JPH023622Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is a semiconductor pellet mount using a lead frame in which a land portion for mounting a semiconductor pellet and a plurality of leads extending from the vicinity of the land portion to the periphery are connected and integrated by tie bars. Regarding equipment.

BACKGROUND TECHNOLOGY Recently, there has been a significant demand for semiconductor devices to be smaller and more multifunctional, and as the degree of circuit integration of ICs and other devices improves,
As the number of external lead-out terminals increases, the number of leads used in one semiconductor device tends to increase. Therefore, lead frames used in the manufacture of this type of semiconductor device are becoming finely patterned year by year. In addition, lead frames used for special purposes are formed by etching, but lead frames for general transistors, linear ICs, hybrid ICs, etc. are made by stamping metal plates, which is much cheaper to produce. And it's common.

A conventional semiconductor device using a lead frame will be described below with reference to FIGS. 4 to 6. In FIGS. 4 and 5, reference numeral 1 denotes a fine-patterned lead frame, and in the drawings, there is one land portion 2 for pellet mounting, and a large number of leads 3 arranged near the periphery of this land portion 2. , 3... are connected by tie bars 4, 4.... This lead frame 1 is of a flat base type, in which land portions 2 and leads 3, 3, . . . are arranged on the same surface. 5 is one semiconductor pellet mounted on the land portion 2, 6, 6... are surface electrodes of the device pellet 5 and corresponding leads 3, 3...
This is an Au wire that is bridge-connected between the end portions 3', 3', . . . of the land portion side. After this wire bonding, an exterior resin material m is molded in the dashed line area in the drawing, and then the tie bars 4, 4, . . . are cut and removed from the lead frame 1 to obtain individual resin-sealed semiconductor devices.

The semiconductor pellet 5 has a thickness of approximately 200 to 300 μm.
The semiconductor pellet 5 is for high power use, and is for small signals with a thickness of about 400 to 500 μm, which is even larger without restrictions such as thermal resistance. The height difference between the surface electrodes 5 and the leads 3, 3, . . . increases, and the wires 6, 6, . Therefore, when using the semiconductor pellet 5 for small signals, as shown in Fig. 6, the land portion 2' should be lowered a little lower than the leads 3, 3... so that the surface of the semiconductor pellet 5 and the leads 3, 3... are at the same level. A dimple-type lead frame 1' has been widely used because it eliminates the problems of edge contact and the like by adjusting the height of the lead frame 1'.

Problems that the invention aims to solve As mentioned above, if a dimpled lead frame is used, the problem of edge attachment due to wire sagging can be solved to some extent, but the dimpled lead frame is naturally more expensive to manufacture than the flat base type lead frame. Furthermore, the number of lead frames stored in the lead frame storage magazine is extremely small, which is disadvantageous in terms of semiconductor device manufacturing equipment. Furthermore, even if a dimple-type lead frame is used, the distance between the surface electrode of the semiconductor pellet and the corresponding lead tip may have to be longer than necessary due to layout considerations. Even with a dimpled structure, if an attempt is made to speed up the bonding process, there remains a risk of sagging and edge contact, making it difficult to increase the reliability of bonding.

Furthermore, in the case where only one semiconductor pellet is mounted on one land portion of a lead frame, the single semiconductor pellet is naturally limited to a single function, and multifunctionality cannot be achieved. Therefore, there are multifunctional hybrid ICs in which multiple types of semiconductor pellets are mounted on one land of a lead frame, connected by wire bonding, and molded.
However, in this hybrid IC, it is actually impossible to arrange all of the multiple semiconductor pellets and their corresponding leads in a dimple structure, and the wire length is always too long due to the arrangement of the multiple semiconductor pellets. Because of the presence of wires, there was still the problem of edge attachment due to sagging wires.

Means for Solving the Problems The present invention was proposed mainly to solve the problems in wire edge attachment of semiconductor devices using the above-mentioned lead frame. The above-mentioned conventional problems are solved by arranging an insulator to prevent wires from sagging in a portion directly below.
Specifically, a wiring board is fixed across the lower part of the land of the lead frame and the lower end of the land part side of a plurality of leads extending from the vicinity of the land part to the periphery, and semiconductor pellets are included on the land part and the wiring board. A semiconductor device is provided in which electronic components are mounted and connected by wire bonding, and insulating projections are formed on the wiring board at locations corresponding to the lower portions of the wires.

Function: The insulating protrusions on the wiring board are set at a height where they will come into contact with the wires bridged above if they droop even slightly, so that even if the wires droop, the protrusions will restrict the drooping and the land will There is no need to worry about contact with conductive parts or other conductive parts, improving the reliability of bonding work. Furthermore, if a conductive land (bonding pad) is formed on the top surface of this protrusion to connect the two wires, the protrusion can be used as a relay terminal for the two wires, making it possible to eliminate excessively long wires. can. Furthermore, by mounting and wiring other electronic components on the wiring board, a multifunctional, compact, and low-cost hybrid IC can be provided. Furthermore, by fixing the wiring board to the bottom surface of the leads, the leads corresponding to the semiconductor pellets on the wiring board have a dimple structure, which eliminates the need for a dimple structure in the lead frame, allowing the use of a lead frame that is inexpensive and easy to handle. becomes.

Embodiment An embodiment in which the present invention is applied to a hybrid IC will be described below with reference to FIGS. 1 to 3.

1 to 3, reference numeral 7 denotes a fine patterned lead frame, and in the drawings, one land portion 8 and a number of leads 9, 9, . . . extending from the vicinity of this land portion 8 are connected to tie bars 10, 10, . shows the connected and integrated part. Reference numeral 11 denotes a wiring board, which includes the lower surface of the land portion 8 and the tips 9' of the leads 9, 9...
9'... is pasted and fixed with an insulating adhesive 12 so as to extend over the lower surfaces thereof. The wiring board 11 is a circuit element pattern 14a such as wiring, resistors, bonding pads, and soldering lands on the front surface of an insulating substrate 13 made of silicon or plastic, and a circuit mainly containing passive elements such as resistors, capacitors, and inductances on the back surface. An element pattern 14b is formed, and the feature of the present invention is that insulating protrusions 15, 15, .

Further, 16 is a high power semiconductor pellet mounted on the land portion 8, 17 is a small signal semiconductor pellet mounted on a soldering land on the wiring board 11, and 18, 18 is a semiconductor pellet for soldering on the wiring board 11. Mounted chip components such as resistors and capacitors, 19, 19, etc. are Au wires, and are connected to the surface electrodes of both semiconductor pellets 16, 17, each lead tip 9', 9', and bonding pads on the wiring board 11. 20, 20... and for example one protrusion 15'
Two corresponding points of the relay bonding pads 21, 21 formed at the upper two locations are connected.

The protrusions 15, 15... are selectively protruded from the lower portions of the wires 19, 19... which will be bonded later on the wiring board 11 and are relatively long and tend to sag due to external force, that is, directly below. , its protruding height and width are large enough not to interfere with wire bonding, and to ensure that the bonded wire 1
When 9, 19, etc. hang down, the size is set to receive the hanging part and prevent it from coming into contact with conductive parts such as the land part 8. Moreover, if the upper end surfaces of the projections 15, 15, . In addition, there is a bonding pad 21 on the upper end surface.
The upper end surface of protrusion 15' having 21 is flat to ensure wire bonding to bonding pads 21,21.

The production of this hybrid IC involves fixing the wiring board 11 under the lead frame 7, mounting the semiconductor pellets 16, 17 and chip parts 18, 18, etc., wire bonding, molding the exterior resin material 22 indicated by the chain line in FIG. This is performed in each step of cutting and removing the tie bars 10, 10, . . . from the lead frame 7 to obtain individual hybrid ICs, and in this manufacturing process, the wiring board 11 enables the following.

First, protrusions 15, 15 protruding from the wiring board 11
Even if the wires 19, 19... bridged above the wires 19, 19... hang down as shown by the chain lines in FIG. This prevents shot accidents to parts 8, etc., and greatly reduces the incidence of defective products due to wire edge touching.

Further, some of the relay protrusions 15' are used, for example, as relay terminals between the high-power semiconductor pellet 16 and the corresponding leads 9, 9, which are relatively far apart,
Due to this interruption, only two short wires are required to connect two points that are far apart, and good bonding properties with less wire sagging can be obtained.

In addition, since the wiring board 11 is fixed to the lead tips 9', 9', etc., even if the lead tips 9', 9', etc. are warped or twisted during the formation stage of the lead frame 7, the wiring board This is corrected when fixing the adhesive 11, so that wire bonding to the lead tips 9', 9', . . . can be easily and reliably performed. Furthermore, since the lead tips 9', 9', .
Accidents such as wire breakage and form collapse are prevented. Furthermore, even if the form of the wires 19, 19... is greatly disturbed and sagging occurs, it is safe as most of the wires are supported by the protrusions 15, 15..., and therefore it is not necessary to do this after wire bonding. This eliminates the trouble of modifying the wire form.

Further, since the small signal semiconductor pellet 17 on the wiring board 11 and the corresponding leads 9, 9, . Further, this dimple structure can be realized without making the lead frame 7 into a dimple type, so that a flat base type lead frame 7 that is convenient to handle and inexpensive can be used.

Furthermore, by attaching the wiring board 11, it becomes possible to add a wide variety of passive elements and active elements such as resistors and capacitors, thereby realizing further miniaturization, high-density packaging, and multifunctionality of the hybrid IC.

Note that the present invention is not limited to hybrid ICs, but can be similarly applied to other semiconductor devices such as linear ICs.
Further, the insulating protrusions on the wiring board may be provided directly below all the wires if there is space or manufacturing allowance. Further, the wiring board may be fixed so as to straddle a part of the lead frame below the land and the lower surface of the selected lead tip.

Effects of the invention According to the invention, there are almost no edge-touching accidents caused by sagging bonding wires, thereby improving the reliability of wire bonding work and the yield of semiconductor device manufacturing. Furthermore, since there is no need to worry about the wire edge touching, manufacturing after wire bonding becomes easier, and the number of man-hours can be reduced by eliminating the number of wire form corrections.

[Brief explanation of drawings]

FIG. 1 is a plan view of a lead frame used in a semiconductor device which is an embodiment of the present invention, and FIGS. 2 and 3 are enlarged cross-sections of essential parts taken along lines A-A and B-B in FIG. 4 and 5 are plan views and C of lead frames used in conventional semiconductor devices.
FIG. 6 is an enlarged cross-sectional view of the main part taken along the line -C, and is a cross-sectional view of a lead frame used in another conventional semiconductor device. 7... Lead frame, 8... Land portion, 9...
...Lead, 9'... Lead tip, 11... Wiring board, 15, 15'... Insulating protrusion, 16, 17,
18...Electronic parts, 19...Wire.

Claims (1)

[Scope of utility model registration request] A wiring board is fixed across the lower part of the land of the lead frame and the lower end of the land part side of a plurality of leads extending from the vicinity of the land part to the periphery, and electronic components including semiconductor pellets are mounted on the land part and the wiring board. What is claimed is: 1. A semiconductor device which is connected by wire bonding, wherein an insulating protrusion is formed at a location corresponding to a lower part of the wire on the wiring board.