JP4143564B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a semiconductor device in which a semiconductor chip is mounted on a circuit board, and in particular, a semiconductor in which a circuit board and a semiconductor chip are electrically connected using a wire bonding method and the circuit board is resin-sealed by a transfer molding method. The present invention relates to an apparatus and a manufacturing method thereof.

  In a semiconductor device in which a semiconductor chip is mounted on a flexible substrate, it is necessary to reduce the mounting area in order to mount it on a portable device or the like. For this reason, there has been a tendency in recent years to increase the number of semiconductor devices in which the functions of a plurality of semiconductor chips are integrated into one semiconductor chip to reduce the number of components mounted. Since the functions of a plurality of semiconductor chips are integrated into one chip, the number of electrical connection terminals increases.

  In particular, in a semiconductor device in which a substrate, a lead frame, and the like and a semiconductor chip are electrically connected by a wire bonding method, the wire length increases due to an increase in electrical connection terminals, and the interval between adjacent wires becomes very narrow. Therefore, when the transfer mold method is used for resin sealing of the semiconductor package, there is a risk of causing a short circuit failure due to contact between wires due to wire flow. The wire flow means that the wire is deformed by the pressure at the time of resin injection.

  Here, a wire flow is demonstrated using Fig.15 (a) (b). The wire flow is generated by three-dimensional deformation of the wire due to the pressure of the resin at the time of resin sealing. Due to the pressure of the injected resin, the place where the wire is stretched the highest or the place where the wire is bent falls down (deforms). FIG. 15A is a view of the vicinity of the wire 100 before resin injection when viewed from above and from the side when the wire 100 is stretched, and FIG. 15B is the upper view of the vicinity of the wire 100 after resin injection. It is the drawing seen from the side. The highest stretched portion of the wire 100 marked with ○ is collapsed by the pressure of the resin, the wire length (two-dimensional wire length) seen from the upper surface is increased, and the wire flow is generated. When a wire flow occurs, there is a possibility that adjacent wires come into contact with each other depending on the flow amount. In addition, the arrow 102 in Fig.15 (a) has shown the injection direction of resin.

As a conventional technique for solving such a problem caused by the wire flow, the development of a resin suitable for the semiconductor package form and the sealing mold shape can prevent the occurrence of the wire flow itself, or in advance the resin There is a technique of preventing short circuit failure when a wire flow is generated by using a wire that is insulated and coated. Furthermore, Patent Document 1 describes a technique for preventing wire flow by sealing only a wire with a liquid resin before resin sealing by transfer molding.
JP 2002-299494 A (published on October 11, 2002)

  However, the conventional measures for the wire flow cause an increase in cost, the applicable semiconductor package form is limited, and cannot be applied to a wide variety of wires, or the volume of resin supply that is very difficult There are problems such as requiring control.

  In other words, the method of preventing wire flow by developing a resin that is compatible with the semiconductor package form and sealing mold shape involves the development and study of a new resin each time. Become. Also, depending on the semiconductor package form, wire flow countermeasures in resin development may be very difficult.

  The method of preventing short-circuit failure at the time of wire flow generation by using a wire that has been pre-insulated with a resin reduces the degree of freedom of the wire because the wire is insulated, and the wire bonding design is greatly reduced. The number of wire-bondable semiconductor packages is greatly reduced.

  The technique disclosed in Patent Document 1 that prevents the flow of the wire by sealing only the wire with the liquid resin before the resin sealing by the transfer molding method is to drop the liquid resin onto the wire. Is concerned about contact between the dripping nozzle and the wire. In addition, there is a concern about a decrease in reliability due to entrainment of bubbles at the time of dropping, and it is very difficult to control the volume of resin supply. In addition, it is necessary to study the resin dripping and the resin supply amount suitable for each wire bonding design of the semiconductor chip, and when applied to a wide variety of semiconductor packages, the productivity is lowered, and the cost is increased as in the case of resin development. It becomes a factor.

  The present invention has been made in view of the above problems, and its purpose is not to increase the cost or reduce the reliability of the semiconductor device, and to limit the applicable semiconductor package form. Semiconductor device capable of reliably preventing short-circuit failure due to wire flow of a wide variety of wires by an inexpensive method and ensuring a stable yield rate without requiring difficult resin supply volume control, and its It is to provide a manufacturing method.

  In order to solve the above problems, a first semiconductor device of the present invention includes a semiconductor chip mounted on a circuit board with a circuit formation surface facing upward and connected to the circuit board by wire bonding, In a semiconductor device in which the circuit board is resin-sealed by a transfer mold method, a sheet that covers the wire group formed by wire bonding from above and that holds the wire group in a state of maintaining a distance between adjacent wires. It is characterized in that a shaped resin layer is provided.

  According to this, since the sheet-shaped resin layer covering the wire group by wire bonding from above is fixing the wire group in a state where the interval between adjacent wires is maintained, when resin-sealing by the transfer molding method It becomes possible to maintain the space | interval between wires also with respect to the pressure of this resin, and the short circuit defect of the wires by a wire flow can be eliminated.

  Here, the sheet-like resin layer only needs to cover the wire group from above and fix the wire group in a state in which the interval between adjacent wires is maintained. Therefore, a common resin can be used as the resin constituting the sheet-shaped resin layer regardless of the semiconductor package form.

  In addition, such a sheet-like resin layer is placed on a wire group formed by wire bonding, and a sheet-like resin (hereinafter referred to as a resin sheet) is placed and softened / melted to conform to the shape of the wire group. At the same time, since at least the surface of each wire in contact with the resin sheet is buried in the resin sheet and then cured, it can be easily formed, so that it can be applied regardless of the form of the semiconductor package.

  In addition, since the sheet-like resin layer can be formed by placing the resin sheet on the wire group, as in the case of dripping the liquid resin onto the wire, contact between the dripping nozzle and the wire, or bubbles at the time of dripping The occurrence rate of defective products can be kept low. Furthermore, since it is a solid resin sheet, it is possible to control the volume of resin supply by the size by keeping the thickness uniform, and manufacture is easier compared to liquid resin.

  Therefore, there is no increase in cost or reduction in reliability of the semiconductor device, and there is no need to limit the semiconductor package form that can be applied, or to control the volume of the resin supply that is very difficult. Therefore, it is possible to provide a semiconductor device that can reliably prevent short-circuit defects due to wire flows of a wide variety of wires by an inexpensive method and ensure a stable yield rate.

  The first semiconductor device of the present invention having such a sheet-like resin layer is not limited to one semiconductor chip mounted on the circuit board, and a plurality of semiconductor chips are mounted on the circuit board. It is good also as a structure by which the sheet-like resin layer is formed on the wire group by the wire bonding in each semiconductor chip arranged in the area array form.

  In addition, when a plurality of semiconductor chips are arranged in an area array, a sheet-like resin layer is arranged for each unit with a plurality of semiconductor chips corresponding to the arrangement of the semiconductor chips as one unit. With the configuration, manufacturing can be facilitated.

  The said sheet-like resin layer can have a thermosetting resin as a main component, for example, and it is preferable to have an epoxy resin as a main component especially.

  In order to solve the above problems, a second semiconductor device of the present invention includes a semiconductor chip mounted on a circuit board with a circuit formation surface facing upward and connected to the circuit board by wire bonding, In the semiconductor device in which the circuit board is resin-sealed by the transfer molding method, the wire group by the wire bonding is respectively resin-coated by melting the resin sheet disposed on the wire group. It is characterized by.

  According to this, since each wire which comprises the wire group by wire bonding is each resin-coated by the resin sheet arrange | positioned on a wire group being fuse | melted, it resin-seal | transfers by the transfer mold method Even if a wire flow occurs with respect to the pressure of the resin at the time, a short circuit failure between wires due to the wire flow can be eliminated.

  Here, the resin sheet should just be what can arrange | position each wire by resin arrangement | positioning by being arrange | positioned on a wire group and being fuse | melted. Therefore, the resin constituting the resin sheet can use a common resin regardless of the form of the semiconductor package.

  Moreover, it can be easily formed by placing a resin sheet on a wire group by wire bonding, melting (liquefying) it, covering each wire, and then curing the resin sheet. And can be applied more easily than the first semiconductor device described above.

  This means that the resin sheet is melted (liquefied) here, so that the shape at the time of resin sheet arrangement does not remain unlike the first semiconductor device, and a plurality of semiconductor chips are arranged on the circuit board. Even if it is, it can be placed in a batch regardless of the layout, and even if the semiconductor chip is laminated with extra resin other than covering each wire, the wires by wire bonding are arranged three-dimensionally This is because the wire group of each layer can be coated with the resin at the same time.

  Also in this case, as in the case of the sheet-like resin layer, the resin sheet can be formed by placing it on the wire group, so that the contact between the dropping nozzle and the wire or In addition, entrainment of bubbles at the time of dropping does not occur, and the occurrence rate of defective products can be kept low. Furthermore, since it is a solid resin sheet, it is possible to control the volume of resin supply by the size by keeping the thickness uniform, and manufacture is easier compared to liquid resin.

  Therefore, there is no increase in cost or reduction in reliability of the semiconductor device, and there is no need to limit the semiconductor package form that can be applied, or to control the volume of the resin supply that is very difficult. Therefore, it is possible to provide a semiconductor device that can reliably prevent short-circuit defects due to wire flows of a wide variety of wires by an inexpensive method and ensure a stable yield rate.

  As described above, the second semiconductor device of the present invention in which the wires of the wire group are respectively coated with the resin by melting the resin sheet is limited to one semiconductor chip mounted on the circuit board. Instead, a plurality of semiconductor chips are arranged in an area array on the circuit board, and a wire group by wire bonding in each semiconductor chip is coated with resin by melting a resin sheet Also good.

Similarly to the sheet-like resin layer, the resin sheet can also contain, for example, a thermosetting resin as a main component, and preferably has an epoxy resin as a main component.
The second semiconductor device of the present invention, in which the wires of the wire group are respectively coated with the resin by melting the resin sheet, is located on the inner side of the end portion of the resin-sealed portion on the mounting surface of the semiconductor chip on the circuit board. It is preferable that a depressed portion for collecting the resin that has flowed out when the resin sheet is melted or a convex portion for blocking the resin that has flowed out when the resin sheet is melted is formed.

  The melted and liquefied resin spreads on the circuit board, but if the resin spreads to the part clamped by the mold during resin sealing, sealing with the mold becomes impossible and resin sealing is performed. become unable. According to this, the resin spreading on the circuit board is accumulated in the recessed portion provided on the circuit board, or is dammed by the convex part provided on the circuit board, so that the resin is clamped by the mold. It is possible to avoid problems such as not spreading and being unable to be sealed with a mold.

  In the first and second semiconductor devices of the present invention described above, the semiconductor chip connected to the circuit board by wire bonding may be stacked with another semiconductor chip. Various configurations such as a configuration in which the semiconductor chip is connected to the circuit board by wire bonding are conceivable.

  In order to solve the above problems, a first method of manufacturing a semiconductor device according to the present invention includes a step of mounting at least one semiconductor chip on a circuit board with a circuit formation surface facing upward, the circuit board, and the circuit board A step of connecting the semiconductor chip mounted on the substrate by wire bonding, a step of arranging a resin sheet on the wire group by the wire bonding, and heating the resin sheet to cover the wire group from above And the process of deforming the resin sheet so that at least the surface on the side in contact with the resin sheet of each wire constituting the wire group is buried in the resin sheet; A step of curing, and a step of resin-sealing the circuit board by transfer molding after the resin sheet is cured. It is characterized in.

  Thereby, the above-described first semiconductor device of the present invention that can eliminate the short-circuit failure between the wires due to the wire flow can be obtained.

  And as already demonstrated, in such a manufacturing method, resin which comprises a sheet-like resin layer can use common resin irrespective of the form of a semiconductor package, and is in the form of a semiconductor package. Applicable regardless. Further, unlike the case where the liquid resin is dripped onto the wire, contact between the dripping nozzle and the wire, entrapment of bubbles at the time of dripping, and the like do not occur, and the generation rate of defective products can be kept low. Furthermore, since it is a solid resin sheet, it is possible to control the volume of resin supply by the size by keeping the thickness uniform, and manufacture is easier compared to liquid resin.

  Therefore, there is no increase in cost or reduction in reliability of the semiconductor device, and there is no need to limit the semiconductor package form that can be applied, or to control the volume of the resin supply that is very difficult. Therefore, it is possible to provide a method for manufacturing a semiconductor device capable of reliably preventing short-circuit defects due to wire flows of a wide variety of wires by an inexpensive method and ensuring a stable yield rate.

  Further, in the first manufacturing method, in the step of mounting the semiconductor chip on the circuit board, the step of disposing a plurality of semiconductor chips in an area array and disposing the resin sheet on the wire group. Then, it is preferable that a plurality of semiconductor chips arranged in a direction orthogonal to the resin pressure direction in the subsequent process of resin sealing according to the arrangement of the semiconductor chips be one unit, and a resin sheet be arranged for each unit. .

  By doing in this way, it is the 1st semiconductor device of the present invention, Comprising: The 1st semiconductor device by which a plurality of semiconductor chips are arranged in an area array form does not arrange a resin sheet for every semiconductor chip In addition, a plurality of semiconductor chips can be arranged together, and the resin flow can be prevented from being hindered during resin sealing.

  In order to solve the above-described problem, a second method of manufacturing a semiconductor device according to the present invention includes a step of mounting at least one semiconductor chip on a circuit board with a circuit forming surface facing upward, the circuit board, and the circuit board. The step of connecting the semiconductor chip mounted on the wire by wire bonding, the step of placing a resin sheet on the wire group by the wire bonding, and heating and melting the resin sheet to constitute the wire group A step of coating each wire with a resin, a step of curing a molten resin in a state where each of the wires is coated with a resin, and a step of resin-sealing the circuit board by a transfer molding method after the resin is cured It is characterized by having.

  Thereby, the above-mentioned 2nd semiconductor device of this invention which can eliminate the short circuit defect of the wires by a wire flow can be obtained.

  And as already explained, in such a manufacturing method, the resin constituting the resin sheet can use a common resin regardless of the form of the semiconductor package, and regardless of the form of the semiconductor package. Applicable.

  Further, unlike the case where the liquid resin is dripped onto the wire, contact between the dripping nozzle and the wire, entrapment of bubbles at the time of dripping, and the like do not occur, and the generation rate of defective products can be kept low. Furthermore, since it is a solid resin sheet, it is possible to control the volume of resin supply by the size by keeping the thickness uniform, and manufacture is easier compared to liquid resin.

  In addition, since the resin sheet is melted (liquefied) here, the shape at the time of resin sheet arrangement does not remain unlike the first manufacturing method, and a plurality of semiconductor chips are arranged on the circuit board. Even in this case, it can be placed all at once regardless of the layout. Moreover, even if the semiconductor chip is laminated with an extra resin other than covering each wire and the wires by wire bonding are arranged three-dimensionally, the wire group of each layer can be coated with the resin simultaneously. . Therefore, the present invention can be easily applied to various forms of semiconductor packages more easily than the first manufacturing method described above.

  Therefore, there is no increase in cost or reduction in reliability of the semiconductor device, and there is no need to limit the semiconductor package form that can be applied, or to control the volume of the resin supply that is very difficult. Therefore, it is possible to provide a method for manufacturing a semiconductor device capable of reliably preventing short-circuit defects due to wire flows of a wide variety of wires by an inexpensive method and ensuring a stable yield rate.

  Further, in the second manufacturing method, in the step of mounting the semiconductor chip on the circuit board, the step of disposing a plurality of semiconductor chips in an area array and disposing the resin sheet on the wire group. Then, it is preferable to arrange the resin sheets corresponding to all the semiconductor chips together.

  As described above, since the resin sheet is melted (liquefied) here, even when a plurality of semiconductor chips are arranged on the circuit board, they can be placed in a lump regardless of the layout, and manufacturing is possible. It becomes easy.

  In the first and second manufacturing methods described above, in the step of placing the resin sheet on the wire group, the resin sheet is held on a heat-resistant carrier sheet, and the carrier is utilized using heat. The resin sheet is preferably peeled from the sheet.

  According to this, since the resin sheet can be mounted on the wire group by heating the carrier sheet, it can be arranged on the wire group without difficulty even with a thin resin sheet, as compared with the case where the resin sheet is handled and mounted. , Can reduce the damage to the wire.

  In this case, the productivity is improved by further rolling the resin sheet and the carrier sheet holding the resin sheet, and continuously feeding the resin sheet onto the wire group by winding up one end. From the point of view, it is preferable.

  As described above, the first semiconductor device of the present invention includes the semiconductor chip mounted on the circuit board with the circuit formation surface facing upward and connected to the circuit board by wire bonding. In a semiconductor device that is resin-sealed by a transfer molding method, a sheet-like resin layer that covers the wire group formed by wire bonding from above and that fixes the wire group in a state in which an interval between adjacent wires is maintained. It is characterized by being provided.

  As described above, the second semiconductor device of the present invention includes the semiconductor chip mounted on the circuit board with the circuit formation surface facing upward and connected to the circuit board by wire bonding. In the semiconductor device which is resin-sealed by the transfer molding method, the wire group by the wire bonding is characterized in that the resin sheet disposed on the wire group is respectively resin-coated by melting. Yes.

  As described above, the first method of manufacturing a semiconductor device according to the present invention includes a step of mounting at least one semiconductor chip on a circuit board with a circuit formation surface facing upward, and the circuit board and the circuit board. The step of connecting the semiconductor chip by wire bonding, the step of placing a resin sheet on the wire group by the wire bonding, and heating the resin sheet, covering the wire group from above, and A step of deforming the resin sheet so that at least a surface in contact with the resin sheet of each wire constituting the wire group is buried in the resin sheet, and a step of curing the resin sheet in a state where the deformation is caused And a step of resin-sealing the circuit board by a transfer molding method after the resin sheet is cured. There.

  As described above, the second method for manufacturing a semiconductor device according to the present invention includes a step of mounting at least one semiconductor chip on a circuit board with a circuit formation surface facing upward, and the circuit board and the circuit board. The step of connecting the semiconductor chip by wire bonding, the step of arranging a resin sheet on the wire group by the wire bonding, and heating and melting the resin sheet, each wire constituting the wire group A step of curing the melted resin in a state where each of the wires is coated with a resin, and a step of resin-sealing the circuit board by a transfer molding method after the resin is cured. It is characterized by that.

  Therefore, there is no increase in cost or reduction in reliability of the semiconductor device, and there is no need to limit the semiconductor package form that can be applied, or to control the volume of the resin supply that is very difficult. There is an effect that it is possible to provide a semiconductor device capable of reliably preventing a short circuit failure due to a wire flow of a wide variety of wires by an inexpensive method and ensuring a stable yield rate and a manufacturing method thereof.

  Embodiments according to the present invention will be described below with reference to FIGS.

  FIG. 1 is a perspective view showing a configuration of a semiconductor device 30 according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line A-A ′ of FIG. 1. However, in FIG. 1, the description of the mold resin 9 is omitted.

  The semiconductor device 30 is a CSP (Chip Size (Scale) Package), has a circuit board 2, and one semiconductor chip 1 is mounted face-up on the circuit board 2. The circuit board 2 and the semiconductor chip 1 are mechanically connected with a paste adhesive or a sheet adhesive.

  On the other hand, the electrical connection between the circuit board 2 and the semiconductor chip 1 is performed using a wire bonding method. Specifically, a plurality of electrodes (not shown) on the circuit formation surface 1a of the semiconductor chip 1 and a plurality of connection pads 10 formed on the surface (hereinafter referred to as a chip mounting surface) on the circuit board 2 on which the semiconductor chip 1 is mounted. Are connected by wires 3 (wire group) by wire bonding.

  The chip mounting surface of the circuit board 2 is resin-sealed by the transfer molding method with the semiconductor chip 1 mounted, and is covered with the mold resin 9. A plurality of bumps 11 for external connection are formed on the opposite side (back side) of the chip mounting surface of the circuit board 2.

  Note that the configuration of the semiconductor chip 1 wire-bonded to the circuit board 2 is not particularly limited in any of the embodiments described below including this embodiment, and any type of semiconductor chip can be used. The circuit board 2 is also the same. In any of the embodiments described below, various substrates such as a metal lead frame, an organic substrate such as a BT (bismaleimide / triazine) resin, and polyimide can be used. .

  And in the semiconductor device 30 which is this embodiment, the sheet-like resin layer 4 is provided so that the wire 3 by wire bonding which connects the circuit board 2 and the semiconductor chip 1 may be covered as a remarkable structure, Each wire 3 is shaped to be buried in the sheet-like resin layer 4.

  The sheet-like resin layer 4 is formed by the wire 3 that connects the semiconductor chip 1 and the circuit board 2 with the pressure of the resin (mold resin 9) described above when the resin sealing is performed by a transfer molding method in a later step. It is for generating a flow and preventing a short circuit failure due to the flow.

  The wires 3 are embedded in the sheet-shaped resin layer 4 at least on the surface in contact with the sheet-shaped resin layer 4, and the sheet-shaped resin layer 4 maintains a gap between the adjacent wires 3 and 3. It is fixed. Therefore, even if the mold resin is injected at the time of resin sealing, the wire flow in which each wire 3 is deformed by the pressure does not occur, and the interval between the adjacent wires 3 and 3 is reliably maintained.・ Three shorts do not contact each other and no short circuit failure occurs.

  In addition, since the sheet-like resin layer 4 should just be what prevents the wire flow of wire 3 ..., it is not necessary to hold | maintain wire 3 ... so that wire 3 ... may be buried, and wire 3 ... is mutually spaced. What is necessary is just to be able to fix in the state which secured.

  As a material of the sheet-like resin layer 4 for the purpose of preventing such a wire flow, the resin sheet 4 ′ is softened or melted by heating when mounted on the semiconductor chip 1 or after mounting, and thereafter It is preferable to use a resin material that cures. In particular, it is desirable to use a material that uses a thermosetting resin that maintains a solid state at room temperature, melts into a liquid state when heated, and then solidifies completely by heat treatment. The one using is desirable.

  Further, as the supply size of the resin sheet 4 ′ supplied onto the semiconductor chip 1, the wire flow can be surely prevented by setting the size to be able to cover the entire length of the wire bonded wires 3. As described with reference to a) and (b), the highest part of the wire 100 is deformed to generate a wire flow. Therefore, by fixing at least the highest part of the wires 3 ..., the flow amount can be reduced and the wire flow can be suppressed. Therefore, the supply size of the resin sheet 4 ′ is determined from the circuit formation surface 1 a of the semiconductor chip 1. It is good also as a size which covers even the part with the highest height of wire 3 ....

  In addition, when there is a bent part in the wire, a wire flow is generated by the deformation of the bent part. In that case, as the supply size of the resin sheet, the wire is bent from the circuit forming surface of the semiconductor chip. What is necessary is just to set it as the size which covers even a part.

  Further, as the shape of the resin sheet 4 ′ supplied onto the semiconductor chip 1, a rectangular shape covering the wires 3 including the circuit forming surface 1 a of the semiconductor chip 1 is used here, but the height of the wires 3 is the highest. Since the generation of the wire flow can be prevented by covering only the portion, a hollow shape in which the central portion of the rectangle is opened may be used. However, considering the handling of the thin resin sheet 4 ′, the rectangular shape is preferable.

  Next, a method for manufacturing the semiconductor device 30 will be described. First, the semiconductor chip 1 is mounted on the circuit board 2 with the circuit formation surface 1a facing upward (face up), and both are bonded using a paste adhesive or a sheet adhesive. Next, the connection pads 10 of the circuit board 2 and the electrodes of the semiconductor chip 1 are connected by wire bonding using a wire bonding apparatus.

  After the wire bonding, as shown in FIGS. 3, 4 (a) and 4 (b), the resin sheet 4 ′ to be the sheet-like resin layer 4 is placed on the wire 3 including the semiconductor chip 1 from above the semiconductor chip 1. It is mounted to cover ... Subsequently, as shown in FIG. 4C, after the resin sheet 4 ′ is heated and melted (softened) to conform to the shape of the wires 3 ..., each wire 3 is buried in the resin sheet 4 ′. In this state, the resin sheet 4 ′ is cured. Thereby, the sheet-like resin layer 4 as described above that covers the semiconductor chip 1 including the wires 3 can be formed.

  Thereafter, the circuit board 2 is resin-sealed by a transfer molding method. Specifically, a mold die 5 (see FIGS. 8, 11, and 12), which will be described later, is clamped on the circuit board 2, and a space for injecting the mold resin 9 is formed between the circuit board 2 and the die 5. Then, mold resin 9 is injected into this. The semiconductor device 30 can be obtained through such steps.

  Next, the semiconductor device 31 which is the 2nd Embodiment of this invention is demonstrated. For convenience of explanation, members having the same functions as those used in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 5 is a perspective view of the semiconductor device 31, and the description of the mold resin 9 is also omitted here. 1 differs from the semiconductor device 30 in FIG. 1 in that the resin disposed on the wires 3 instead of the sheet-like resin layer 4 that has fixed the wires 3 while maintaining the sheet-like shape. The sheet 11 ′ (see FIGS. 4A and 4B) is completely melted and liquefied, so that each wire 3 is covered with the resin 11 one by one. Further, the difference in manufacturing from the semiconductor device 30 is that the resin sheet 11 ′ (see FIGS. 4A and 4B) disposed on the wires 3 is melted and completely liquefied.

  In this way, each wire 3 is individually coated with the resin 11, so that a wire flow is generated in the wires 3... However, a short circuit failure does not occur. Further, the wire 3 itself is also covered with the resin 11 so that it is difficult to be deformed, and even if a wire flow occurs, the flow amount is small.

  In this way, in the method in which the resin sheet 11 ′ is melted and completely liquefied, the molten resin that is not used for covering the wire 3 spreads on the circuit board 2, and FIG. Shows the resin spread by reference numeral 11a. The mounting surface of the circuit board 2 including the circuit forming surface 1a of the semiconductor chip 1 is a part that is resin-sealed with the mold resin 9 in a later process, and therefore there is no problem even if it is covered with the resin 11a.

  As such a resin sheet 11 ′, it is preferable to use a resin material that is melted and liquefied completely by heating when mounted on the semiconductor chip 1 or after mounting, and then cured. In particular, it is desirable to use a material that uses a thermosetting resin that maintains a solid state at normal temperature, melts into a liquid state when heated, and then solidifies completely by heat treatment, and is particularly an epoxy resin among thermosetting resins. The one using is desirable.

  In addition, the structure which prevents the short circuit defect by a wire flow by melt | dissolving and liquefying such resin sheet 11 'completely, and coat | covering each wire 3 is mentioned later in Embodiment 4. A configuration in which a plurality of semiconductor chips are mounted on a circuit board is more suitable.

  Next, a semiconductor device according to a third embodiment of the present invention will be described. For convenience of explanation, members having the same functions as those used in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 7, the semiconductor device of this embodiment has a plurality of semiconductor chips 1 arranged in an area array on a circuit board 2, and this point is the same as that of the first embodiment. It differs from the semiconductor device 30 of FIG. FIG. 7 is a schematic view when the mold resin 9 is sealed in a state where the mold 5 is sealed.

  As shown in FIG. 6A, also in this semiconductor device, the resin sheet 4 ′ is mounted on the semiconductor chip 1 on the circuit board 2 on which wire bonding has been completed. The sheet 4 ′ is heated and softened and melted, and the resin sheet 4 ′ is cured in a state along the shape of the wires 3 and each wire 3 embedded in the resin sheet 4 ′.

  In the configuration in which a plurality of semiconductor chips 1 are mounted on the circuit board 2 in an area array like the semiconductor device, when the sheet-shaped resin layer 4 having a secured sheet shape is provided, It is necessary to mount the resin sheet 4 ′ so as not to obstruct the resin flow path of the mold resin 9 when stopped.

  Therefore, here, as shown in FIG. 7, a plurality of lines arranged in the direction (row direction) orthogonal to the pressure direction (same as the flow path direction) of the mold resin 9 in the subsequent process of resin sealing, as indicated by an arrow 25. The semiconductor chips 1 are defined as one unit, and a resin sheet 4 ′ is arranged for each unit. By disposing the resin sheet 4 ′ in this way, the resin sheet 4 ′ is not disposed for each semiconductor chip 1 but arranged to some extent, but the flow of the mold resin 9 is inhibited during resin sealing. Therefore, the mold resin 9 can be sufficiently distributed to every corner on the circuit board 2. The thickness of the resin sheet 4 ′ is about 20 μm to 50 μm in view of handling. In addition, the area | region enclosed with the line 12 in the figure is an area sealed with the mold resin 9. In FIG. 7, the resin sheet 4 ′ is shown for convenience. However, the resin sheet 4 ′ is already heated at the time of resin sealing, so that the sheet-like resin layer 4 is formed.

  8 shows an example of a mounting position when the resin sheet 4 'is mounted with a plurality of semiconductor chips 1 as a unit. Wires 3 are connected to the semiconductor chip 1 in four directions. The resin sheet 4 ′ is placed so as to be orthogonal to the flow path direction 25 of the mold resin 9 at the time of resin sealing. In such a case, with respect to the flow path direction 25 of the mold resin 9, all the wires are inevitably covered with the portion that is wire-connected in the vertical direction. The covering range of the resin sheet 4 ′ in the portion wire-connected in the same direction with respect to the flow path direction 25 is a portion having a minimum height of the wire 3.

  Next, a semiconductor device according to a fourth embodiment of the present invention will be described. For convenience of explanation, members having the same functions as those used in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  A difference between the semiconductor device of this embodiment and the semiconductor device 31 of FIG. 5 is that a plurality of semiconductor chips 1 are arranged on the circuit board 2 in an array of areas.

  As shown in FIG. 9A, also in the semiconductor device of this embodiment, the resin sheet 11 'is mounted on the semiconductor chip 1 (wire-bonded) on the circuit board 2. However, the supply size of the resin sheet 11 ′ is a size that covers all of the plurality of semiconductor chips 1 arranged in an area array, and is mounted on all the semiconductor chips 1 at a time. Then, as shown in FIGS. 9B and 9C, the resin sheet 11 ′ is heated, melted and completely liquefied, so that each wire 3 is coated with the resin 11 one by one and cured. Thereafter, resin sealing is performed by a transfer molding method. Reference numeral 11 a is a resin 11 a that is not used for covering the wire 3 and spreads on the circuit board 2.

  In the case of a substrate design in which a plurality of semiconductor chips 1... Are mounted in an area array on a circuit board 2 and then encapsulated with resin, a sheet shape as in the semiconductor device of the third embodiment. The resin layer 4 is completely liquefied by heating at the time of mounting or after mounting the resin sheet 11 ′, as in this embodiment, rather than the state in which the shape of the resin sheet 4 ′ is fixed. It is more efficient to use an insulating coating on the surface.

  The reason is that the resin sheet 11 ′ is completely liquefied and does not retain its original sheet shape, so that the size of the entire semiconductor chip 1 is covered when supplying the material of the resin sheet 11 ′ for preventing wire flow. Can be supplied to all the semiconductor chips 1 at a time, and can be supplied without depending on the layout difference of the arrangement of the semiconductor chips 1, as shown in FIG. It can be mentioned that it is possible to coat even if it is laminated with another semiconductor chip and is three-dimensional.

  By the way, although it is the same also with the semiconductor device 31 of 2nd Embodiment, when resin sheet | seat 11 'is completely liquefied and each wire 3 is coat | covered like this embodiment, Fig.10 (a) (b) The liquefied resin spreads on the circuit board 2, as shown by reference numeral 11b, in that case, if it spreads to the part clamped by the mold die 5 at the time of resin sealing, There is a risk that the mold 5 cannot be sealed.

  In order to prevent such a problem, a resin reservoir is provided on the surface of the circuit board 2 on which the semiconductor chip 1 is mounted and inside the end portion of the resin-sealed portion, as shown in FIGS. It is preferable to provide a depressed portion 6 that performs a function, or to provide a convex portion (dam bar) 7 that dams and prevents the flow of resin flowing on the circuit board 2 as shown in FIGS. .

  The depressed portion 6 that functions as a resin reservoir can be formed using, for example, a solder resist 14 that is coated on a portion other than the connection pads 10 on the circuit board 2. As shown in FIGS. 11A and 11B, it is possible to create a depressed portion by opening the solder resist 14 in the vicinity of the clamp portion of the mold 5. The depressed portion 6 may be formed in a continuous frame shape in the inner portion near the clamp portion of the mold 5 or may be partially formed.

  About the convex part 7 which blocks | prevents resin flow, for example, as shown in FIGS. 12A and 12B, a part obtained by cutting a glass epoxy substrate or the like in the vicinity of the clamp part of the mold 5 is bonded with a semiconductor adhesive. It is possible to create it by using it. The convex portion 7 may also be formed in a continuous wall shape in the inner portion near the clamp portion of the mold 5 or may be partially formed.

  As for the method of supplying the resin sheets 4 ′ and 11 ′ onto the wire-bonded semiconductor chip 1, a method of handling and mounting only the resin sheets 4 ′ and 11 ′ is generally used. When “11” is thin, handling becomes difficult. When handling is difficult, as shown in FIGS. 13A to 13C, resin sheets 4 ′ and 11 ′ are carried on a heat-resistant carrier tape (support) 8 for each required supply size, and the carrier It is preferable to use a resin sheet roll 15 that is wound into a roll integrally with the tape.

  By using the resin sheet roll 15 and having one end wound up by the rotary shaft 19 or the like, the resin sheets 4 'and 11' are continuously supplied to the semiconductor chips 1 installed below the supply position. It becomes possible to do. In addition, by using heat-resistant carrier tape, resin sheets 4 'and 11' and carrier rape can be separated and placed on the semiconductor chip 1 ... by using heat, thus reducing damage to the wire 3 it can. Note that superheating means for heating the tape carrier is not shown. The rollers 16 and 16 are tension rollers for holding the carrier tape at the supply position.

  Finally, in the first to fourth embodiments described above, the semiconductor chip 1 connected to the circuit board 2 by wire bonding has been described as being not stacked with other semiconductor chips. The semiconductor chip 1 connected to the circuit board 2 by bonding may be stacked on the circuit board 2 with other semiconductor chips.

  In that case, the second semiconductor chip to be stacked is stacked on the semiconductor chip 1 connected by the wire bonding, but on the contrary (between the semiconductor chip 1 and the circuit board 2). Even if it is laminated, it may be arranged on both upper and lower sides, or a plurality may be arranged in the same direction.

  For example, when the second semiconductor chip is stacked under the semiconductor chip 1, even if the second semiconductor chip is a face-up type with the circuit formation surface facing upward, the circuit formation surface faces the circuit substrate 2 and the circuit board 2 and the Philip chip bonding are performed. It may be a face-down type connected electrically and mechanically.

  Similarly, when stacked on the semiconductor chip 1, even if the second semiconductor chip is a face-up type with the circuit formation surface facing upward, the circuit formation surface faces the circuit formation surface of the semiconductor chip 1. 1 may be a face-down type electrically and mechanically connected to each other by Philip chip bonding.

  That is, when two or more semiconductor chips are stacked, it is sufficient that at least one of them is connected to the circuit board by the wire bonding method.

  In FIG. 14, the second semiconductor chip 18 is mounted face-up on the circuit board 2 on the circuit board 2. The second semiconductor chip 18 is mounted face-up on the semiconductor chip 1 connected to the circuit board 2 by wire bonding. In a state where the circuit board 2 is connected to the wires 18 by wire bonding, the resin sheet 4 ′ or the resin sheet 11 ′ is mounted so as to cover the wires 3 and 18. Show.

1 is a perspective view illustrating a configuration of a semiconductor device according to an embodiment of the present invention. It is the sectional view on the AA line of FIG. FIG. 2 is a perspective view showing a state in the process of manufacturing the semiconductor device of FIG. 1 and showing a state in which a resin sheet is arranged on a semiconductor chip. 4 (a) to 4 (c) are drawings for explaining a process in which a resin sheet fixes a wire in the semiconductor device of FIG. FIG. 25 is a perspective view illustrating another configuration of the present invention and illustrating a configuration of a semiconductor device. The other form of implementation of this invention is shown, and both FIG. 6 (a) (b) is drawing for demonstrating the process in which the resin sheet in a semiconductor device fixes a wire. It is the schematic at the time of mold resin sealing in the mold die sealing state for demonstrating the layout which does not obstruct the resin flow path at the time of resin sealing. It is drawing for demonstrating the position which mounts a resin sheet on a semiconductor chip. FIG. 9 shows another embodiment of the present invention, and FIGS. 9A to 9C are views for explaining a process in which a resin sheet fixes a wire in a semiconductor device. FIGS. 10 (a) and 10 (b) are diagrams for explaining a problem caused by the flow of resin that occurs when a resin sheet is melted and completely liquefied. 11 (a) and 11 (b) are diagrams for explaining a depressed portion that avoids a problem caused by a resin flow that occurs when a resin sheet is melted and completely liquefied. 12 (a) and 12 (b) are drawings for explaining a convex portion for avoiding a problem caused by a resin flow that occurs when a resin sheet is melted and completely liquefied. FIGS. 13A to 13C are diagrams for explaining a state in which a resin sheet is continuously supplied by using a heat-resistant carrier tape in a process of mounting the resin sheet on a semiconductor chip. The perspective view which shows the other state of embodiment of this invention, shows one state in the middle of manufacture of the semiconductor device by which the several semiconductor chip is laminated | stacked, and shows the state by which the resin sheet has been arrange | positioned on the semiconductor chip Is 15 (a) and 15 (b) are drawings for explaining the wire flow.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor chip 2 Circuit board 3 Wire 4 Sheet-like resin layer 4 'Resin sheet 5 Mold die 6 Depressed part 7 Convex part 8 Carrier tape 9 Mold resin 10 Connection pad 11 Resin 11' Resin sheet

Claims (12)

In a semiconductor device comprising a semiconductor chip mounted on a circuit board with the circuit forming surface facing upward and connected to the circuit board by wire bonding, and the circuit board is resin-sealed by a transfer molding method.
Covering the wire group by the wire bonding from above, and a sheet-like resin layer is provided to fix the wire group in a state of maintaining the interval between adjacent wires,
A plurality of the semiconductor chips are arranged in an array on the circuit board in an area array,
The semiconductor device according to claim 1, wherein the sheet-like resin layer is arranged for each unit with a plurality of semiconductor chips corresponding to the arrangement of the semiconductor chips as one unit.   The semiconductor device according to claim 1, wherein the sheet-like resin layer contains a thermosetting resin as a main component. In a semiconductor device comprising a semiconductor chip mounted on a circuit board with the circuit forming surface facing upward and connected to the circuit board by wire bonding, and the circuit board is resin-sealed by a transfer molding method.
The wire group by the wire bonding is individually coated with the individual wires constituting the wire group by melting the resin sheet disposed on the wire group ,
The semiconductor chip mounting surface of the circuit board is provided with a recessed portion for collecting the resin that has flowed out when the resin sheet is melted inside the end of the resin-sealed portion. A semiconductor device. In a semiconductor device comprising a semiconductor chip mounted on a circuit board with the circuit forming surface facing upward and connected to the circuit board by wire bonding, and the circuit board is resin-sealed by a transfer molding method.
The wire group by the wire bonding is individually coated with the individual wires constituting the wire group by melting the resin sheet disposed on the wire group ,
On the mounting surface of the semiconductor chip on the circuit board, on the inner side of the end portion of the portion to be sealed with the resin, a convex portion for damming the resin that has flowed out by melting the resin sheet is formed. A featured semiconductor device. 5. The semiconductor device according to claim 3 , wherein a plurality of the semiconductor chips are arranged in an area array on the circuit board. The semiconductor device according to claim 3, wherein the resin sheet contains a thermosetting resin as a main component. 6. The semiconductor device according to claim 1 , wherein the semiconductor chip connected to the circuit board by the wire bonding is stacked with another semiconductor chip. Mounting at least one semiconductor chip on a circuit board with a circuit forming surface facing upward;
Connecting the circuit board and the semiconductor chip mounted thereon by wire bonding;
Arranging the resin sheet on the wire group by the wire bonding;
By heating the resin sheet, the resin sheet is deformed so that the wire group is covered from above and at least the surface of each wire constituting the wire group that is in contact with the resin sheet is buried in the resin sheet. A process of
Curing the resin sheet in a state where the deformation occurs,
And a step of resin-sealing the circuit board by transfer molding after the resin sheet is cured,
In the above process of mounting semiconductor chips on a circuit board, a plurality of semiconductor chips are arranged in an area array,
In the above step of arranging the resin sheet on the wire group, a plurality of semiconductor chips arranged in a direction orthogonal to the pressure direction of the resin in the subsequent step of resin sealing according to the arrangement of the semiconductor chips is defined as one unit, A method of manufacturing a semiconductor device, comprising disposing a resin sheet on the substrate. Mounting at least one semiconductor chip on a circuit board with a circuit forming surface facing upward;
Connecting the circuit board and the semiconductor chip mounted thereon by wire bonding;
Arranging the resin sheet on the wire group by the wire bonding;
Heating and melting the resin sheet, and individually coating each wire constituting the wire group with a resin; and
Curing the molten resin in a state where the individual wires are individually coated with the resin,
And a step of resin-sealing the circuit board by transfer molding after the resin is cured. In the above process of mounting semiconductor chips on a circuit board, a plurality of semiconductor chips are arranged in an area array,
The method for manufacturing a semiconductor device according to claim 9 , wherein in the step of arranging the resin sheet on the wire group, resin sheets corresponding to all semiconductor chips are collectively arranged. In the step of placing a resin sheet on top of the wire group, claims, characterized in that peeling off the resin sheet allowed to retain the heat resistance of the carrier sheet, by utilizing the heat from the carrier sheet to the resin sheet A method for manufacturing a semiconductor device according to 8, 9 or 10 . The semiconductor according to claim 11 , wherein the resin sheet and the carrier sheet holding the resin sheet are in a roll shape, and the resin sheet is continuously supplied onto the wire group by winding up one end. Device manufacturing method.

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