JP2000236060A - Semiconductor device - Google Patents

Abstract

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. SOLUTION: A lead frame is fabricated, such that a plurality of protrusions 9 are made on the side of a die pad 1 and that the protrusions 9 are bent to the side of the mounting surface where a 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 to increase the contact strength between the die pad 1 and the sealing resin 7, which reduces the deformation of the die pad 1, when the device is mounted and hence can keep good resistance to moisture, after the device has been mounted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device adapted to mount a semiconductor element having a large amount of heat, such as a motor driver or a sound amplifier.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become more multifunctional and smaller and thinner, semiconductor devices have been demanded to be thin and have good heat dissipation. Therefore, as such a thin semiconductor device, Japanese Patent Application Laid-Open No. 9-199639 proposes the following.

Hereinafter, a conventional semiconductor device will be described. FIG. 12 is a diagram showing a conventional semiconductor device, and FIG.
FIG. 2A is a sectional view of a main part of the semiconductor device, and FIG.
(B) is a rear view thereof.

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

[0005] This semiconductor device usually has a sealing resin body 7.
The exposed surface of the die pad 1 exposed from the substrate is mounted so as to be 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 radiation can be maintained.

[0006]

However, in the conventional semiconductor device, since the moisture resistance is secured only by the adhesive force between the die pad 1 and the sealing resin body 7, when the semiconductor device is soldered to a printed circuit board, the sealing is not performed. Moisture stored in the resin body 7 causes rapid thermal expansion and deforms the die pad 1. Therefore, a gap is easily formed between the die pad 1 and the sealing resin body 7, and the moisture resistance after mounting on the printed board is easily deteriorated. When the exposed surface of the die pad 1 is soldered to the printed circuit board in order to further enhance the heat radiation property compared to the state in which the die pad 1 is in contact with the printed circuit board, the heat expansion of the moisture occurs more rapidly, and the die pad 1 becomes a sealing resin body. 7 to deteriorate the moisture resistance. Therefore, it is necessary to ensure not only the moisture resistance of a single semiconductor device but also the moisture resistance after mounting on a printed circuit board.

When the back surface of the die pad 1 is pressed against a sealing mold (not shown) to seal the resin, the resin is pressed between the die pad 1 and the sealing mold by an injection pressure at the time of injecting the resin. It flows out in between, and thin burrs are generated on the back surface side of the die pad 1. If this thin burr is left, 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 in the above-mentioned moisture resistance, when removing thin burrs with a chemical or a water jet, the moisture or the chemical is not sealed.
There was a problem that it penetrated inside and hindered reliability.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a semiconductor device having a high heat radiation effect capable of securing moisture resistance after being mounted on a printed circuit board, and a method of manufacturing the same.

[0009]

According to the present invention, there is provided a semiconductor device comprising:
A semiconductor element mounted on a rectangular die pad; a plurality of protrusions provided on side surfaces of the die pad and bent toward a mounting surface of the semiconductor element; and support leads provided on short sides of the die pad to support the die pad A plurality of inner leads each electrically connected to the semiconductor element by a thin metal wire, each outer lead integrally connected to each inner lead, the mounting surface, the semiconductor element, the plurality of A sealing resin body formed into a rectangular flat plate for resin-sealing the projections, the thin metal wires, and the inner lead group, and pulling out the plurality of outer leads from long sides of the sealing resin body, respectively. And an exposed surface of the die pad is exposed from the sealing resin body.

With this configuration, heat is directly radiated to the outside from the exposed portion of the die pad on which the semiconductor element is mounted, so that the heat radiation effect is extremely good. Further, since a 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. Also, when the moisture accumulated in the sealing resin expands thermally during soldering, it has moderate air permeability and escapes vapor, so the deformation of the die pad is reduced, and the die pad separates from the sealing resin. Can be prevented.

Further, when the tips of the plurality of projections provided on the side surfaces of the die pad are formed in a T-shape, the engagement between the sealing resin body and the projections 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.

When a ring-shaped groove is provided along the periphery of the back surface of the die pad, the resin prevents the resin from flowing around between the sealing die and the exposed surface of the die pad during resin sealing. The size of the thin burrs formed on the exposed surface can be restricted. When the ring-shaped groove is provided twice, thin burrs can be more reliably prevented.

Further, when a 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 on the sealing mold during resin sealing is increased. In addition, the deformation of the die pad in the surface direction is reduced, and not only the occurrence of thin burrs is reduced, but also when mounting this semiconductor device, heat is radiated from both the inner leads connected to the die pad and the exposed surface of the die pad. This makes it possible to expect a considerable heat dissipation effect without soldering the exposed surface of the die pad, which is difficult to solder.

In addition, when the width of the first or second support lead is set to be twice or more 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 is reduced. it can.

[0015]

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,
The shape of the sealing resin body is indicated by a broken line. 2A and 2B are views for explaining the semiconductor device according to the first embodiment. FIG. 2A is a cross-sectional view showing a main part cross-sectional structure of the semiconductor device, and FIG. FIG. 2C
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. A thin metal wire 4 is connected to the semiconductor element 3 and is electrically connected to a plurality of inner leads 5 a around the die pad 1. Each of the outer leads 6 integrally connected to each of the inner leads 5a is led out of the sealing resin body 7, and the die pad 1, the adhesive 2, the semiconductor element 3, the thin metal wire 4, and the inner leads 5a are connected by the sealing resin body 7. It is sealed. The sealing resin body 7 is formed so as to have a substantially rectangular planar shape, 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.

Each of the short sides of the die pad 1 having a substantially rectangular planar shape is connected to a support lead 10 having a width which is at least twice the lead width of the inner lead 5a. After the support lead 10 has been punched out of a single metal plate and formed into a lead frame, 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 used alone. Although there are other features. The support lead 10 is located at a position separated from the die pad 1 at the same height as the inner lead 5a, and is bent at two positions 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,
It is also used to apply a force to the die pad 1 to press the die pad 1 against the bottom of the resin sealing mold (not shown) when molding the sealing resin body 7.

The lead width of the support lead 10 may be 0.3 mm to 0.3 mm when a semiconductor device for small signals is manufactured.
6 mm may be used, and when manufacturing a high power semiconductor device, a configuration in which the support lead 10 is connected to a radiator is also conceivable, but in this case, the width may be further increased as necessary. .

Each side surface of the die pad 1 has a plurality of protrusions 8 each having a T-shaped tip, and the protrusions 8 are bent toward the mounting surface of the semiconductor element 3. Since the projections 8 are buried in the sealing resin body 7, the engagement with the sealing resin body 7 is good, the adhesion between the die pad 1 and the sealing resin body 7 is improved, and the moisture resistance of the semiconductor device is improved. Can be secured. On the other hand, when the moisture accumulated in the sealing resin body 7 thermally expands at the time of soldering, there is a good air permeability between the plurality of projections 8 and the vapor inside can be easily released. Can,
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 allows the resin injection pressure at the time of resin sealing to be released, and at the same time, restricts the flow of the resin, so that thin burrs can be suppressed within a certain range. Therefore, the effective area of the exposed surface can be reliably ensured, the exposed surface can be soldered, and the higher heat radiation effect can be enhanced.

Next, the semiconductor device according to the second embodiment will be explained with reference to FIG. FIG. 3 is a diagram 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, in which a broken line indicates a shape of a resin sealing body, and FIG. 3B is a cross-sectional view of a main part of a 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 semiconductor element 3
Is connected to a plurality of inner leads 5 a around the die pad 1. Each of the outer leads 6 integrally connected to each of the inner leads 5a is led out of the sealing resin body 7, and the die pad 1, the adhesive 2, the semiconductor element 3, the thin metal wire 4, and the inner leads 5a are connected by the sealing resin body 7. It is sealed. The sealing resin body 7 is formed so as to have a substantially rectangular planar shape, 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 leads 10 connected to each short side of the die pad 1 having a substantially rectangular planar shape support the die pad 1 so as to maintain the integrated state even after the lid frame is integrally formed. However, the two portions close to the die pad 1 are bent so that the die pad 1
It is down set to a position lower than a. When the outer lead 6 and the support lead 10 having such a configuration are clamped to a resin sealing mold, the rigidity of the support lead 10 causes
The die pad 1 can be pressed against the bottom of a resin sealing mold (not shown).

Each side surface of the die pad 1 has a plurality of projections 9, and between the plurality of projections 9, a portion (connection portion) for connecting the tip of the projection 9 is provided. The protrusion 9 is bent toward the mounting surface of the semiconductor element 3. Since the plurality of projections 9 and their connection 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 secured. Moreover, the connection portion and the die pad 1
When the moisture accumulated in the sealing resin body 7 thermally expands during soldering, the slit-shaped hole is Good air permeability can be ensured, 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 allows the resin injection pressure at the time of resin sealing to be released, and at the same time, restricts the flow of the resin, so that thin burrs can be suppressed within a certain range. Therefore, the effective area of the exposed surface can be reliably ensured, the exposed surface can be soldered, and the higher heat radiation effect can be enhanced.

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

The third embodiment shown in FIG.
Since this embodiment is almost the same as the second embodiment, a description will be given focusing on differences from the second embodiment.

In addition to a support lead (first support lead provided on the short side) 10 for supporting the die pad 1, an inner lead 5a near the center of the long side of the die pad 1 is connected to the die pad 1. The inner lead 5a 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 or the mounting direction to be changed, and the distribution of force when the die pad 1 is pressed against the sealing mold is reduced. It becomes uniform and can be stably pressed. Further, the pressing force of the die pad 1 against the sealing die can be increased by pressing the support leads (10 and 5a) from all sides, and the synergistic effect of these forces makes it possible to form the sealing resin on the exposed surface of the die pad 1 easily. Thin burrs can be further reduced. As described above, when the exposed surface of the die pad 1 is soldered, the heat radiation effect is improved. However, the exposed surface is generally mounted in close contact with the wiring board. Although it is difficult to perform soldering because of the surrounding area, the soldered outer lead and the inner lead 5 connected thereto can be used without forcing the exposed surface directly.
a, the heat of the die pad 1 can be dissipated, and a considerable heat dissipating effect can be expected, though 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 width of the inner lead 5b connected to the die pad 1 is changed to other inner leads 5a.
2 to 5 times the lead width of the original support lead 10
May be made narrower, or both the inner lead 5b and the support lead 10 may be made wider.

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

FIG. 5 is a configuration diagram showing a lead frame used for manufacturing a semiconductor device. FIG. 5A is a plan view of the lead frame, FIG.
(C) is a longitudinal sectional view.

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

The wire bonding area (not shown) on the surface of the lead frame 15 is plated with Ag or the whole is plated with three layers of Ni, Pd and Au. In this case, by applying the Au flash to the outermost layer, the adhesion to the sealing resin is improved as compared with the case where the Ag plating is applied, and good moisture resistance can be obtained. Further, since the outer plating is applied before the resin sealing, even if a thin burr is generated on the exposed portion of the die pad at the time of the resin sealing, the problem of the obstacle of the outer plating does not occur, so that Ni, Pd, Au can be used. It is desirable to apply three-layer plating.

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

At this time, since the lead frame material is elongated by the cutting of the groove 16, the portion of the die pad 1 outside the groove 16 may be warped by several to several tens μm toward the semiconductor element 3 mounting surface. In this case, die pad 1
By providing a groove (not shown) having substantially the same shape as the groove 16 also on the mounting surface side of the semiconductor element 3, the elongation of the material can be canceled and the warpage can be prevented. The groove (not shown) provided on the mounting surface side of the die pad 1 does not need to be closed in a ring shape because it is not for damping thin burrs unlike the groove 16.

Further, thin burrs are likely to occur in a portion where the resin is injected. This is because the sealing resin is applied to the die pad 1 before the filling pressure for pressing the die pad against the sealing mold is applied.
This is because the wraparound occurs between the mold and the sealing mold. In this case, by forming a double groove at least in the portion of the die pad 1 that matches the direction in which the sealing resin is injected, thin burrs can be dammed.

Next, two portions of the support lead 10 near the die pad 1 are bent to down-set the die pad 1 to a position lower than the inner lead 5a, and to each other provided on four side surfaces of the die pad 1. A projection bending process is performed to bend the projection 9 to which the tip is connected to the mounting surface side of the semiconductor element 3.

When performing such a downset process, the first stage of bending is performed at a position exactly intermediate between the two bent portions, instead of using the bending mold only once. Then, the bending process is performed at the final predetermined bent portion while performing the forming to return the bent portion in the first stage to a linear shape. This is because a stress that stretches the metal is applied at the bending process, so that if the bending process is performed at once, the metal fatigue increases and a crack occurs at the bent portion of the support lead 10. The metal fatigue of the support lead 10 is reduced by bending and bending different positions in the second step and the second step.

As an example, the thickness of the resin sealing body is about 1 m
An example in which a surface mount package having a plane shape of about 6 mm × 17 mm with a 0.15 mm thick copper alloy plate will be described. In this case, the plane shape of the die pad 1 is about 3 mm × 6.
mm, the plurality of protrusions 9 are about 0.5 mm in length, 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 located below the inner lead 5a so as not to contact the thin metal wire. The support lead 10 is bent so that the die pad 1 is set lower than the position of the inner lead 5a (down set).
However, the downset amount (the step between the die pad 1 and the inner lead 5a) is set to about 0.47 mm.
As a result, if the position is not regulated by the sealing die, the position of the die pad 1 is 0.02 to 0.2 m from the bottom of the sealing die.
The downset amount is set so as to fall within the range of m.
If the depth of the groove 16 of the die pad 1 is about 0.01 mm, there is no problem that the lead frame is caught when the lead frame is moved in the process.

In the multiple lead frame 15 thus configured, the semiconductor element bonding step of fixing the semiconductor element 3 to the die pad 1 and the wire bonding step of electrically connecting the semiconductor element 3 and the inner lead 5a are performed by: This is performed for each unit lead frame. These bonding operations are sequentially performed for each lead frame per unit by being fed in a pitch in the horizontal direction.

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

First, as shown in FIG. 6, on a stage 17 of a semiconductor device bonding apparatus (not shown),
An adhesive 2 for fixing the semiconductor element 3 to the die pad 1 is applied. The application of the adhesive is performed by dropping the adhesive 2 using a dispenser 18. Adhesive 2
As an example, it 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 to which the adhesive 2 has been applied by using a collet 19, and then heated on a heat stage (not shown). 2 is cured. As an example, the semiconductor device 3
Has an outer dimension of 2 mm x 3 mm in planar shape and a thickness of 0.
It is a silicon single crystal of about 3 mm. The heating conditions are 200 to 250 ° C. for about 30 seconds to about 1 minute. In addition,
The adhesive 2 may be cured using an oven.

Next, as shown in FIG. 8, the bonding pads 21 of the semiconductor element 3 fixed on the die pad 1 are formed.
And the inner leads 5a are electrically connected using the thin metal wires 4. Heat stage 20 of wire bonding equipment
A relief portion for receiving the die pad 1, the support lead 10 and a part of the inner lead 5 b and the die pad 1 is formed, and the outer peripheral portion of the wire bond area of the inner lead 5 a is fixed by a fixing jig 22. As an example, as the thin metal wire, an Au wire having a diameter of 20 to 35 μm is used.

After die bonding and wire bonding are performed for each unit lead frame in this way, a plurality of sealing resin bodies 7 are simultaneously molded by resin sealing the unit lead frame group.

Next, the resin sealing step will be described with reference to FIG. 9 which is a process 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 which are clamped by a cylinder device (not shown). The upper mold cavity 26a and the lower mold cavity 26b are respectively buried in the mating surfaces so as to form the cavities 26. On the mating surface of the upper mold 24, a pot 27 is opened.
A plunger 28 which is advanced and retracted by a cylinder device (not shown) is inserted 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, respectively. Further, the other end of each runner 30 is connected to the lower mold cavity 26b, and a gate 31 is formed at the connection portion so that resin can be injected into the cavity 26. The mating surface of the lower mold 25 is a rectangle slightly larger than its outer shape and slightly shallower than its 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 mounted on the relief portion 32 of the sealing die of the transfer apparatus heated to about 180 ° C., and the sealing die is clamped. Next, a resin (not shown) compressed into a cone is inserted into the pot 27,
Resin is cull 29 and runner 3 by plunger 28
0, press-fit into each cavity 26 through gate 31. After the injection, the resin is thermally cured to form the sealing resin body 7, and the upper mold 24 and the lower mold 25 are opened, and the group of sealing resin bodies 7 is separated by ejector pins (not shown). The lead frame polymer 23 molded and resin-molded is removed from the transfer molding apparatus.

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 projection 9, and the support The leads 10 are sealed with resin. At this time, if there is no position regulation by the lower mold 25, the depth of the bottom of the lower mold 25 is 0.02 to 0.2 mm.
When the lead frame having the die pad 1 set down so as to be fixed at a low position is clamped by a sealing mold, the exposed surface opposite to the mounting surface of the semiconductor element 3 is the lower die 25.
In order to prevent the resin from squeezing to the lower side (exposed surface side) of the die pad 1, resin sealing can be performed so that the exposed surface of the die pad 1 is exposed from the sealing resin body 7.

The cavity portion of the normally used sealing mold is subjected to a pear finishing process to make it easy to recognize the substrate mounting, and the surface thereof is roughened. By performing the mirror finishing (not shown), the gap between the die pad 1 and the sealing mold can be eliminated, so that the generation of thin burrs can be further suppressed. Furthermore, by providing a mechanism (not shown) for adsorbing the die pad 1 at a portion of the lower mold 25 where the die pad 1 contacts, it is possible to further suppress the generation of thin burrs.

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

As shown in FIG. 10, the exposed surface of the die pad 1 leaks and adheres to the thin burr 33 of the resin from the outer periphery of the die pad 1 due to the resin injection pressure. The thin burr stops at the formed groove 16, an effective exposed surface inside the groove 16 can be secured to a certain area or more, and the exposed surface of the die pad 1 is mounted by soldering on a printed circuit board (not shown). It becomes possible. In addition, as shown in FIG. 10, the ring-shaped groove 16 can be more reliably provided by providing the ring-shaped groove 16 twice than by providing the ring-shaped groove 16 in a single manner.

Next, the resin-molded lead frame polymer 23
In the case of g-plated, a portion of the lead frame polymer 23 other than the sealing resin body 7 is plated with a solder exterior (not shown). In the case where at least a part of the lead frame 15 which is a completed product of the semiconductor device is plated with Pd, the solder outer plating is not required.

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

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

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

[0057]

As described above, the semiconductor device of the present invention has a plurality of projections on each side surface of the die pad, and the projections are formed on the mounting surface side of the semiconductor element by using a lead frame formed by bending. Because of the packaging, the protrusions can improve the adhesion to the sealing resin body and improve the moisture resistance. Further, when moisture stored in the package expands thermally during solder dip, the moisture easily escapes, deformation and curling of the die pad can be prevented, and moisture resistance can be maintained even after mounting on a printed circuit board. . Moreover, heat can be radiated directly from the exposed surface of the die pad to the printed circuit board, and the semiconductor device has good heat radiation and excellent quality.

Further, if a groove is provided along the periphery of the die pad, the sealing pressure at the time of performing resin sealing is released along the groove, and if the resin goes around, the resin is stopped by the groove. And resin burrs can be minimized.

[Brief description of the drawings]

FIG. 1 is a plan view of a lead frame used for a semiconductor device according to a first embodiment of the present invention.

FIGS. 2A and 2B are views showing a semiconductor device according to a first embodiment of the present invention; FIG. 2A is a cross-sectional view of a main part of the semiconductor device; FIG. Rear view of the device

FIGS. 3A and 3B are views showing a semiconductor device according to a second embodiment; FIG. 3A is a plan view of a lead frame used in the semiconductor device; FIG.

FIGS. 4A and 4B are diagrams showing a semiconductor device according to a third embodiment; FIG. 4A is a plan view of a lead frame used in the semiconductor device; FIG.

5A and 5B show a lead frame used in a fourth embodiment. FIG. 5A is a plan view of the lead frame. FIG. 5B is a sectional view of a main part of the lead frame.

FIG. 6 is a process cross-sectional view for explaining a pre-process of a die bonding process of the fourth embodiment.

FIG. 7 is a process cross-sectional view for explaining a die bonding process according to a fourth embodiment.

FIG. 8 is a process cross-sectional view illustrating a wire bonding process according to a fourth embodiment.

FIG. 9 is a process cross-sectional view for explaining a resin sealing process of the fourth embodiment.

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

FIG. 11 shows a semiconductor device after dam bar cutting.

12A and 12B are views showing a conventional semiconductor device, wherein FIG. 12A is a sectional view of a main part of the semiconductor device, and FIG. 12B is a rear view of the semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Die pad 2 Adhesive 3 Semiconductor element 4 Thin metal wire 5a Inner lead 5b Inner lead (second support lead) 6 Outer lead 7 Sealing resin body 8 Projection 9 Projection 10 Support lead (first support lead) 11 Dam bar Reference Signs List 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 above cavity 26b below cavity 27 Pot 28 plunger 29 cull 30 runner 31 gate 32 relief part 33 thin burr

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toshiyuki Fukuda 1-1, Komachi, Takatsuki-shi, Osaka Matsushita Electronics Co., Ltd. F-term (reference) 4M109 AA01 BA02 CA21 DA02 DA04 DB02 DB17 FA03 FA04 GA05 5F061 AA01 BA02 CA21 EA03 FA05 5F067 AA04 AA05 AA09 AB03 BD02 BD05 BE02 BE05 BE07 CA07 DA11 DA14 DA16 DC13 DC17 DC19 DF17 EA01 EA04

Claims (10)

[Claims] A semiconductor device 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 of the semiconductor device; and a die pad provided on a short side of the die pad. And a plurality of inner leads each electrically connected to the semiconductor element by a thin metal wire, and each outer lead integrally connected to each inner lead,
The plurality of outer leads, comprising: a mounting plate, the semiconductor element, the plurality of protrusions, the thin metal wires, and a sealing resin body molded into a rectangular flat plate for resin-sealing the inner lead group. Wherein the exposed surface of the die pad is exposed from the sealing resin body. 2. The semiconductor device according to claim 1, wherein a plurality of protrusions provided on a side surface of the die pad have a T-shaped tip. 3. The semiconductor device according to claim 1, wherein a plurality of protrusions provided on one side surface of the die pad are connected at a tip. 4. The semiconductor device according to claim 1, wherein a ring-shaped groove is provided along a peripheral edge of the exposed surface of the die pad. 5. A groove provided on an exposed surface of a die pad has two grooves.
5. The semiconductor device according to claim 4, wherein the semiconductor device is formed to be doubly formed. 6. Ni, Pd, A on the surface of the lead frame.
2. The semiconductor device according to claim 1, wherein three layers of u are plated. 7. The semiconductor device according to claim 1, wherein the support lead is set down from the height of the inner lead. 8. A first support lead not connected to the inner lead is provided on each of the short sides of the die pad, and a second support lead connecting the long side of the die pad and the inner lead is provided on each of the long sides of the die pad. The semiconductor device according to claim 1, wherein: 9. The first or second support lead is 0.3 m
9. The semiconductor device according to claim 8, wherein the semiconductor device has a width of m to 0.6 mm. 10. The semiconductor device according to claim 8, wherein the width of the first or second support lead is at least twice the width of the inner lead.