JP2009170444A - Semiconductor integrated circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit in which the number of pins of lead frames can be more reduced than before. <P>SOLUTION: The semiconductor integrated circuit is not provided with lead frames for each of a first function-specific circuit 19 and a second function-specific circuit 20 formed on a semiconductor chip 14 and allowing alternative selection of output signals for use in the outside (i.e., not provided with two lead frames), but provided with only the lead frame 12c for the number of output signals supplied for use in the outside (i.e., only one signal). With this configuration, the number of lead frames can be reduced, compared to a case where lead frames are provided for each of the first function-specific circuit 19 and the second function-specific circuit 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor integrated circuit.

  As is well known, a semiconductor integrated circuit is formed by sealing a semiconductor chip connected to a lead frame with a bonding wire in a resin package or a ceramic package. Such a semiconductor integrated circuit is generally mounted on a printed wiring board and connected to an external circuit formed on the printed wiring board. The lead frame is a kind of connection terminal, one end of which protrudes outside the package, and is connected to the pattern wiring formed on the printed wiring board. The semiconductor chip is provided with an electronic circuit having a predetermined function and a plurality of pads (connection electrodes). The electronic circuit receives signals from the outside by connecting the pads to the lead frame by bonding wires. And outputs a signal to the outside. The bonding wire is a thin wire made of a material having a low electrical resistance, such as gold, platinum, or silver.

For example, Patent Document 1 below discloses a vehicle electronic control unit that includes a CPU, a memory, and the like made of the semiconductor integrated circuit described above. This vehicle electronic control unit controls an actuator, W / L (warning lamp), and the like mounted on the vehicle by a CPU, and is composed of a large number of electronic components including a semiconductor integrated circuit as a main component. .
JP 2002-002419 A

  By the way, in recent years, vehicles such as four-wheeled vehicles have become increasingly multifunctional, and there is a tendency that more detection functions and more operation functions are required. Therefore, it is necessary for a semiconductor integrated circuit mounted in a vehicle electronic control unit to accept more detection signals and to control more control objects, and accordingly, it is formed on a semiconductor chip. The number of pads and the number of pins of the lead frame (number of external connections) connected to the pads tend to increase as the electronic circuit to be processed becomes complicated.

  As is well known, the package structure of a semiconductor integrated circuit includes a DFP structure, a QFP structure, or a BGA structure. Among these package structures, the BGA structure increases the number of external connections more than the DFP structure or the QFP structure. Is possible. However, with the increase in the number of functions of the vehicle described above, the actual situation is that reduction in the number of pins of the lead frame is required in any of these structures.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a semiconductor integrated circuit capable of reducing the number of pins of a lead frame as compared with the related art.

  In order to achieve the above object, the present invention provides a plurality of function-specific circuits that are provided in a semiconductor chip, a part of which is selected for use, and a number of lead frames corresponding to the number of the part of the function-specific circuits. And a bonding wire for connecting the part of the circuit by function and the lead frame.

  According to the present invention, a lead frame is provided only for a function-specific circuit to be used instead of a function-specific circuit provided in a plurality of functions in a semiconductor chip. The number of pins of the lead frame can be reduced compared to

The present invention is characterized in that when the output signals of some of the functional circuits are used, lead frames are provided corresponding to the number of the output signals.
According to the present invention, when the output signals of some function-specific circuits are used, the lead frame is provided corresponding to the number of output signals, so that the number of pins of the lead frame for output signals can be reduced. Can do.

In the invention, it is preferable that the function-specific circuit is an input / output circuit that mediates transmission / reception of a signal between a control subject and an external device.
According to the present invention, since the circuit according to function is an input / output circuit that mediates transmission / reception of signals between the control subject and the external device, the number of pins of the lead frame of the input / output circuit can be reduced.

In the invention, it is preferable that the function-specific circuit is an input / output circuit constituting a vehicle electronic control unit.
For semiconductor integrated circuits mounted on electronic control units for vehicles, it is necessary to accept more detection signals and control more objects to be controlled, and lead frames tend to have more pins. Therefore, it is particularly strongly required to reduce the number of pins of the lead frame. According to the present invention, since the function-specific circuit is an input / output circuit that constitutes the vehicle electronic control unit, there is a need to reduce the number of lead frame pins of the input / output circuit that constitutes the vehicle electronic control unit. I can respond.

  According to the present invention, it is possible to provide a semiconductor integrated circuit capable of reducing the number of pins of a lead frame as compared with the conventional case.

[First Embodiment]
A first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram illustrating a configuration of a vehicle electronic control unit (ECU) according to the present embodiment. The electronic control unit 1 controls various displays 4 provided on various actuators 3 such as motors and control valves and an instrument panel based on detection signals of various sensors 2 that detect the state of the vehicle. It is provided near the engine of the vehicle.

  The electronic control unit 1 has a CPU 5, an external memory 6 and an input / output circuit 7 as main components as shown in the figure. These CPU 5, external memory 6, and input / output circuit 7 are mounted on a printed wiring board 9 having a predetermined size in a state where they are interconnected by a bus line 8.

  The CPU 5 is a control entity that controls the input / output circuit 7 based on a control program stored in the external memory 6, and is designed based on, for example, a RISC (Reduced Instruction Set Computer) architecture. The external memory 6 is composed of a ROM (Read Only Memory) and a RAM (Randam Access Memory), and outputs various instructions of the control program stored in the ROM to the CPU 5 under the control of the CPU 5 and the calculation of the CPU 5. The result is temporarily stored in RAM.

  The input / output circuit 7 is a semiconductor integrated circuit that mediates transmission / reception of signals between the external device including the sensor 2, the actuator 3, and the display 4 and the CPU 5 under the control of the CPU 5. The package is adopted. The input / output circuit 7 is a characteristic component (semiconductor integrated circuit) in the present embodiment, and details of the configuration will be described later. The bus line 8 is composed of a predetermined number of address lines, data data lines, and a predetermined number of control lines, and interconnects the CPU 5, external memory 6 and input / output circuit 7.

  The printed wiring board 9 is housed in a housing 10 and is supplied with electric power from an in-vehicle battery. The printed wiring board 9 is connected to the external device by a signal cable 11 in order to exchange signals between the input / output circuit 7 and the external device. The housing 10 is a metal container having a function as a protection component and a heat dissipation component, and is formed by, for example, aluminum die casting. The signal cable 11 is an electric wire shielded so as to prevent noise from entering, and connects the input / output circuit 7 and the external device.

FIG. 2 is a schematic diagram showing a detailed configuration of the input / output circuit 7.
2 shows a part of the input / output circuit 7 extracted for convenience of explanation, and the actual input / output circuit 7 is a signal between the plurality of sensors 2, the actuator 3 and the display 4. In order to send and receive, a number of electronic circuits and lead frames (external connection pins) are further provided.

  As shown in FIG. 2, the input / output circuit 7 is a semiconductor integrated circuit having lead frames 12 (12 a to 12 c), bonding wires 13 (13 a to 13 c), and a semiconductor chip 14 as main components. The input / output circuit 7 is configured to include all functions required by the multiple-spec electronic control unit in order to support multiple-spec electronic control units (that is, multiple types of vehicles). That is, the contents of the external device including the sensor 2, the actuator 3, and the display 4 differ depending on the vehicle type of the vehicle, but the input / output circuit 7 includes all of the contents of the sensor 2, the actuator 3, and the display 4 of a plurality of vehicle types. It is comprised so that it can respond to.

  The semiconductor chip 14 includes an input pad 15 (15a, 15b), an input side metal wiring 16 (16a, 16b), a common input processing circuit 17, a branch wiring 18, a first function-specific circuit 19, and a second function-specific circuit. 20, the output side metal wiring 21 (21a, 21b) and the output pad 22 (22a, 22b) are main components.

The input / output circuit 7 employs a DFP structure package as described above, and a rectangular semiconductor chip 14 is provided in the approximate center of the package. The lead frame 12 (12a to 12c) is for supplying a signal input from the outside to the semiconductor chip 14 and for supplying a signal output from the semiconductor chip 14 to the outside. It is formed from metal materials, such as. Among such lead frames 12 (12a to 12c), the signal input lead frames 12a and 12b are provided along the left side of the semiconductor chip 14 in the figure, and the signal output lead frame 12c in the figure. It is provided along the right side.
The bonding wires 13 (13a to 13c) are made of a highly conductive metal such as gold, platinum, or silver, and connect the lead frame 12 (12a to 12c) and the semiconductor chip 14. That is, the bonding wire 13a connects the lead frame 12a and the input pad 15a of the semiconductor chip 14, the bonding wire 13b connects the lead frame 12b and the input pad 15b of the semiconductor chip 14, and the bonding wire 13c is a semiconductor. The output pad 22ca of the chip 14 and the lead frame 12c are connected.

  The input pads 15 (15a, 15b) are connection electrodes provided on the semiconductor chip 14 in order to supply input signals to the common input processing circuit 17. The input pad 15a is connected to one end of the input side metal wiring 16a, and the input pad 15b is connected to one end of the input side metal wiring 16b. The input side metal wiring 16 (16 a, 16 b) is a metal wiring (for example, aluminum wiring) for supplying the input signal to the common input processing circuit 17. The input side metal wirings 16 a and 16 b are connected to input terminals (not shown) of the common input processing circuit 17, respectively.

  The common input processing circuit 17 is an electronic circuit that performs predetermined signal processing (common processing) on the input signal supplied to the input terminal by the input side metal wirings 16a and 16b and outputs the signal to the output terminal (not shown). The common input processing circuit 17 is alternatively supplied with an input signal from an external circuit via lead frames 12a and 12b, bonding wires 13a and 13b, input pads 15a and 15b, and input-side metal wirings 16a and 16b. . The branch wiring 18 is for supplying the output signal of the common input processing circuit 17 to the first function-specific circuit 19 and the second function-specific circuit 20, and one end is an output terminal (not shown) of the common input processing circuit 17. And the other end is a metal wiring commonly connected to an input end (not shown) of the first function-specific circuit 19 and an input end (not shown) of the second function-specific circuit 20.

  The first function-specific circuit 19 and the second function-specific circuit 20 are electronic circuits that perform individual signal processing on the output signals of the common input processing circuit 17 and output them to output terminals (not shown), respectively. One is selected and used for the external circuit. When the first function-specific circuit 19 and the second function-specific circuit 20 generate, for example, a drive signal supplied to the display 4 based on the signal input from the common input processing circuit 17, the display 4 Since the contents differ depending on the vehicle type, the display 4 driven by the first function-specific circuit 19 may be provided depending on the vehicle, but the display 4 driven by the second function-specific circuit 20 may not be provided. In such a case, although the first function-specific circuit 19 and the second function-specific circuit 20 are formed on the semiconductor chip 14, one of the second function-specific circuits 20 is considered unnecessary in terms of vehicle specifications. Become.

  The output side metal wiring 21 (21a, 21b) is a metal wiring for supplying the output signals of the first function-specific circuit 19 and the second function-specific circuit 20 to the output pad 22 (22a, 22b). The output side metal wiring 21a has one end connected to the output end (not shown) of the first function-specific circuit 19 and the other end connected to the output pad 22a. The output side metal wiring 21b has one end having the second function. The other circuit 20 is connected to an output end (not shown) and the other end is connected to the output pad 22b. The output pads 22 (22a, 22b) are connection terminals for supplying the output signals of the first function-specific circuit 19 and the second function-specific circuit 20 to the outside.

  The input / output circuit 7 (semiconductor integrated circuit), which is a characteristic component of the present embodiment, is configured as described above, but includes two first function-specific circuits 19, second function-specific circuits 20, and the first functions. One lead frame 12c is provided for the two output pads 22a and 22b for supplying the output signals of the function-specific circuit 19 and the second function-specific circuit 20 to an external circuit, and the two output pads 22a, Only one of the output pads 22a, which is alternatively selected from 22b, is connected to the lead frame 12c by the bonding wire 13c.

  That is, the second function-specific circuit 20 is formed on the semiconductor chip 14 as one of the function-specific circuits, but the output signal of the second function-specific circuit 20 is mounted on the printed wiring board 9 described above. Since it is unnecessary in relation to the external circuit, a dedicated lead frame is not provided for the output pad 22b for outputting the output signal of the second function-specific circuit 20 to the outside.

  According to the present embodiment as described above, the first function-specific circuit 19 and the second function-specific circuit 20 that are formed on the semiconductor chip 14 and in which the output signal is alternatively selected and used for external use are provided. Instead of providing a lead frame for each (that is, not providing two lead frames), only the number of lead frames 12c corresponding to the number of output signals used in the external circuit (that is, one) is provided. The number of lead frames can be reduced as compared with the case where lead frames are provided for each of the function-specific circuit 19 and the second function-specific circuit 20.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
Since this embodiment is different from the first embodiment in the configuration of the input / output circuit, this point will be mainly described. However, the description of the same components as those in the first embodiment is omitted.

  As shown in FIG. 3, the input / output circuit 7A in the present embodiment is a semiconductor integrated circuit including lead frames 121 (121a and 121b), bonding wires 122 (122a and 122b), and a semiconductor chip 123 as main components. Further, the semiconductor chip 123 includes an input pad 124 (124a, 124b), an input side metal wiring 125 (125a, 125b), a first function-specific circuit 126, a second function-specific circuit 127, and an output side metal wiring 128 (128a, 128b). ) And the output pad 129 (129a, 129b).

  As can be easily seen from FIG. 3, the input / output circuit 7A includes only the lead frame 121a for signal input, and the input pads 124 (124a, 124b) are connected via the input side metal wiring 125 (125a, 125b). A semiconductor chip 123 that is directly connected to the first function-specific circuit 126 and the second function-specific circuit 127 (that is, does not include components corresponding to the common input processing circuit 17 and the branch wiring 18 in the first embodiment); The lead frame 121a is connected to the input pad 124a by a bonding wire 122a.

  The lead frame 121b, bonding wire 122b, input pad 124b, first function-specific circuit 126, second function-specific circuit 127, output-side metal wiring 128 (128a, 128b) and output pad 129 (129a) in the input / output circuit 7A. , 129b) are the lead frame 12c, bonding wire 13c, input pad 15b, first function-specific circuit 19, second function-specific circuit 20, and output-side metal wiring 21 (21a, 21b) of the input / output circuit 7 in the first embodiment. ) And output pad 22 (22a, 22b).

  According to the second embodiment, one of the first function-specific circuit 126 and the second function-specific circuit 127 that are alternatively selected and used is provided via the lead frame 121a provided. An input signal is supplied only to the first function-specific circuit 126 that is used for the external circuit. Therefore, the number of lead frames for signal input can be reduced as compared with the case where the second function-specific circuit 127 that is not used for an external circuit is also provided with a dedicated lead frame.

The present invention is not limited to the above embodiments, and for example, the following modifications can be considered.
(1) In each of the above-described embodiments, the case where the present invention is applied to the input / output circuits 7 and 7A constituting the vehicle electronic control unit has been described, but the present invention is not limited to this. The present invention can be applied to any semiconductor integrated circuit provided with a plurality of circuits according to function which are formed on a semiconductor chip and selectively used for use.
(2) In the above embodiments, the case where the first function-specific circuits 19 and 126 and the second function-specific circuits 20 and 127 are selected alternatively is described, but the present invention is not limited to this. In the present invention, among three or more function-specific circuits (n function-specific circuits), a smaller number of function-specific circuits ((n-1) function-specific circuits) than the number of the function-specific circuits are selected. It can also be applied to the case of use (n is a natural number of 3 or more).
(3) Further, in each of the above embodiments, the case where the input / output circuits 7 and 7A have the DFP structure has been described, but the present invention is not limited to this. The present invention can be applied to a QFP structure or a BGA structure other than the DFP structure.

It is a block diagram which shows the structure of the electronic control unit which concerns on 1st Embodiment of this invention. 1 is a diagram illustrating a configuration of an input / output circuit according to a first embodiment of the present invention. It is a figure which shows the structure of the input / output circuit which concerns on 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electronic control unit 2 ... Sensor 3 ... Actuator 4 ... Indicator 7, 7A ... Input / output circuit 12a, 12b, 12c, 121a, 121b ... Lead frame 13a, 13b, 13c, 122a, 122b ... Bonding wire 14, 123 ... Semiconductor chip 19, 126... First function-specific circuit 20, 127... Second function-specific circuit

Claims (4)

A plurality of circuits provided on a semiconductor chip, a part of which is selected and used for use,
A number of lead frames corresponding to the number of the partial circuit by function;
A semiconductor integrated circuit comprising: a bonding wire that connects the part of the functional circuit and the lead frame.   2. The semiconductor integrated circuit according to claim 1, wherein when the output signals of the partial function-specific circuits are used, lead frames are provided corresponding to the number of the output signals.   3. The semiconductor integrated circuit according to claim 1, wherein the function-specific circuit is an input / output circuit that mediates transmission / reception of a signal between a control subject and an external device.   4. The semiconductor integrated circuit according to claim 1, wherein the function-specific circuit is an input / output circuit constituting a vehicle electronic control unit. 5.

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