JP2614681B2 - Semiconductor device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, in particular, a power IC which requires a large current to flow, and a pad of a semiconductor chip on which a semiconductor integrated circuit constituting various drive circuits is mounted. The present invention relates to a technique which is effective when applied to a semiconductor device in which a lead is electrically connected to a lead and the package is sealed with a package. 2. Description of the Related Art There are various types of lead frames used for semiconductor integrated circuits.
No. 5,107,250. In general, a pad provided on an IC chip and each inner lead are individually wire-bonded. And a plurality of external connection terminals for GND. This is because a large current flows through the power supply circuit, and eventually through the ground line, and the above method is employed to reduce the resistance. For example, the present inventors have developed a 32-bit thermal head driver. The bonding pad configuration of the semiconductor chip is such that one output pad is provided with a GND pad. That is, in the 56-pin package, the majority of the GND pins are closed. This means that the larger the bit capacity, the more G
The number of ND pins increases, which means that the package body also becomes larger. However, as a technical trend of the package, miniaturization is advantageous in improving the mounting density.
Furthermore, realizing a large-capacity semiconductor device with a small package leads to cost reduction. On the other hand, when the capacity is increased, the amount of heat generated based on the circuit operation of the semiconductor integrated circuit increases. When the amount of generated heat increases, circuit operation failure or physical damage of the semiconductor integrated circuit occurs. [0007] The present invention has been made in view of the above. OBJECTS OF THE INVENTION It is an object of the invention to use the same
Signal input by reducing the number of external connection terminals
An object of the present invention is to provide a semiconductor device in which the number of output pins can be increased. The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings. SUMMARY OF THE INVENTION The summary of the invention disclosed in the present application is briefly described as follows. That is, a semiconductor chip having a plurality of pads on a main surface thereof, and a plurality of leads each having one end disposed close to the pad of the semiconductor chip, wherein the pads and the plurality of leads are provided. is one end becomes are electrically connected by wires, in a semiconductor device to which one end of the semiconductor chip and the wires and the plurality leads are sealed with resin, electric
The leads used for common purposes, such as
Semiconductor chip between the semiconductor chip and one end of multiple leads
Along with the lead used for said purpose
Extends around the inner lead of another desired multiple lead.
The plurality of free ends are exposed outside the resin sealing body. An embodiment of a lead frame to which the present invention is applied will be described below with reference to FIG. This embodiment is characterized in that the number of external connection terminals for GND in the semiconductor integrated circuit is reduced and the number of signal input / output pins is increased. The feature of the present embodiment is that the efficiency of radiating heat generated by the operation of the semiconductor integrated circuit is improved. [0015] As shown in FIG.
0 indicates the case of 44 pins. Same frame 1
At 00, the inner leads 23, 29, 3 for GND
9 are integrally connected as shown by oblique lines. Then, despite the connection of as many as nine wires from the GND pad of the IC chip 51, a package (not shown)
Only three external terminals (outer leads) are required. That is, the inner leads 25, 27, 3 originally used as the inner leads for GND.
1, 33, 35, and 37 are all unnecessary, and the space between the inner leads is accordingly increased. So, in practice,
The inner leads 25 to 37 can be used for other purposes such as signal input / output pins. Thus, even if the integration degree of the IC chip is increased and a capacity of 32 bits or more can be realized in one IC chip, the lead frame 100 can be used. Further, the intervals between the inner leads 23 to 39 are made uniform, and in particular, the inner leads 23 for GND,
The lead widths of the hatched portions 29 and 39 may be expanded as compared with the lead widths of the other inner leads 30 and the like, so that the electric resistance is reduced and a larger current can flow. Further, an inner lead used for a common purpose is arranged between the IC chip 51 and one end of the inner leads 24 to 28 and 30 to 38 for input / output signals to which wires are connected. The inner lead used for this common purpose is the above-described inner lead 2 for GND.
The surfaces of the inner leads used for a common purpose are integrally formed with each of 3, 29, and 39, and are formed in substantially the same plane as the surfaces of other inner leads, for example, the inner leads 24 for input / output signals. . That is, the inner lead used for the common purpose is the semiconductor chip 5
1. Used as a conductor layer arranged in a heat radiation path including a part of the package, inner leads 24 for input / output signals, etc. Usually, a resin package is used for the package, Since the conductivity is small, the thermal resistance of the heat radiation path can be reduced. Further, the inner lead 23 for GND,
Since each of 29 and 39 is around the tab 52,
The distance from the GND pad of the IC chip 51 to the GND inner lead can be reduced, and the amount of gold wire used can be reduced. In addition, bonding can be performed at the shortest distance, and cost can be reduced. The tab 52, the tab suspension lead 53a,
Each of the 53b and the dam 54 is known to those skilled in the art. FIG. 2 shows the lead frame 100 of FIG.
1 shows a form of an IC package using the same. As shown in the figure, since there are only three GND pins 23, 29, and 39, the other pins can be effectively used for power supply, signal input, and signal output. Although not shown, the present invention is also effective when there are many power supply pins. (1) Since the heat resistance of the heat radiation path between the semiconductor chip and the lead in the package can be reduced by the conductor layer,
It is possible to provide a semiconductor device capable of efficiently releasing heat generated by the operation of a circuit mounted on a semiconductor chip to the outside of a package through each of a conductor layer and a lead. (2) Since the conductor layers use leads used for a common purpose, a semiconductor device capable of increasing the number of input / output pins can be provided. Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the invention. Needless to say. For example, in the above embodiment, the present invention is applied to the GND pin, but may be applied to a power supply circuit. In the above embodiment, three GND pins are used. However, the inner leads 34 and 44 may be formed as the same GND inner lead so that wire bonding can be performed satisfactorily. In the above description, a case has been described in which the invention made by the present inventor is mainly applied to a lead frame which is a field of application as the background, but the invention is not limited to this. The present invention can also be used for an analog IC incorporating a drive circuit, a power amplifier circuit, and the like. Then, according to the present invention, such a large current flows.
Even a resin-encapsulated semiconductor device that requires
Use multiple output pins and reduce thermal problems
Is possible, and the effect of expanding the application of products
You can drop it.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing one embodiment of a lead frame to which the present invention is applied. FIG. 2 is a perspective view of an IC package using the lead frame of the present invention. [Description of Signs] 1 to 44: inner lead, 51: IC chip, 52:
Tab, 53a, 53b: Tab suspension lead, 54: Dam,
100 ... lead frame.

Continued on the front page (51) Int.Cl. ⁶ Identification number Reference number in the agency FI Technical display location H01L 23/50 H01L 23/50 X

Claims (1)

(57) [Claims] A semiconductor chip having a plurality of pads on a main surface, and a plurality of leads each having one end disposed close to a pad of the semiconductor chip, wherein the pad and one end of the plurality of leads are connected by wires. In a semiconductor device which is electrically connected and one end of the semiconductor chip and the wire and the plurality of leads are sealed with a resin, a lead used for a common purpose such as a power supply and an earth is
The semiconductor chip is placed between the semiconductor chip and one end of the leads.
Lead placed along the loop and used for said purpose
To surround the inner lead of another desired multiple lead
Extending and exposing the plurality of free ends outside the resin sealing body.
Wherein a composed.