JPH09232494A - Lead frame, semiconductor device and manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the back leakage of silver plating and to make depressing unnecessary by filling and sealing the gaps among a plurality of inner leads and the gaps between the inner leads and a semiconductor mounted part with resin beforehand. SOLUTION: Concerning a lead frame 1, gaps formed between a plurality of inner leads 3 and a plurality of die pads for mounting semiconductor devices on a metallic plate on a long substance are filled and sealed with resin 4 made out of an electric insulator. As the result of this, a silver plating solution does not creep into the rear sides of the lead frames 2, and back leakage of silver plating can be prevented, since the gaps between those inner leads 3 and the die pads 2 have been filled and sealed with resin 4, when each lead frame 2 and each inner lead 3 are silver-plated. Accordingly, it becomes possible to prevent the malisolation of the lead frames 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame for mounting a semiconductor element and making an electrical connection when manufacturing a semiconductor device, a semiconductor device and a method for manufacturing the semiconductor device.

[0002]

2. Description of the Related Art Generally, a semiconductor device is mounted on a die pad on which a semiconductor element is mounted and a lead frame on which leads used for signal input / output are formed, and then the input / output terminals of the semiconductor element and the leads are mounted. It is manufactured by connecting with a metal wire and then molding the periphery with resin or the like. In the lead frame, the die pad, the lead and the like are formed by pressing or etching a long metal plate. In addition, usually, a plurality of die pads are formed on one lead frame, so that a plurality of semiconductor devices can be manufactured at once.

Here, FIG. 7 is a schematic view showing a conventional lead frame, FIG. 7A is a plan view seen from the side on which a semiconductor element is mounted, and FIG. 7B is a back side plan view. is there.
Further, FIG. 8 is a cross-sectional view showing a state in which a lead frame on which a semiconductor element is mounted is set in a mold for molding with a resin using a conventional lead frame.
In the figure, only one element of the lead frame is shown for easy understanding.

In FIG. 7A, the lead frame 1
Is a die pad 2 for mounting the chip-shaped semiconductor element 10, suspension leads 21, 21 for holding the die pad 2, and the semiconductor element 1 via a metal wire (not shown).
, 3 provided in a comb shape for making electrical connection with 0, and outer leads (not shown) for making electrical connection with an external substrate. Usually, in the die pad 2 and the inner leads 3, silver plating is applied to portions to which metal wires (not shown) are connected.

Next, a method of manufacturing a semiconductor device using the above lead frame 1 will be described. First, after mounting the semiconductor element 10 on the die pad 2 plated with silver, the semiconductor element 10 and the inner leads 3, 3 ,.
3 and 3 are connected by a metal wire (not shown). Next, the lead frame 1 in which the semiconductor element 10 is mounted on the die pad 2 is set between the metal molds including the upper mold 11 and the lower mold 12, as shown in FIG. 7B. Recesses 11a and 12a are provided on the surfaces of the upper die 11 and the lower die 12 that face each other, and in the set state, a predetermined capacity is provided around the lead frame 1 on which the semiconductor element 10 is mounted. The cavity 13 is formed. Therefore, the die pad 2 on which the semiconductor element 10 is mounted is the cavity 1 of the mold.
It will be arranged at a substantially central portion within 3.

Next, a resin (not shown) is fed from the gate 14 into the cavity 13 formed between the upper die 11 and the lower die 12 to seal the semiconductor element 10 on the die pad 2 with the resin. Then, after curing the resin (not shown), the outer leads (not shown) and the suspension leads 21 are separated to form the outer leads, thereby manufacturing the semiconductor device.

[0007]

By the way, in the conventional lead frame described above, the die pad 2 and the inner leads 3, 3 ,. As shown, after setting the illustrated plating mask 6 on the lead frame 1, by spraying a silver plating solution on the lead frame 1, the portions not covered with the plating mask 6, that is, the die pad 2 and the inner leads 3 are silver-plated. Has been given.
At this time, the die pad 2 and the inner leads 3, 3, ...
.., 3 are punched out, so that the silver plating solution wraps around to the back surface of the die pad 2 as shown in FIG. For this reason, the back leakage 20 of the silver plating may cause the separation failure of the lead frame 1, or the semiconductor device after resin encapsulation may have poor adhesion to the resin, resulting in deterioration of moisture resistance of the semiconductor device. There was a problem.

Further, in the above-described conventional method for manufacturing a semiconductor device, when the semiconductor element 10 is sealed with resin, the resin injection pressure is higher in the cavity 13 above the semiconductor element 10 and below the die pad 2. Both spaces must be set equal so that they are equal. Therefore,
Conventionally, depending on the thickness of the semiconductor element 10, the suspension leads 2
1 is bent, and the die pad 2 is lowered. However, it is difficult to perform the depressing process with high accuracy, and even if the lead frame 1 is subjected to the above depressing process, it may be different from the upper side of the semiconductor element 10 in the cavity 13 due to variations in the process and differences in resin flow conditions. The resin injection pressure is not always equal to that of the lower side of the die pad 2.

Therefore, for example, when the injection pressure of the resin 5 on the upper side of the semiconductor element 10 in the cavity 13 becomes higher than that on the lower side of the die pad 2, FIG.
As shown in (a), a stay shift (inclination) occurs in the semiconductor element 10 and the die pad 2. The stay shift also occurs when the injection pressure of the resin 5 on the lower side of the die pad 2 is higher than that on the upper side of the semiconductor element 10. Also, when the precision of the depressing process is not sufficient, the stay shift similarly occurs.

As described above, when the stay shift occurs in the semiconductor element 10 and the die pad 2 due to the imbalance of the injection pressure of the resin 5, the inner leads 3, 3, ..., 3 are deformed, and FIG. As shown in FIG.
Since a load is applied to the metal wire 31 for connecting the inner wires 3, 3, ..., 3 with each other, the metal wire 31 is broken. Further, when the die pad 2 and the metal wire 31 come into contact with the inner surface of the cavity 13 due to the stay shift, the die pad 2 and the metal wire 31 are exposed from the package surface of the semiconductor device after resin sealing, resulting in poor appearance and sealing. The problem of causing a stop problem occurs.

That is, the conventional lead frame, semiconductor device and semiconductor device manufacturing method have the following problems. (A) Due to the back leakage of the silver plating on the back surface of the lead frame, there are problems that the lead frame 1 becomes poorly separated, and the moisture resistance of the semiconductor device after resin sealing is lowered. (B) The inner leads 3, 3, ..., 3 are deformed due to the stay shift of the semiconductor element 10 and the die pad 2. (D) The stay shift causes a load on the metal wire 31, and the metal wire 31 connecting the semiconductor element 10 and the leads 3, 3, ..., 3 is broken. (E) Due to the stay shift, there is a problem that the die pad 2 and the metal wire 31 are exposed from the package surface, resulting in poor appearance and poor sealing.

Therefore, the present invention can prevent back leakage of silver plating, eliminate the need for depressing, and
An object of the present invention is to provide a lead frame, a semiconductor device, and a method of manufacturing a semiconductor device, which can prevent stay shift.

[0013]

In order to achieve the above object, a lead frame according to a first aspect of the present invention comprises a semiconductor mounting portion on which a semiconductor element is mounted and a plurality of inner leads from which signal input / output of the semiconductor element is drawn out. In the lead frame formed with, the gap between the plurality of inner leads and the gap between the plurality of inner leads and the semiconductor mounting portion are filled with resin in advance.

In a preferred embodiment, the semiconductor mounting portion may be made of the resin as described in claim 2, for example. Further, as described in claim 3, a through hole may be provided in a part of the resin. Moreover, as described in claim 4,
You may provide a convex part in a part of said resin.

To achieve the above object, in a semiconductor device according to a fifth aspect of the present invention, a semiconductor mounting portion on which a semiconductor element is mounted, a plurality of inner leads from which signal input / output of the semiconductor element is drawn, and the plurality of inner leads are provided. Of the inner leads, and a gap between the inner leads and the semiconductor mounting portion, and a plurality of semiconductor elements mounted on the front and back surfaces of the semiconductor mounting portion. .

In a preferred embodiment, for example, the semiconductor mounting portion may be the resin, and a plurality of semiconductor elements may be mounted on the front and back surfaces of the resin. Further, for example, as described in claim 7, a through hole may be provided in a part of the resin. Further, for example, claim 8
As described above, a convex portion may be provided on a part of the resin.

In order to achieve the above object, a method of manufacturing a semiconductor device according to a ninth aspect of the present invention is a semiconductor mounting portion on which a semiconductor element is mounted by pressing or etching a long metal plate, After forming a plurality of inner leads from which the signal input / output of the semiconductor element is drawn out, and then encapsulating resin in the gap between the plurality of inner leads and the gap between the plurality of inner leads and the semiconductor mounting portion, An inner plating is applied to the semiconductor mounting portion and the inner lead.

In order to achieve the above object, a semiconductor device manufacturing method according to a tenth aspect of the present invention is characterized in that a long metal plate is pressed or etched.
Forming a plurality of inner leads through which signal input / output of the semiconductor element is led out, encapsulating a resin in a gap between the plurality of inner leads, and then performing inner plating on the semiconductor mounting portion and the inner leads. Characterize.

Further, as a preferable mode, for example, as described in claim 11, after the resin is filled in the gaps of the plurality of inner leads, a through hole may be provided in a part of the resin. Further, for example, as described in claim 12, after the resin is filled in the gap between the plurality of inner leads, a convex portion may be provided on a part of the resin.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

A. First Embodiment FIG. 1 is a plan view of a lead frame according to a first embodiment of the present invention viewed from the side on which a semiconductor element is mounted. It should be noted that, in order to make the description easy to understand, only one element unit of the lead frame is shown in the drawing, and the corresponding parts shown in FIG. In the figure, the lead frame 1 according to the first embodiment is a resin made of an electrically insulating material which is sealed in a gap formed between the die pad 2 and the inner leads 3, 3 ,. It is equipped with 4. The resin 4 is formed between the inner leads 3, 3, ..., 3 and the die pad 2 after forming the die pad, the lead and the like by pressing or etching.

According to the lead frame of the first embodiment described above, as shown in the drawing, the inner leads 3,
Since 3, ..., 3 are supported by the resin 4, the inner leads 3, 3 ,. Also, in the silver plating process, the gap between the inner leads 3 and the inner leads 3, the inner leads 3, 3 ,.
After the resin 4 is sealed in the space between the die pad 2 and the die pad 2, the plating mask 6 shown in the figure is set on the lead frame 1 as shown in FIG. Not the part, ie, die pad 2
And inner leads 3, 3, ..., 3 are plated with silver. At this time, since the resin 4 is sealed in the gap between the inner leads 3, 3, ..., 3 and the die pad 2, the silver plating liquid does not wrap around to the back side of the lead frame 2, so that back leakage of the silver plating is prevented. it can. Therefore, the separation failure of the lead frame 1 can be prevented, and the moisture resistance of the semiconductor device can be prevented from lowering.

Next, FIG. 2 shows the lead frame 1 described above.
FIG. 6 is a schematic diagram for explaining a method of manufacturing a semiconductor device using. In the figure, a lead frame 1 in which a semiconductor element 10 is mounted on a die pad 2 is attached to an upper die 11 and a lower die 12 of a die.
Then, the resin 5 is injected from the gate 14 of the mold to fill the cavity 13. At this time, even if the injection pressure of the resin 5 is applied to the semiconductor element 10 and the die pad 2,
Since the die pad 2 is supported by the resin 4 sealed in the gap between the inner lead 3 and the die pad 2,
No stay shift occurs in the semiconductor element 10 and the die pad 2. Further, since the stay shift does not occur, the display processing step can be omitted and the manufacturing process can be simplified.

B. Second Embodiment Next, FIG. 3 is a plan view of a lead frame according to a second embodiment of the present invention viewed from the side on which a semiconductor element is mounted. In the second embodiment, the die pad for mounting the semiconductor element 10 is omitted, and the gap between the inner leads 3, 3 ,.
Are evenly enclosed. The semiconductor element 10 is mounted on the resin 4 at a substantially central portion. In the second embodiment, by omitting the die pad, it is possible to simplify the mold and etching process when manufacturing the lead frame.

C. Third Embodiment Next, FIG. 4 is a plan view of a lead frame according to a third embodiment of the present invention viewed from the side on which a semiconductor element is mounted. In the third embodiment, similar to the second embodiment described above, the die pad for mounting the semiconductor element 10 is omitted, and the inner leads 3, 3, ..., Including the semiconductor element mounting portion are included. The gap 3 is uniformly filled with resin 4,
Through holes 41, 41, ..., 41 are provided in the resin 4. When a semiconductor device is manufactured using the lead frame according to the third embodiment, the upper and lower cavities are sealed through the one or more through holes 41, so that the resin 5 filled in the upper and lower cavities is closely attached. As a result,
The reliability of the semiconductor device can be improved.

D. Fourth Embodiment Next, FIG. 5A is a plan view seen from the side on which a semiconductor element is mounted in a lead frame according to a fourth embodiment of the present invention, and FIG. It is a side view showing a state where a semiconductor element and an inner lead are connected using a frame. In the fourth embodiment, similarly to the first embodiment described above, the inner leads 3, 3 ,.
After uniformly sealing the resin 4 in the gap between the die pad 2 and
As shown in FIGS. 5A and 5B, convex portions 42, 42 having a height larger than the thickness of the semiconductor element 10 are provided around the die pad 2 of the resin 4. When a semiconductor device is manufactured using the lead frame according to the fourth embodiment, contact between the metal wire 31 and the edge portion of the semiconductor element 10 can be prevented as shown in FIG. 5B. When the resin 5 is set in the mold and injected, the metal wire 31 is not burdened and it is possible to prevent the metal wire 31 from breaking.

E. Fifth Embodiment Next, FIGS. 6A to 6D are views for explaining a fifth embodiment of the present invention, and the first, second to third embodiments described above are provided. FIG. 6 is a side view showing a method for manufacturing a semiconductor device using the lead frame according to the embodiment. First, in the lead frame 1 according to the above-described first, second, and third embodiments, as shown in FIG.
After mounting 0 on the die pad 2 or the resin 4 which is sealed in advance, the semiconductor element 10 and the inner leads 3, 3, ..., 3 are connected by the metal wire 31. Next, the lead frame 1 having the semiconductor element 10 mounted thereon is set in a mold,
As shown in FIG. 6B, the resin 5 is injected and sealed only in the upper mold cavity. Next, as shown in FIG. 6C, another semiconductor element 11 is mounted on the back surface of the die pad 2 or the resin 4 which has been previously sealed. Then, the semiconductor element 11 and the inner leads 3, 3, ...
After connecting by 1, set it in the mold again, and
As shown in (d), the resin 5 is injected and sealed only in the lower mold cavity.

According to the fifth embodiment, in the lead frame 1 shown in FIGS. 1, 3 and 4, particularly in the lead frame having no through hole 41, the upper mold cavity and the lower mold cavity are formed. By separately encapsulating each of them with a resin, a plurality of semiconductor elements 10 and 11 can be easily mounted in one package, and high integration can be easily realized.

[0029]

According to the lead frame of the first aspect of the present invention, the gap between the plurality of inner leads and the gap between the plurality of inner leads and the semiconductor mounting portion are filled with resin in advance. In the process,
Since the resin is sealed in the gap between the inner lead and the semiconductor mounting part, the silver plating liquid does not get around to the back side of the inner lead, so back leakage of the silver plating can be prevented, and thus the lead frame separation failure can be prevented. At the same time, there is an advantage that the moisture resistance of the semiconductor device can be prevented from lowering. Further, in manufacturing the semiconductor device, since the semiconductor mounting portion is supported by the resin, the stay shift does not occur, the display processing step can be omitted, and the manufacturing step can be simplified. The advantage is obtained.

According to the lead frame of the invention of claim 2, since the semiconductor mounting portion is made of the resin,
This has the advantage that the mold and etching process for manufacturing the lead frame can be simplified. Also,
According to the lead frame of the invention described in claim 3, since the through hole is provided in a part of the resin, the adhesiveness between the resins filled in the upper and lower cavities is improved, and as a result, the semiconductor device The advantage is that reliability can be improved. Further, according to the lead frame of the invention of claim 4, since the convex portion is provided on a part of the resin, the metal wire connecting the semiconductor element and the inner lead is not burdened, and the metal wire is The advantage of being able to prevent disconnection is obtained.

According to a fifth aspect of the semiconductor device of the present invention, a semiconductor mounting portion on which a semiconductor element is mounted, a plurality of inner leads from which signal input / output of the semiconductor element is drawn, and a plurality of inner leads are provided. Since a plurality of semiconductor elements are mounted on the front and back surfaces of the semiconductor mounting portion, a gap and a plurality of inner leads and a resin pre-filled in the gap between the semiconductor mounting portion are provided, so that high integration is easy. The advantage that can be realized is obtained.

Further, according to the semiconductor device of the invention described in claim 6, since the semiconductor mounting portion is made of the resin and a plurality of semiconductor elements are mounted on the front and back surfaces of the resin, high integration can be easily realized. The advantage is obtained. Claim 7
According to the semiconductor device of the invention described above, since the through hole is provided in a part of the resin, the adhesion between the resins filled in the upper and lower cavities is improved, and as a result, the reliability of the semiconductor device is improved. The advantage is that it can be improved. According to the semiconductor device of the invention described in claim 8,
Since the convex portion is provided on a part of the resin, there is an advantage that the metal wire connecting the semiconductor element and the inner lead is not burdened and the metal wire can be prevented from being broken.

According to the method of manufacturing a semiconductor device of the present invention, a semiconductor mounting portion on which a semiconductor element is mounted is formed by pressing or etching a long metal plate, and a signal of the semiconductor element. After forming a plurality of inner leads from which inputs and outputs are drawn out, and then encapsulating resin in the gap between the plurality of inner leads and the gap between the plurality of inner leads and the semiconductor mounting portion, the semiconductor mounting portion and Since the inner lead is subjected to inner plating, since the resin is sealed in the gap between the inner lead and the semiconductor mounting portion in the silver plating process, the silver plating liquid does not wrap around to the back side of the silver. It is possible to prevent back leakage of the plating, which can prevent the lead frame from being separated incorrectly and can also be used in semiconductor devices with moisture resistance. Advantage that it is possible to prevent a reduction can be obtained.

According to the method of manufacturing a semiconductor device of the tenth aspect of the present invention, a plurality of inner leads from which signal input / output of the semiconductor element is drawn out by pressing or etching a long metal plate. Formed,
Next, after the resin is sealed in the gaps between the plurality of inner leads, the semiconductor mounting portion and the inner leads are subjected to inner plating. Therefore, in the silver plating step, the gap between the inner leads and the semiconductor mounting portion is Since the resin is sealed, the silver plating liquid does not get around to the back side of, so it is possible to prevent back leakage of the silver plating.
It is possible to prevent the separation failure of the lead frame and prevent the deterioration of the moisture resistance of the semiconductor device.

According to the semiconductor device manufacturing method of the present invention, since the resin is filled in the gaps of the plurality of inner leads, the through holes are provided in a part of the resin. The adhesiveness between the resins filled in the upper and lower cavities is improved, and as a result, the reliability of the semiconductor device can be improved. According to the method of manufacturing a semiconductor device of the invention described in claim 12,
After encapsulating the resin in the gap between the plurality of inner leads,
Since the convex portion is provided on a part of the resin, there is an advantage that the metal wire connecting the semiconductor element and the inner lead is not burdened and the metal wire can be prevented from being broken.

[Brief description of drawings]

FIG. 1 is a plan view of a lead frame according to a first embodiment of the present invention viewed from a side on which a semiconductor element is mounted.

FIG. 2 is a schematic diagram for explaining the method for manufacturing a semiconductor device using the lead frame according to the first embodiment.

FIG. 3 is a plan view of the lead frame according to the second embodiment of the present invention as viewed from the side on which a semiconductor element is mounted.

FIG. 4 is a plan view of a lead frame according to a third embodiment of the present invention viewed from a side on which a semiconductor element is mounted.

FIG. 5 is a schematic diagram for explaining a fourth embodiment of the present invention.

FIG. 6 is a schematic diagram for explaining a fifth embodiment of the present invention.

FIG. 7 is a schematic view showing a conventional lead frame.

FIG. 8 is a cross-sectional view showing a state in which a lead frame on which a semiconductor element is mounted is set in a mold for molding with a resin when a semiconductor device is manufactured using a conventional lead frame.

FIG. 9 is a schematic diagram for explaining a stay shift that occurs when a semiconductor device is manufactured using a conventional lead frame.

[Explanation of symbols]

1 ... Lead frame, 2 ... Die pad (semiconductor mounting part), 3, 3, ..., 3 ... Inner lead, 5 ... Resin, 10, 11 ... Semiconductor element, 41, 41 ,.
1 ... through hole, 42, 42 ... convex portion

Claims (12)

[Claims] 1. A lead frame in which a semiconductor mounting portion on which a semiconductor element is mounted and a plurality of inner leads from which signal input / output of the semiconductor element is formed are formed, and a gap between the plurality of inner leads and the plurality of inner leads. A lead frame, characterized in that a gap between the semiconductor mounting portion and the semiconductor mounting portion is previously filled with resin. 2. The lead frame according to claim 1, wherein the semiconductor mounting portion is made of the resin. 3. The lead frame according to claim 1, wherein a through hole is provided in a part of the resin. 4. The lead frame according to claim 1, wherein a convex portion is provided on a part of the resin. 5. A semiconductor mounting portion on which a semiconductor element is mounted, a plurality of inner leads from which signal input / output of the semiconductor element is drawn out, a gap between the plurality of inner leads, and the plurality of inner leads and the semiconductor mounting. A semiconductor device comprising: a resin pre-encapsulated in a gap between the semiconductor mounting portion and a plurality of semiconductor elements mounted on the front and back surfaces of the semiconductor mounting portion. 6. The semiconductor device according to claim 5, wherein the semiconductor mounting portion is made of the resin, and a plurality of semiconductor elements are mounted on the front and back surfaces of the resin. 7. The semiconductor device according to claim 5, wherein a through hole is provided in a part of the resin. 8. The semiconductor device according to claim 5, wherein a convex portion is provided on a part of the resin. 9. A long metal plate is formed by pressing or etching to form a semiconductor mounting portion on which a semiconductor element is mounted and a plurality of inner leads from which signal input / output of the semiconductor element is extracted. Next, a resin is filled in a gap between the plurality of inner leads and a gap between the plurality of inner leads and the semiconductor mounting portion, and then inner plating is applied to the semiconductor mounting portion and the inner lead. Device manufacturing method. 10. A long metal plate is formed by pressing or etching to form a plurality of inner leads from which signal input / output of the semiconductor element is drawn out, and then a resin is formed in the gap between the plurality of inner leads. After encapsulating, the semiconductor mounting part and the inner lead are subjected to inner plating, and a method of manufacturing a semiconductor device. 11. The method of manufacturing a semiconductor device according to claim 9, wherein a resin is filled in a gap between the plurality of inner leads, and then a through hole is provided in a part of the resin. 12. The method for manufacturing a semiconductor device according to claim 9, wherein after the resin is filled in the gaps between the plurality of inner leads, a convex portion is provided on a part of the resin.