Substrate for semiconductor device, method of manufacturing the substrate, semiconductor device, and method of manufacturing the semiconductor device

Abstract

To provide a substrate for a semiconductor device capable of efficiently manufacturing a miniaturized semiconductor device by adopting a structure in which a semiconductor element is easily arranged on a metal part to be an electrode part.SOLUTION: A conductor 20 is arranged on a metal part 10 as an electrode part formed on a mother board 50, and a semiconductor element can be mounted on the conductor 20, thus suppressing the height from the lower surface of the metal part 10 to the upper surface of the semiconductor element in a state that the semiconductor element is mounted on the metal part 10 and electrically connected, and hence suppressing the height of the semiconductor device. In addition, by disposing the conductors 20 having the same shape on the respective metal portions 10, the conductors 20 having the same height can be easily provided on the metal portions 10 in an appropriate state, and the electrical connection state between the semiconductor element to be mounted and the metal portions 10 can be ensured.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a substrate for a semiconductor device used to manufacture a semiconductor device having metal parts such as electrodes exposed at the bottom. [Background technology]

[0002] Conventional semiconductor devices have a structure in which a semiconductor element is mounted on a substrate for supporting the semiconductor element, the semiconductor element is connected to a metal terminal for external conduction by wire bonding, and the entire substrate including the semiconductor element is covered with a protective material such as resin. Due to their structure, there are limitations to how miniaturized they can be.

[0003] In response to this, a semiconductor device is known that uses a flip-chip technique in which the semiconductor element is turned upside down and connects the semiconductor element to metal terminals using bumps instead of bonding wires, thereby achieving a thinner package. An example of a conventional semiconductor device using such a flip-chip method is disclosed in Japanese Patent Laid-Open Publication No. 10-116935. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-116935 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional semiconductor devices have the configuration shown in the above-mentioned patent document, and are designed to be miniaturized by connecting a metal film serving as an electrode terminal and a semiconductor element via a bump in the shortest distance.

[0006] The protruding bumps are formed on the electrodes (pads) of semiconductor elements or on circuit boards, and are often made of solder. When forming bumps with solder, a commonly used method is to apply solder paste by printing using a mask, and then heat and melt it in a reflow furnace to obtain the bumps.

[0007] In recent years, with the miniaturization of packages, there has been an increasing demand for further miniaturization of electrodes and their arrangement intervals in semiconductor devices and internal semiconductor elements (chips). In contrast, with the method of applying solder paste to form bumps by printing using a mask, there is a certain limit to how fine the solder particles in the solder paste can be made, making it difficult to stably and accurately apply a small amount of solder paste to a narrow target area.

[0008] In addition, as miniaturization progresses, the pitch of patterns inevitably becomes narrower, and as the spacing between patterns becomes narrower, there is a risk that solder paste that has escaped from a pattern position may come into contact with other patterns and cause a short circuit.

[0009] Furthermore, the height of the solder paste applied by printing is prone to variation, and if variation does occur, the height of the bumps obtained will be uneven. If the bump height is not uniform, there is a risk that the connection between the semiconductor element and the electrode terminal will be poor.

[0010] Furthermore, if the pattern shape is uneven or if there is misalignment between the pads or electrode terminals and the mask, it becomes difficult to uniformly control the amount of solder paste in the printing process. As described above, there are many problems with applying the solder paste printing method to miniaturizing electrodes and their spacing in semiconductor devices, etc.

[0011] The present invention has been made to solve the above-mentioned problems, and aims to provide a substrate for a semiconductor device, a method for manufacturing the substrate, and a semiconductor device manufactured using the substrate for a semiconductor device, which employs a structure that makes it easy to arrange a semiconductor element on a metal part that serves as an electrode part, thereby enabling efficient manufacturing of a miniaturized semiconductor device. [Means for solving the problem]

[0012] The substrate for a semiconductor device disclosed in the present invention is used in the manufacture of a semiconductor device in which a plurality of metal portions that become at least electrode portions are exposed at the bottom of the device, and in the substrate for a semiconductor device in which the metal portions are each formed on a mother substrate, spherical or columnar conductors, at least the surface portion of which is made of solder, are arranged on the surface side of the electrode portions.

[0013] According to the disclosure of the present invention, among the metal parts formed on the mother substrate, conductors are arranged on a plurality of electrode parts, and by making it possible to mount a semiconductor element on these conductors, it is easier to provide conductors of uniform height on the electrodes in an appropriate state compared to forming bumps by applying solder paste to the electrodes, and it is possible to ensure a reliable electrical connection between the mounted semiconductor element and the electrodes. Furthermore, when manufacturing a semiconductor device using the semiconductor device substrate, with the semiconductor element mounted on the electrode part and electrically connected, the height from the lower surface of the electrode part to the upper surface of the semiconductor element can be reduced, and the height of the semiconductor device can also be reduced. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is an enlarged view of a main part of a substrate for a semiconductor device according to a first embodiment of the present invention. [Figure 2] 3A to 3C are explanatory views of a resist layer forming step in the method for manufacturing a substrate for a semiconductor device according to the first embodiment of the present invention. [Figure 3] 3A to 3C are explanatory views of a metal portion forming step in the method for manufacturing a substrate for a semiconductor device according to the first embodiment of the present invention. [Figure 4] 3 is an explanatory diagram of a state in which a flux is provided on a substrate for a semiconductor device according to the first embodiment of the present invention, and a state in which a conductor mask is provided on the substrate. FIG. [Figure 5] 1 is an explanatory diagram of a state in which conductors and semiconductor elements are arranged on a substrate for a semiconductor device according to a first embodiment of the present invention. [Figure 6]1A and 1B are explanatory views of a state in which semiconductor elements are integrated and sealed in a substrate for a semiconductor device according to a first embodiment of the present invention, and a state in which the semiconductor device is assembled after separation from a mother substrate. [Figure 7] 1A and 1B are a cross-sectional view and a bottom view of a semiconductor device according to a first embodiment of the present invention. [Figure 8] 5A and 5B are explanatory views of a state in which semiconductor elements are arranged and a state in which the semiconductor elements are integrated on another substrate for a semiconductor device according to the first embodiment of the present invention. [Figure 9] 10A and 10B are explanatory views of a process of disposing a wafer on a substrate for a semiconductor device according to a second embodiment of the present invention. [Figure 10] 10A and 10B are explanatory views of a sealed state of a substrate for a semiconductor device according to a second embodiment of the present invention, a state in which semiconductor devices are assembled after separation from a mother substrate, and semiconductor devices after cutting. [Figure 11] FIG. 10 is an explanatory view of a step of forming a second resist layer in the method for manufacturing a substrate for a semiconductor device according to the third embodiment of the present invention. [Figure 12] 10A to 10C are explanatory views showing steps of forming a pedestal and removing a resist layer in a manufacturing method of a substrate for a semiconductor device according to a third embodiment of the present invention, and showing a state in which flux is provided on the substrate for a semiconductor device. [Figure 13] 10A to 10C are explanatory views of a process for providing a conductor on a substrate for a semiconductor device according to a third embodiment of the present invention. [Figure 14] 10A and 10B are explanatory views of a semiconductor element arrangement state, a semiconductor element integration state, and a sealed state of a substrate for a semiconductor device according to a third embodiment of the present invention. [Figure 15] 10 is an explanatory diagram of a state in which a flux is provided on a substrate for a semiconductor device according to a fourth embodiment of the present invention, and a state in which a conductor mask is provided on the substrate. FIG. [Figure 16] 10A and 10B are explanatory views of a state in which conductors are disposed on a substrate for a semiconductor device according to a fourth embodiment of the present invention and a state in which the conductors are integrated. [Figure 17] 10A and 10B are explanatory views of a semiconductor element arrangement state, a wire bonding state, and a sealing state of a substrate for a semiconductor device according to a fourth embodiment of the present invention. [Figure 18]10A and 10B are explanatory views of a state in which semiconductor devices are assembled after a mother substrate is separated from a substrate for a semiconductor device according to a fourth embodiment of the present invention, and the semiconductor devices after cutting. DETAILED DESCRIPTION OF THE INVENTION

[0015] (First embodiment of the present invention) A substrate for a semiconductor device according to a first embodiment of the present invention will be described below with reference to FIGS. In each of the above figures, the substrate 1 for a semiconductor device according to this embodiment comprises a mother substrate (mother mold) 50 made of a conductive material, a metal part 10 formed on this mother substrate 50 and serving as an electrode part of a semiconductor device 100 manufactured using this substrate, and a spherical conductor 20 arranged on the surface side of this metal part 10.

[0016] The manufacturing process for the semiconductor device substrate 1 requires multiple steps, including the steps of forming a resist layer 60 on a mother substrate 50, forming metal parts 10 in exposed areas of the mother substrate 50 that are not covered by the resist layer 60, removing the resist layer 60, and providing conductors 20 on the metal parts 10.

[0017] In detail, first, a resist layer 60 corresponding to non-arrangement areas (non-arrangement regions) of the metal portions 10 is formed on the mother substrate 50, and then the metal portions 10 are formed by electrolytic plating. Next, the resist layer 60 is removed, and a printing mask is placed on the mother substrate 50 and the metal portions 10, and flux is applied to and arranged on the metal portions 10. Then, a conductor mask (arrangement mask) 80 is placed on the mother substrate 50 and the metal portions 10, and the conductors 20 are arranged, completing the series of manufacturing steps.

[0018] The mother substrate 50 is formed from a conductive metal plate (approximately 0.1 mm thick) made of stainless steel (such as SUS430), aluminum, copper, or the like, and forms a key part of the substrate 1 for a semiconductor device until it is removed in the manufacturing process of the semiconductor device, and at each stage in the manufacturing process of the substrate for a semiconductor device, a resist layer 60 and a metal part 10 are formed on the front side, and a resist layer 63 is disposed on the back side. When forming the metal part 10, electricity is passed through the mother substrate 50, and the metal part 10 is formed by electrolytic plating (electroplating, plating, electroforming) on ​​the electrically conductive parts of the surface of the mother substrate 50 that are not covered by the resist layer 60.

[0019] In the manufacturing process of a semiconductor device using the substrate 1 for a semiconductor device, the surface side of the metal part 10 on the mother substrate 50 is covered with the sealing material 40 (see Figure 6(B)), and when the mother substrate 50 has obtained sufficient strength without supporting the metal part 10 and the sealing material 40 (a state in which the metal part 10 is protected by the sealing material 40), it is separated and removed from them (see Figure 6(C)).

[0020] The metal parts 10 are made of nickel or copper, or a nickel alloy such as nickel-cobalt, which are suitable for electrolytic plating, and are formed by electrolytic plating in the areas of the mother substrate 50 where the resist layer 60 is not present (areas exposed from the resist layer 60). In the substrate 1 for semiconductor device, a plurality of metal parts 10 are arranged as electrode parts on the surface of the mother substrate 50 near the position where the semiconductor element is mounted. Then, a combination of a plurality of these metal parts 10 is treated as one unit, and a large number of such combinations are formed in an aligned state, equal to the number of semiconductor devices to be manufactured.

[0021] The metal portion 10 has a thickness exceeding that of the resist layer 60 (for example, a thickness of about 60 to 80 μm), and is formed in a shape having a generally eaves-shaped protruding portion 10c at its upper peripheral edge that protrudes toward the resist layer 60 (see FIG. 3(C)). The protruding portion 10c is obtained by continuing the electrolytic plating even after the metal portion 10 is formed to the thickness of the resist layer 60, so that the growth of the metal portion proceeds not only in the thickness direction but also in other directions not restricted by the resist layer 60, resulting in a shape that protrudes from the upper end of the metal portion 10 beyond the resist layer 60 toward the resist layer 60. As the metal portion 10 is sealed with the sealing material 40, the protruding portion 10c is sandwiched and fixed by the sealing material 40. The metal portion 10 may have no protruding portion 10c. In this case, the metal portion 10 is formed within the thickness of the resist layer 60 in electrolytic plating.

[0022] If necessary, to ensure proper soldering when mounting the semiconductor device, a thin film 10d made of a metal with better solder wettability than the main material portion such as nickel, such as gold, silver, tin, palladium, solder, etc., may be provided on the back side (mother substrate side) of the metal portion 10. The thickness of this thin film 10d is preferably about 0.03 to 1 μm.

[0023] When the thin film 10d is provided, prior to the formation of the metal portion 10, the thin film 10d is formed by plating or the like on the portions of the mother substrate 50 where the resist layer 60 is not present (see FIG. 3(B)). Thereafter, the main material portion of the metal portion 10, such as nickel, is formed on the thin film 10d by further electrolytic plating. This thin film 10d can also be given the function of preventing the metal portion 10 from being corroded and deteriorated by an etching solution when the mother substrate 50 is removed by etching, and in this case, it is preferable to provide a thin film of gold, silver, tin, or the like.

[0024] In addition, when the purpose of forming this thin film on the back side of the metal part 10 is to prevent soldering, it is not limited to forming the main material part of the metal part 10 by electrolytic plating, but it is also possible to form a thin film on the exposed back side of the metal part 10 by plating after the semiconductor device 100 is completed.

[0025] The resist layer 60 is formed from an insulating material that is resistant to dissolution in the plating solution used in the electrolytic plating of the metal part 10, and is arranged on the mother substrate 50 in correspondence with the non-placement areas of the metal part 10 that are previously set, and is removed after the metal part 10 is formed (see Figure 4(A)).

[0026] This resist layer 60 is disposed on the mother substrate 50 prior to the formation of the metal portion 10. More specifically, for example, an approximately 50 μm thick alkali-developable photosensitive film resist is adhered to the mother substrate 50 by thermocompression or the like, and a mask film 65 of a predetermined pattern corresponding to the position of the metal portion 10 of the semiconductor device 100 is placed on top of it. After that, the resist layer 60 is hardened by exposure to ultraviolet light (see Figure 2(C)), and developed to remove the resist material from the non-irradiated portions, and is formed into a shape corresponding to the non-positioned portions of the metal portion 10.

[0027] The resist layer 60 is not limited to photosensitive resist, and can also be formed by applying a paint that does not deteriorate in the plating solution and provides a strong coating film to the non-placement areas of the metal part 10 on the mother substrate 50 using electro-deposition coating or the like to achieve the required coating thickness.

[0028] Meanwhile, in addition to the resist layer 60 on the front surface side, a resist layer 63 can also be formed on the back surface of the mother substrate 10 as needed, for example, when plating on the back surface side of the mother substrate 10 is to be avoided (see FIG. 2). The back surface side resist layer 63, like the resist layer 60 on the front surface side, is made of a material that is resistant to plating solution in a hardened state and that can be easily dissolved and removed when no longer needed, for example, an approximately 50 μm thick alkali-developable photosensitive film resist that is applied by thermocompression bonding or the like, and then hardened and formed over the entire back surface by processing such as exposure to ultraviolet light without a mask.

[0029] The resist layer 60 is configured to be removed after the metal portion 10 is formed, but this is not limited to this. It is also possible to use a material that has excellent resistance to dissolution in the plating solution, resistance to deterioration, and physical strength, and to leave it in place after the metal portion is formed and use it as part of the sealing material.

[0030] The conductor 20 is a spherical body disposed on the surface side of the metal part 10, which is an electrode part. The entire conductor 20, including the surface layer, is made of solder. The conductor may also be a columnar body.

[0031] The conductor 20 is disposed on the metal part 10 with the flux 70 interposed therebetween, and the flux 70 fixes the conductor 20 in a fixed state so that it does not easily separate from the metal part 10 . Since the conductor 20 is joined to the metal part 10 and the semiconductor element 30 by soldering using solder that has been heated and melted, it is sufficient that at least the surface layer is made of solder, and the parts other than the surface layer may be made of other materials.

[0032] During the manufacturing process of a substrate for a semiconductor device, in the process of arranging the conductors 20 on the metal parts 10, the conductors 20 are arranged one by one on each metal part 10 through the through holes 81 of the conductor mask 80 placed on the mother substrate 50 and the metal parts 10.

[0033] The conductor mask 80 used when disposing the conductors 20 on the metal parts 10 has a configuration in which a large number of independent through holes 81 for introducing the conductors 20 are provided in an arrangement pattern corresponding to each metal part 10 on the mother substrate 50. The through holes 81 are drilled as circular through holes with an inner diameter slightly larger than the outer diameter of the conductors 20, which are spherical bodies. This conductor mask 80 has the same structure as a known mask used for arranging solder balls, etc., and a detailed description thereof will be omitted.

[0034] As shown in Figure 7, the semiconductor device 100 manufactured using the semiconductor device substrate 1 is configured to include, in addition to the metal part 10 and conductor 20 obtained from the semiconductor device substrate 1, a semiconductor element 30 mounted on the conductor 20, and a sealing material 40 that covers and seals the surface side of the metal part 10 including the semiconductor element 30 and the conductor 20.

[0035] In this semiconductor device 100, the back side of the metal part 10 serving as an electrode part is exposed at the bottom (see FIG. 7(B)), and the back side of this exposed metal part 10 and the back side of the sealing material 40 appearing as part of the device exterior are positioned on approximately the same plane. On each side of the semiconductor device 100 other than the bottom part (bottom surface), only the sealing material 40 forming the device exterior is exposed. Alternatively, the semiconductor device may have a configuration in which the metal part is exposed on the side surface.

[0036] In the manufacturing process of a semiconductor device using the semiconductor device substrate 1, the surface side of the metal part 10 on the mother substrate 50 is covered with the sealing material 40 (see FIG. 6(B)), and when the mother substrate 50 has sufficient strength without supporting the metal part 10 and the sealing material 40, the mother substrate 50 is separated and removed from them (see FIG. 6(C)). If the mother substrate 50 is made of stainless steel, a method is used in which it is physically peeled off from the semiconductor device by applying force, and if the mother substrate 50 is made of copper or the like, an etching method is used in which a chemical solution is used to dissolve and remove it. In the etching, an etching solution is used that has selective etching properties that dissolves the mother substrate 50 but does not damage the material of the metal part 10, such as nickel. By removing this mother substrate 50, the semiconductor device 100 is obtained in a state where the metal part 10 and the sealing material 40 are exposed at the bottom.

[0037] The semiconductor element 30 is a so-called chip on which a fine electronic circuit is formed, and is mounted on a conductor 20 on a metal part 10, which is an electrode part. Then, through pressure bonding, heating, etc. after mounting, parts of the solder constituting the conductor 20 are bonded to the electrodes (pads) provided on the surface of the semiconductor element 30 and to the metal part 10, respectively, thereby electrically connecting the semiconductor element 30 and the metal part 10.

[0038] Since this semiconductor element 30 is arranged in a flip-chip format, compared to the conventional case in which the semiconductor element is mounted on the top surface of the semiconductor element mounting portion of the metal part, no wire bonding is performed and there are no wires joined to the top surface of the semiconductor element, so the thickness of the semiconductor device 100 can be reduced when manufactured, thereby achieving a low profile of the semiconductor device 100.

[0039] The sealing material 40 is a thermosetting resin such as epoxy resin having high physical strength, and covers and seals the semiconductor element 30 and the conductor 20 on the surface side of the metal part 10, isolating structurally weak parts of the semiconductor element 30, the conductor 20, etc. from the outside and providing a protective state. Note that when the semiconductor element 30 is a light-emitting element such as an LED, a light-transmitting material is used.

[0040] In the sealing process using this sealing material 40, the area of ​​the substrate 1 for the semiconductor device on the front side of the mother substrate 50 that will become the semiconductor device, including the semiconductor elements 30 and metal parts 10, is covered with a mold that will become an upper mold, and then unhardened resin material that will become the sealing material 40 is pressed between this mold and the mother substrate 50 and hardened, thereby completing the sealing with the sealing material 40. However, in the sealing process, many combinations of semiconductor elements 30 that will become one semiconductor device and multiple metal parts 10 as electrode parts are uniformly sealed while remaining aligned, so that many semiconductor devices 100 are connected via the sealing material 40.

[0041] This sealing material 40 has sufficient physical strength and functions as part of the exterior of the semiconductor device 100 to adequately protect the interior, and even when the mother substrate 50 is physically removed by applying force, such as by peeling it off from the semiconductor device, it will maintain its integrated state with the metal part 10 without cracking or other damage.

[0042] Next, each step of manufacturing a substrate for a semiconductor device according to this embodiment and manufacturing a semiconductor device using the substrate for a semiconductor device will be described. In the manufacturing process for a semiconductor device substrate, first, a resist layer 60 is provided on the mother substrate 50 so as to correspond to the predetermined non-positioned portions of the mother substrate 50 where the metal portions 10 are not to be disposed. Specifically, a photosensitive resist material 60a is provided on the front side of the mother substrate 50 in close contact with the mother substrate 50 to a predetermined thickness (e.g., approximately 50 μm) corresponding to the height of the metal portions 10 to be formed (see FIG. 2(B)). A mask film 65 having a predetermined pattern corresponding to the positions of the metal portions 10 is placed on the photosensitive resist material, and the photosensitive resist material is then subjected to known processes such as curing by exposure to ultraviolet light (see FIG. 2(C)) and development to remove the resist material from the non-irradiated portions, thereby forming a resist layer 60 corresponding to the non-positioned portions of the metal portions 10 (see FIG. 3(A)). A photosensitive resist material is also provided on the back side of the mother substrate 50 in the same manner as on the front side, and this is then subjected to processes such as exposure to light to form a resist layer 63 over the entire back side (see FIG. 2(C)).

[0043] After forming the resist layers 60, 63 that are resistant to dissolution in the plating solution used to plate the metal part 10, the exposed portions of the surface of the mother substrate 50 that are not covered with the resist layer 60 are subjected to pre-plating treatment (surface oxide film removal and surface activation treatment) as needed. Then, a thin gold film 10d for improving solder wettability is formed on the exposed portions by plating or the like to a thickness of, for example, 0.03 to 1 μm (see FIG. 3(B)). Then, nickel is layered on the thin gold film 10d by electrolytic plating to form the metal part 10 (see FIG. 3(C)).

[0044] In this metal portion 10 forming process, the metal portion 10 is formed to a predetermined thickness (for example, a thickness of about 60 μm) that exceeds the thickness of the resist layer 60 (see FIG. 3(C)). A plurality of metal portions 10 are arranged on the surface of the mother substrate 50 near the intended mounting position of the semiconductor element 30, and a combination of these plurality of arranged metal portions 10 is treated as one unit, and a large number of such combinations are formed in an aligned state, equal to the number of semiconductor devices to be manufactured.

[0045] The metal portion 10 is formed to a thickness that exceeds the thickness of the resist layer 60, so that a roughly eave-shaped protrusion 10c that protrudes toward the resist layer 60 is formed on the upper peripheral edge of the metal portion 10 near the resist layer 60.

[0046] Once the metal part 10 of the desired thickness and shape is obtained, the resist layer 60 on the front side of the mother substrate 50 and the resist layer 63 on the back side are dissolved (swelled) with a predetermined remover and removed (see Figure 4(A)).

[0047] After removing the resist layer, flux is applied to the metal part 10 by printing. The printing process is performed using a procedure similar to that of a known process using a printing mask. Specifically, the printing mask is placed in contact with the surface of the metal part 10 on the matrix substrate 50 where the printing is to be performed (in the case of contact printing), or in a non-contact state with a gap between the printing mask and the surface (in the case of off-contact printing). A squeegee is then moved over the printing mask, scraping off the paste or liquid flux 70 while applying the flux 70 through the openings in the printing mask to the printing target area of ​​the metal part 10. After this application, the printing mask is removed from the metal part 10, completing the application of the flux 70 to the metal part 10 by printing (see FIG. 4(B)).

[0048] After the flux 70 is applied, the process moves to the step of applying the conductor 20 onto the metal part 10 . In this step, first, the conductor mask 80 is placed on the matrix substrate 50 and the metal portion 10, and the conductor mask 80 is aligned so that the through-holes 81 of the conductor mask 80 are aligned with the metal portion 10, and then the conductor mask 80 is fixed onto the matrix substrate 50 (see FIG. 4(C)). In this fixed state, the lower portion (not shown) of the conductor mask 80 abuts against the matrix substrate 50 or the metal portion 10, and the conductor mask 80 is held in a position with at least an appropriate gap between it and the metal portion 10.

[0049] Next, a large number of conductors 20 are supplied onto the conductor mask 80, and the squeegee is moved to distribute the conductors 20 on the conductor mask 80, and the conductors 20 are placed one by one into the through holes 81. The conductors 20 that have passed through the through holes 81 and reached the metal part 10 are held by the flux 70 and are temporarily fixed to the metal part 10 (see FIG. 5(A)).

[0050] After the conductor 20 has been placed on the metal portion 10, the conductor mask 80 is removed from the mother substrate 50 and the metal portion 10, completing the manufacturing process of the substrate 1 for the semiconductor device (see Figure 5(B)). If necessary, the conductor 20 arranged on the metal part 10 may be slightly heated to melt the solder at the point where it comes into contact with the metal part 10 (soldering to the surface of the metal part 10), thereby more securely integrating the conductor 20 with the metal part 10 and making it possible to consider it as a kind of bump.

[0051] Next, a description will be given of the manufacture of a semiconductor device using the obtained substrate 1 for a semiconductor device. First, a semiconductor element 30 is mounted on a conductor 20 provided on a metal portion 10 forming an electrode portion of the substrate 1 for a semiconductor device (see FIG. 5(C)). Then, the semiconductor element 30 is fixed to the conductor 20 by pressure bonding, heating, or the like, and at the same time, the electrodes (pads) on the surface of the semiconductor element 30 and the corresponding metal portions 10 are wired (electrically connected) via the conductor 20 (see FIG. 6(A)).

[0052] When the semiconductor element 30 is fixed to the conductor 20, the conductor 20 and the metal part 10 are also joined together. At this time, residue of the flux 70 that was present between the conductor 20 and the metal part 10 may adhere to the periphery of the joint between the conductor 20 and the metal part 10. It is desirable to remove such flux residue before the sealing process to prevent it from leading to defects such as bridging.

[0053] Once the electrical connection between the semiconductor element 30 and each metal part 10 via the conductor 20 is completed, the area on the surface side of the mother substrate 50 that will become the semiconductor device, including the metal parts 10, is sealed with a sealing material 40 such as epoxy resin, thereby isolating the semiconductor element 30 and the conductor 20 from the outside and protecting them (see Figure 6(B)).

[0054] In detail, the surface side of the mother substrate 50 is attached to a mold die which serves as the upper die, and the mother substrate 50 acts as the lower die while pre-hardened epoxy resin which will become the sealing material 40 is pressed into the mold die to perform sealing. On the mother substrate 50, a large number of combinations of semiconductor elements 30 and a plurality of metal parts 10 which will form one semiconductor device are uniformly sealed in an aligned state, and a large number of semiconductor devices emerge in a connected state.

[0055] Once this large number of connected semiconductor devices have been obtained, the mother substrate 50 is removed, leaving the back side of the metal part 10 exposed at the bottom of each semiconductor device (see FIG. 6(C)). The mother substrate 50, which is made of stainless steel, is removed by physically peeling it off from the semiconductor device. By using stainless steel, which has excellent strength and peelability, for the mother substrate 50, it can be quickly peeled off and removed from the semiconductor device.

[0056] Alternatively, when the mother substrate is made of another metal material, the mother substrate can be removed by immersing it in an etching solution and dissolving it. In this etching, an etching solution with selective etching properties is used, which dissolves the mother substrate but does not damage the material of the metal portion 10. Alternatively, a thin film 10d may be formed in advance on the back side (mother substrate side) of the metal portion 10, so that this thin film 10d prevents the metal portion 10 from being corroded and deteriorated by the etching solution during etching. When the mother substrate is removed by dissolving it through etching, no excessive force is applied to the semiconductor device, which reduces the likelihood of adverse effects occurring when the mother substrate is removed.

[0057] At the bottom of the semiconductor device after the mother substrate 50 has been removed, the exposed back side of the metal part 10 and the back side of the sealing material 40 are positioned on the same plane. After removing the mother substrate 50, the multiple connected semiconductor devices are separated one by one to complete the semiconductor device 100.

[0058] As described above, the substrate for a semiconductor device according to this embodiment has conductors 20 disposed on metal portions 10 serving as electrodes formed on a mother substrate 50, and allows semiconductor elements 30 to be mounted on these conductors 20. In manufacturing a semiconductor device using the substrate for a semiconductor device 1, when the semiconductor elements 30 are mounted on the metal portions 10 by flip-chip mounting and electrically connected, the height from the lower surface of the metal portions 10 to the upper surface of the semiconductor elements 30 can be reduced, thereby enabling the semiconductor device 100 to have a reduced height. Furthermore, by disposing conductors 20 of the same shape on each metal portion 10, it is easier to provide conductors 20 of uniform height on the metal portions 10 in an appropriate state, compared to forming bumps by applying solder paste to the metal portions 10, and this ensures a reliable electrical connection between the semiconductor elements 30 and the metal portions 10 to be mounted.

[0059] In the semiconductor device substrate according to this embodiment, the spherical conductors 20 arranged on the surface side of the metal portion 10 are configured to be formed entirely from solder, but this is not limited to this. As long as the material of the surface layer of the spherical or columnar conductor is at least solder, conductors of other structures may be used. For example, as shown in FIG. 8, the conductor 25 may be configured to have a core portion 26 that is a sphere made of metal or resin, and a solder layer 27 that is arranged to cover the surface of this core portion 26.

[0060] In this case, even when the conductor 25 and the metal part 10, and the conductor 25 and the semiconductor element 30 are integrally joined and electrically connected by soldering, which involves heating a portion of the solder layer 27 of the conductor 25 to a molten state, the core part 26 of the conductor 25 can maintain the shape it had before being heated. This allows the conductors 25, which are of uniform height, to be uniformly joined to the semiconductor element 30 mounted thereon, and ensures a reliable electrical connection between the semiconductor element 30 and the metal part 10 via the conductor 25.

[0061] Alternatively, a metal having good connectivity with electrodes, such as gold, silver, or palladium, may be disposed as a surface layer instead of the solder layer 27 in the conductor 25. Furthermore, the entire conductor may be formed solely from such a metal having good connectivity with electrodes.

[0062] Furthermore, in the substrate for the semiconductor device according to the above embodiment, the metal portion 10 is configured so that only the portion electrically connected to the semiconductor element 30 and forming an electrode portion is disposed, but this is not limited to this, and the metal portion may be configured to have a portion other than an electrode portion that contacts the semiconductor element and is partially exposed on the surface of the semiconductor device, for purposes such as heat dissipation from the semiconductor element.

[0063] Furthermore, in the semiconductor device manufactured from the semiconductor device substrate according to the above embodiment, the semiconductor element 30 is surrounded by the sealing material 40 so that it does not appear on the surface of the semiconductor device. However, this is not limited to this, and for purposes such as bringing a heat dissipation means into direct contact with the semiconductor element, it is also possible to configure the semiconductor element not to be entirely covered with the sealing material, but to expose a part of the semiconductor element, for example, the side opposite to the side connected to the metal portion as an electrode portion, on the surface of the semiconductor device.

[0064] (Second embodiment of the present invention) In manufacturing a semiconductor device using the semiconductor device substrate according to the above embodiment, the semiconductor element 30 is mounted on the conductor 20 on the metal part 10, but this is not limited to this. As a second embodiment, the wafer 90 may be mounted on the conductor 20 at a stage before the semiconductor element is cut.

[0065] Specifically, a wafer 90 is mounted on a conductor 20 provided on a metal portion 10 serving as an electrode portion of the semiconductor device substrate 1 (see FIG. 9(B)). Then, the wafer 90 is fixed to the conductor 20 by compression bonding, heating, or the like, and at the same time, the electrodes (pads) on the surface of the wafer 90 and the corresponding metal portions 10 are electrically connected via the conductor 20 (see FIG. 9(C)).

[0066] Once the connection between the wafer 90 and each metal part 10 via the conductors 20 is complete, the area between the mother substrate 50 and the wafer 90 that will become the semiconductor device containing the metal parts 10 and the like is sealed with a sealant 40 such as epoxy resin, and the connection parts between the conductors 20 and the wafer 90 or the metal parts 10 are isolated from the outside and protected (see FIG. 10(A)). Note that the area sealed with the sealant 40 may be expanded so that the surface of the wafer 90 is also sealed with the sealant 40. In this state, a large number of combinations of each semiconductor element 30 and a plurality of metal parts 10 provided on the wafer 90 are aligned and connected together.

[0067] Once the wafer 90 and the metal part 10 are integrally connected with their essential parts sealed in this way, the mother substrate 50 is removed (see FIG. 10(B)). As in the first embodiment, the mother substrate 50 can be removed by physically peeling it off or by immersing it in an etching solution to dissolve it.

[0068] After the mother substrate 50 is removed, the back side of the exposed metal portion 10 and the back side of the encapsulant 40 are positioned on the same plane with respect to the wafer 90. When each semiconductor element of the wafer 90 is separated one by one together with the integrated metal portion 10 and encapsulant 40 from the connected state, a semiconductor device 100 with a structure in which the semiconductor element 30 is partially exposed is completed (see FIG. 10(C)).

[0069] In this way, in manufacturing a semiconductor device using the semiconductor device substrate of this embodiment, a wafer 90 is mounted on the conductor 20 provided on the metal portion 10 of the semiconductor device substrate 1, the wafer 90 is connected to each metal portion 10 via the conductor 20, the space between the mother substrate 50 and the wafer 90 is sealed with the sealing material 40, and then the mother substrate 50 is removed and each semiconductor element of the wafer 90 is cut together with the integrated metal portion 10 and sealing material 40.This allows the process of separating each semiconductor element on the wafer and the process of separating each semiconductor device from the assembled semiconductor device to be performed together at the same time, reducing the number of processes and suppressing manufacturing costs.

[0070] (Third embodiment of the present invention) A substrate for a semiconductor device according to a third embodiment of the present invention will be described with reference to FIGS. In each of the figures, the substrate 2 for a semiconductor device according to this embodiment has a configuration comprising a mother substrate 50, a metal part 10, and a conductor 20, similar to the first embodiment, but differs in that it has a configuration in which a base part 13 is provided on the metal part 10. The conductor 20 is the same as that in the first embodiment, and a detailed description thereof will be omitted.

[0071] As with the first embodiment, the main manufacturing steps of the substrate 2 for a semiconductor device include a step of forming a resist layer on a mother substrate 50, a step of forming a metal part 10 in the exposed area of ​​the mother substrate 50 that is not covered by the resist layer, a step of removing the resist layer, and a step of arranging a conductor 20 on the metal part 10.

[0072] Specifically, first, a first resist layer 61 is formed on the mother substrate 50 corresponding to the areas where the metal portion 10 will not be placed, and then the metal portion 10 is formed by electrolytic plating. Next, a second resist layer 62, separate from the first resist layer 61, is formed on the areas where the base portion 13 will not be placed, and then a metal layer serving as the base portion 13 is formed by plating on the surface of the metal portion 10. Thereafter, the first resist layer 12 and the second resist layer 16 are removed, and then a printing mask is placed on the mother substrate 50 and the metal portion 10, and flux is applied to and disposed on the metal portion 10. Then, a conductor mask is placed on the mother substrate 50 and the metal portion 10, and the conductor 20 is disposed on the metal portion 10, completing the series of manufacturing steps.

[0073] As in the first embodiment, the mother substrate 50 is formed of a conductive metal plate and forms a main part of the semiconductor device substrate 2 until it is removed in the manufacturing process of the semiconductor device. When the metal part 10 is formed in the manufacturing process of the semiconductor device substrate 2, electricity is passed through the mother substrate 50, and the metal part 10 is formed by electrolytic plating in the electrically conductive part of the surface of the mother substrate 50 that is not covered by the first resist layer 61. Similarly, when the base part 13 is formed, electricity is passed through the mother substrate 50 and the metal part 10, and the base part 13 is formed by electrolytic plating in the electrically conductive part of the metal part 10 that is not covered by the second resist layer 62.

[0074] The metal portions 10 are made of nickel or copper, or a nickel alloy such as nickel-cobalt, which are suitable for electrolytic plating, and are formed by electrolytic plating in areas of the mother substrate 50 where the first resist layer 61 is not present. In the substrate 2 for semiconductor device, the metal portions 10 are formed in a form in which a number of combinations of metal portions 10 arranged near the semiconductor element mounting position on the surface of the mother substrate 50 are arranged in an aligned state, the number of such combinations being equal to the number of semiconductor devices to be manufactured, as in the first embodiment.

[0075] This metal portion 10 has a thickness that exceeds the thickness of the first resist layer 61 (for example, a thickness of approximately 60 to 80 μm), and is formed in a shape that has an approximately eave-shaped protrusion 10c at the upper edge that protrudes toward the first resist layer 61, as in the first embodiment.

[0076] As in the first embodiment, if necessary, a thin film 10d of a metal or alloy having better solder wettability than the main material portion such as nickel may be provided on the back side of the metal portion 10 to ensure proper soldering when mounting the semiconductor device.

[0077] The base portion 13 is a convex metal layer provided on the surface side of the metal portion 10. In detail, the base portion 13 is configured as an annular convex portion surrounding a recess in the center. This base 13 is formed by forming the metal portion 10, and then disposing a second resist layer 62 on the metal portion 10 at locations where the base 13 will not be located, and then plating the metal portion 10. Various metals such as nickel and copper can be used for the base 13, and it is preferable to form the base 13 from a metal that has better bonding properties with the conductor 20 than the metal portion 10, specifically, a metal or alloy with good solder wettability such as gold or silver.

[0078] The base 13 restrains the conductor 20 so that it is positioned on the metal part 10 without shifting. Meanwhile, when the conductor 20 placed on the base 13 is heated and the molten solder of the conductor 20 is soldered to the surface of the base 13, the solder spreads to the area where the base 13 is present. If the width of the base 13 is increased, the proportion of the molten solder that spreads laterally along the base 13 increases, thereby decreasing the height of the conductor 20. Conversely, if the width of the base 13 is narrowed, the lateral spread of the molten solder is suppressed, thereby reducing the amount of reduction in the height of the conductor 20 from its initial height and allowing the conductor 20 to be taller. Based on these points, the width of the base 13 is set according to the desired final height of the conductor 20.

[0079] The first resist layer 61 is formed of an insulating material that is resistant to dissolution in the plating solution used in the electrolytic plating of the metal part 10 and the plating of the base part 13, and is arranged on the mother substrate 50 in correspondence with the non-placement areas of the metal part 10 that are previously set, and is removed after the metal part 10 and the base part 13 are formed (see Figure 12 (B)).

[0080] Like the resist layer 60 in the first embodiment, this first resist layer 61 is disposed on the mother substrate 50 prior to the formation of the metal portions 10. In detail, a known photosensitive resist material is closely disposed on the mother substrate 50 to a predetermined thickness, for example, a thickness of about 50 μm, and then, with a mask film of a predetermined pattern corresponding to the positions of the metal portions 10 of the semiconductor device 100 placed thereon, the resist layer is hardened by exposure to ultraviolet light and developed to remove the photosensitive material in the non-irradiated portions, and is formed into a shape corresponding to the areas where the metal portions 10 will not be located.

[0081] The second resist layer 62, like the first resist layer 61, is formed of an insulating material that is resistant to dissolution in a plating solution. After the metal portion 10 is formed, the second resist layer 62 is disposed corresponding to a predetermined non-positioned portion of the base 13. The second resist layer 62 is removed after the base 13 is formed. As with the first resist layer 61, a photosensitive resist material or the like can be used for the second resist layer 62. The resist material is coated on the surfaces of the metal portion 10 and the first resist layer 61 to a predetermined thickness required for forming the base 13 (see FIG. 11(A)). A mask film 66 with a predetermined pattern corresponding to the non-positioned portion of the base 13 is placed on the resist material, and the resist material is then cured by exposure to ultraviolet light (see FIG. 11(B)). This results in the formation of a fixed second resist layer 62 (see FIG. 11(C)). The second resist layer 62 allows electrolytic plating to proceed only in the portion of the metal portion 10 corresponding to the base 13, forming the base 13, which is a metal layer, on the metal portion 10.

[0082] As with the resist layer 60 in the first embodiment, the first resist layer 61 and the second resist layer 62 are not limited to photosensitive resists, but can also be formed by applying a paint that is not altered by the plating solution and that provides a strong coating film to the non-positioned parts of the metal part 10 and the non-positioned parts of the base part 13 on the mother substrate 50 using electro-deposition coating or the like to achieve the required coating thickness. On the other hand, the resist layer 63 formed on the back surface of the mother substrate 50 is the same as that in the first embodiment, and a detailed description thereof will be omitted.

[0083] The semiconductor device 100 manufactured using the substrate 2 for the semiconductor device is configured to include, in addition to the metal part 10 and conductor 20 obtained from the substrate 2 for the semiconductor device, a semiconductor element 30 mounted on the conductor 20, and a sealing material 40 that covers and seals the surface side of the metal part 10 including the semiconductor element 30 and the conductor 20, as in the first embodiment. The semiconductor element 30 and the sealing material 40 are the same as those in the first embodiment, and detailed description thereof will be omitted.

[0084] In the manufacturing process of a semiconductor device using the substrate 2 for a semiconductor device, the surface side of the metal part 10 on the mother substrate 50 is covered with the sealing material 40 (see FIG. 14(C)), as in the first embodiment, and when the mother substrate 50 has sufficient strength to support the metal part 10 and the sealing material 40, the mother substrate 50 is separated and removed from them. If the mother substrate 50 is made of stainless steel, a method is used in which it is physically peeled off from the semiconductor device by applying force, and if the mother substrate 50 is made of copper or the like, an etching method is used in which it is dissolved and removed using a chemical solution. By removing this mother substrate 50, the semiconductor device 100 is obtained in a state where the metal part 10 and the sealing material 40 are exposed at the bottom.

[0085] Next, each step of manufacturing a substrate for a semiconductor device according to this embodiment and manufacturing a semiconductor device using the substrate for a semiconductor device will be described. In the manufacturing process of the substrate for the semiconductor device, first, a first resist layer 61 is disposed on the mother substrate 50 so as to correspond to the non-positioned portions of the metal portion 10 that are set in advance on the mother substrate 50. The disposition of this first resist layer 61 is similar to the disposition of the resist layer 60 in the first embodiment, and a detailed description thereof will be omitted. Furthermore, the formation of the resist layer 63 on the rear surface of the mother substrate 50 is similar to that in the first embodiment, and a detailed description thereof will be omitted.

[0086] After the resist layers 61 and 63 are formed, the exposed portions of the surface of the mother substrate 50 that are not covered by the first resist layer 61 are subjected to surface oxide film removal and surface activation treatment as necessary, as in the first embodiment, and then a thin gold film 10d for improving solder wettability is formed on this exposed portion, and further, a metal portion 10 is formed on this thin film 10d by electrolytic plating.

[0087] Once the metal portion 10 of the desired thickness and shape is obtained, the surfaces of the metal portion 10 and the first resist layer 61 are cleaned, and then a second resist layer 62 is disposed thereon in correspondence with the base portion 13. Specifically, a photosensitive resist material 62a is disposed in close contact with the surface side of the metal portion 10 and the first resist layer 61 to a predetermined thickness (e.g., about 30 μm) greater than the height of the base portion 13 (see FIG. 11(A)). This photosensitive resist material is then subjected to known processes, such as curing by exposure to ultraviolet light (see FIG. 11(B)) and development to remove the resist material from the non-irradiated portions, with a mask film 66 of a predetermined pattern corresponding to the position of the base portion 13 placed on it, to harden and form a second resist layer 62 corresponding to the non-positioned portion of the base portion 13 (see FIG. 11(C)).

[0088] After the second resist layer 62 is formed, the exposed portions of the metal portion 10 that are not covered with the second resist layer 62 are subjected to known surface treatments, such as cleaning treatments and adhesion treatments, as necessary, and then a process is carried out in which gold, silver, or the like, which has excellent solder wettability, is layered by electroplating to form the base portion 13, and the base portion 13 is formed to a predetermined thickness (for example, a thickness of approximately 10 μm) (see Figure 12(A)).

[0089] Once the base portion 13 of the desired thickness and shape is obtained, the first resist layer 61 and the second resist layer 62 on the front side of the mother substrate 50, and the resist layer 63 on the back side are each removed by dissolving them with a predetermined remover (see Figure 12(B)).

[0090] After removing the resist layer, flux is applied to the metal part 10 by printing. The printing process is performed in a similar manner to processes using a known printing mask. Specifically, the printing mask is placed in contact with the surface of the metal part 10 on the matrix substrate 50 where the flux 70 is to be printed. A squeegee is then moved over the printing mask, scraping off the paste-like flux 70 with the squeegee while applying the flux 70 to the printing area of ​​the metal part 10 through the openings in the printing mask. After application, the printing mask is removed from the metal part 10, completing the deposition of the flux 70 on the metal part 10 by printing. Note that the printing area of ​​the flux 70 on the metal part 10 overlaps with the placement area of ​​the base 13, so the flux 70 is deposited on the base 13 (see FIG. 12(C)). Note that if the conductor 20 can be placed directly on the base 13 and held immobile by the base 13, the deposition of the flux 70 on the base 13 by printing may be omitted.

[0091] After the flux 70 is applied and disposed, the process moves to the step of disposing the conductor 20 on the metal part 10. In this process, as in the first embodiment, the conductor mask 80 is placed on the mother substrate 50 and the metal part 10, and the conductor mask 80 is aligned so that the through holes 81 of the conductor mask 80 coincide with the metal part 10, and then the conductor mask 80 is fixed onto the mother substrate 50 (see Figure 13(A)).

[0092] Next, a large number of conductors 20 are supplied onto the conductor mask 80, and the squeegee is moved to distribute the conductors 20 on the conductor mask 80, and the conductors 20 are placed one by one into the through-holes 81. The conductors 20 that have passed through the through-holes 81 come into contact with the flux 70 on the base 13 and are held with a portion inserted into the recess 13a inside the base 13, and are temporarily fixed to the metal part 10 (see FIG. 13(B)). The conductors 20 are positioned on the annular base 13, and with a portion inserted into the recess 13a inside the base 13, so that they are less likely to slip out of place.

[0093] After the conductor 20 has been placed on the metal portion 10, the conductor mask 80 is removed from the mother substrate 50 and the metal portion 10, completing the manufacturing process of the substrate 1 for the semiconductor device (see Figure 13(C)). If necessary, the conductor 20 arranged on the metal part 10 may be slightly heated to melt the solder on the metal part 10 near the base part 13 and solder it to the surface of the base part 13, thereby more securely integrating the conductor 20 with the metal part 10 and making it possible to consider it as a kind of bump.

[0094] Next, a description will be given of the manufacture of a semiconductor device using the obtained substrate 2 for a semiconductor device. As in the first embodiment, a semiconductor element 30 is mounted on a conductor 20 provided on a metal portion 10 of the substrate 1 for a semiconductor device (see FIG. 14(A)). Then, the semiconductor element 30 is fixed to the conductor 20 by pressure bonding, heating, or the like, and at the same time, the electrodes (pads) on the surface of the semiconductor element 30 and the corresponding metal portions 10 are wired (electrically connected) via the conductor 20 and the base portion 13 (see FIG. 14(B)).

[0095] In addition to the conductor 20 penetrating further into the recess 13a inside the base 13, the molten solder of the conductor 20 adheres securely to and integrates with the surface of the base 13, which is made of a material with excellent solder wettability, thereby further improving the fixing strength and electrical connection of the conductor 20 to the metal part 10.

[0096] Once the electrical connection between the semiconductor element 30 and each metal part 10 via the conductor 20 is completed, as in the first embodiment, the area on the surface side of the mother substrate 50 that will become the semiconductor device, including the metal parts 10, is sealed with a sealing material 40 such as epoxy resin, thereby isolating the semiconductor element 30 and the conductor 20 from the outside and protecting them (see Figure 14(C)). After the sealing with the sealing material 40 is completed, the mother substrate 50 is removed, and the multiple connected semiconductor devices are separated one by one, thereby completing the semiconductor device 100.

[0097] As described above, the semiconductor device substrate according to this embodiment has a convex base 13 on the surface of the metal portion 10, and the conductor 20 is arranged on the metal portion 10 while being restrained by the base 13. This allows the spherical conductor 20 to be held in a state where it is difficult to move on the metal portion 10, improving the handleability of the substrate. Furthermore, by providing the base 13 as a metal layer, the base 13 can be formed in the same process as providing the metal portion 10 by plating, thereby reducing the cost of providing the base 13. Furthermore, when the conductor 20 is integrated with the metal portion 10 by heating, the conductor 20 can also be soldered to the base 13, ensuring a reliable electrical connection between the conductor 20 and the metal portion 10.

[0098] Furthermore, by providing the base portion 13 as a ring-shaped convex portion and creating a recess 13a in the center, the conductor 20 is arranged on the metal portion 10 with part of the conductor 20 inserted into the recess 13a of the base portion 13, and the spherical conductor 20 can be securely held on the metal portion 10 in a state where it is difficult for it to move, thereby preventing the conductor 20 from coming off the substrate.

[0099] In the substrate for a semiconductor device according to the above embodiment, a convex base portion 13 made of a metal layer is provided on the metal portion 10, and the conductor 20 can be restrained by the base portion 13. However, this is not limited to this, and the base can also be made of another material, for example, a resin layer (resist, epoxy, etc.) of a predetermined thickness, as long as it is capable of restraining the conductor without easily deforming. In this case, the height of the resin layer forming the base is preferably at least 1 / 3 of the diameter of the spherical conductor, and more preferably at least 1 / 2 of the diameter.

[0100] Furthermore, the base portion 13 is configured as a ring-shaped convex portion surrounding the central recess 13a, but it can also be configured as a shape other than a ring as long as it can restrain the conductor and prevent it from shifting.

[0101] Furthermore, in the substrate for the semiconductor device according to the above embodiment, a convex base 13 is provided on the metal part 10, and the conductor 20 is arranged on the metal part 10 while being restrained by the base 13 and prevented from shifting. However, this is not limited to this, and any structure other than a base may be used as long as it allows the conductor to be arranged on the electrode part (metal part) while being restrained and prevented from shifting, for example, a recess of a size that allows part of the conductor to be inserted can be provided on the surface side of the electrode part, and the conductor can be arranged on the electrode part with part of it inserted into the recess.

[0102] In this case, the conductor is arranged on the electrode portion with part of the conductor inserted into the recess, so that the spherical conductor can be held in a state where it is difficult to move on the electrode portion, improving the handleability of the substrate, as in the case of the base portion.

[0103] Such a recess may be created when, during the process of forming a metal portion by electrolytic plating, plating tends to form (grow) along the edge face of the resist layer, and plating does not proceed uniformly in the exposed portion not covered by the resist layer, resulting in a recess in the center of the upper end of the metal portion due to uneven plating.

[0104] (Fourth embodiment of the present invention) A substrate for a semiconductor device according to a fourth embodiment of the present invention will be described with reference to FIGS. In each of the figures, the substrate 3 for a semiconductor device according to this embodiment has a configuration comprising a mother substrate 50, a metal portion 11, and a conductor 20, similar to the first embodiment, but differs in that the metal portion 11 has a configuration in which a semiconductor element mounting portion 11a is provided in addition to an electrode portion 11b. The conductor 20 has the same configuration as in the first embodiment, and a detailed description thereof will be omitted.

[0105] As in the first embodiment, the main manufacturing steps of the substrate 3 for a semiconductor device include a step of forming a resist layer 60 on a mother substrate 50, a step of forming a metal portion 11 in the exposed area of ​​the mother substrate 50 that is not covered by the resist layer 60, a step of removing the resist layer 60, and a step of arranging a conductor 20 on the electrode portion 11b of the metal portion 11.

[0106] Specifically, first, a resist layer 60 is formed on the mother substrate 50 in areas where the metal portions 11 will not be placed, and then the metal portions 11 are formed by electrolytic plating. Next, the resist layer 60 is removed, and a printing mask is placed on the mother substrate 50 and the metal portions 11, and flux is applied to and disposed on the electrode portions 11b of the metal portions 11. Then, a conductor mask is placed on the mother substrate 50 and the metal portions 11, and the conductors 20 are disposed on the electrode portions 11b of the metal portions 11, completing the series of manufacturing steps.

[0107] In forming the metal parts 11 in the substrate 3 for a semiconductor device, the resist layer 60 provided on the mother substrate 50 and finally removed is the same as in the first embodiment, and is formed, disposed, and removed in the same steps as in the first embodiment, so a detailed description thereof will be omitted. Similarly, the resist layer 63 formed on the back side of the mother substrate 50 is the same as in the first embodiment, so a detailed description thereof will be omitted.

[0108] As in the first embodiment, the mother substrate 50 is formed of a conductive metal plate and forms a main part of the semiconductor device substrate 3 until it is removed in the manufacturing process of the semiconductor device. When the metal parts 11 are formed in the manufacturing process of the semiconductor device substrate 3, electricity is passed through the mother substrate 50, and the metal parts 11 are formed by electrolytic plating in the electrically conductive parts that are not covered by the resist layer 60 on the surface of the mother substrate 50.

[0109] The metal portion 11 has a semiconductor element mounting portion 11a on which the semiconductor element 30 is mounted without becoming an electrode, and a plurality of electrode portions 11b arranged around the semiconductor element mounting portion 11a. The metal portion 11 is made of nickel, copper, or a nickel alloy such as nickel-cobalt, which is suitable for electrolytic plating, and is formed by electrolytic plating on the portions of the mother substrate 50 where there is no resist layer 60. In the substrate 3 for semiconductor device, the metal portion 11 is formed on the surface of the mother substrate 50 in a form in which a combination of a semiconductor element mounting portion 11a and a plurality of electrode portions 11b arranged in the vicinity thereof is regarded as one unit, and a large number of such combinations are aligned in an orderly manner, the number of which is equal to the number of semiconductor devices to be manufactured.

[0110] As in the first embodiment, this metal portion 11 is formed to a thickness that exceeds the thickness of the resist layer 60 (for example, a thickness of approximately 60 to 80 μm), and has a shape with an approximately eave-shaped protrusion portion 11c at the upper edge that protrudes toward the resist layer 60.

[0111] In addition, a conductor 20 is provided on the electrode portion 11b of the metal portion 11. When wiring is performed on the conductor 20 provided on the electrode portion 11b, the bonding portions of the wire 15 on the semiconductor element 30 and the conductor 20 are brought closer to each other by the height of the conductor 20 compared to the conventional case where wiring is performed on the upper surface of the electrode portion 11b, and the length of the wire can be shortened. As in the first embodiment, a thin film 11d of a metal or alloy having better solder wettability than the main material portion, such as nickel, can be provided on the back surface of the metal portion 11, if necessary, to ensure appropriate soldering when mounting the semiconductor device.

[0112] The semiconductor device 100 manufactured using the semiconductor device substrate 3 is configured to include, in addition to the metal part 11 and conductor 20 obtained from the semiconductor device substrate 3, a semiconductor element 30 mounted on the semiconductor element mounting portion 11a of the metal part 11, a wire 15 electrically connecting this semiconductor element 30 to the conductor 20 on the electrode portion 11b, and a sealing material 40 covering and sealing the surface side of the metal part 11 including the semiconductor element 30, the wire 15, and the conductor 20.

[0113] In this semiconductor device 100, the back side of the metal part 11 is exposed at the bottom as an electrode, a heat dissipation pad, etc., and the back side of this exposed metal part 11 and the back side of the sealing material 40 that appears as part of the device exterior are positioned on approximately the same plane. On each surface of the semiconductor device 100 other than the bottom, only the sealing material 40 that forms the device exterior is exposed.

[0114] In the manufacturing process of a semiconductor device using the substrate 3 for a semiconductor device, the surface side of the metal part 11 on the mother substrate 50 is covered with the sealing material 40 (see FIG. 17(C)), as in the first embodiment, and when the mother substrate 50 has sufficient strength without supporting the metal part 11 and the sealing material 40, the mother substrate 50 is separated and removed from them (see FIG. 18(A)). If the mother substrate 50 is made of stainless steel, a method is used in which it is physically peeled off from the semiconductor device by applying force, and if the mother substrate 50 is made of copper or the like, an etching method is used in which it is dissolved and removed using a chemical solution. By removing this mother substrate 50, the semiconductor device 100 is obtained in a state in which the semiconductor element mounting portion 11a and electrode portion 11b of the metal portion 11, and the sealing material 40 are exposed at the bottom.

[0115] The semiconductor element 30 is a so-called chip on which a fine electronic circuit is formed, and is mounted on the semiconductor element mounting portion 11a of the metal portion 11. Wires 15 for wiring (bonding), which are made of a conductive wire material such as gold or copper, are bonded to electrodes (pads) provided on the surface of the semiconductor element 30 and to conductors 20 that are pre-disposed on the electrode portion 11b of the metal portion 11, thereby electrically connecting the semiconductor element 30 and the electrode portion 11b. It is preferable that the materials of the wires 15 and the conductors 20 be selected so that one material is appropriately matched to the other material.

[0116] As in the first embodiment, the sealing material 40 is a thermosetting resin such as epoxy resin having high physical strength, and covers and seals the semiconductor element 30, wire 15, and conductor 20 on the surface side of the metal part 11, thereby isolating and protecting structurally weak parts such as the semiconductor element 30, wire 15, and conductor 20 from the outside.

[0117] In the sealing process using this sealing material 40, as in the first embodiment, the area of ​​the substrate 1 for semiconductor device on the front side of the mother substrate 50 that will become the semiconductor device, including the semiconductor element 30, metal portion 11, etc., is covered with a mold that will become an upper mold, and then unhardened resin material that will become the sealing material 40 is pressed between this mold and the mother substrate 50 and hardened, thereby completing the sealing with the sealing material 40. However, in the sealing process, many combinations of semiconductor element mounting portions 11a and multiple electrode portions 11b that will become one semiconductor device are uniformly sealed while remaining aligned, so that many semiconductor devices 100 are connected via the sealing material 40.

[0118] Next, each step of manufacturing a substrate for a semiconductor device according to this embodiment and manufacturing a semiconductor device using the substrate for a semiconductor device will be described. In the manufacturing process of the substrate for the semiconductor device, first, as in the first embodiment, a resist layer 60 is provided on the mother substrate 50 in correspondence with the areas on the mother substrate 50 where no metal portions 11 are to be arranged, which are set in advance. Also, as in the first embodiment, a resist layer 63 is hardened and formed over the entire back surface of the mother substrate 50.

[0119] After the resist layers 60 and 63 have been formed in this manner, the exposed portions of the surface of the mother substrate 50 that are not covered with the resist layer 60 are subjected to surface oxide film removal and surface activation treatment as necessary, as in the first embodiment, and then a thin gold film 11d for improving solder wettability is formed on this exposed portion, and furthermore, a metal portion 11 is formed on this thin film 11d by electrolytic plating.

[0120] In this process of forming the metal portion 11, the metal portion 11 is formed to a predetermined thickness (for example, a thickness of about 60 μm) that exceeds the thickness of the resist layer 60. The metal portion 11 is formed on the surface of the mother substrate 50 in a form in which a combination of a semiconductor element mounting portion 11a and a plurality of electrode portions 11b arranged in the vicinity thereof is regarded as one unit, and a large number of such combinations are aligned in an orderly manner, the number of which is equal to the number of semiconductor devices to be manufactured.

[0121] Once the metal portion 11 has the desired thickness and shape, the resist layer 60 on the front side of the mother substrate 50 and the resist layer 63 on the back side are dissolved and removed with a predetermined remover (see FIG. 15(A)).

[0122] After removing the resist layer, flux is applied to the metal portion 11 by printing. As in the first embodiment, the printing process is performed in a similar manner to a process using a known printing mask. Specifically, the printing mask is placed in contact with the surface of the metal portion 11 on the mother substrate 50 where the printing is to be performed. A squeegee is then moved over the printing mask, scraping off the paste-like flux 70 with the squeegee while applying the flux 70 through the openings in the printing mask to the printing target portions of the electrode portions 11b. After this application, the printing mask is removed from the metal portion 11, completing the application of the flux 70 to the electrode portions 11b of the metal portion 11 by printing (see FIG. 15(B)).

[0123] After the flux 70 is applied, the process moves to a step of applying the conductor 20 onto the electrode portion 11b of the metal portion 11. In this step, the conductor mask 80 is placed on the mother substrate 50 and the metal portion 11, and after aligning the conductor mask 80 so that the through-holes 81 of the conductor mask 80 and the electrode portions 11b are aligned, the conductor mask 80 is fixed onto the mother substrate 50 (see FIG. 15(C)). In this fixed state, the lower portion (not shown) of the conductor mask 80 abuts against the mother substrate 50 or the metal portion 11, and the conductor mask 80 is held in a position with an appropriate gap between it and the mother substrate 50 and the metal portion 11.

[0124] Next, a large number of conductors 20 are supplied onto the conductor mask 80, and the squeegee is moved to distribute the conductors 20 on the conductor mask 80, and the conductors 20 are placed one by one into the through-holes 81. The conductors 20 that have passed through the through-holes 81 and reached the electrode portion 11b are held by the flux 70 and are temporarily fixed to the electrode portion 11b (see FIG. 16(A)).

[0125] After the conductor 20 has been placed on the metal portion 11, the conductor mask 80 is removed from the mother substrate 50 and the metal portion 11, completing the manufacturing process of the substrate 1 for the semiconductor device (see Figure 16(B)). If necessary, the conductor 20 disposed on the electrode portion 11b may be slightly heated to temporarily flow the solder at the point of contact with the electrode portion 11b, thereby soldering the conductor 20 to the surface of the electrode portion 11b, thereby more strongly integrating the conductor 20 with the electrode portion 11b.

[0126] Next, the manufacturing of a semiconductor device using the obtained substrate 3 for a semiconductor device will be described. First, the conductor 20 disposed on the electrode portion 11b is heated to melt the solder at the portion in contact with the electrode portion 11b, thereby soldering the conductor 20 to the surface of the electrode portion 11b, thereby reliably integrating the conductor 20 with the electrode portion 11b and establishing an electrical connection (see FIG. 16(C)). Next, a semiconductor element 30 is mounted on the semiconductor element mounting portion 11a of the metal portion 11 in the substrate 1 for a semiconductor device (see FIG. 17(A)). Then, the electrodes (pads) on the surface of the semiconductor element 30 and the corresponding conductors 20 on the electrode portions 11b are electrically connected by wiring of wires 15 (see FIG. 17(B)). This electrical connection by wiring is achieved using a known ultrasonic bonding device or the like.

[0127] Once the electrical connection between the semiconductor element 30 and each electrode portion 11b via the wires 15 and conductors 20 is completed, as in the first embodiment, the area on the surface side of the mother substrate 50 that will become the semiconductor device, including the metal portions 11, etc., is sealed with a sealing material 40 such as a thermosetting epoxy resin, thereby isolating and protecting the semiconductor element 30, wires 15, and conductors 20 from the outside (see Figure 17(C)).

[0128] In the sealing process, a large number of combinations of semiconductor element mounting portions 11a and multiple electrode portions 11b that form one semiconductor device are uniformly sealed in an aligned state on the mother substrate 50, and a large number of semiconductor devices emerge in a connected state.

[0129] Once these multiple connected semiconductor devices have been obtained, the mother substrate 50 is removed, leaving the back side of the metal part 11 exposed at the bottom of each semiconductor device (see FIG. 18(A)). As in the first embodiment, the mother substrate 50 can be removed by physically peeling it off from the semiconductor device, or by immersing the mother substrate in an etching solution and dissolving it.

[0130] At the bottom of the semiconductor device after the mother substrate 50 has been removed, the back surface of the exposed metal portion 11 and the back surface of the sealing material 40 are located on the same plane. After the mother substrate 50 has been removed, the multiple connected semiconductor devices are separated one by one to complete the semiconductor device 100 (see FIG. 18(B)).

[0131] In this way, in a semiconductor device using the semiconductor device substrate of this embodiment, a semiconductor element 30 is mounted on the semiconductor element mounting portion 11a of the metal portion 11, while a conductor 20 is provided on the electrode portion 11b, and this conductor 20 and the semiconductor element 30 are wired together by a wire 15. Compared to a conventional structure in which the semiconductor element and the electrode portion are directly wired together by a wire, the bonding position of the wire 15 on the electrode portion 11b can be raised by the amount of the conductor 20 provided on the electrode portion 11b, and the other end of the wire 15 is closer to the semiconductor element 30 to be joined, so the wire length can be shortened, reducing the amount of wire used and reducing costs. Furthermore, since the height of the wires 15 located above the semiconductor element 30 can be reduced, the thickness of the semiconductor device 100 can be reduced accordingly, and the height of the semiconductor device 100 can be reduced.

[0132] In the substrate for semiconductor device according to each of the above embodiments, after the metal portion 10 is formed by electrolytic plating, the metal portion 10 is left in a state where the surface is exposed. However, this is not limited to this. After a metal portion of a desired thickness and shape is formed, the surface of this metal portion may be further plated to form another metal layer made of a metal different from the metal portion, such as gold or silver, which has excellent bonding properties with conductors.

[0133] In this case, a plating solution corresponding to the metal that forms the metal layer is used, such as a plating solution different from that used to plate the metal part. On the other hand, the resist layer used to plate the metal part has sufficient resistance to such a plating solution, so it does not deteriorate, maintains its function as a resist layer, and can prevent plating from adhering to areas other than the required areas, such as the metal part.

[0134] When plating another metal layer on the surface of a metal part in this way, if the metal part is made of a material to which plating such as nickel does not easily adhere, it is desirable to first apply a base plating (copper strike, silver strike, or gold strike) to the surface of the metal part before plating the metal layer, in order to improve the adhesion of the metal layer to the metal part.

[0135] The substrate for semiconductor device according to the disclosure of the present invention, specifically shown in the first to fourth embodiments, is expected to contribute to the achievement of some of the 17 goals set out in the "Sustainable Development Goals (SDGs)" established by the United Nations, such as "9: Build resilient infrastructure, promote inclusive and sustainable industrialization, and foster innovation" and "12: Responsible consumption and production (Ensure sustainable production and consumption patterns)."

[0136] Possible embodiments of the substrate for a semiconductor device, the method for manufacturing the substrate, the semiconductor device, and the method for manufacturing the semiconductor device according to the present disclosure will be described again.

[0137] The substrate for a semiconductor device disclosed in the present invention is used in the manufacture of a semiconductor device in which a plurality of metal portions that become at least electrode portions are exposed at the bottom of the device, and in the substrate for a semiconductor device in which the metal portions are each formed on a mother substrate, spherical or columnar conductors, at least the surface portion of which is made of solder, are arranged on the surface side of the electrode portions.

[0138] According to the disclosure of the present invention, among the metal parts formed on the mother substrate, conductors are arranged on a plurality of electrode parts, and by making it possible to mount a semiconductor element on these conductors, it is easier to provide conductors of uniform height on the electrodes in an appropriate state compared to forming bumps by applying solder paste to the electrodes, and it is possible to ensure a reliable electrical connection between the mounted semiconductor element and the electrodes. Furthermore, when manufacturing a semiconductor device using the semiconductor device substrate, with the semiconductor element mounted on the electrode part and electrically connected, the height from the lower surface of the electrode part to the upper surface of the semiconductor element can be reduced, and the height of the semiconductor device can also be reduced.

[0139] In addition, in the substrate for a semiconductor device according to the present disclosure, the conductor is disposed on the electrode portion with flux interposed therebetween, if necessary.

[0140] Thus, according to the disclosure of the present invention, a conductor is placed on an electrode portion with flux disposed thereon, and the flux is interposed between the conductor and the electrode portion, thereby making it possible to keep the conductor from easily moving on the electrode portion, and even when heat is applied to integrate the conductor and electrode portion, the solder is made to spread easily along the surface of the electrode portion, promoting integration with the electrode portion, thereby improving the handleability of the board.

[0141] Furthermore, the substrate for a semiconductor device disclosed in the present invention may, if necessary, have a recess on the surface side of the electrode portion that is large enough to allow a portion of the conductor to be inserted, and the conductor may be partially inserted into the recess.

[0142] Thus, according to the disclosure of the present invention, a recess is provided on the surface side of the electrode portion, and the conductor is arranged on the electrode portion with part of the conductor inserted into the recess, thereby making it possible to hold the spherical conductor in a state where it is difficult to move on the electrode portion, thereby improving the handleability of the substrate.

[0143] Furthermore, the substrate for a semiconductor device according to the present disclosure may be provided with a convex base on the surface side of the electrode portion, as required, and the conductor may be restrained by the base.

[0144] Thus, according to the disclosure of the present invention, a convex base is provided on the surface side of the electrode portion, and the conductor is arranged on the electrode portion while being restrained by the base, thereby making it possible to hold the spherical conductor in a state where it is difficult for it to move easily on the electrode portion, thereby improving the handleability of the substrate.

[0145] Furthermore, in the substrate for a semiconductor device according to the present disclosure, the pedestal portion may be provided as a metal layer, if necessary.

[0146] According to the disclosure of the present invention, by providing the base on the electrode as a metal layer, when the conductor and the electrode are integrated by heating, the conductor can also be soldered to the base, ensuring a reliable electrical connection between the conductor and the electrode. Furthermore, the base can be formed in the same process as the electrode by plating, reducing the cost of providing the base.

[0147] Furthermore, in the substrate for a semiconductor device according to the present disclosure, the base portion may be provided as a resin layer having a predetermined thickness, if necessary.

[0148] According to the disclosure of the present invention, by providing the base on the electrode portion as a resin layer, the base can restrain and hold the conductor, while the exposed portion of the base, which is the resin layer, can easily adhere to the sealing resin material of the semiconductor device, thereby strengthening the resin sealing structure of the semiconductor device manufactured from the substrate. Furthermore, if the resin layer is formed from a resist, for example, the equipment for applying the resist can be used as is in the series of processes for applying the electrode portion by plating, eliminating the need for special equipment for applying the resin layer and reducing the cost of providing the base.

[0149] Furthermore, in the substrate for a semiconductor device according to the present disclosure, the pedestal portion may be provided as an annular protruding portion surrounding a recessed portion in the center, as required.

[0150] Thus, according to the disclosure of the present invention, by providing the base on the electrode portion as a ring-shaped convex portion and creating a recess in the center, part of the conductor is inserted into the recess in the base, and the spherical conductor can be held in a state where it is difficult for it to move easily on the electrode portion, further improving the handleability of the substrate.

[0151] Furthermore, in the substrate for a semiconductor device disclosed herein, the conductor may have a core portion which is a sphere made of metal or resin, and a solder layer which is arranged to cover the surface of the core portion, as required.

[0152] Thus, according to the disclosure of the present invention, the conductor is structured to consist of a core portion and a solder layer, and even when the conductor is integrated with the electrode portion by heating, the core portion other than the solder layer can maintain its shape, so that conductors of uniform height can be uniformly joined to the semiconductor element mounted above them, thereby ensuring a reliable electrical connection between the semiconductor element and the electrode portion via the conductor.

[0153] In addition, the method for manufacturing a substrate for a semiconductor device disclosed in the present invention involves plating a plurality of metal parts that will become at least the electrode parts of the semiconductor device at predetermined locations on a mother substrate to obtain a substrate to be used in manufacturing a semiconductor device having a structure in which the metal parts are exposed at the bottom, and the method includes a step of arranging spherical or columnar conductors, at least the surface portion of which is made of solder, on the electrode parts.

[0154] According to the disclosure of the present invention, by forming a metal portion including electrodes on a mother substrate and providing conductors on the electrodes of the metal portion to obtain a substrate, conductors of the same shape can be easily arranged on each electrode portion. Unlike when solder paste is applied to the electrodes to form bumps, the conductors can be arranged on the electrodes in an appropriate, uniform height. By using conductors of an appropriate size depending on the application, it is possible to accommodate narrower pads and electrode portions on semiconductor elements, thereby increasing the flexibility of the substrate structure. In particular, it is possible to efficiently manufacture a substrate that is compatible with mounting a semiconductor element on the electrode portion of the metal portion using a flip-chip method, and that ensures reliable electrical connection between the electrode portion and the semiconductor element mounted thereon. Furthermore, by reducing the height from the underside of the electrode portion to the top surface of the semiconductor element on the substrate, it is possible to achieve a low-profile semiconductor device manufactured using this substrate.

[0155] In addition, the method for manufacturing a substrate for a semiconductor device disclosed in the present invention includes, as necessary, a step of placing a printing mask having through holes corresponding to the positions of the electrode portions on the mother substrate and metal portion, applying flux to the electrode portions by printing, and arranging the conductor at the flux-applied locations of the electrode portions, and adhering and fixing the conductor to the electrode portions with the flux.

[0156] Thus, according to the disclosure of the present invention, flux is applied to the electrode portion of the metal portion on the mother substrate through the holes in the printing mask, and the conductor is then placed on this flux. This allows the flux to be interposed between the conductor and the electrode portion, preventing the conductor from easily moving on the electrode portion. When heat is applied to integrate the conductor and the electrode portion, the solder can be made to spread more easily along the surface of the electrode portion, promoting integration with the electrode portion, thereby improving the handleability of the substrate.

[0157] In addition, in the method for manufacturing a substrate for a semiconductor device disclosed herein, if necessary, the step of arranging the conductor on the electrode portion is a step of placing a mask having through holes corresponding to the electrode portion positions on the mother substrate and metal portion, and arranging the conductor on the electrode portion through the through holes.

[0158] Thus, according to the disclosure of the present invention, by providing a conductor through a through hole in a mask on the electrode portion of the metal portion formed on a mother substrate to obtain a substrate, it is possible to reliably provide conductors of the same shape on each electrode portion, and unlike the case where solder paste is applied to the electrode portion to form bumps, the conductors can be provided on the electrode portion in an appropriate state with the same height, and by using conductors of an appropriate size depending on the application, it is possible to accommodate narrowing of the pads and electrode portions on semiconductor elements, thereby increasing the flexibility of the substrate structure.

[0159] Furthermore, the semiconductor device disclosed in the present invention has at least a semiconductor element and a metal portion that serves as an electrode portion, the semiconductor element being mounted on the surface side of the metal portion, wiring between the electrode portion of the metal portion and the semiconductor element, and sealing with a sealing material, with the back side of the metal portion being exposed at the bottom of the device, and in this semiconductor device, a spherical or columnar conductor, at least the surface portion of which is made of solder, is arranged on the surface side of the electrode portion of the metal portion, the semiconductor element being mounted on the conductor in the electrode portion and being wired with the electrode portion through the conductor, and at least the surface side of the electrode portion is sealed with the sealing material together with the semiconductor element and the conductive portion.

[0160] Thus, according to the disclosure of the present invention, among the metal parts whose back side is exposed at the bottom of the semiconductor device, a conductor is arranged on the electrode part, and a semiconductor element is mounted on this conductor, and the conductor is used for wiring between the electrode part and the semiconductor element, i.e., for electrical connection. Compared to the case where solder paste is applied to the electrode part to form a bump, based on the structure in which conductors of the same shape are arranged on each electrode part, it is possible to easily and reliably align the heights of the conductors arranged on the electrode part, and improve the reliability of the electrical connection between the semiconductor element and the electrode part.

[0161] Furthermore, if a semiconductor element is mounted on the electrode portion of the metal part using the flip-chip method and electrically connected, the height from the underside of the electrode portion to the upper surface of the semiconductor element can be reduced, resulting in a structure with a reduced height as a semiconductor device.

[0162] Furthermore, the semiconductor device disclosed in the present invention has at least a semiconductor element and a metal portion that serves as an electrode portion, the semiconductor element is mounted on the surface side of the metal portion, the electrode portion of the metal portion is wired to the semiconductor element, and the semiconductor element is sealed with a sealing material, and the back side of the metal portion is exposed at the bottom of the device, in which the metal portion has one or more semiconductor element mounting portions in addition to the electrode portion, the semiconductor element is mounted on the surface side of the semiconductor element mounting portion, and a spherical or columnar conductive portion, at least the surface layer of which is made of solder, is arranged on the surface side of the electrode portion of the metal portion and is in an electrically connected state, and the conductive portion on the electrode portion and the semiconductor element are wired via a bonding wire and sealed with the sealing material.

[0163] Thus, according to the disclosure of the present invention, a semiconductor element is mounted on the semiconductor element mounting portion of the metal portion, while a conductor is provided on the electrode portion, and this conductor and the semiconductor element are wired by a bonding wire.As a result, compared to a conventional structure in which the semiconductor element and the electrode portion are directly wired by a wire, the bonding position of the wire on the electrode portion can be raised by the amount of the conductor provided on the electrode portion, and the other end of the wire is closer to the semiconductor element to be joined, so the wire length can be shortened, thereby reducing the amount of wire used and reducing costs.

[0164] Furthermore, in the semiconductor device disclosed herein, if necessary, a recess of a size that allows a portion of the conductor to be inserted is provided on the surface side of the electrode portion, and the conductor is partially inserted into the recess.

[0165] Thus, according to the disclosure of the present invention, a recess is provided on the surface side of the electrode portion, and the conductor is arranged on the electrode portion with part of the conductor inserted into the recess, thereby making it possible to hold the spherical conductor in a state where it is difficult to move on the electrode portion, thereby improving the integration of the conductor and the electrode portion and the reliability of the electrical connection.

[0166] Furthermore, in the semiconductor device according to the disclosure of the present invention, a convex base portion may be provided on the surface side of the electrode portion, if necessary, and the conductor may be restrained by the base portion.

[0167] Thus, according to the disclosure of the present invention, a convex base is provided on the surface side of the electrode portion, and the conductor is arranged on the electrode portion while being restrained by the base, thereby making it possible to hold the spherical conductor in a state where it is difficult for it to move easily on the electrode portion, thereby improving the integration of the conductor and the electrode portion and the reliability of the electrical connection.

[0168] In addition, in the semiconductor device according to the present disclosure, the pedestal portion may be provided as a metal layer, if necessary.

[0169] Thus, according to the disclosure of the present invention, by providing a base portion on the electrode portion as a metal layer, when joining the electrode portion and the conductor with solder, the solder of the conductor can also be joined to the base portion, thereby achieving a reliable electrical connection between the conductor and the electrode portion.

[0170] In addition, in the semiconductor device according to the present disclosure, the base portion may be provided as a resin layer having a predetermined thickness, if necessary.

[0171] Thus, according to the disclosure of the present invention, by providing a base on the electrode portion as a resin layer, when joining the electrode portion and the conductor with solder, the solder of the conductor can be guided to a position on the electrode portion where there is no base and joined, and by appropriately setting the position of the base, a reliable electrical connection between the conductor and the electrode portion can be obtained.

[0172] In addition, in the semiconductor device according to the present disclosure, the pedestal portion may be provided as an annular protruding portion surrounding a recessed portion in the center, as required.

[0173] Thus, according to the disclosure of the present invention, by providing the base on the electrode portion as a ring-shaped convex portion and creating a recess in the center, part of the conductor is inserted into the recess in the base, and the spherical conductor can be held in a state where it is difficult to move on the electrode portion, further improving the integration of the conductor and the electrode portion and the reliability of the electrical connection.

[0174] In addition, the method for manufacturing a semiconductor device disclosed in the present invention performs the following steps on the semiconductor device substrate: mounting a semiconductor element on the conductor arranged in the electrode portion of the metal portion; electrically connecting the electrode portion and the semiconductor element through the conductor; sealing with a sealing material; and removing the mother substrate covering the back side of the metal portion, thereby obtaining an assembly of semiconductor devices with the back side of the metal portion exposed.

[0175] Thus, according to the disclosure of the present invention, a semiconductor element is mounted on an electrode portion of a metal portion provided on a substrate by placing the semiconductor element on a conductor arranged on the electrode portion, and the electrode portion and the semiconductor element are electrically connected through the conductor. Compared to mounting a semiconductor element on a bump formed by applying solder paste to the electrode portion, the semiconductor element and the electrode portion can be reliably electrically connected based on the arrangement of conductors of the same shape on each electrode portion and the alignment of the heights of the conductors, thereby improving the reliability of the electrical connection.

[0176] In addition, the method for manufacturing a semiconductor device disclosed in the present invention performs the following steps on the semiconductor device substrate: mounting a semiconductor element on a semiconductor element mounting portion formed on the mother substrate as one or more metal portions other than the electrode portion; wiring the conductor in the electrode portion and the semiconductor element with a bonding wire; sealing with a sealing material; and removing the mother substrate covering the back side of the metal portion, thereby obtaining an assembly of semiconductor devices with the back side of the metal portion exposed.

[0177] As described above, according to the disclosure of the present invention, a semiconductor element is mounted on the semiconductor element mounting portion of the metal portion provided on the substrate, and then the conductor on the electrode portion and the semiconductor element mounted on the semiconductor element mounting portion are wired with a bonding wire.In this way, when manufacturing a semiconductor device, compared to the conventional method of directly wiring the semiconductor element and the electrode portion with a wire, the bonding position of the wire on the electrode portion can be raised by the amount of the conductor disposed on the electrode portion, and the other end of the wire can be brought closer to the semiconductor element to be joined, thereby shortening the wire length, thereby reducing the amount of wire used and reducing costs.

[0178] In addition, the method for manufacturing a semiconductor device disclosed in the present invention performs the following steps on the semiconductor device substrate: mounting a wafer on which multiple semiconductor elements are formed on the conductor arranged in the electrode portion of the metal portion; electrically connecting the electrode portion and the semiconductor elements on the wafer through the conductor; sealing the side of the wafer facing the electrode portion with a sealing material; and removing the mother substrate covering the back side of the metal portion, thereby obtaining a collection of semiconductor devices with the back side of the metal portion exposed.

[0179] Thus, according to the disclosure of the present invention, a wafer having semiconductor elements is mounted on an electrode portion of a metal portion provided on a substrate by placing the wafer on a conductor arranged on the electrode portion, and the electrode portion and each semiconductor element on the wafer are electrically connected through the conductor. Compared to mounting semiconductor elements on bumps formed by applying solder paste to the electrode portion, by arranging conductors of the same shape on each electrode portion and aligning the height of the conductors, it is possible to reliably establish an electrical connection between each semiconductor element on the wafer and the electrode portion, thereby improving the reliability of the electrical connection. [Explanation of symbols]

[0180] 1, 2, 3 Substrate for semiconductor device 10, 11 Metal parts 10c Overhang 10d thin film 11a Semiconductor element mounting section 11b Electrode part 11c Overhang 11d thin film 13 Daibu 13a Recess 15 wires 20, 25 Conductors 26 Core 27 Solder layer 30 Semiconductor elements 40 Encapsulating material 50 Motherboard 60 resist layer 60a resist material 61 First resist layer 62 Second resist layer 62a Resist material 63 Resist layer 65, 66 Mask film 70 Flux 80 Conductor mask 81 Through hole 90 wafers 100 Semiconductor device

Claims

1. A substrate for a semiconductor device is used in the manufacture of a semiconductor device having a plurality of exposed metal portions that will become at least electrode portions at the bottom of the device, the metal portions being formed on a mother substrate, A spherical or columnar conductor, at least the surface of which is made of solder, is disposed on the surface side of the electrode portion. A substrate for a semiconductor device.

2. 2. The substrate for a semiconductor device according to claim 1, The conductor is disposed on the electrode portion with flux interposed therebetween. A substrate for a semiconductor device.

3. 2. The substrate for a semiconductor device according to claim 1, a recess having a size that allows a portion of the conductor to be inserted therein is provided on the surface side of the electrode portion; The conductor is partially inserted into the recess. A substrate for a semiconductor device.

4. 2. The substrate for a semiconductor device according to claim 1, A convex base portion is provided on the surface side of the electrode portion, The conductor is restrained by the base. A substrate for a semiconductor device.

5. 5. The substrate for a semiconductor device according to claim 4, The base is provided as a metal layer. A substrate for a semiconductor device.

6. 5. The substrate for a semiconductor device according to claim 4, The base portion is provided as a resin layer having a predetermined thickness. A substrate for a semiconductor device.

7. 5. The substrate for a semiconductor device according to claim 4, The base portion is provided as an annular protruding portion surrounding a recessed portion in the center. A substrate for a semiconductor device.

8. 8. The substrate for a semiconductor device according to claim 1, The conductor has a core portion that is a sphere made of metal or resin, and a solder layer that is disposed to cover the surface of the core portion. A substrate for a semiconductor device.

9. A method for manufacturing a substrate for a semiconductor device, comprising plating a plurality of metal portions that will become at least electrode portions of a semiconductor device on predetermined portions of a mother substrate, to obtain a substrate to be used in manufacturing a semiconductor device having a structure in which the metal portions are exposed at the bottom, The method further comprises a step of disposing a spherical or columnar conductor, at least the surface of which is made of solder, on the electrode portion. A method for manufacturing a substrate for a semiconductor device.

10. 10. The method for manufacturing a substrate for a semiconductor device according to claim 9, a step of placing a printing mask having through holes corresponding to the positions of the electrode portions on the mother substrate and the metal portion, and applying flux to the electrode portions by printing; The conductor is disposed at a portion of the electrode portion where the flux is applied, and the conductor is adhered and fixed to the electrode portion by the flux. A method for manufacturing a substrate for a semiconductor device.

11. 10. The method for manufacturing a substrate for a semiconductor device according to claim 9, The step of disposing the conductor on the electrode portion is a step of placing a mask having through holes corresponding to the positions of the electrode portions on the mother substrate and the metal portion, and disposing the conductor on the electrode portion through the through holes. A method for manufacturing a substrate for a semiconductor device.

12. A semiconductor device having at least a semiconductor element and a metal portion serving as an electrode portion, the semiconductor element being mounted on the surface side of the metal portion, wiring between the electrode portion of the metal portion and the semiconductor element, and sealing with a sealing material, with the back side of the metal portion exposed at the bottom of the device, a spherical or columnar conductor, at least a surface layer of which is made of solder, is disposed on the surface side of the electrode portion of the metal portion; the semiconductor element is mounted on the conductor in the electrode portion and is in a wiring state with the electrode portion through the conductor; At least the front surface side of the electrode portion is sealed with the sealing material together with the semiconductor element and the conductive portion. The semiconductor device is characterized by:

13. A semiconductor device having at least a semiconductor element and a metal portion serving as an electrode portion, the semiconductor element being mounted on the surface side of the metal portion, wiring between the electrode portion of the metal portion and the semiconductor element, and sealing with a sealing material, with the back side of the metal portion exposed at the bottom of the device, the metal portion has one or more semiconductor element mounting portions in addition to the electrode portions, and the semiconductor element is mounted on the front surface side of the semiconductor element mounting portion; a spherical or columnar conductive portion, at least a surface layer of which is made of solder, is disposed on a surface side of the electrode portion of the metal portion and is electrically connected to the surface; The conductive portion on the electrode portion and the semiconductor element are wired together via bonding wires and sealed with the sealing material. The semiconductor device is characterized by:

14. 14. The semiconductor device according to claim 12, a recess having a size that allows a portion of the conductor to be inserted therein is provided on the surface side of the electrode portion; The conductor is partially inserted into the recess. The semiconductor device is characterized by:

15. 14. The semiconductor device according to claim 12, A convex base portion is provided on the surface side of the electrode portion, The conductor is restrained by the base. The semiconductor device is characterized by:

16. 16. The semiconductor device according to claim 15, The base is provided as a metal layer. The semiconductor device is characterized by:

17. 16. The semiconductor device according to claim 15, The base portion is provided as a resin layer having a predetermined thickness. The semiconductor device is characterized by:

18. 16. The semiconductor device according to claim 15, The base portion is provided as an annular protruding portion surrounding a recessed portion in the center. The semiconductor device is characterized by:

19. The substrate for a semiconductor device according to any one of claims 1 to 8, a step of mounting a semiconductor element on the conductor disposed on the electrode portion of the metal portion; a step of electrically connecting the electrode portion and the semiconductor element through the conductor; a step of sealing with a sealing material; performing a step of removing the mother substrate covering the back surface side of the metal portion, Obtaining an assembly of semiconductor devices with the back side of the metal part exposed. A method for manufacturing a semiconductor device.

20. The substrate for a semiconductor device according to any one of claims 1 to 8, a step of mounting a semiconductor element on one or more semiconductor element mounting portions formed on the mother substrate as metal portions other than the electrode portions; a step of wiring the conductor in the electrode portion and the semiconductor element with a bonding wire; a step of sealing with a sealing material; performing a step of removing the mother substrate covering the back surface side of the metal portion, Obtaining an assembly of semiconductor devices with the back side of the metal part exposed. A method for manufacturing a semiconductor device.

21. The substrate for a semiconductor device according to any one of claims 1 to 8, a step of mounting a wafer on which a plurality of semiconductor elements are formed on the conductor disposed on the electrode portion of the metal portion; a step of electrically connecting the electrode portion and the semiconductor element on the wafer through the conductor; sealing the side of the wafer facing the electrode portion with a sealing material; performing a step of removing the mother substrate covering the back surface side of the metal portion, Obtaining an assembly of semiconductor devices with the back side of the metal part exposed. A method for manufacturing a semiconductor device.

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