a conductive portion are sealed with a sealing resin in a state where a lower side that is not connected to the back is exposed on the back surface, and is manufactured by the above-described manufacturing method. The

  According to the method for manufacturing a semiconductor device of the present invention, it is possible to manufacture a semiconductor device that has a leadless structure that does not use a lead frame and that is thoroughly thinned so that nothing exists under the semiconductor element. In addition, there can be obtained a semiconductor device in which there is no positional deviation of the semiconductor element, the cost is low, and the damage in the manufacturing process is small.

  The adhesive tape of the present invention has a multilayer structure in which a first adhesive layer, a resin base layer, and a second adhesive layer are sequentially laminated on a metal base layer, and the first adhesive layer is bonded by heating. Since it has the property of losing its strength, the adhesive strength of the first adhesive layer in the adhesive tape disappears by heating to a predetermined temperature in the adhesive tape removing process for separating the adhesive tape from the semiconductor device, and the metal substrate After the layer is peeled off, the resin base material layer is folded back together with the first adhesive layer and the second adhesive layer to cause damage to the semiconductor device such as chipping of the terminal or chip damage or sealing resin cracking. Without giving, the terminal and the second adhesive, the sealing resin and the second adhesive can be easily peeled off with a light force.

  1 to 3 are process diagrams showing a method of manufacturing a semiconductor device according to the present invention, and the manufacturing procedure will be described below with reference to FIG.

  First, as shown in FIG. 1A, an adhesive tape 50 having a multilayer structure in which a first adhesive layer 52, a resin base layer 53, and a second adhesive layer 54 are sequentially laminated on a metal base layer 51 is formed. prepare. The first adhesive layer 52 in the adhesive tape 50 is formed of an adhesive having a property of losing adhesive force by heating. In such an adhesive tape 50, another adhesive is applied to each surface of the resin base layer 53 to form a first adhesive layer 52 and a second adhesive layer 54, and a metal base layer 51 is formed thereon. It is produced by sticking together. And as shown in FIG.1 (b), the some electroconductive part 20 is partially formed on the 2nd adhesive bond layer 54 in the adhesive tape 50, and a board | substrate is produced. In addition, although the electroconductive part 20 has the overhang | projection part 20a respectively up and down like illustration, the board | substrate preparation process which forms such an electroconductive part 20 is mentioned later. Further, a form in which a die pad is formed in addition to the conductive portion 20 can be adopted.

  FIG. 4 schematically shows a plan view of the adhesive tape 50, that is, the substrate when the conductive portion 20 is formed. A plurality of conductive portions 20 corresponding to the number of electrodes of the semiconductor element are formed on the adhesive tape 50, but the plurality of conductive portions 20 are all electrically independent.

  Next, as shown in FIG. 1C, the second adhesive layer 54 is formed at a predetermined position on the substrate so that the semiconductor element 10 on which the electrode 11 is formed is on the substrate side. The plurality of conductive portions 20 and the electrodes 11 of the semiconductor element 10 are electrically connected by wires 30. If the chip size is small and the adhesive force by the adhesive tape 50 is insufficient, the semiconductor element 10 is firmly fixed on the adhesive tape 50 with a commercially available die attach material such as silver paste or die attach film. It doesn't matter. 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. Even when a die pad is manufactured, it can be reduced in thickness by 50 to 100 μm as compared with a conventional package.

  Next, as shown in FIG. 1D, the semiconductor element 10, the wire 30, and the conductive portion 20 are sealed with a sealing resin 40 to form a semiconductor device on the adhesive tape 50. Sealing with the sealing resin 40 is performed using a mold by a normal transfer molding method. Note that 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 tape 50 described later.

Subsequently, the adhesive tape is separated from the semiconductor device. In this case, as shown in FIG. 2, by heating to a predetermined temperature allowed lost adhesion of the Ichise' Chakuzaiso 52, to remove the metal base layer 51 in the easy peeling state. Here, depending on the type of adhesive used for the first adhesive layer 52, the metal base layer 51 can be separated by heat applied during molding of the sealing resin. Thereafter, the resin base material layer 53 is folded and peeled together with the first adhesive layer 52 and the second adhesive layer 54 to obtain the semiconductor device shown in FIG.

  In the semiconductor device shown in FIG. 3, the plurality of electrodes 11 on the upper side of the semiconductor element 10 and the upper parts of the plurality of conductive portions 20 are electrically connected by wires 30, respectively. Are sealed with a sealing resin 40 to protect them from the external environment. And the back surface of the sealing resin 40 in a state where the lower side where the electrode 11 of the semiconductor element 10 is not formed and the lower side which is not connected to the wire 30 of the conductive portion 20 are located on the same surface as the sealing resin 40 Is exposed. As described above, the semiconductor device obtained by the manufacturing method of the present invention has a structure in which the lower surface of the semiconductor element 10 and the lower surface of the conductive portion 20 are exposed on the surface of the sealing resin 40, and the adhesive for fixing the die pad or the semiconductor element. It is a leadless structure without a layer. In addition, in this semiconductor device, the conductive portion 20 has a shape having a protruding portion 20a in the vertical direction, and the protruding portion 20a exhibits an anchor effect in the sealing resin 40. The bonding strength with the sealing resin 40 is high.

  In the conventional semiconductor device, the thickness of the die pad is about 100 to 200 μm, and the thickness of the adhesive layer for fixing the semiconductor element is about 10 to 50 μm. Therefore, in the case where the thickness of the semiconductor element and the thickness of the sealing resin covering the semiconductor element are the same, according to the present invention, it is possible to reduce the thickness to about 110 to 250 μm in the configuration without the die pad. Thinning of about ˜50 μm is possible.

  FIG. 5 shows a substrate forming step in the method for manufacturing a semiconductor device of the present invention, that is, a procedure for partially forming the conductive portion 20 on the second adhesive layer 52 in the adhesive tape 50. This substrate creation process will be described as follows.

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

  Next, as shown in FIG. 5B, using the dry film resist 61 as a mask, the nickel plating as the copper diffusion barrier layer 62 and the noble metal plating layer 63 are partially plated in the shape of the conductive portion, and then the FIG. The dry film resist 61 is removed as shown in FIG. Here, the noble metal used for the noble metal plating layer 63 is at least one of Au, Ag, Pt, and Pd, or a combination thereof.

  Subsequently, as shown in FIG. 5 (d), the metal foil 60 on which the diffusion barrier layer 62 and the noble metal plating layer 63 are formed is attached to the adhesive layer 52 side of the adhesive tape 50, 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 tape 50 is further processed by pressing. Then, in the process of etching the metal foil 60 using the noble metal plating layer 63 as a resist to make the conductive portion 20 independent, the side surfaces of the metal foil 60 are also etched, so that the overhang portions made of noble metal and nickel are formed above and below the metal foil 60. The shape is provided with 20a.

  As described above, the process diagram of FIG. 5 shows a case where a conductive portion of a type having protruding portions on both upper and lower surfaces is formed, but the protruding portion 20 is provided only on the functional surface (upper surface) of the metal foil. When the conductive portion 20 is formed, the diffusion barrier layer and the noble metal plating layer are applied only to the functional surface of the metal foil, and the metal foil is attached to the adhesive tape on the non-plated side, and the metal foil is attached in this attached state. Etching is performed. Thereby, the electroconductive part which has an overhang | projection part only in a functional surface can be made independent.

  Note that it is practical that the semiconductor device manufacturing method of the present invention manufactures a plurality of semiconductor devices together. An example is shown in FIG. FIG. 6A is an explanatory view schematically showing a plan view of the adhesive tape 50. On the upper surface of the adhesive tape 50, a region for fixing one semiconductor element and a conductive portion formed in the periphery of the region are shown. 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 tape 50 is 500 mm, and a plurality of blocks 70 are formed on the adhesive tape 50 through a predetermined process and continuously wound on a roll. A substrate is produced. The adhesive tape 50 having a width of 500 mm obtained in this manner is used after being appropriately cut 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 tape is separated after the resin is encapsulated, and then cut into a predetermined size by dicer cutting or punching. A semiconductor device is obtained.

  The adhesive tape used in the method for manufacturing a semiconductor device according to the present invention securely fixes the semiconductor element 10 and the conductive part 20 until the resin sealing process is completed, and damages the terminals when separated from the semiconductor device. Those that can be easily peeled off are preferred. The adhesive tape 50 satisfying such conditions has a multilayer structure in which the first adhesive layer 52, the resin base layer 53, and the second adhesive layer 54 are sequentially laminated on the metal base layer 51 as described above. ing.

  In the semiconductor element mounting process in which wire bonding or the like is performed, the temperature is set to a high temperature condition of about 150 to 200 ° C. Therefore, each layer constituting the adhesive tape 50 is required to have heat resistance that can withstand this. From this viewpoint, as the metal base material layer 51 and the resin base material layer 53, those having an elastic modulus at 200 ° C. of 1.0 GPa or more, preferably 10 GPa or more are preferably used, but usually about 1.0 GPa to 1000 GPa. Is preferred. Further, as the first adhesive layer 52 and the second adhesive layer 54, those having an elastic modulus of 0.1 MPa or more, preferably 0.5 MPa or more, more preferably 1 MPa or more are preferably used. It is preferably about 1 MPa to 100 MPa. The first adhesive layer 52 and the second adhesive layer 54 having such elastic modulus are less likely to soften and flow in a semiconductor element mounting process or the like, and can be connected more stably. The elastic modulus is measured in detail by the method described in the examples.

  The metal base layer 51 of the adhesive tape 50 is preferably a metal foil in consideration of handling at the time of conveyance, warping at the time of molding, and the like. Examples of such metal foil include SUS foil, Ni foil, Al foil, copper foil, copper alloy foil, and the like, but it is selected from copper and copper alloy because of its availability at low cost and variety. Is preferred. Moreover, in order to ensure anchoring property with the first adhesive layer 52, it is preferable that the metal foil to be the metal base layer 51 is subjected to roughening treatment on one side. As a roughening treatment method, a conventionally known physical roughening method such as sandblasting or a chemical roughening method such as etching can be used. The thickness of the metal substrate layer 51 is about 12 to 200 μm, preferably 50 to 150 μm.

  As the first adhesive layer 52 of the adhesive tape 50, an acrylic pressure-sensitive adhesive is preferable. In order to further improve the easy peelability of the acrylic pressure-sensitive adhesive layer, an additive that expresses and improves a peelable function by heating foaming. Can be added. Examples of the additive capable of imparting the heating foam peeling function include thermally expandable fine particles. As the thermally expandable fine particles, thermally expandable microcapsules encapsulating appropriate gas foaming components having a low boiling point such as butane, propane and pentane can be used. Although it does not restrict | limit in particular regarding the thickness of the 1st adhesive bond layer 52, Usually, about 1-50 micrometers, Preferably it is 5-20 micrometers.

  Although the resin base material layer 53 of the adhesive tape 50 does not specifically limit the resin material, polyimide, liquid crystal polymer, PEEK, PEK, PES, or the like is preferably used from the viewpoint of heat resistance. The resin base material layer 53 has a thickness of about 12 to 100 μm, preferably 25 to 50 μm.

The second adhesive layer 54 of the adhesive tape 50 is preferably one that securely fixes the semiconductor element 10 or the conductive part 20 until the resin sealing step is completed, and can be easily peeled when separated from the semiconductor device, as the adhesive, an epoxy resin, an epoxy curing agent, to use a thermosetting adhesive containing an elastic body as an essential component preferable. For thermosetting adhesive, usually, bonding of the base material, it is cured after the so-called B-stage of the uncured, i.e. can perform bonding at a relatively low temperature of 0.99 ° C. or less, and bonding Thus, the elastic modulus can be improved and the heat resistance can be improved. The thickness of the second adhesive layer 54 is not particularly limited, but is usually about 1 to 50 μm, preferably 5 to 20 μm.

  Here, as the epoxy resin, glycidylamine type epoxy resin, bisphenol F type epoxy resin, bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, Aliphatic epoxy resins, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, halogenated epoxy resins and the like can be mentioned, and these can be used alone or in combination of two or more. Examples of the epoxy curing agent include various imidazole compounds and derivatives thereof, amine compounds, dicyandiamide, hydrazine compounds, and phenol resins, and these can be used alone or in combination of two or more. Examples of the elastic body include acrylic resin, acrylonitrile butadiene copolymer, phenoxy resin, polyamide resin, and the like, and these can be used alone or in combination of two or more.

  Moreover, it is preferable that the adhesive force with respect to the metal foil of the 2nd adhesive bond layer 54 is 0.1-15N / 20mm. Furthermore, it is preferable that it is 0.3-15N / 20mm. Here, the adhesive force can be appropriately selected within the above range depending on the size of the conductive portion. That is, when the size of the conductive portion is large, the adhesive force is relatively small, and when the size of the conductive portion is small, the adhesive force is preferably set large. The adhesive tape having this adhesive force has an appropriate adhesive force, and the conductive portion fixed to the adhesive layer is unlikely to shift in the substrate preparation process to the semiconductor element mounting process. In the adhesive tape removing step, the separation of the adhesive tape from the semiconductor device is good, and damage to the semiconductor device can be reduced. In addition, the measurement of adhesive force is based on the method as described in an Example in detail.

  The adhesive tape 50 can be provided with an antistatic function as necessary. In order to impart an antistatic function to the adhesive tape 50, there is a method of mixing an antistatic agent and a conductive filler in at least one layer. Further, there is a method of applying an antistatic agent to the interface of each layer or the back surface of the metal substrate layer 51. By providing this antistatic function, static electricity generated when the adhesive tape is separated from the semiconductor device can be suppressed.

  The antistatic agent is not particularly limited as long as it has an antistatic function. Specific examples include surfactants such as acrylic amphoteric, acrylic cation, maleic anhydride-styrene anion, and the like. Specific examples of the material for the antistatic layer include Bondip PA, Bondip PX, Bondip P (manufactured by Konishi Co., Ltd.), and the like. Moreover, as a conductive filler, a conventional thing can be used, for example, metals, such as Ni, Fe, Cr, Co, Al, Sb, Mo, Cu, Ag, Pt, Au, these alloys or oxides, carbon Examples thereof include carbon such as black. These can be used alone or in combination of two or more. The conductive filler may be powdery or fibrous. In addition, various conventionally known additives such as anti-aging agents, pigments, plasticizers, fillers and tackifiers can be added to the adhesive tape.

[Production of adhesive tape]
First, 100 parts by weight of a bisphenol A type epoxy resin (“Ebicoat 1002” manufactured by Japan Epoxy Resin), 35 parts by weight of an acrylonitrile butadiene copolymer (“Nippol 1072J” manufactured by Nippon Zeon), phenol resin (“P” manufactured by Arakawa Chemical Co., Ltd.) -180 ") 4 parts by weight and 2 parts by weight of imidazole (" C11Z "manufactured by Shikoku Fine Co., Ltd.) were dissolved in 350 parts by weight of methyl ethyl ketone to obtain an adhesive solution. This is applied to one side of a 25 μm thick polyimide base material (“UPILEX S” manufactured by Ube Industries), and then dried at 150 ° C. for 3 minutes, whereby a second adhesive having a thickness of 15 μm is applied to one side of the resin base material layer. A layer was formed. The elastic modulus at 100 ° C. before curing of the second adhesive layer was 2.5 × 10 ⁻³ Pa, and the elastic modulus at 200 ° C. after curing was 4.3 MPa.

Next, 100 parts of a base polymer comprising 50 parts by weight of ethyl acrylate, 50 parts by weight of butyl acrylate and 1 part by weight of 2-hydroxyethyl acrylate (weight average molecular weight of about 600,000), polyurethane-based crosslinking agent 5 And a toluene solution in which 30 parts of thermally expandable fine particles (average particle size 15 μm, specific gravity 1.01) were added and mixed. After this was applied to the opposite surface of the polyimide substrate, it was dried at 150 ° C. for 3 minutes to form a first adhesive layer having a thickness of 15 μm on the other surface of the resin substrate layer. The elastic modulus at 100 ° C. before curing of the first adhesive layer was 2.5 × 10 ⁻³ Pa, and the elastic modulus at 200 ° C. after curing was 4.3 MPa. Thereby, the double-sided tape which each has a 1st adhesive bond layer and a 2nd adhesive bond layer on both surfaces of the resin base material layer was produced.

  Next, using a laminator with a temperature of 80 ° C. and a laminating pressure of 0.5 Mpa, the double-sided tape produced above was made into a 100 μm thick single-side roughened copper alloy foil (Japan Energy). The adhesive tape for manufacture of a semiconductor device was obtained by pasting together with “BHY-13B-7005”).

[Production of substrate]
First, a dry film resist (“Audir AR330” manufactured by Tokyo Ohka Kogyo Co., Ltd.) was laminated on both sides of a 40 μm thick copper foil (“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 arranged was attached to an adhesive tape 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 tape was processed by pressing.

  And the electroconductive part 20 was formed on the adhesive tape 50 with the pattern as shown in the example (W is 500 mm) of FIG. Sixteen conductive portions 20 were formed on each side of the square in one block 70, and a total of 64 conductive portions 20 were formed.

[Installation of semiconductor elements]
An aluminum-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 tape. 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 (“HC-100” manufactured by Nitto Denko) was molded by transfer molding. During the resin molding, the first adhesive layer in the adhesive tape was heated and foamed, and the copper foil was peeled off. Therefore, the remaining resin base material layer was peeled off together with the first adhesive layer and the second adhesive layer on the knife edge at an angle of 15 degrees. After peeling off the adhesive tape in this way, 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.

  When this semiconductor device was internally observed with a soft X-ray device (microfocus X-ray TV fluoroscopy device: “SMX-100” manufactured by Shimadzu Corporation), there was no wire deformation or chip misalignment, and the conductive portion was extended. It was confirmed that a semiconductor device having a high bonding strength between the conductive portion and the sealing resin was obtained because the portion was embedded in the sealing resin.

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

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

[Transfer mold conditions]
Equipment: TOWA molding machine Molding temperature: 175 ° C
Time: 90 seconds Clamping pressure: 200KN
Transfer speed: 3mm / sec Transfer pressure: 5KN

[Elastic modulus measurement method]
Both base material layer and adhesive layer Evaluation device: Viscoelasticity spectrum meter “ARES” manufactured by Rheometrics
Temperature increase rate: 5 ° C / min
Frequency: 1HZ
Measurement mode: Tensile mode

[Adhesive strength measurement method]
After laminating an adhesive tape with a width of 20 mm and a length of 50 mm on a 35 μm copper foil (Japan Energy “C7025”) under the conditions of 120 ° C. × 0.5 MPa × 0.5 m / min, in a hot air oven at 150 ° C. After standing for 1 hour, a 35 μm copper foil was pulled in a 180 ° direction at a pulling speed of 300 mm / min under an atmospheric condition of a temperature of 23 ° C. and a humidity of 65% RH, and the center value was taken as the adhesive strength.

[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 the pull strength 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.

  In Example 2, a semiconductor device was manufactured in the same manner as Example 1 except that the adhesive tape removing process was changed. That is, after the resin molding, the semiconductor device was heated on a hot plate at 200 ° C., the first adhesive layer of the adhesive tape was heated and foamed, and the copper foil was peeled off. The resin base material layer was peeled off together with the first adhesive layer and the second adhesive layer on a knife edge at an angle of 15 degrees.

(Comparative example)
In this comparative example, a semiconductor device was manufactured in the same manner as in Example 1 except that the configuration of the adhesive tape and the removal process thereof were changed. That is, after applying the adhesive solution for the second adhesive layer used in Example 1 to a 100 μm thick single-sided roughened copper alloy foil (“BHY-13B-7025” manufactured by Japan Energy Co., Ltd.), 150 ° C. Was dried for 3 minutes to produce an adhesive sheet having an adhesive layer having a thickness of 15 μm. After the resin molding, the adhesive sheet was peeled off at a room temperature on a knife edge with an angle of 15 degrees.

  The semiconductor devices manufactured in Examples 1 and 2 and the comparative example were evaluated with respect to two points of terminal loss and chip breakage (chip breakage, sealing resin cracking) in the adhesive tape removing process. The number of samples was 64. As a result, the semiconductor devices manufactured in Examples 1 and 2 did not generate any defects, but the semiconductor device manufactured in Comparative Example had 5 out of 64 semiconductors with terminal defects. 2 out of 64 were found.

It is process drawing of the first half which shows the manufacturing method of the semiconductor device which concerns on this invention. It is explanatory drawing which shows the adhesive tape removal process following FIG. It is a schematic block diagram which shows the semiconductor device obtained with the manufacturing method of this invention. It is the explanatory example which showed typically the top view of the adhesive tape (board | substrate) at the time of forming an electroconductive part in the process of FIG. It is process drawing which shows the procedure of board | substrate preparation. It is a top view of the state which formed the electroconductive part in the adhesive tape at the board | substrate preparation process in the manufacturing method of the semiconductor device of this invention. It is explanatory drawing which shows an example of the conventional semiconductor device which has a leadless structure. It is explanatory drawing which shows another example of the conventional semiconductor device which has a leadless structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Semiconductor element 11 Electrode 20 Conductive part 20a Overhang | projection part 30 Wire 40 Sealing resin 50 Adhesive tape 51 Metal base material layer 52 1st adhesive layer 53 Resin base material layer 54 2nd adhesive layer 60 Metal foil 61 Dry film resist 62 Barrier layer 63 Precious metal plating layer 70 Block 71 Semiconductor element fixing region

Claims (6)

A substrate forming step of forming at least a plurality of conductive portions partially on the adhesive surface of the adhesive tape; and at least one semiconductor element on which the electrode is formed on the substrate so that the side on which the electrode is not formed is the substrate side A semiconductor element mounting step in which the upper side of the plurality of conductive parts and the electrode on the upper side of the semiconductor element are electrically connected by a wire, and the semiconductor element, the wire, and the conductive part are sealed and sealed with a sealing resin A method for manufacturing a semiconductor device comprising a resin sealing step for forming a semiconductor device on a tape, an adhesive tape removing step for separating the adhesive tape from the semiconductor device, a cutting step for dicing into pieces by dicer cutting or punching,
The adhesive tape has a multilayer structure in which a first adhesive layer, a resin base layer, and a second adhesive layer are sequentially laminated on a metal base layer, and the first adhesive layer of which has an adhesive force by heating. Use adhesive tape with the property of losing,
In the adhesive tape removing step, by heating to a predetermined temperature, the adhesive strength of the first adhesive layer in the adhesive tape is lost and the metal base material layer is peeled off, and then the resin base material layer is first bonded. A method of manufacturing a semiconductor device, wherein the adhesive layer and the second adhesive layer are folded back and peeled off. It is the adhesive tape used for the manufacturing method of Claim 1, Comprising: It is a multilayer structure by which the 1st adhesive bond layer, the resin base material layer, and the 2nd adhesive bond layer were laminated | stacked one by one on the metal base material layer, the with one adhesive layer to have the property of losing the adhesive force by heating, the second adhesive layer consists of thermosetting adhesive, an elastic modulus before curing at 100 to 150 ° C. is 0.1MPa less, adhesive tapes elastic modulus after curing, characterized in der Rukoto least 0.1MPa at 200 ° C.. Adhesive tape according to claim 2 first Ichise' Chakuzaiso, characterized in that it has a heating foaming peeling function as a property of losing the adhesive force by heating. Both the elastic modulus at 200 ° C. of the metal substrate layer and the resin substrate layer is 1.0 GPa or more, and the elastic modulus at 200 ° C. of the first adhesive layer and the second adhesive layer is 0.1 MPa or more. The adhesive tape according to claim 2 or 3 characterized by these. The adhesive tape according to any one of claims 2 to 4, wherein the thermosetting adhesive of the second adhesive layer contains an epoxy resin, an epoxy curing agent, and an elastic body as essential components.   The electrode on the upper side of the semiconductor element and the upper side of the plurality of conductive parts are electrically connected by wires, respectively, and the lower side where the electrode of the semiconductor element is not formed and the lower side not connected to the wire of the conductive part A semiconductor device having a leadless structure in which a semiconductor element, a wire, and a conductive portion are sealed with a sealing resin in a state of being exposed on the back surface, wherein the semiconductor device is manufactured by the manufacturing method according to claim 1. Semiconductor device.

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