JPH02139954A - Lead frame and resin-sealed semiconductor device using same - Google Patents

Abstract

PURPOSE:To perform bonding easily with accuracy by the use of a wire between a semiconductor element and each inner end part of a lead by causing a stepped part to be formed outside the region for sealing of a suspended lead with resin so that an element loading part is located at a position lower than the inner end part. CONSTITUTION:A plurality ot leads 42 are disposed near an element loading part 41 of a lead frame 40 and each lead has inner and outer end parts 42a and 42b and respective leads 42 are coupled and supported by a tiebar 43-1 which is fixed to a frame part 44. As the element loading part 41 is spaced at a prescribed interval (h) 2 from the inner end part 42a and is located at a position lower than the above inner end part, a stepped part 45a is formed at a suspended lead 45 that is outside the region of resin-sealing and accordingly, the stepped part 43-2a is formed even at a tiebar 43-2. Since the stepped part 45a of the suspended lead 45 is formed outside the region of resin-sealing, such a large stepped part 45a is formed in this way and its formation of the stepped part makes it possible to prevent an edge short circuit which takes place between a wire 53 and a semiconductor element 50 and further, it makes the wire 53 longer. Connection work is thus performed easily with accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a lead frame and a resin-sealed semiconductor device in which a semiconductor element mounted on the lead frame is sealed with a resin.

(Prior art) Conventionally, as a technology in this field, for example, as shown in Fig. 2 (
There were things like a), (b), and (c). The configuration will be explained below using figures.

FIGS. 2(a), 2(b), and 2(c) are diagrams showing an example of the configuration of a conventional resin-sealed semiconductor device, in which FIG. 2(a) is a plan view and FIG. 2(b) is an A - A sectional view, and the same figure (c) is the BB sectional view.

This semiconductor device is used by being fixed to the surface of a printed circuit board or the like with solder or the like, and consists of a lead frame 10, a semiconductor element 20 mounted on the lead frame 10, and a resin member 30 in which they are sealed with resin. It is configured. The lead frame 10 includes an element mounting section 11 and a stepped section 12.
It consists of a suspension lead 12 for supporting the element mounting part 11 having a diameter of
a is arranged at a position close to the element mounting portion 11, and the outer end portion 13b is bent into a substantially J shape. In the semiconductor device using such a lead frame 10, the semiconductor element 20 is fixed on the element mounting part 11 via the mounting material 21, and the semiconductor element 20 is fixed on the element mounting part 11 via the mounting material 21.
The electrode pad portion 22 formed on the surface of the lead 13 and the inner end portion 13a of the lead 13 are connected by a wire 23. The element mounting portion 11, the hanging lead 12, the vicinity of the inner end 13a of the lead 13, the semiconductor element 20, etc. are sealed with resin using a resin member 30. Here, the suspension lead 12 embedded in the resin member 30 is formed with a stepped portion 12a, and the element mounting portion 11 connected to this is formed at an inner end 13a.
It is set at a lower position by a predetermined interval h than

The resin-sealed semiconductor device configured as described above is manufactured, for example, as follows.

First, a lead frame 10 in which an element mounting part 11, a hanging lead 12, a plurality of leads 13, etc. are supported and fixed to a frame part is prepared, and a semiconductor element 20 is fixed onto the element mounting part 11 using a mounting material 21. At the same time, the pad electrode portion 22 of the semiconductor element 20 and the inner end portion 13a of the lead 13 are connected with a wire 23. After resin-sealing the semiconductor element 20 and the like with the resin member 30 using a molding die, unnecessary parts of the lead frame 10 are cut and removed from the lead frame 10, and the outer end portion 13b is bent. If the shape is approximately J-shaped, Figure 2 (a>, (b), (c)
A resin-sealed semiconductor device having the structure is obtained.

Such a resin-sealed semiconductor device has the following advantages. When increasing the diameter of a silicon wafer in order to improve manufacturing efficiency, the thickness of the silicon wafer is set large in order to increase the mechanical strength against warping and defects, so the thickness of the silicon wafer is increased. The thickness of semiconductor devices also increases. Therefore, a short circuit failure (hereinafter referred to as an edge short) due to the wire 23 coming into contact with the peripheral edge of the semiconductor element 20 is likely to occur. In the semiconductor device having the above configuration, the step portion 12a is formed on the suspension lead 12 and the element mounting portion 11 is set at a position lower than the inner end portion 13a by a predetermined interval h1, thereby reducing and avoiding the occurrence of edge shorts. It is possible to do so.

(Problems to be Solved by the Invention) However, the lead frame having the above structure and the resin-sealed semiconductor device using the lead frame have a problem as shown in FIG. 3. Incidentally, FIG. 3 is a diagram showing problems with the conventional resin-sealed semiconductor device.

In the semiconductor device having the above configuration, the element mounting portion 11 of the lead frame 10 is set at a lower position than the inner end portion 13a to prevent the occurrence of edge short, but the prevention is not possible in the following cases. It becomes very difficult.

For example, when increasing the integration of integrated circuits within the semiconductor element 20, the semiconductor element 20 also becomes larger accordingly, so the overall length of the suspension leads 12 within the resin member 30 becomes shorter and a sufficient angle of inclination is required. The step portion 12a having the above structure cannot be formed. Therefore, as shown in FIG.
1 and the inner end portion 13 cannot be ensured satisfactorily, and the edge short 31 is encouraged to occur. Further, as the size of the semiconductor element 20 increases, the length of the wire 23 is reduced, so there is a risk that an edge short 31 may occur due to misbonding caused by the wire 23, and it is difficult to solve this problem.

Note that as a countermeasure against this, it is also possible to increase the size of the resin member 30 and increase the length of the suspension lead 12 within the resin member 30 to form a larger step portion 12a, thereby increasing the height difference h1. However, such a method would increase the size of the resin-sealed semiconductor device itself, so it was not technically satisfactory.

The present invention provides a lead frame and a resin-sealed semiconductor device using the lead frame that solves the problem of the prior art, which is that it is difficult to avoid edge shorts as semiconductor elements become larger. This is what we provide.

(Means for Solving the Problems) In order to solve the above problems, the invention of claim 1 provides an element mounting portion on which a semiconductor element is mounted, and a plurality of semiconductor devices having an inner end portion close to the element mounting portion. , a tie bar connected to a frame portion and interconnecting the leads, and a suspension lead connecting and supporting the element mounting portion to the frame portion, wherein the element mounting portion is connected to the inner end. A stepped portion located at a lower position than the lower portion is formed outside the resin-sealed region of the suspension lead.

According to a second aspect of the invention, there is provided a resin-sealed semiconductor device using a lead frame, the lead frame according to the first aspect, and a semiconductor fixed to the element mounting portion and connected to the inner end of the lead with a wire. The device includes an element, and a resin member that seals the semiconductor element, the element mounting portion, all of the wires, the leads, and a part of the suspension lead with resin.

(Function) According to the invention of claim 1, since the lead frame is configured as described above, the suspension lead can be mounted with an element connected and supported by the suspension lead by forming a stepped portion outside the resin-sealed area. The function is to position the part at a position sufficiently lower than the inner end of the lead.

With this, for example, a semiconductor element can be mounted on the element mounting part,
When bonding the semiconductor element and the inner end portion with wire, the work becomes easy and accurate.

Further, in the invention of claim 2, since the lead frame according to the invention of claim 1 is used, the element mounting portion of the lead frame is set at a sufficiently low position with respect to the inner end. Therefore, even if the semiconductor element mounted on the element mounting section becomes larger, for example, the edge short circuit that may occur between the wire and the semiconductor element can be significantly reduced and avoided. Therefore,
The above problem can be solved.

(Embodiment) FIGS. 1, 4, 5, and 6 are diagrams showing the structure of a lead frame and a resin-sealed semiconductor device using the lead frame according to a first embodiment of the present invention. , FIG. 1 is a perspective view of the main part, FIG. 4 is a plan view of FIG. 1, and FIG.
Cl, i sectional view, and FIG. 6 are sectional views taken along line D-D in FIG. 4.

This semiconductor device, as shown in FIGS. 1 and 4,
A lead frame 40, a semiconductor element 50 including a MOS transistor mounted on the lead frame 40, a transistor, etc.
and a thermosetting resin member 60 in which they are sealed with resin, such as epoxy resin or silicone resin. The lead frame 40 is made of a conductive metal plate such as a copper alloy or an alloy of iron and nickel, and has an element mounting portion 41 approximately in the middle thereof.
A plurality of boards 42 are arranged close to each other. The lead 42 has an inner end 42a sealed with resin,
Each lead 42 is connected and supported by a tie bar 43-1, and the tie bar 43-1 is connected to the frame portion 42b.
4 is supported and fixed. In addition to the tie bars 43-1, a suspension lead 45 for supporting the element mounting section 41 is connected to the frame section 44, and the suspension lead 45 is provided outside the resin sealing area of the resin member 60. It is connected to tie bar 43-1 by tie bar 43-2. These tie bars 43-1 and 43-2 also have the role of preventing the resin member 6o from cracking during resin sealing. Also,
As shown in FIG. 6, in order to set the element mounting portion 41 at a lower position by a predetermined interval h2 than the inner end portion 42a of the lead 42, a stepped portion 45a is formed on the suspension lead 45 outside the resin-sealed area. and tie bar 43 accordingly.
-2 also has a stepped portion 43-2a formed therein.

The manufacturing of the lead frame 40 configured as described above is as follows:
For example, a metal plate made of copper alloy or the like is formed into a predetermined planar shape by pressing, etching, etc., and then step portions 43-2a and 45a are formed on the tie bar 43-2 and the suspension lead 45, respectively, using pressing, etc. This can be done by doing this.

The structure of the resin-sealed semiconductor device using such a lead frame 40 will be described below with reference to FIGS. 1 and 4 to 6.

In the resin-sealed semiconductor device, the semiconductor element 50 is fixed on the element mounting part 41 via a mounting material 51 made of silver-epoxy adhesive, etc.
A plurality of electrode pad portions 52 formed on the surface of the lead 42 are bonded to the inner end portions 42a of each lead 42 by wires 53 made of gold wire or the like. Element mounting part 41, inner end 42a vicinity of lead 42, part of suspension lead 45, semiconductor element 50, electrode pad part 52, and wire 53
is resin-sealed with a resin member 60. Since the lead frame 40 is used in this manner, the element mounting portion 41 is located at a lower position by a predetermined distance h2 with respect to the inner end portion 42a, as shown in FIGS. 5 and 6, for example. .

An example of a manufacturing method for a resin-sealed semiconductor device configured as described above is shown in FIGS. 1, 4 to 6, and 7(a), (b).
). 7(a) and 7(b) are schematic side views of the resin member 60 molded as shown in FIG. 1 using a mold, and FIG. 7(a) is a side view of the lead 42 side. and the side view of the same figure (b) are the suspension leads 45.
FIG.

First, a molding die (not shown) consisting of an upper die and a lower die is prepared. For example, as shown in FIG. 1, this molding die is used for molding a resin member 60 with the inner end 42a of the lead frame 40 and the suspension lead 45 being held between upper and lower dies. It is something. Therefore, for example, as shown in FIG. 7 (a), when molding is performed between the upper mold and the lower mold, the gap between the inner end 42a, that is, the parting line 60-1. Set the shape of the upper and lower molds so that the shape is a straight line.

On the other hand, as shown in FIG. 7(b), on the side surface of the hanging lead 45, the parting line 60
The shapes of the upper and lower molds are set so that -1 approximately matches the shape of the tie bar 43-2 having the stepped portion 43-2a.

In this way, when the resin member 60 is molded, it becomes possible to effectively prevent particles of epoxy resin or the like leaking from between the upper and lower molds using the tie bar 43-2.

Next, as shown in FIG.
At the same time, the pad electrode portion 52 of the semiconductor element 50 and the inner end portion 42a of the lead 42 are connected with a wire 53. Using the molding die, the lead 42
near the inner end 42a, the semiconductor element 50 and the wire 53
If the resin member 60 is formed by resin-sealing with epoxy resin or the like, the resin-sealed semiconductor device shown in FIG. 1 can be obtained. After that, by cutting off unnecessary parts of the lead frame 40 and cutting off the hanging door 45 and tie bars 43-1, 43-2 on the outside of the resin member 60, each lead 4
2 are considered separate evils. Furthermore, by bending the outer end portions 42b of each separated lead 42 in a predetermined direction, the outer end portions 42b can be directly flat-attached to a circuit such as a printed circuit board, resulting in a resin-sealed semiconductor device. be able to.

This embodiment has the following advantages.

i) Since the stepped portion 45a of the suspension lead 45 is formed outside the resin sealing region on the lead 42 side 40, the suspension lead 45 can be sufficiently deformed to form a large stepped portion 45a. Therefore, it is possible to position the element mounting portion 41 connected to the suspension lead 45 at a sufficiently low position with respect to the inner end portion 42a, for example, at a predetermined distance h2 shown in FIG. Therefore, this lead frame 4
When a resin-sealed semiconductor device is manufactured using 0, for example, even if the semiconductor element 50 mounted on the element mounting part 41 becomes larger, edge shorts that occur between the wire 53 and the semiconductor element 50 can be prevented. It becomes possible to do so. Also,
Since the element mounting portion 41 is located at a sufficiently low position relative to the inner end portion 42a, the length of the wire 53 connecting the inner end portion 42a and the electrode pad portion 52 can be made sufficiently long. . This can also be expected to make the connection work using the wire 53 easier and more accurate.

ii) When manufacturing the lead frame of this example,
The manufacturing process does not complicate conventional manufacturing processes in any way. Further, when manufacturing the resin-sealed semiconductor device of this embodiment, a molding die in which a parting line 60-1 shown in FIGS. 7(a) and 7(b) is formed on the resin member 60 is prepared in advance. If this is done, it is possible to manufacture it through a substantially conventional manufacturing process using existing manufacturing equipment.

Next, a second embodiment of the present invention will be described.

8, 9, and 10 are diagrams showing the structure of a lead frame and a resin-sealed semiconductor device using the same according to a second embodiment of the present invention, and FIG. 8 is a perspective view of the main parts thereof. Figure, No. 9
8 is a plan view of FIG. 8, and FIG. 10 is a cross-sectional view taken along the line E--E of FIG. 9. Elements common to those in FIG. 1 are given the same reference numerals.

The difference between this lead frame 40a and the resin-sealed semiconductor device from that shown in FIG. 1 is that in the lead frame 40a, a tie bar 43-2 is not disposed between the hanging lead 45 and the tie bar 43-1. . In the lead frame 40a having such a structure, when manufacturing a resin-sealed semiconductor device using the lead frame 40a, the frame portion 44 is attached to the tie bar 43-
Instead of 2, it has the function of suppressing the breakage of the resin member 60. In this case, the molding die used for molding the resin member 60 may have a structure in which the side surface on the suspension lead 45 side conforms to the shapes of the suspension lead 45 and the frame portion 44. Even if the lead frame 40a and the resin-sealed semiconductor device have such a structure, substantially the same functions and effects as in the first embodiment can be obtained.

Note that the present invention is not limited to the illustrated embodiment, and various modifications are possible. Examples of such modifications include the following.

■ The shape of the lead frame 40, 40a is not limited to that shown in the drawings, and for example, the shape of the lead frame 40, 40a is not limited to that shown in the figure.
In this case, if it is difficult to form the stepped portion 45a with a sufficient inclination angle, the element mounting portion 41 is positioned sufficiently lower than the inner end portion 42a by forming a stepped portion on the frame portion 44 as well. Is possible.

■ No. 1 above. In the second embodiment, a plurality of boards 42
Although they are arranged in two opposing directions of the element mounting section 41, the present invention is not limited thereto, and they may be arranged in four directions around the element mounting section 41, for example.

(2) The shape of the resin member 60 can be modified in various ways depending on the application of the resin-sealed semiconductor device.

(Effects of the Invention) As described above in detail, according to the lead frame of the invention of claim 1, the step portion is formed on the suspension lead outside the resin-sealed area, so that the element mounting portion is moved inward. It is possible to position it at a position sufficiently lower than the end,
For example, when a semiconductor element is mounted on the element mounting part and the semiconductor element and the inner end are bonded with a wire, the work becomes easier and more accurate, and the work efficiency can be improved.

According to the resin-sealed semiconductor device according to the second aspect of the invention, the lead frame according to the first aspect is used. It becomes possible to avoid electrical defects caused by contact between the wire and the wire, and it becomes possible to provide a highly reliable resin-sealed semiconductor device with good bonding properties.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of main parts of a lead frame and a resin-sealed semiconductor device using the lead frame according to the first embodiment of the present invention, and FIGS. 2(a), (b), and (c) are conventional A diagram showing an example of the configuration of a resin-sealed semiconductor device, FIG. 3 is a diagram showing problems with a conventional resin-sealed semiconductor device, and FIG. 4 is a plan view of FIG. 1.
Figure 5 is a sectional view taken along the line C-C in Figure 4, and Figure 6 is a cross-sectional view taken along line D-- in Figure 4.
7(a) and 7(b) are side views of the resin member 60 in FIG. 1, and FIG. 8 is a lead frame according to the second actual male side of the present invention and a resin seal using the same. FIG. 9 is a perspective view of the main parts of a stop-type semiconductor device, and FIG. 9 is a plan view of FIG.
FIG. 0 is a sectional view taken along line E-E in FIG. 9. 40.40a...Lead frame, 41...
...Element mounting part, 42...Lead, 42a.
...Inner end, 43-1.43-2...
Tie bar, 44...Frame part, 45...Hanging lead, 45a...Step part, 50...
・Semiconductor element, 53... Wire, 60...
...Resin parts.

Claims (1)

[Scope of Claims] 1. An element mounting part on which a semiconductor element is mounted, a plurality of leads having inner ends close to the element mounting part, and a frame part connected to the leads to mutually connect them. tie bar and
In a lead frame including a suspension lead that connects and supports the element mounting portion to the frame portion, a step portion in which the element mounting portion is located at a lower position than the inner end portion is sealed with a resin of the suspension lead. A lead frame characterized in that it is formed outside the stop area. 2. A lead frame according to claim 1, a semiconductor element fixed to the element mounting part and connected to an inner end of the lead with a wire, the semiconductor element, the element mounting part, all of the wires, and the lead; 1. A resin-sealed semiconductor device comprising: a resin member that seals a portion of a suspension lead with resin.