JPH07153894A - Semiconductor device, and lead frame used for manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent the faulty contact (tab-short) of a sagging wire. CONSTITUTION:A semiconductor device 1 comprises a supporter (tab) 5, a semiconductor chip 9 fixed on the tab 5, leads 3 whose inner ends are extended respectively to the periphery of the tab 5, wires 10 whereby the respective electrodes of the semiconductor chip 9 and the respective inner ends of the leads 3 are connected electrically, and a resin package 2 for covering the tab 5, the semiconductor chip 9, the wires 10 and the inner end parts of the leads 3. Further, the whole of the surface of the tab 5 is covered with an insulator 6. As a result, even when the wire 10, which connects the electrode of the semiconductor chip 9 on the tab 5 with the inner end of the lead 3 extending to the periphery of the tab 5, hangs down and touches the tab 5, no electric short- circuit (tab-short) occurs since the edge of the tab 5 is covered with the insulator 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin package type semiconductor device and a lead frame used for manufacturing the semiconductor device.

[0002]

2. Description of the Related Art Electronic devices are required to have high-density mounting in terms of functions, and to be lightweight, compact, and thin in terms of mounting. Further, in order to reduce the manufacturing cost of electronic components, a resin package (plastic package) made of a resin (resin) that is inexpensive and has high productivity is often used as a package form. For small and thin packages, December 1989 issue of "Electronic Materials" published by the Industrial Research Group, the same year
Issued December 1, P37-P43. This document describes, as a technical subject in the miniaturization and thinness of a resin package type semiconductor device, correspondence to a reduction in lead pitch and prevention of wire short circuit in wire bonding. The following is an excerpt from the section for reducing lead pitch. "It seems that the lead pitch is about 0.2 mm per 42 NiFe alloy of t0.15 mm whether pressing or etching. At this plate thickness, the lead width is about half of this, 0.1 mm,
In order to bond in this, the lead bonding width must also be made stable and small. For this purpose, it is important to improve the lead frame fixing state, especially in the case of the ultrasonic combined use method. There are methods such as fixing the leads by taping, but there are large variations in the lead position accuracy, and it is necessary to confirm the position of all pins. ”

The following is an excerpt from the item of wire short circuit prevention. “It has been standard until now that the wire length is set to 3 mm or less. However, as shown in FIG. 5, there is an unavoidable situation where the wire length must be increased due to the working limit of the inner lead. In the example of Fig. 5, the maximum length is 4.2 mm, and the pitch of both pads and leads is narrowed, and the risk of short-circuiting between wires due to wire flow during molding becomes extremely high. The higher the value, the more easily the wire flow occurs, so the loop must be made as low as possible, but on the other hand, there is a risk of short-circuiting between the tip end and the wire, and as a wire bonder, the wire loop shape must be precisely controlled. Also, in the thin package as shown in Fig. 9, the wire loop must be bonded low and stably. 10 shows an example of a capillary movement locus for this purpose, and an example of a loop shape resulting from this, in addition to the method of making the wire diameter thicker from the material surface to make it difficult to flow, other than this, Development is also underway in the direction of using a wire with an insulating coating such as heat-resistant polyurethane so that it will not short-circuit even if it flows. ”Fig. 5 discloses the relationship between pad pitch, lead pitch and wire length. In FIG. 9, 1
A cross-sectional structure of a thin package having a thickness of mm is disclosed, and FIG. 10 discloses a chip short circuit, a tab short circuit, and a wire sagging phenomenon as a wire contact failure phenomenon when a wire hangs down.

[0004]

The height of the wire loop tends to decrease as the semiconductor device becomes thinner, and the wire length tends to increase as the semiconductor chip increases in size. As a result, a tab short occurs in which the wire contacts the support (tab) that fixes the semiconductor chip.
In addition, when a lead frame is attached on a wiring board, there is a problem that a hung wire (wire sag) contacts the conductor layer on the surface of the wiring board.

It is an object of the present invention to provide a semiconductor device capable of preventing a defective wire contact phenomenon caused by the sagging of the wire, and a lead frame used for manufacturing the same. The above and other objects and novel features of the present invention will be apparent from the description of the present specification and the accompanying drawings.

[0006]

The outline of the representative ones of the inventions disclosed in the present application will be briefly described as follows. That is, the resin package type semiconductor device of the present invention includes a support, a semiconductor chip fixed on the support, leads having an inner end extending around the support, electrodes of the semiconductor chip, and It is composed of a wire for electrically connecting the inner end of the lead and the support, the semiconductor chip, the wire, and a resin package covering the inner end of the lead, and the entire surface of the support is covered with an insulator. There is. A lead frame for manufacturing such a semiconductor device has a support for fixing a semiconductor chip, and a lead for extending an inner end around the support, and the entire surface of the support is an insulator. The structure is covered with.

A semiconductor device according to another embodiment of the present invention is
A support and a semiconductor chip fixed on the support,
A lead having an inner end extending around the support, a wire electrically connecting the electrode of the semiconductor chip and the inner end of the lead, and the support, the semiconductor chip, the wire, and the lead inner end portion. A semiconductor device comprising a resin package to be covered, which has a structure in which an insulating tape is attached from at least a peripheral portion of a semiconductor chip fixing surface of the support member to an inner end of a lead. A lead frame for manufacturing such a semiconductor device has a support body for fixing a semiconductor chip, and leads for extending an inner end around the support body, and at the same time, a semiconductor chip fixing surface of the support body is provided. An insulating tape is attached at least from the peripheral edge portion to the inner end of the lead.

[0008]

The resin package type semiconductor device of the present invention is manufactured by using the lead frame in which the entire surface of the semiconductor chip of the support is covered with the insulator. As a result, even if the wire that electrically connects the electrode of the semiconductor chip on the support and the inner end of the lead that extends the inner end around the support hangs down and contacts the edge of the support (tab). Since the edge of the support is covered with the insulator, electrical short (tab short) does not occur.

A semiconductor device according to another embodiment of the present invention is manufactured using a lead frame to which an insulating tape is attached from at least a peripheral portion of a semiconductor chip fixing surface of a support to an inner end of a lead. Has been done. As a result, even if the wire that electrically connects the electrode of the semiconductor chip on the support and the inner end of the lead that extends the inner end around the support hangs down and contacts the edge of the support (tab). Since the edge of the support is covered with the insulating tape, electrical short (tab short) does not occur. Further, in this semiconductor device, since the inner end portions of the leads are attached with the insulating tape, the dimensions between the inner ends of the leads are unlikely to vary and the wire bondability is improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a sectional view of a semiconductor device according to an embodiment of the present invention, and FIG. 2 is a schematic plan view showing a lead frame according to an embodiment of the present invention.

The resin package type semiconductor device 1 of the present invention
As shown in FIG. 1, it comprises a rectangular package 2 and a plurality of leads 3 extending inside and outside the package 2. In this example, the shape of the lead 3 protruding from the package 2 is a gull wing type, and as shown in the figure, the tip is a flat lead foot portion 4. A support 5 called a tab is arranged inside the package 2. The surface of the support 5 is covered with an insulator 6. An insulator 6 is also provided on the surface of the lead 3 extending inside the package 2 except for the wire bonding region. A semiconductor chip 9 is fixed to the upper surface of the support 5 via a bonding material 7. The electrodes (not shown) of the semiconductor chip 9 and the inner ends of the leads 3 are electrically connected by a conductive wire 10.

Next, a method of manufacturing the semiconductor device of the present invention will be described. When manufacturing the semiconductor device 1 of the present invention, the lead frame 21 is prepared as shown in FIG. The lead frame 21 is made of a Fe-Ni alloy plate or C.
It is manufactured by patterning a u alloy plate or the like by etching or pressing. As shown in the figure, the lead frame 21 includes a pair of outer frames 22 extending in parallel, and a pair of inner frames 23 connecting the pair of outer frames 22 and extending in a direction orthogonal to the outer frame 22. It has a frame structure formed by. A rectangular tab (support) 5 is arranged in the center of the frame, and the tab 5 is supported by a tab suspension lead 25 extending from the wide width portion 24 at the corner of the pair of frames. There is. Further, a plurality of leads 3 extend from the inner frame 23 and the outer frame 22 toward the tab 5. In addition, in the lead portions extending in parallel to each other, the leads 3 are connected by the dam 26. The dam 26 is arranged in parallel with the inner frame 23 or the outer frame 22 and has a wide width portion 24 at a corner of the frame.
Are linked to.

This is one of the features of the present invention. In the lead frame 21 of the present invention, the surface of the tab (support) 5 and the surface of the lead 3 are also insulated except for the wire bonding region. A body 6 is formed.
The insulator 6 is formed of, for example, a coating film of polyimide resin and has a thickness of 25 μm. It is preferable that the insulator 6 has good adhesiveness to the package 2 and has a thermal expansion coefficient similar to the insulator 6, because the package performance is not deteriorated. The insulator 6 is formed by coating, spraying, dipping or the like. Also, the outer frame 2
2 is provided with guide holes 27 and 29. In the figure, the lead frame 21 is shown with a small number of leads 3 for convenience of explanation, but in reality, there are many.

Next, chip bonding and wire bonding are performed on such lead frame 21. That is, the semiconductor chip 9 is fixed onto the tab 5 of the lead frame 21 via the bonding material 9 (see FIG. 1). After that, the electrodes (not shown) of the semiconductor chip 9 are connected to the inner ends of the leads 3 by the conductive wires 10. Figure 3
FIG. 7 is a diagram also showing the assembled lead frame 21 after chip bonding and wire bonding are completed.

Next, the assembled lead frame 2
1, a package 2 is formed by molding a predetermined portion by a conventional transfer molding device. After that, the lead frame 21 is removed from the transfer mold, the unnecessary lead frame portion is cut and removed, and lead molding is performed to manufacture the gull wing type semiconductor device 1 as shown in FIG.

[0016]

【The invention's effect】

(1) The resin package type semiconductor device of the present invention is manufactured using a lead frame in which at least a peripheral portion of the semiconductor chip fixing surface of the support is covered with an insulator. As a result, even if the wire that electrically connects the electrode of the semiconductor chip on the support and the inner end of the lead that extends the inner end around the support hangs down and contacts the edge of the support (tab). Since the edges of the support are covered with the insulator, the effect that electrical shorts (tab shorts) do not occur can be obtained.

(2) According to the above (1), in the semiconductor device of the present invention, a tab short does not occur even if the wire hangs down and comes into contact with the tab, so that the wire length can be increased and the semiconductor chip can be made large. It is possible to obtain an effect that it is easy to deal with the change. That is, it is effective when the wire length is as long as 3.0 mm or more.

(3) Because of the above (1), the semiconductor device of the present invention does not need to worry about a tab short circuit.
Since the height of the wire loop can be reduced, the resin package can be made thinner.

(4) In the semiconductor device of the present invention, the surface of the inner end portion of the lead is covered with the insulating material except for the wire bonding area as a part of the area. Even if it contacts the end, it is possible to obtain an effect that it is possible to prevent a short circuit between the adjacent wire and the lead.

(5) Since the lead frame of the present invention does not cause a tab short circuit, it has the effect of increasing the yield when used in the manufacture of semiconductor devices.

(6) Since the lead frame of the present invention does not cause a tab short circuit, the tab can be made large in advance so that a semiconductor chip of a small size can be fixed to a semiconductor chip of a large size. Therefore, the effect of increasing the versatility of the lead frame can be obtained.

(7) Due to the above (1) to (6), according to the present invention, a semiconductor device can be manufactured using a lead frame which has high versatility and is less likely to cause a tab short circuit. There is a synergistic effect that the manufacturing cost of the semiconductor device can be reduced by the improvement and the reduction of the lead frame cost.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say. FIG. 3 is a sectional view of a semiconductor device according to another embodiment of the present invention. In the semiconductor device 1 of this embodiment, the insulator 6 is formed only on the peripheral edge of the support (tab) 5, so that a tab short circuit does not occur even if the wire 10 hangs down.

FIG. 4 is a sectional view of a semiconductor device according to another embodiment of the present invention, and FIG. 5 is a schematic plan view showing a lead frame used for manufacturing the semiconductor device 1 of this embodiment. The semiconductor device 1 according to this embodiment has a support (tab).
5, a semiconductor chip 9 fixed on the support 5,
The support 3 includes a lead 3 having an inner end extending around the support 5, and a wire 10 electrically connecting the electrode of the semiconductor chip 9 and the inner end of the lead 3 to each other. The chip 9, the wire 10, and the inner ends of the leads 3 are covered with a package 2 made of a resin. Further, in this semiconductor device 1, an insulating tape 15 is attached from at least the peripheral portion of the fixing surface of the semiconductor chip 9 of the support 5 to the inner end of the lead. As shown in FIG. 5, a lead frame 21 for manufacturing such a semiconductor device 1 includes a support 5 for fixing a semiconductor chip 9 and a lead 3 having an inner end extending around the support 5. In addition, the insulating tape 15 is attached from at least the peripheral portion of the fixing surface of the semiconductor chip 9 of the support 5 to the inner end of the lead. In such a semiconductor device 1, a wire 10 that electrically connects the electrode of the semiconductor chip 9 on the support 5 and the inner end of the lead 3 that extends the inner end around the support 5 hangs down. Even if the edge of the (tab) 5 is contacted, the edge of the support 5 is covered with the insulating tape 15, so that an electrical short (tab short) does not occur. Further, in this semiconductor device 1, the inner end portion of the lead 3 has an insulating tape 15
Since it is affixed by, it is difficult for the dimensions between the inner ends of the leads to come apart, and the wire bondability is improved.

In the above description, the case where the invention made by the present inventor is mainly applied to the manufacturing technology of the resin package type semiconductor device which is the field of application which is the background has been described, but the invention is not limited thereto. The present invention can be applied to a semiconductor device having a structure having at least a tab (support) to which a semiconductor chip is fixed, a semiconductor device (hybrid integrated circuit device) that causes a short circuit failure (wire contact failure phenomenon) due to wire sagging, and the like.

[Brief description of drawings]

FIG. 1 is a sectional view of a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a schematic plan view showing a lead frame according to an embodiment of the present invention.

FIG. 3 is a sectional view of a semiconductor device according to another embodiment of the present invention.

FIG. 4 is a sectional view of a semiconductor device according to another embodiment of the present invention.

FIG. 5 is a schematic plan view showing a lead frame according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor device, 2 ... Package, 3 ... Lead, 4 ... Lead foot part, 5 ... Support body, 6 ... Insulator, 7 ... Bonding material,
9 ... Semiconductor chip, 10 ... Wire, 15 ... Insulating tape, 21 ... Lead frame, 22 ... Outer frame, 23 ... Inner frame,
24 ... Wide part, 25 ... Tab suspension lead, 26 ... Dam, 2
7, 29 ... Guide holes.

Claims (4)

[Claims] 1. A support, a semiconductor chip fixed on the support, a lead having an inner end extending around the support, an electrode of the semiconductor chip and an inner end of the lead are electrically connected. A semiconductor device comprising a wire for electrical connection, a support, a semiconductor chip, a wire, and a resin package covering the inner end portions of the leads, wherein at least a peripheral portion of a semiconductor chip fixing surface of the support is an insulator. A semiconductor device characterized by being covered. 2. A support, a semiconductor chip fixed on the support, a lead having an inner end extending around the support, an electrode of the semiconductor chip and an inner end of the lead are electrically connected. A semiconductor device comprising a wire for electrical connection, a support, a semiconductor chip, a wire, and a resin package covering the inner end portion of the lead, wherein at least the peripheral portion of the semiconductor chip fixing surface of the support inner end of the lead. A semiconductor device, wherein an insulating tape is attached over the entire area. 3. A lead frame having a support for fixing a semiconductor chip and a lead having an inner end extending around the support, wherein at least a peripheral portion of a semiconductor chip fixing surface of the support is insulated. A lead frame characterized by being covered by the body. 4. A lead frame having a support for fixing a semiconductor chip and a lead having an inner end extending around the support, wherein the lead is provided from at least a peripheral portion of a semiconductor chip fixing surface of the support. A lead frame, characterized in that an insulating tape is attached over the inner end.