JP2006191143A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device, having improved contact strength between a die pad and sealing resin and improved resistance to moisture. <P>SOLUTION: A lead frame is worked, such that a plurality of protrusions 9 are made on the side of the die pad 1 and that the protrusions 9 are bent to the side of the mounting surface, where the semiconductor device 3 is mounted. Then, the semiconductor 3 is mounted on the mounting surface, the surface to be exposed of the die pad 1 is exposed, and then the semiconductor 3, the protrusions 9, inner leads (5a, 5b) are sealed with sealing resin 7. The protrusions 9 and their connected portions bite into the sealing resin 7, and the contact strength is increased. Deformation of the die pad 1 is reduced when the device is mounted, and proper resistance against moisture is kept, after the mounting of the device. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor device adapted for mounting a semiconductor element having a large calorific value, such as a motor driver and a sound amplifier.

  2. Description of the Related Art As electronic devices have become more multifunctional and smaller and thinner in recent years, semiconductor devices have been required to be thin and have good heat dissipation. Therefore, as such a thin semiconductor device, Patent Document 1 proposes the following.

  A conventional semiconductor device will be described below. FIG. 12 is a view showing a conventional semiconductor device, FIG. 12 (a) is a cross-sectional view of an essential part of the semiconductor device, and FIG. 12 (b) is a rear view thereof.

  As shown in FIG. 12, in the conventional semiconductor device, an adhesive 2 is applied to a die pad 1 and a semiconductor element 3 is fixed thereon. The metal element 4 is connected to the semiconductor element 3 and is electrically connected to a plurality of inner leads 5a around the die pad 1 respectively. Each outer lead 6 integrally connected to each inner lead 5 a is led out from the sealing resin body 7, and the die pad 1, the adhesive 2, the semiconductor element 3, the metal thin wire 4 and the inner lead 5 a are the sealing resin body 7. It is sealed. The sealing resin body 7 is formed into a quadrilateral flat plate shape, and the outer leads 6 are drawn from the four sides of the sealing resin body 7. The exposed surface of the die pad 1 (the surface opposite to the surface on which the semiconductor element 3 is mounted) is exposed from the sealing resin body 7.

This semiconductor device is usually mounted such that the exposed surface of the die pad 1 exposed from the sealing resin body 7 is in contact with a printed circuit board (not shown). Since the die pad 1 on which the semiconductor element 3 as a heat source is mounted is exposed from the sealing resin body 7, heat can be directly radiated to the outside air, and high heat dissipation can be maintained.
JP-A-9-199639

  However, since the conventional semiconductor device ensures moisture resistance only by the adhesion between the die pad 1 and the sealing resin body 7, when the solder is soldered to the printed circuit board, moisture accumulated in the sealing resin body 7 is retained. The die pad 1 is deformed by causing rapid thermal expansion. Therefore, a gap is likely to be generated between the die pad 1 and the sealing resin body 7 and the moisture resistance after mounting on the printed board is likely to be deteriorated. If the exposed surface of the die pad 1 is soldered to the printed board in order to further improve the heat dissipation than the state where it is in contact with the printed board, further rapid thermal expansion of moisture occurs, and the die pad 1 becomes a sealing resin body. There was a problem that it peeled from 7 and impaired moisture resistance. Therefore, it is necessary to ensure not only the moisture resistance of a single semiconductor device but also moisture resistance after mounting on a printed circuit board.

  Further, when the resin pad is pressed by pressing the back surface of the die pad 1 against a sealing mold (not shown), the resin flows out between the die pad 1 and the sealing mold due to the injection pressure when the resin is injected. A thin burr is generated on the back side of the die pad 1. If this thin burr is left undisturbed, heat radiation from the back surface of the die pad 1 is hindered, so it is necessary to remove the thin burr with a chemical or a water jet. However, since there is a problem with the moisture resistance described above, when removing thin burrs with chemicals or water jets, moisture and chemicals penetrate into the sealing resin body 7 and impair reliability. There was a problem.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described conventional problems, and to provide a semiconductor device having a high heat dissipation effect that can secure moisture resistance after being mounted on a printed circuit board and a method for manufacturing the same.

  A semiconductor device according to the present invention is provided on a semiconductor element mounted on a rectangular die pad, a plurality of protrusions provided on a side surface of the die pad and bent toward a mounting surface side of the semiconductor element, and provided on a short side of the die pad. A support lead that supports the die pad, a plurality of inner leads that are electrically connected to the semiconductor element by thin metal wires, outer leads that are integrally connected to the inner leads, and the mounting surface; A sealing resin body formed into a rectangular flat plate for resin-sealing the semiconductor element, the plurality of protrusions, the fine metal wires, and the inner lead group, and sealing the plurality of outer leads. It is the structure which pulled out from the long side of the body, respectively, and exposed the exposed surface of the die pad from the sealing resin body.

  With this configuration, heat is radiated directly from the exposed portion of the die pad on which the semiconductor element is mounted, so that the heat radiation effect is extremely good. In addition, since the plurality of protrusions are provided on the side surface of the die pad, the engagement with the sealing resin body is good and the adhesion is improved. In addition, when the moisture accumulated in the sealing resin body thermally expands during soldering, it has adequate air permeability and escapes steam, so that the deformation of the die pad is reduced and the die pad is peeled off from the sealing resin body. Can be prevented.

  Furthermore, if the tips of the plurality of protrusions provided on the side surface of the die pad are T-shaped, the engagement between the sealing resin body and the protrusions is further improved, and the adhesion is further improved. Further, when the adjacent protrusions are connected to each other at the tip, the engagement with the sealing resin body is further improved.

  Also, if a ring-shaped groove is provided along the periphery of the back surface of the die pad, the resin prevents the resin from flowing between the sealing mold and the exposed surface of the die pad during resin sealing, and the exposed surface of the die pad The size of the thin burr that can be reduced can be restricted. If this ring-shaped groove is provided twice, thin burr can be prevented more reliably.

  Further, when the second support lead connecting the long side of the die pad and the inner lead is added to the long side of the die pad, the pressing pressure to the sealing mold when the resin is sealed is increased, while the die pad In addition to reducing the deformation in the surface direction and reducing the occurrence of thin burrs, it is possible to dissipate heat from both the inner leads connected to the die pad and the exposed surface of the die pad when mounting this semiconductor device. Even if the exposed surface of the die pad, which is difficult to solder, is not soldered, a considerable heat dissipation effect can be expected.

  In addition, if the width of the first or second support lead is made more than twice the width of the inner lead, the pressing pressure at the time of resin sealing is increased, and the thin burr formed on the exposed surface of the die pad can be reduced.

  As described above, the semiconductor device of the present invention has a plurality of protrusions on each side surface of the die pad, and the protrusions package the semiconductor element using a lead frame that is bent on the mounting surface side of the semiconductor element. This protrusion can improve the adhesion to the sealing resin body and improve the moisture resistance. Also, when the moisture accumulated in the package during solder dipping thermally expands, the moisture can easily escape, can prevent deformation and dripping of the die pad, and can maintain moisture resistance even after mounting on a printed circuit board. . Moreover, it is possible to directly radiate heat from the exposed surface of the die pad to the printed circuit board, and the semiconductor device has excellent heat dissipation and excellent quality.

  Also, if a groove is provided along the periphery of the die pad, the sealing pressure when resin sealing is performed is released along the groove, and if the resin wraps around, the resin can be stopped by the groove. Resin burr can be minimized.

  Embodiments of a semiconductor device according to the present invention will be described below. FIG. 1 is a plan view showing a lead frame used in the semiconductor device of the first embodiment, and the shape of the sealing resin body is indicated by a broken line. FIG. 2 is a diagram for explaining the semiconductor device according to the first embodiment. FIG. 2A is a cross-sectional view showing a cross-sectional structure of a main part of the semiconductor device, and FIG. FIG. 2 (c) is a rear view.

  As shown in FIGS. 1 and 2, in the semiconductor device according to the first embodiment, an adhesive 2 is applied to a die pad 1 and a semiconductor element 3 is fixed thereon. The metal element 4 is connected to the semiconductor element 3 and is electrically connected to a plurality of inner leads 5a around the die pad 1 respectively. Each outer lead 6 integrally connected to each inner lead 5 a is led out from the sealing resin body 7, and the die pad 1, adhesive 2, semiconductor element 3, metal wire 4 and inner lead 5 a are sealed resin body 7. It is sealed. Further, the sealing resin body 7 is shaped so that the planar shape is substantially rectangular, and the outer leads 6 are drawn out from the respective long sides of the sealing resin body 7. The exposed surface of the die pad 1 is exposed from the sealing resin body 7.

  A support lead 10 is connected to each short side of the die pad 1 having a substantially rectangular planar shape, which is wider than the lead width of the inner lead 5a. The support lead 10 supports the die pad 1 and maintains an integrated state with the peripheral inner leads 5a and the like even when the lead frame is alone after the metal plate is die-cut and formed into a lead frame. Although there are other functions. The support lead 10 is located at a position away from the die pad 1 at the same height as the inner lead 5a, and is bent at two places close to the die pad 1 to fix the die pad 1 at a position lower than the inner lead 5a. ing. In other words, it is downset. This is also used to give the die pad 1 a force for pressing the die pad 1 against the bottom of a resin sealing mold (not shown) when the sealing resin body 7 is molded.

  Note that the lead width of the support lead 10 may be 0.3 mm to 0.6 mm when manufacturing a small signal semiconductor device, and when manufacturing a high power semiconductor device. A configuration in which the support lead 10 is connected to a heatsink is also conceivable, but in this case, it may be made wider as necessary.

  Each side surface of the die pad 1 has a plurality of protrusions 8 whose tips are formed in a T shape, and the protrusions 8 are bent toward the mounting surface side of the semiconductor element 3. Since the protrusion 8 is embedded in the sealing resin body 7, the protrusion 8 has good engagement with the sealing resin body 7, improves the adhesion between the die pad 1 and the sealing resin body 7, and improves the moisture resistance of the semiconductor device. It can be secured. On the other hand, when the moisture accumulated in the sealing resin body 7 thermally expands during soldering, there is a moderate air permeability between the plurality of protrusions 8, and the internal vapor can be easily released. In addition, the deformation of the die pad 1 can be reduced and the moisture resistance after mounting can be improved.

  A ring-shaped groove 16 is formed on the exposed surface of the die pad 1 opposite to the surface on which the semiconductor element 3 is mounted. The groove 16 can release the resin injection pressure at the time of resin sealing and can block the flow of the resin, and can suppress the thin burr within a certain range. Therefore, the effective area of the exposed surface can be ensured, the exposed surface can be soldered, and a higher heat dissipation effect can be enhanced.

  Next, the semiconductor device according to the second embodiment will be explained with reference to FIG. FIG. 3 is a view for explaining the semiconductor device according to the second embodiment. FIG. 3A is a plan view of a lead frame used in the second embodiment. FIG. 3B is a cross-sectional view of a main part of the semiconductor device.

  As shown in FIG. 3, in the semiconductor device according to the second embodiment, an adhesive 2 is applied to a die pad 1 and a semiconductor element 3 is fixed thereon. The metal element 4 is connected to the semiconductor element 3 and is electrically connected to a plurality of inner leads 5a around the die pad 1 respectively. Each outer lead 6 integrally connected to each inner lead 5 a is led out from the sealing resin body 7, and the die pad 1, adhesive 2, semiconductor element 3, metal wire 4 and inner lead 5 a are sealed resin body 7. It is sealed. Further, the sealing resin body 7 is shaped so that the planar shape is substantially rectangular, and the outer leads 6 are drawn out from the respective long sides of the sealing resin body 7. The exposed surface of the die pad 1 is exposed from the sealing resin body 7.

  The support lead 10 connected to each short side of the die pad 1 having a substantially rectangular plane shape supports the die pad 1 in order to maintain the integrated state even after the lid frame is integrally formed. The two parts close to 1 are bent, and the die pad 1 is set to a position lower than the inner lead 5a. When the outer lead 6 and the support lead 10 having such a structure are clamped to the resin-sealed mold, the die pad 1 can be pressed against the bottom of the resin-sealed mold (not shown) by the rigidity of the support lead 10. it can.

  Each side surface of the die pad 1 has a plurality of protrusions 9, and between the plurality of protrusions 9, there is a portion (connection portion) that connects the tips of the protrusions 9. Is bent toward the mounting surface side of the semiconductor element 3. Since the plurality of protrusions 9 and their connecting portions are embedded in the sealing resin body 7, the engagement with the sealing resin body 7 is better than in the first embodiment, and the die pad 1 and the sealing resin body 7 can be further improved, and better moisture resistance can be ensured. In addition, there is a slit-like hole along the periphery of the die pad 1 between the connecting portion and the die pad 1, and when moisture accumulated in the sealing resin body 7 is thermally expanded during soldering. The slit-shaped hole can ensure a good air permeability, and the internal vapor can be easily released, the deformation of the die pad 1 can be reduced, and the moisture resistance after mounting can be improved.

  A ring-shaped groove 16 is formed on the exposed surface of the die pad 1 opposite to the surface on which the semiconductor element 3 is mounted. The groove 16 can release the resin injection pressure at the time of resin sealing and can block the flow of the resin, and can suppress the thin burr within a certain range. Therefore, the effective area of the exposed surface can be ensured, the exposed surface can be soldered, and a higher heat dissipation effect can be enhanced.

  Next, the semiconductor device according to the third embodiment will be explained with reference to FIG. FIG. 4 is a view for explaining the semiconductor device according to the third embodiment. FIG. 4A is a plan view of a lead frame used in the third embodiment. A broken line in the figure indicates a sealing resin body. FIG. 4B is a cross-sectional view of the main part.

  Since the third embodiment shown in FIG. 4 is almost the same as the second embodiment described above, the description will focus on the differences from the second embodiment.

  In addition to the support lead (first support lead provided on the short side) 10 that supports the die pad 1, the inner lead 5 a near the center of the long side of the die pad 1 is connected to the die pad 1, and the inner lead 5 a Can function as a support lead (second support lead). With such a configuration, since the die pad 1 is supported from all sides, it is difficult for the shape of the die pad 1 to be deformed and the mounting direction to be changed, and the force distribution when pressing the die pad 1 against the sealing mold is reduced. It becomes uniform and can be pressed stably. Further, the pressing force from the four sides by the support leads (10 and 5a) can increase the force for pressing the die pad 1 against the sealing mold, and the synergistic effect of the sealing resin that can be easily formed on the exposed surface of the die pad 1 Thin burr can be further reduced. As described above, when the exposed surface of the die pad 1 is soldered, the heat dissipation effect is improved. However, the exposed surface is generally mounted in close contact with the wiring board, and the periphery of the exposed surface is a sealing resin. However, even if the exposed surface is not forcibly directly soldered, the die pad can be passed through the soldered outer lead and the inner lead 5a connected to the outer lead. 1 heat can be dissipated, and a considerable heat dissipating effect can be expected although it is not as good as when the exposed surface of the die pad 1 is directly soldered.

  When the inner lead 5b is used as a support lead, the lead width of the inner lead 5b connected to the die pad 1 is set to be 2 to 5 times the lead width of the other inner leads 5a, so that the original support lead 10 The width may be narrowed, and both the inner lead 5b and the support lead 10 may be widened.

  Next, a method for manufacturing the semiconductor device as the fourth embodiment will be described with reference to FIGS. 5 to 10 by taking the method for manufacturing the semiconductor device shown in FIG. 4 as an example.

  5A and 5B are configuration diagrams showing a lead frame used for manufacturing a semiconductor device. FIG. 5A is a plan view of the lead frame, FIG. 5B is a cross-sectional view of the main part, and FIG. It is sectional drawing of a direction.

  As the lead frame material, a thin plate of iron, iron alloy, copper or copper alloy having good heat conduction and relatively high mechanical strength is used. Then, as shown in FIG. 5, the thin plate is etched or pressed to form a plurality of protrusions 9 having tips connected to the four side surfaces of the die pad 1, inner lead 5a, inner lead 5b, outer lead 6, and die pad 1. The support lead 10, the dam bar 11, the outer frame 12, the inner frame 13, and the guide hole 14 are integrally formed. The lead frame 15 shown in FIG. 5 illustrates one unit of the lead frame 15 configured in multiples by an outer frame.

  Ag plating is performed on a wire bonding region (not shown) on the surface of the lead frame 15, or three layers of Ni, Pd, and Au are applied to the whole. In this case, by applying Au flash to the outermost layer, the adhesion with the sealing resin is improved as compared with the one subjected to Ag plating, and good moisture resistance can be obtained. Moreover, since exterior plating is performed before resin sealing, even if a thin burr is generated in the die pad exposed portion at the time of resin sealing, there is no problem of failure of exterior plating. Therefore, Ni, Pd, Au It is desirable to apply three-layer plating.

  Next, a ring-shaped groove 16 is formed on the exposed surface of the die pad 1 opposite to the mounting surface of the semiconductor element 3 in order to stop resin thin burrs generated on the exposed surface of the die pad 1 during resin sealing.

  At this time, since the lead frame material is stretched by cutting the groove 16, the portion outside the groove 16 of the die pad 1 may be warped several to several tens of μm toward the semiconductor element 3 mounting surface. In this case, by providing a groove (not shown) having substantially the same shape as the groove 16 on the mounting surface side of the semiconductor element 3 of the die pad 1, the elongation of the material can be offset and the warping can be prevented. Since the groove (not shown) provided on the mounting surface side of the die pad 1 is not intended to stop the thin burr unlike the groove 16, it does not have to be closed in a ring shape.

  Further, many thin burrs are likely to occur in the portion where the resin is injected. This is because the sealing resin wraps around between the die pad 1 and the sealing mold before the filling pressure for pressing the die pad against the sealing mold is applied. In this case, at least a portion of the die pad 1 that matches the direction in which the sealing resin is injected is formed with a double groove so that thin burr can be prevented.

  Next, two places near the die pad 1 of the support lead 10 are bent to downset the die pad 1 to a position lower than the inner lead 5a, and the tips provided on the four side surfaces of the die pad 1 are connected. The protruding portion 9 is bent so that the protruding portion 9 is bent toward the mounting surface side of the semiconductor element 3.

  When such a downset process is performed, the first-stage bending is performed at an intermediate position between the two bent portions, rather than using the bending die only once. In the second stage, Bending is performed at the final predetermined folding position while forming the portion bent at the stage into a straight line. This is because the stress that stretches the metal is applied at the location of the bending process, so that if the metal is downset at once, the metal fatigue increases and the bent portion of the support lead 10 is cracked. And the second stage, the metal fatigue of the support lead 10 is reduced by bending at different positions.

  As an example, a case will be described in which a surface mount package having a resin sealing body thickness of about 1 mm and a planar shape of about 6 mm × 17 mm is made of a 0.15 mm thick copper alloy plate. In this case, the planar shape of the die pad 1 is about 3 mm × 6 mm, and the plurality of protrusions 9 are about 0.5 mm long and are bent at an angle of about 45 degrees toward the mounting surface side of the semiconductor element 3. The tip of the bent projection 9 is formed so as to be positioned below the inner lead 5a so as not to contact the fine metal wire. The support lead 10 is bent to set the die pad 1 lower than the position of the inner lead 5a (downset), but the amount of downset (step difference between the die pad 1 and the inner lead 5a) is set to about 0.47 mm. As a result, the amount of downset is set so that the position of the die pad 1 falls within the range of 0.02 to 0.2 mm from the bottom of the sealing mold if there is no position restriction by the sealing mold. Further, if the depth of the groove 16 of the die pad 1 is about 0.01 mm, there will be no problem that causes a catch when the lead frame is moved in the process.

  The multiple lead frame 15 configured as described above includes a semiconductor element bonding process for fixing the semiconductor element 3 to the die pad 1 and a wire bonding process for electrically connecting the semiconductor element 3 and the inner lead 5a. This is performed for each frame. These bonding operations are sequentially performed for each lead frame per unit by pitch-feeding in the horizontal direction.

  Next, the die bonding process and the wire bonding process will be described. 6 is a process cross-sectional view for explaining the pre-process of die bonding, FIG. 7 is a process cross-sectional view for explaining the die bonding process, and FIG. 8 is a process cross-sectional view for explaining the wire bonding process. .

  First, as shown in FIG. 6, an adhesive 2 for fixing the semiconductor element 3 on the die pad 1 is applied on a stage 17 of a semiconductor element bonding apparatus (not shown). Application of the adhesive is performed by dropping the adhesive 2 using the dispenser 18. For example, the adhesive 2 is made of a silver paste in which Ag powder is mixed with a thermosetting epoxy resin.

  Next, as shown in FIG. 7, the semiconductor element 3 is mounted on the die pad 1 coated with the adhesive 2 using the collet 19, and then heated on a heat stage (not shown) to cure the adhesive 2. Let As an example, the semiconductor element 3 is a silicon single crystal whose outer dimensions are a planar shape of 2 mm × 3 mm and a thickness of about 0.3 mm. The heating conditions are 200 to 250 ° C. and about 30 seconds to 1 minute. The adhesive 2 may be cured using an oven.

  Next, as shown in FIG. 8, the bonding pad 21 of the semiconductor element 3 fixed on the die pad 1 and the inner lead 5 a are electrically connected using the metal thin wire 4. In the heat stage 20 of the wire bonding apparatus, a part of the die pad 1, the support lead 10 and the inner lead 5b and a relief part for inserting the die pad 1 are formed, and the outer periphery of the wire bond region of the inner lead 5a is fixed to the fixing jig 22. While fixed by. As an example, an Au wire having a diameter of 20 to 35 μm is used as the metal thin wire.

  Thus, after die bonding and wire bonding are performed for each unit lead frame, the unit lead frame group is collectively resin-sealed to form a plurality of sealing resin bodies 7 simultaneously.

  Next, the resin sealing step will be described with reference to FIG. 9 which is a process cross-sectional view for explaining the resin sealing step.

  FIG. 9 shows a transfer molding apparatus, which includes a pair of an upper mold 24 and a lower mold 25 that are clamped by a cylinder device (not shown), and a mating surface between the upper mold 24 and the lower mold 25. Each of the upper mold cavity 26a and the lower mold cavity 26b is embedded in a plurality so as to form the cavity 26. A pot 27 is opened on the mating surface of the upper mold 24, and a plunger 28 that is advanced and retracted by a cylinder device (not shown) is inserted into the pot 27 so that resin as a molding material can be fed. . On the mating surface of the lower mold 25, a cull 29 is arranged and buried at a position facing the pot 27, and a runner 30 is connected to the pot 27. Further, the other end portion of each runner 30 is connected to the lower mold cavity 26 b, and a gate 31 is formed at the connecting portion so that the resin can be injected into the cavity 26. In addition, on the mating surface of the lower mold 25, a rectangular shape slightly larger than the outer shape and a depth slightly shallower than the thickness so that the escape portion 32 can escape the thickness of the lead frame 15 in the lead frame polymer 23. Is formed. Using the transfer molding apparatus having such a configuration, resin sealing is performed by the following method.

  The lead frame polymer 23 is attached to the relief portion 32 of the sealing mold of the transfer device heated to about 180 ° C., and the sealing mold is clamped. Next, a resin (not shown) compressed in a conical shape is inserted into the pot 27, and the resin is press-fitted into the cavities 26 through the cull 29, the runner 30, and the gate 31 by the plunger 28. After the injection, when the resin is thermally cured to form the sealing resin body 7, the upper mold 24 and the lower mold 25 are opened, and the sealing resin body 7 group is separated by an ejector pin (not shown). The molded and resin-molded lead frame polymer 23 is detached from the transfer molding apparatus.

  Thus, the die pad 1, the adhesive 2, the semiconductor element 3, the fine metal wire 4, the inner lead 5a, the inner lead 5b, the protruding portion 9, and the support lead 10 are formed inside the resin-molded resin sealing body. It will be resin-sealed. At this time, if there is no position restriction by the lower mold 25, the lead frame having the die pad 1 downset so as to be fixed at a position 0.02 to 0.2 mm lower than the depth of the bottom of the lower mold 25 is sealed. When the mold is clamped, the exposed surface opposite to the mounting surface of the semiconductor element 3 is pressed against the lower mold 25 to prevent the resin from flowing around to the lower side (exposed surface side) of the die pad 1. Can be resin-sealed so as to expose the exposed surface from the sealing resin body 7.

  Note that the cavity part of the normally used sealing mold is pear-finished and roughened to make it easier to recognize for board mounting, but at least the part where the die pad contacts is mirror-finished. By applying (not shown), the gap between the die pad 1 and the sealing mold can be eliminated, and the generation of thin burrs can be further suppressed. Furthermore, by providing a mechanism (not shown) for adsorbing the die pad 1 to the portion of the lower mold 25 where the die pad 1 abuts, the occurrence of thin burrs can be further suppressed.

  FIG. 10 is a rear view of the semiconductor device after resin sealing, and is a view for explaining a thin burr formed on the exposed surface of the die pad.

  As shown in FIG. 10, the exposed surface of the die pad 1 is formed in a ring shape applied to the die pad 1, although the resin thin burr 33 leaks from the outer peripheral portion of the die pad 1 due to the resin injection pressure and adheres. The thin burrs stop at the groove 16, an effective exposed surface inside the groove 16 can be secured over a certain area, and the exposed surface of the die pad 1 can be soldered and mounted on a printed circuit board (not shown). become. Further, the ring-shaped groove 16 can more reliably prevent the occurrence of thin burrs by providing double the ring-like groove 16 as shown in FIG.

  Next, in the case where the resin-molded lead frame polymer 23 is subjected to Ag plating in the bonding region of the lead frame 15, solder exterior plating is applied to a portion other than the sealing resin body 7 of the lead frame polymer 23. (Not shown). In the case where Pd plating is applied to at least a portion of the lead frame 15 which is a finished product of the semiconductor device, solder exterior plating is not required.

  Next, as shown in FIG. 11, the resin-molded lead frame polymer 23 after the solder exterior plating or before the solder exterior plating is applied to each unit lead frame by a cutting device (not shown). The dam bar 11 is cut sequentially.

  Next, the tip of the outer lead 6 and a part of the inner frame 13 are cut by a lead forming device (not shown), and then the outer lead 6 is bent into a gull wing shape, and a part of the inner frame 13 is cut. Then, the semiconductor device is separated from the outer frame 12.

  As described above, the semiconductor device illustrated in FIG. 3 can be completed.

  The semiconductor device of the present invention is useful as a means for realizing high heat dissipation of electronic equipment.

1 is a plan view of a lead frame used in a semiconductor device according to a first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the semiconductor device which concerns on the 1st Embodiment of this invention, (a) is principal part sectional drawing of a semiconductor device, (b) is sectional drawing of the longitudinal direction of a semiconductor device, (c) is a semiconductor device of FIG. Rear view 4A and 4B are diagrams illustrating a semiconductor device according to a second embodiment, in which FIG. 5A is a plan view of a lead frame used in the semiconductor device, and FIG. 4A and 4B are views showing a semiconductor device according to a third embodiment, wherein FIG. 5A is a plan view of a lead frame used in the semiconductor device, and FIG. The figure which shows the lead frame used for 4th Embodiment, (a) is a top view of a lead frame, (b) is principal part sectional drawing of a lead frame, (c) is sectional drawing of the longitudinal direction of a lead frame Process sectional drawing for demonstrating the pre-process of the die-bonding process of 4th Embodiment Process sectional drawing for demonstrating the die bonding process of 4th Embodiment Process sectional drawing for demonstrating the wire bonding process of 4th Embodiment Process sectional drawing for demonstrating the resin sealing process of 4th Embodiment It is a rear view of the semiconductor device after resin sealing, and is a diagram for explaining a thin burr formed on the exposed surface of the die pad The figure which shows the semiconductor device after dam bar cutting It is a figure which shows the conventional semiconductor device, (a) is principal part sectional drawing of a semiconductor device, (b) is a rear view of a semiconductor device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Die pad 2 Adhesive 3 Semiconductor element 4 Metal thin wire 5a Inner lead 5b Inner lead (2nd support lead)
6 Outer lead 7 Sealing resin body 8 Protrusion 9 Protrusion 10 Support lead (first support lead)
DESCRIPTION OF SYMBOLS 11 Dam bar 12 Outer frame 13 Inner frame 14 Guide hole 15 Lead frame 16 Groove 17 Stage 18 Dispenser 19 Collet 20 Heat stage 21 Bonding pad 22 Fixing jig 23 Lead frame polymer 24 Upper mold 25 Lower mold 26a Cavity upper 26b Cavity Lower 27 Pot 28 Plunger 29 Cull 30 Runner 31 Gate 32 Relief part 33 Thin burr

Claims (9)

A semiconductor element mounted on a rectangular die pad; a plurality of protrusions provided on a side surface of the die pad and bent toward the mounting surface side of the semiconductor element; and a support lead provided on a short side of the die pad and supporting the die pad A plurality of inner leads electrically connected to the semiconductor element by thin metal wires, outer leads integrally connected to the inner leads, the mounting surface, the semiconductor element, and the plurality of the plurality of inner leads, respectively. A projection resin, a thin metal wire, and a sealing resin body molded into a rectangular flat plate for resin-sealing the inner lead group, and each of the plurality of outer leads is drawn out from the long side of the sealing resin body The exposed surface of the die pad is exposed from the sealing resin body, and the plurality of protrusions provided on the side surface of the die pad have a T-shaped tip. Wherein a it is. The semiconductor device according to claim 1, wherein a plurality of protrusions provided on one side surface of the die pad are connected at the tip. 2. The semiconductor device according to claim 1, wherein a ring-shaped groove is provided along the periphery of the exposed surface of the die pad. 5. The semiconductor device according to claim 4, wherein the groove provided on the exposed surface of the die pad is formed in a double manner. 2. The semiconductor device according to claim 1, wherein the surface of the lead frame is plated with three layers of Ni, Pd, and Au. The semiconductor device according to claim 1, wherein the support lead is downset from the height of the inner lead. A first support lead that is not connected to the inner lead is provided on each short side of the die pad, and a second support lead that is connected to the long side of the die pad and the inner lead is provided on each long side of the die pad. Item 14. A semiconductor device according to Item 1. 8. The semiconductor device according to claim 7, wherein the first or second support lead is configured with a width of 0.3 mm to 0.6 mm. 8. The semiconductor device according to claim 7, wherein the width of the first or second support lead is set to be twice or more the inner lead width.

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