Substrate for semiconductor device and semiconductor device

Abstract

To provide a substrate for a semiconductor device, which can constitute a semiconductor device that can be easily and reliably mounted even on a mounting substrate on which wiring is densely formed, and a semiconductor device constituted by using the substrate for a semiconductor device. [Solution] This is a substrate for a semiconductor device, in which a metal portion 11 that becomes at least an electrode portion 11b is formed on a substrate 10, and a protrusion 11d that partially protrudes from the substrate surface of the metal portion 11 and is bonded to a mounting substrate is provided. The metal portion 11 has a connection region that is electrically connected to a semiconductor element. The metal portion 11 is configured so that the formation region of the protrusion 11d and the connection region of the metal portion 11 do not overlap in the thickness direction of the metal portion 11.

Description

[Technical field]

[0001] The present invention relates to a substrate for a semiconductor device having leads formed thereon, and a semiconductor device constructed using the substrate for a semiconductor device. [Background technology]

[0002] Conventional semiconductor devices, in which a semiconductor element is mounted on a glass epoxy substrate, the semiconductor element is connected to a terminal for external output by wiring, and the substrate surface including the semiconductor element is covered with a protective material such as resin, have limitations in terms of miniaturization due to their structure. In contrast, semiconductor devices in which a metal portion that will become the semiconductor element mounting portion and electrode portion is formed, the semiconductor element is mounted on this metal portion, wiring is performed, and then the surface side of the metal portion containing the semiconductor element and wiring is sealed with a sealing material such as resin, with the metal portion partially exposed at the bottom, can be made low in height and space-saving, and are increasingly being used in fields requiring ultra-small semiconductor devices such as chip size.

[0003] Such semiconductor devices are mainly manufactured through a manufacturing process in which metal parts that will become semiconductor element mounting parts and electrode parts are formed on a conductive mother substrate by plating (electroforming) in a desired number of semiconductor devices at once, the front side of the metal parts on which the semiconductor elements are mounted and which have been subjected to wiring and other processing is sealed with a sealant, and then only the mother substrate is removed and the many integrated semiconductor devices are cut into individual pieces. An example of a manufacturing method for such a semiconductor device is disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-9196 A [Patent Document 2] JP 2004-214265 A Summary of the Invention [Problem to be solved by the invention]

[0005] Patent Document 1 discloses a semiconductor device in which a semiconductor element mounting portion and an electrode portion are resin-sealed with a sealing material and are configured to slightly protrude (stand off) from the back surface of the sealing material. By making the back surfaces of the semiconductor element mounting portion and the electrode portion protrude from the back surface of the sealing material in this way, when the semiconductor device is mounted on a mounting board, it is possible to improve the bonding between the electrode portions (leads) of the semiconductor device and the electrode portions (pads) of the mounting board.

[0006] However, in recent years, in order to achieve miniaturization of electronic devices, the electrode portions and wiring portions of the mounting board have been formed in a dense manner, and in the structure of the above-mentioned semiconductor device, the entire back surfaces of the semiconductor element mounting portion and electrode portions protrude from the back surface of the sealing material, so there is a risk that the semiconductor element mounting portion (die pad) and electrode portions (leads) of the semiconductor device will come into contact with the electrode portions (pads) and wiring portions of the mounting board at undesired locations.

[0007] An object of the present invention is to provide a substrate for a semiconductor device that can form a semiconductor device having a protruding portion partially protruding from the semiconductor element mounting portion or electrode portion, thereby enabling easy and reliable mounting of the semiconductor device even on a mounting board having densely packed wiring, and a semiconductor device using the substrate for a semiconductor device. [Means for solving the problem]

[0008] The substrate for a semiconductor device according to the present invention is characterized in that a metal portion 11 which becomes at least an electrode portion 11b is formed on a mother substrate 10, a protrusion 11d which partially protrudes is provided on the mother substrate surface side of the metal portion 11, and a metal film 21 is formed on at least the surface of the protrusion 11d on the mother substrate surface side of the metal portion 11.

[0009] Moreover, the metal film 21 is characterized in that it is formed only on the surface of the protruding portion 11d.

[0010] Also, the metal part 11 is characterized in that a recess 11e is provided on the surface opposite to the mother substrate surface side.

[0011] Another feature is that the protrusion 11d and the recess 11e are provided at positions where they overlap in the thickness direction of the metal part 11.

[0012] The manufacturing method of a substrate for a semiconductor device according to the present invention is a manufacturing method of a substrate for a semiconductor device in which a metal part 11 which becomes at least an electrode part 11b is formed on a mother substrate 10, a protrusion 11d which partially protrudes is provided on the mother substrate surface side of the metal part 11, and a metal film 21 is formed on at least the surface of the protrusion 11d on the mother substrate surface side of the metal part 11, and is characterized by having a step of forming a first resist layer 12 on the mother substrate 10, a step of forming a recess 20 in an exposed area of ​​the mother substrate 10 which is not covered by the first resist layer 12, a step of forming a metal film 21 on at least the surface of the recess 20, a step of removing the first resist layer 12, a step of forming a second resist layer 16 on the mother substrate 10, and a step of forming a metal layer 22 in an exposed area of ​​the mother substrate 10 which is not covered by the second resist layer 16.

[0013] In addition, in the step of forming the metal film 21, the metal film 21 is formed only on the surface of the recess 20. Furthermore, in the step of forming the metal layer 22, the metal layer 22 is grown by plating on the surface inside the recess 20 (the metal film 21), so that a recess 11e is formed on the surface of the metal layer 22.

[0014] The semiconductor device of the present invention has a semiconductor element 14 and a metal part 11 which serves as an electrode part 11b electrically connected to the semiconductor element 14, and is a semiconductor device in which the semiconductor element 14 is mounted on the metal part 11, the semiconductor element 14 is electrically connected to the metal part 11, and the semiconductor element 14 is sealed with a sealing material 19, and is characterized in that a protrusion 11d which protrudes partially is provided on the back surface of the metal part 11 exposed from the bottom of the sealing material 19, and a metal film 21 is formed on at least the surface of the protrusion 11d.

[0015] Moreover, the metal film 21 is characterized in that it is formed only on the surface of the protruding portion 11d.

[0016] Also, the metal portion 11 is characterized in that a recess 11e is provided on the surface thereof.

[0017] Another feature is that the protrusion 11d and the recess 11e are provided at positions where they overlap in the thickness direction of the metal part 11. Effect of the Invention

[0018] According to the present invention, the back surface of the metal part 11 is provided with the protruding part 11d that is partially protruding, so that the semiconductor device having the metal part 11 can be easily and accurately mounted on a mounting board on which electrodes and wiring are densely arranged. Even if the shape and dimensions of the protruding part 11d must be made small to correspond to the electrodes of the mounting board, the surface (surface area) of the metal part 11 can be made larger than the protruding part 11d, so that the degree of freedom in selecting the semiconductor element 14 to be mounted can be increased. Furthermore, at least the back surface of the metal part 11 is formed with the metal film 21, and by forming the metal film 21 only on the surface of the protruding part 11d, the solder used when mounting the semiconductor device on the mounting board is prevented from spreading over the entire back surface of the metal part 11, and unnecessary contact and connection with the electrodes and wiring on the mounting board can be prevented at positions other than the protruding part 11d. [Brief description of the drawings]

[0019] [Figure 1] 1 is a partial plan view of a substrate for a semiconductor device according to a first embodiment of the present invention. [Diagram 2] 1A and 1B are a cross-sectional view and a plan view of a substrate for a semiconductor device according to a first embodiment of the present invention. [Diagram 3] 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 4] 1A to 1C are diagrams illustrating steps in a method for manufacturing a substrate for a semiconductor device according to a first embodiment of the present invention. [Diagram 5] 1A to 1C are diagrams illustrating steps in a method for manufacturing a substrate for a semiconductor device according to a first embodiment of the present invention. [Figure 6] 1A to 1C are diagrams illustrating steps in a method for manufacturing a semiconductor device according to a first embodiment of the present invention. [Figure 7] FIG. 11 is a cross-sectional view of a semiconductor device according to another embodiment of the present invention. [Figure 8] 11A and 11B are a cross-sectional view and a bottom view of a semiconductor device according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] (First embodiment) A substrate for a semiconductor device and a semiconductor device according to a first embodiment of the present invention will be described below with reference to Figures 1 to 6. As shown in Figure 2, a substrate for a semiconductor device 1 according to this embodiment includes a mother substrate (substrate) 10 made of a conductive material, and a metal portion 11 serving as an electrode portion 11b formed on the mother substrate 10. A semiconductor device 70 is manufactured using such a substrate.

[0021] The mother substrate 10 is formed from a conductive metal plate (approximately 0.1 mm thick) made of stainless steel (SUS430, etc.), aluminum, copper, etc., and forms a major part of the substrate 1 for the semiconductor device until it is removed in the manufacturing process of the semiconductor device.

[0022] The metal parts 11 are formed by plating, and as shown in Figure 1, one or more metal parts are arranged on the surface of the mother substrate 10 as a unit, and a large number of them are arranged in an aligned state, equal to the number of semiconductor devices to be manufactured.

[0023] A protrusion 11d is formed on the back surface (mother substrate surface) of this metal part 11. The protrusion 11d is formed so as to partially protrude from the back surface of the metal part 11. A recess 11e is formed on the surface of the metal part 11, which is the surface opposite to the mother substrate surface, more specifically, directly above the protrusion 11d in the thickness direction of the metal part 11. And a protrusion 11c that protrudes like an eaves is formed on the upper end of the metal part 11.

[0024] The metal part 11 is mostly composed of a metal layer 22, and this metal layer 22 is made of nickel, copper, or a nickel alloy such as nickel-cobalt, which is suitable for electrolytic plating. On the back side of this metal layer 22, a metal film 21 made of a metal having better solder wettability than the metal layer 22, such as gold, silver, tin, palladium, solder, etc., is formed at least on the surface of the protruding part 11d, and in this embodiment, it is configured to be formed only on the surface of the protruding part 11d. This prevents the solder from spreading over the entire back side of the metal part 11, and allows for an appropriate implementation for, for example, a mounting board with dense electrodes and wiring. In this way, the metal film 21 is configured to be formed only on the surface of the protruding part 11d, but if the metal film 21 is formed on the entire back side of the metal layer 22 including the protruding part 11d, soldering can be performed more reliably when mounting a semiconductor device, and a function of preventing the metal layer 22 from being corroded and deteriorated by an etching solution can be provided when the mother substrate 10 is removed by etching. It is preferable that the thickness of the metal layer 22 is about 20 to 100 μm, and the thickness of the metal film 21 is about 0.01 to 1 μm.

[0025] Furthermore, a surface metal layer 23 is formed on the surface of the metal layer 22. This surface metal layer 23 is formed as a plating layer made of gold, silver, palladium, or the like, which has excellent bonding properties with the electrodes of the semiconductor element 14, and is plated on the surface of the metal layer 22 to a predetermined thickness, for example, about 0.1 to 1 μm in the case of gold plating, and about 1 to 10 μm in the case of silver plating, by plating each mother substrate 10.

[0026] A semiconductor device 70 manufactured using this substrate 1 for a semiconductor device is configured to include, in addition to the metal part 11 obtained from the substrate 1 for a semiconductor device, a semiconductor element 14 electrically connected to the electrode part 11b of the metal part 11, and a sealing material 19 covering and sealing the front side of the semiconductor element 14 and the metal part 11 (electrode part 11b), as shown in FIG. 3.

[0027] In this semiconductor device 70, the back side of the metal part 11 is exposed at the bottom (opposing the mounting board) as an electrode or heat dissipation pad, and a protrusion 11d is formed to protrude from the back side of this exposed metal part 11, and the back side of the metal part 11 excluding the protrusion 11d and the back side of the sealing material 19 appearing as part of the device exterior are positioned on approximately the same plane. Each surface of the semiconductor device 70 other than the bottom is exposed to the sealing material 19 that forms the device exterior (see FIG. 3(B)).

[0028] The semiconductor element 14 is a so-called chip on which a fine electronic circuit is formed, and an electrode provided on one surface of the semiconductor element 14 is directly bonded to the electrode portion 11b, thereby electrically connecting the semiconductor element 14 and the electrode portion 11b.

[0029] The sealing material 19 is a thermosetting epoxy resin or the like having high physical strength, which covers and seals the metal part 11 and the semiconductor element 14, isolating structurally weak parts from the outside, and providing a protective state. When the semiconductor element 14 is a light-emitting element such as an LED, a light-transmitting and transparent material is used.

[0030] This sealing material 19 has sufficient physical strength and functions to adequately protect the inside as part of the exterior of the semiconductor device 70, and even when the mother substrate 10 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 11 without cracking or other damage.

[0031] Next, each step of the method for manufacturing a substrate for a semiconductor device according to this embodiment and the method for manufacturing a semiconductor device using the substrate for a semiconductor device will be described.

[0032] In the manufacturing process of the substrate for the semiconductor device, first, a mother substrate 10 is prepared, and a first resist layer 12 corresponding to the recesses 20 for forming the protrusions 11d of the metal parts 11 (electrode parts 11b) is disposed on the mother substrate 10 (see FIG. 4(A)). Specifically, a photosensitive resist material is disposed on the front surface of the mother substrate 10, and a mask film of a predetermined pattern corresponding to the positions where the recesses 20 (protrusions 11d) are to be formed is placed on the resist material, and processing such as exposure to harden the resist material in the ultraviolet irradiated parts and development to remove the resist material in the non-irradiated parts is performed to form the first resist layer 12 so that the positions where the recesses 20 (protrusions 11d) are to be formed are exposed. The first resist layer 12 is formed of an insulating material that is resistant to dissolution by the etching solution used to form the recesses 20 on the surface of the mother substrate 10, and more specifically, an alkali-developing type photosensitive resist material is closely disposed on the mother substrate 10 to a predetermined thickness, for example, in the range of 5 to 50 μm, 20 μm in this embodiment.

[0033] Next, recesses 20 are formed in the areas of the mother substrate 10 that are exposed from the first resist layer 12 (see FIG. 4(B)). Specifically, the exposed areas of the front surface of the mother substrate 10 that are not covered with the first resist layer 12 are etched to form the recesses 20. The recesses 20 may be circular or polygonal in shape, and the depth of the recesses 20 is preferably 5 to 50 μm. The method for forming the recesses 20 is not limited to etching, and they may be formed by laser processing or blasting.

[0034] Next, after a plating pretreatment is appropriately performed on the recess 20 region, the metal film 21 is formed by plating, and the first resist layer 12 formed on the mother substrate 10 is removed (dissolved and swollen) to obtain the mother substrate 10 with the metal film 21 formed on the surface of the recess 20 (see FIG. 4(C)). Examples of plating pretreatment include degreasing, acid immersion, chemical etching, electrolytic treatment, activation treatment, and strike plating. In this embodiment, the stainless steel mother substrate 10 is subjected to chemical etching on the recess 20 region, and then the gold metal film 21 is plated to a thickness of 0.01 to 1 μm. Here, it is also possible to form the protrusion 11d by plating the metal constituting the metal film 21 until the recess 20 is filled.

[0035] Next, a second resist layer 16 for forming the metal part 11 (electrode part 11b) is disposed on the mother substrate 10 (see FIG. 5(A)). Specifically, a photosensitive resist material is disposed on the front surface side of the mother substrate 10, and a mask film of a predetermined pattern corresponding to the formation position of the metal part 11 (electrode part 11b) is placed on the resist material, and processing such as exposure to harden the resist material in the ultraviolet irradiated part and development to remove the resist material in the non-irradiated part are performed to form the second resist layer 16 so that the formation position of the metal part 11 (electrode part 11b) including the recess 20 (metal film 21) is exposed. The second resist layer 16 is formed of an insulating material having resistance to dissolution in the plating solution used when forming the metal layer 22 and the surface metal layer 23, and more specifically, an alkali development type photosensitive resist material is disposed in close contact with the mother substrate 10 to a predetermined thickness, for example, in the range of 10 to 80 μm, 50 μm in this embodiment. The first resist layer 12 and the second resist layer 16 are not limited to photosensitive resists, and can also be formed by applying a paint that does not deteriorate in etching solutions or plating solutions and can provide a strong coating film by electrochemical coating or the like to a required coating thickness so that the recesses 20 and the areas where the metal parts 11 are located on the mother substrate 10 are exposed.

[0036] Next, the metal part 11 (electrode part 11b) is formed in the region of the mother substrate 10 exposed from the second resist layer 16 (see FIG. 5(B)). Specifically, first, the above-mentioned plating pretreatment is appropriately performed on the exposed region of the front surface side of the mother substrate 10 that is not covered with the second resist layer 16, except for at least the region where the metal film 21 is formed, and then the metal layer 22 is formed by plating (electroforming) on ​​the mother substrate 10 including the metal film 21. In this embodiment, after performing chemical etching, the metal layer 22 of nickel-cobalt having a thickness of 70 μm is formed. Here, the plating pretreatment is selectively performed depending on the materials of the mother substrate 10, the metal film 21, and the metal layer 22. Among them, the chemical etching is performed by dissolving the object (mother substrate 10) itself and removing the oxide film (inactive film) on the surface, and the surface of the object becomes rough. Furthermore, when the purpose is to provide a measure against soldering of the semiconductor device, the formation of the metal film 21 is not limited to before the formation of the metal layer 22, but may be performed after the completion of the semiconductor device 70 (after the mother substrate 10 is removed). For example, after the completion of the semiconductor device 70 (after the mother substrate 10 is removed), an insulating material may be formed on a part or the whole of the region excluding the protruding portion 11d exposed from the back surface of the semiconductor device 70 (sealing material 19), and the metal film 21 may be formed on the surface of the protruding portion 11d by plating. At this time, the height dimension of the protruding portion 11d on which the metal film 21 is formed is preferably greater than or equal to the thickness dimension of the insulating material, and preferably greater than the thickness dimension of the insulating material. Also, the insulating material may be left as it is without being removed.

[0037] In addition, when forming the metal layer 22, the plating is allowed to grow beyond the thickness of the second resist layer 16, so that a protruding portion 11c is formed at the upper end of the metal portion 11 (metal layer 22). Due to the presence of this protruding portion 11c, when sealing with the sealing material 19 in the manufacturing process of the semiconductor device, the sealing material 19 is hardened in a state of being embedded in the protruding portion 11c. Even when the mother substrate 10 is peeled off and removed from the metal portion 11 and the sealing material 19, the metal portion 11 remains reliably in the sealing material 19 due to the bite effect between the sealing material 19 and the protruding portion 11c, and is not attached to the mother substrate 10 and is not pulled off, so that the metal portion 11 can be prevented from being displaced or missing. Note that, when forming the metal layer 22, if the plating is allowed to grow within a range not exceeding the thickness of the second resist layer 16, a straight metal layer 22 (metal portion 11) without a protruding portion at the upper end can be obtained.

[0038] In addition, a protrusion 11d that partially protrudes from a part of the back surface (surface facing the mounting board) of the metal part 11 is formed, and a recess 11e is formed on the upper surface of the metal part 11. The positional relationship between the protrusion 11d and the recess 11e is such that the recess 11e is formed directly above the protrusion 11d, that is, the protrusion 11d and the recess 11e are formed at a position where they overlap in the thickness direction (plan view) of the metal part 11. This is because, when the metal part 11 is formed by plating, the metal layer 22 that constitutes the metal part 11 is plated and grown from the surface of the mother substrate 10 including the inner surface of the recess 20, which is an exposed area not covered by the second resist layer 16, and the protrusion 11d is formed in the recess 20 (surface of the metal film 21) by the metal layer 22 being plated in this way, while the recess 11e is formed following the shape of the recess 20 on the surface of the metal layer 22 located directly above the protrusion 11d (recess 20). In this way, the protrusion 11d and the recess 11e are formed facing each other on the front and back surfaces of the metal part 11, and by using a light-transmitting and transparent material as the sealing material 19, the position of the protrusion 11d can be confirmed (predicted) even in a plan view when mounting the semiconductor device on a mounting board, making it easier to mount the semiconductor device. Note that the protrusion 11d and the recess 11e are similar, that is, the protruding shape of the protrusion 11d and the recessed shape of the recess 11e are similar, and the height dimension of the protrusion 11d and the depth dimension of the recess 11e are due to the shape and dimensions of the recess 20, and have a relationship of the height dimension of the protrusion 11d ≧ the depth dimension of the recess 11e.

[0039] Next, once the metal layer 22 (metal portion 11) in the desired shape is obtained, a surface metal layer 23 is formed on the surface of the metal layer 22 (see FIG. 5(B)). Specifically, the surface metal layer 23 of silver having a thickness of 1 to 10 μm is formed by plating on the surface of the metal layer 22. When plating the surface metal layer 23, if the metal layer 22 is made of a nickel-based metal and it is difficult to form the surface metal layer 23 in an adhesive manner, it is desirable to perform undercoating (copper strike, nickel strike, silver strike, gold strike, or the like) on the surface of the metal layer 22 before plating the surface metal layer 23 to increase the adhesiveness of the surface metal layer 23 to the metal layer 22.

[0040] Next, the second resist layer 16 formed on the mother substrate 10 is removed (dissolved and removed, swelled and removed) to obtain a substrate for a semiconductor device in which metal parts 11 (electrode parts 11b) are formed on the mother substrate 10 (see FIG. 5(C)). The metal parts 11 are formed in a form in which a large number of electrode parts 11b arranged on the surface of the mother substrate 10 are aligned in an orderly manner, with one or more electrode parts 11b being regarded as one unit, the number of which corresponds to the number of semiconductor devices to be manufactured, and in this embodiment, six electrode parts 11b are regarded as one unit.

[0041] Although the first resist layer 12 and the second resist layer 16 are formed on the front side of the mother substrate 10, a resist layer may also be formed on the back side of the mother substrate 10. The resist layer on the back side is made of a material that is resistant to etching solutions and plating solutions in a hardened state and that can be easily removed when no longer needed, for example, an alkaline development type photosensitive film resist having a thickness of about 50 μm is arranged by thermocompression bonding or the like, and then exposed to ultraviolet light without a mask, to form the resist layer over the entire back side. The resist layer on the back side is not limited to resist, and may be, for example, a cover film, as long as it has dissolution resistance and insulating properties.

[0042] Next, the manufacturing of a semiconductor device using the obtained substrate 1 for a semiconductor device will be described. First, the semiconductor element 14 is placed on the metal portion 11 (electrode portion 11b) of the substrate 1 for a semiconductor device, and the electrodes of the semiconductor element 14 are electrically connected to the corresponding electrode portions 11b (see FIG. 6(A)). This electrical connection is performed by soldering. When placing the semiconductor element 14, it is preferable to place and connect the electrodes of the semiconductor element 14 at positions avoiding the recessed portion 11e of the metal portion 11 (electrode portion 11b) so that the electrodes of the semiconductor element 14 do not overlap the recessed portion 11e in a plan view. In addition, in this embodiment, the electrical connection between the semiconductor element 14 and the electrode portion 11b is performed by a flip chip method, but it may be performed by a wire bonding method using wires 15 made of a conductive wire material such as gold or copper (see FIG. 7).

[0043] Next, the front side of the mother substrate 10 is sealed with a sealing material 19 such as a thermosetting epoxy resin, and the semiconductor element 14 is isolated from the outside and protected (see FIG. 6(B)). In detail, the front side of the mother substrate 10 is attached to a molding die which serves as an upper die, and the sealing is performed in the process of pressing the epoxy resin which serves as the sealing material 19 into the molding die while the mother substrate 10 serves as a lower die, and a number of electrode parts 11b which will become one semiconductor device are uniformly sealed while remaining aligned on the mother substrate 10, and a number of semiconductor devices appear in a connected state.

[0044] Next, the mother substrate 10 is removed, leaving the metal portion 11 (electrode portion 11b) exposed at the bottom of each semiconductor device (see FIG. 6(C)). The mother substrate 10, which is made of stainless steel, is removed by physically peeling it off from the semiconductor device side. By using stainless steel, which has excellent strength and peelability, for the mother substrate 10, it can be quickly separated and removed by peeling it off from the semiconductor device side.

[0045] Alternatively, the mother substrate 10 can be removed by etching (dissolving) the mother substrate 10. In this etching, an etching solution is used that has selective etching properties such that the mother substrate 10 dissolves but the materials of the metal film 21 and metal layer 22 are not damaged. When removing the mother substrate 10 by dissolving, no excessive force is applied to the semiconductor device, so the probability of adverse effects occurring due to removal of the mother substrate 10 can be reduced. When removing the mother substrate 10 by etching, it is desirable to form the metal film 21 prior to forming the metal layer 22 in order to obtain corrosion resistance.

[0046] At the bottom of the semiconductor device 70 from which the mother substrate 10 has been removed, the protrusion 11d partially protrudes from the back surface side of the sealing material 19, and the back surface of the metal part 11 excluding the protrusion 11d is positioned substantially on the same plane as the back surface of the sealing material 19. After removing the mother substrate 10, the multiple connected semiconductor devices are separated one by one to obtain a completed semiconductor device 70.

[0047] In this manner, the substrate 1 for a semiconductor device according to this embodiment and the semiconductor device 70 using this substrate 1 for a semiconductor device have a protrusion 11d on the back surface of the metal portion 11 (electrode portion 11b), and since this protrusion 11d is formed to partially protrude from a part of the metal portion 11 (electrode portion 11b), a wiring escape structure is obtained in which the protrusion 11d is formed to protrude from the back surface of the semiconductor device 70 (sealing material 19) by the height dimension of the protrusion 11d. Therefore, compared to a form in which the entire back surface of the electrode portion 11b protrudes from the back surface of the semiconductor device 70 (sealing material 19), it is possible to avoid contact of the electrode portion 11b with parts other than the electrode portion or wiring portion of the mounting substrate to which joining is desired, and a semiconductor device that is highly reliable and has increased freedom of mounting on the mounting substrate can be obtained. Furthermore, since the metal film 21 is formed only on the surface of the protrusion 11d, when the semiconductor device is mounted on a mounting board by soldering, the solder is kept on the surface of the protrusion 11d and is prevented from spreading to the entire back surface of the metal part 11 (electrode part 11b), and contact and bonding with the electrode parts and wiring parts on the mounting board at places other than the protrusion 11d can be avoided as much as possible. Furthermore, by covering the back surface of the metal part 11 (electrode part 11b) except for the surface of the protrusion 11d on which the metal film 21 is formed, with an insulating material, contact and bonding with the electrode parts and wiring parts on the mounting board at places other than the protrusion 11d can be reliably prevented.

[0048] Furthermore, inside the semiconductor device 70, the upper peripheral edge of the metal portion 11 is formed as a protruding portion 11c that protrudes in a roughly eave-like shape, and in a sealed state with the sealing material 19, the protruding portion 11c is surrounded and fixed by the sealing material 19 (anchor effect), so that the protruding portion 11c bites into the sealing material 19, which is firmly integrated with the resins that have adhered to each other, and acts as a resistor against external forces applied to the metal portion 11.In the case where stainless steel or the like is used for the mother substrate 10 and the mother substrate 10 is physically peeled off and removed from the semiconductor device side, even if an external force is applied to the back side of the metal portion 11 to separate it from the exterior of the device, the protruding portion 11c prevents the metal portion 11 from moving, and it is possible to eliminate misalignment of the metal portion 11 relative to other portions, thereby improving the yield during manufacturing and increasing the strength of the semiconductor device, as well as improving the durability during use and the reliability of the operation of the semiconductor device. Furthermore, by providing the recess 11e on the surface of the metal portion 11, the sealing material 19 penetrates into this recess 11e, which, combined with the gripping effect of the protrusion 11c, makes the adhesion between the metal portion 11 and the sealing material 19 stronger, thereby increasing the strength of the semiconductor device and more reliably protecting the semiconductor element 14.

[0049] In the above embodiment, the shape of the protrusion 11d (including plan view and cross-sectional view) may be round, circular, polygonal, spherical, hemispherical, conical, or columnar, and the boundary between the protrusion 11d and the metal part 11 (rear surface) is preferably formed to be a gently continuous surface. In the above embodiment, the method of forming the metal part 11 (metal film 21, metal layer 22, surface metal layer 23) is not limited to electrolytic plating, and may be formed by electroless plating, vapor deposition, sputtering, or the like. In the above embodiment, the semiconductor element 14 is placed so as to overlap the recessed part 11e. More specifically, when the semiconductor element 14 is connected by a flip chip method, the semiconductor element 14 may be placed so that the electrodes of the semiconductor element 14 can be connected to the inner surface of the recessed part 11e, and this allows the height position of the semiconductor element 14 to be lowered by the depth dimension of the recessed part 11e or the height dimension of the electrodes of the semiconductor element 14 at the maximum, which contributes to a low profile package. In addition, when the semiconductor element 14 is connected by a wire bonding method, the connection position between the wire 15 and the electrode portion 11b may be the inner surface of the recessed portion 11e. In the above embodiment, the semiconductor element 14 is mounted on the electrode portion 11b, but as shown in FIG. 7, a semiconductor element mounting portion 11a may be provided as the metal portion 11, and the semiconductor element 14 may be mounted on the semiconductor element mounting portion 11a. In the semiconductor device shown in FIG. 7, a protrusion 11d may be provided on the back surface of the semiconductor element mounting portion 11a, and a metal film 21 may be formed on the surface of the protrusion 11d or the back surface of the semiconductor element mounting portion 11a. In addition, adhesives for mounting the semiconductor element 14 on the metal portion 11 (semiconductor element mounting portion 11a, electrode portion 11b) include solid, viscous, and liquid adhesives, such as solder, silver paste, resin paste, and die attach film.

[0050] In the above embodiment, as shown in Fig. 3, by forming the metal portion 11 (electrode portion 11b) in a straight line, the effective utilization area (area excluding the metal portion 11-forming area) at the bottom of the semiconductor device (rear surface of the sealing material 19) can be maximized, so that the risk of malfunctions occurring can be reduced even if the wiring on the mounting board is arranged in a complex manner. Also, as shown in Fig. 8, by arranging one end of the metal portion 11 at the outer periphery and arranging the other end of the metal portion 11 so as to be concentrated at the center at the bottom of the semiconductor device (rear surface of the sealing material 19), the arrangement interval between adjacent metal portions 11 can be made constant. Such a configuration is effective when a large number of electrodes (electrodes of the mounting board) of the semiconductor element 14 are provided. [Explanation of symbols]

[0051] 1 Substrate for semiconductor device 10 Substrate (mother substrate) 11 Metal Part 11a Semiconductor element mounting section 11b Electrode part 11c Overhang 11d Protrusion 11e Recess 12 First resist layer 14 Semiconductor elements 15 Wire 16 Second resist layer 19 Encapsulating materials 20 Recess 21 Metal Film 22 Metal layer 23 Surface metal layer 70 Semiconductor Devices

Claims

1. A substrate for a semiconductor device, comprising: a metal portion (11) that becomes at least an electrode portion (11b) formed on a substrate (10); and a protrusion (11d) that partially protrudes from a substrate surface of the electrode portion (11b) and is bonded to a mounting substrate; The protrusion (11d) is made of metal, and a metal film (21) is formed only on the surface of the protrusion (11d), The metal portion (11) further has a semiconductor element mounting portion (11a), and the protrusion (11d) is not provided on a substrate surface of the semiconductor element mounting portion (11a), The electrode portion (11b) of the metal portion (11) has a connection region that is electrically connected to a semiconductor element, A substrate for a semiconductor device, characterized in that, in a thickness direction of the metal portion (11), a formation area of ​​the protrusion (11d) provided on the substrate surface of the electrode portion (11b) of the metal portion (11) and a connection area of ​​the electrode portion (11b) provided on the surface of the metal portion (11) opposite the substrate surface of the electrode portion (11b) are configured so as not to overlap.

2. 2. The substrate for a semiconductor device according to claim 1, wherein the connection region of the electrode portion (11b) is a wire connection region that is electrically connected to a semiconductor element by using a wire.

3. A semiconductor device in which a semiconductor element (14) and a metal portion (11) serving as an electrode portion (11b) electrically connected to the semiconductor element (14) are sealed with a sealing material (19), A protrusion (11d) is provided on the back surface of the electrode portion (11b) so as to partially protrude and be joined to a mounting substrate, The protrusion (11d) is made of metal, and a metal film (21) is formed only on the surface of the protrusion (11d), The metal portion (11) further has a semiconductor element mounting portion (11a), The semiconductor element (14) is mounted on the semiconductor element mounting portion (11a), and the protrusion (11d) is not provided on the back surface of the semiconductor element mounting portion (11a), The electrode portion (11b) of the metal portion (11) has a connection region that is electrically connected to the semiconductor element (14), A semiconductor device characterized in that, in the thickness direction of the metal portion (11), a formation area of ​​the protrusion (11d) provided on the back surface of the electrode portion (11b) in the metal portion (11) and a connection area of ​​the electrode portion (11b) provided on the front surface of the electrode portion (11b) in the metal portion (11) are configured so as not to overlap.

4. 4. The semiconductor device according to claim 3, wherein electrical connection to the semiconductor element (14) is made by using wires (15) in connection regions of the electrode portions (11b).

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