This application is based upon and claims the benefits of priority from Japanese patent application No. 2006-345439 filed on Dec. 22, 2006, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to semiconductor devices and, in particular, to power supply for semiconductor devices.
2. Description of the Related Art
Conventionally, power supply to a semiconductor device is performed by connecting the power supply in parallel to a plurality of internal circuits making up the semiconductor device.
Referring to
In the case of a multi-chip package (MCP) semiconductor device composed of a plurality of semiconductor chips, power supply voltage is supplied in parallel to the individual semiconductor chips. As shown in
In order to reduce the voltage drop in a power supply path, there are known techniques for reducing the resistance of the power supply path itself. For example, Japanese Laid-Open Patent Publication 2004-260059 (Patent Reference 1) discloses a technique in which voltage drop is controlled by connecting between a power supply pad for internal circuit of a flip-chip type semiconductor device and a power supply pad for input/output buffer by means of aluminum wiring in the uppermost layer.
The problem of voltage drop occurring in power current paths during power supply has become more notable as a result of refinement of circuit configuration, reduction of power supply voltage, and increase of power consumption.
Patent Reference 1 mentioned in the above tries to solve this problem by reducing the resistance of a power supply path itself.
The present invention seeks to solve the problem mentioned above by improving the connection of the power supply voltage supply path.
The present invention provides a semiconductor device composed of a plurality of components, wherein low-potential side power supply lines and high-potential side power supply lines of the plurality of components are connected such that the components are sequentially connected in series with respect to power supply voltage, so that the semiconductor device is supplied with power supply voltage of a value obtained by adding values of predetermined operating voltage of the respective components.
Desirably, a capacitor is arranged between the low-potential side power supply line and the high-potential side power supply line of each of the plurality of components.
According to one aspect of the present invention, the semiconductor device is composed of a single semiconductor chip, and the plurality of components are n (n is a natural number of two or more) internal circuit regions obtained by dividing the internal circuit of the semiconductor chip into n regions such that they consume substantially equivalent power. Connection is made such that the low-potential side power supply lines of the n internal circuit regions are respectively supplied with ground voltage and voltage of values obtained by multiplying the predetermined operating voltage value by one, two, . . . , and (n−1) while the high-potential side power supply lines are respectively supplied with voltage of values obtained by multiplying the predetermined operating voltage value by one, two, . . . , (n−1), and n, and the respective internal circuit regions are supplied with the predetermined operating voltage.
According to another aspect of the present invention, the semiconductor device is a multi-chip package semiconductor device having a plurality of semiconductor chips as the plurality of components. Low-potential side power supply lines and high-potential side power supply lines of the plurality of semiconductor chips are connected such that the semiconductor chips are sequentially connected in series with respect to power supply voltage, so that the semiconductor device is supplied with power supply voltage of a value obtained by adding values of the predetermined operating voltage of the respective components.
According to still another aspect of the invention, the semiconductor device is a multi-chip package semiconductor device having n (n is a natural number of two or more) semiconductor chips with identical configuration as the plurality of components. Connection is made such that the low-potential side power supply lines of the n internal circuit regions are respectively supplied with ground voltage and voltage of values obtained by multiplying the predetermined operating voltage value by one, two . . . , and (n−1) while the high-potential side power supply lines are respectively supplied with voltage of values obtained by multiplying the predetermined operating voltage value by one, two, . . . , (n−1), and n, and the respective internal circuit regions are supplied with the predetermined operating voltage.
According to still another aspect of the invention, the semiconductor device is a stacked semiconductor device formed by stacking a plurality of semiconductor chips as the plurality of components. Low-potential side power supply lines and high-potential side power supply lines of the plurality of semiconductor chips are connected such that the semiconductor chips are sequentially connected in series with respect to power supply voltage, and the semiconductor device is supplied with power supply voltage of a value obtained by adding values of the predetermined operating voltage of the respective semiconductor chips.
According to still another aspect of the invention, the semiconductor device is a stacked semiconductor device formed by stacking n (n is a natural number of two or more) semiconductor chips having identical configuration as said plurality of components. Connection is made such that the low-potential side power supply lines of the n semiconductor chips are respectively supplied with ground voltage and voltage of values obtained by multiplying the predetermined operating voltage value by one, two . . . , and (n−1) while the high-potential side power supply lines are respectively supplied with voltage of values obtained by multiplying the predetermined operating voltage value by one, two, . . . , (n−1), and n, and the respective semiconductor chips are supplied with the predetermined operating voltage.
Further, the present invention provides a power supply method for a semiconductor device composed of a plurality of components, wherein low-potential side power supply lines and high-potential side power supply lines of the plurality of components are connected such that the components are sequentially connected in series with respect to power supply voltage, and the semiconductor device is supplied with power supply voltage of a value obtained by adding values of predetermined operating voltage of the respective components.
According to the present invention, the semiconductor device has an internal circuit divided into n regions consuming equivalent power or is composed of n semiconductor chips also consuming equivalent power. These internal circuit regions or semiconductor chips are connected in series in terms of the supply of power supply voltage. The semiconductor device is supplied with the power supply voltage of a value obtained by adding values of predetermined operating voltage of the internal circuit regions or the semiconductor chips. In this manner, the plurality of the internal circuit regions or semiconductor chips can be operated while controlling the increase of electric current to be supplied. As a result, the voltage drop in the wiring lines can be reduced.
A semiconductor device according to preferred embodiments of the present invention will be described with reference to the accompanying drawings.
A first exemplary embodiment of the present invention will be described with reference to
As shown in
Accordingly, the internal circuit regions are connected in series with respect to the power supply, while each of the low-potential side internal wiring lines and each of the high-potential side internal wiring lines are connected in series, forming a current supply path for supplying current to the semiconductor device 1.
An inter-connecting wiring line is led out from each connection between the low-potential side wiring lines and the high-potential side wiring lines. The inter-connecting wiring line is supplied with an intermediate voltage between the ground and the power supply voltage VDD. The intermediate voltage is set such that the difference between voltages applied to the high-potential side wiring line and the low-potential side wiring line in each of the internal circuit regions (1-A, 1-B, 1-C, 1-D) is a predetermined operating voltage (1.8 V) for the internal circuit regions. Specifically, the inter-connecting wiring lines (5-4, 5-3, 5-2) are supplied with a voltage of 1.8V, 3.6V, and 5.4V, respectively, via connection terminals.
Further, a capacitor is connected to form capacitance between the ground and the inter-connecting wiring line (5-4), between the inter-connecting wiring lines, and between the inter-connecting wiring line (5-3) and the power supply line.
When the semiconductor device is operated with the internal circuit regions connected as described above and with the power supply VDD of 7.2V, electric current of 0.5 A will flow through the internal circuit regions and the power supply lines including the low-potential side wiring lines and high-potential side wiring lines.
Whereas an electric current of 2 A flows through power supply lines according to the related art shown in
As described above, when the power supply lines are connected in series, any variation in power consumption among the internal circuit regions will lead to variation in voltage supplied to the internal circuit regions. According to the present invention, the power supply lines mutually connecting the internal circuit regions in series are led out as intermediate power supply lines and intermediate voltages are supplied thereto, whereby variation in voltage caused by variation in power can be absorbed. These intermediate power supply lines only have to be supplied with electric current corresponding to the variation in power between the internal circuit regions, and hence very low resistance may not be required of the power supply lines. Further, as for the variation in power occurring in a short period of time, the variation in voltage associated thereto can be absorbed by connecting a capacitance.
The semiconductor device according to the first exemplary embodiment of the invention has an internal circuit divided into n (n is a natural number of two or more) regions, and the low-potential side and high-potential side power supply lines of the internal circuit regions are connected in series. A voltage that is n times higher than a predetermined operating voltage is supplied as power supply, while the predetermined operating voltage is supplied to each of the internal circuit region via the corresponding intermediate power supply line.
Electric current flowing through the semiconductor device is reduced to 1/n, whereby the drop in the power supply voltage can be reduced to 1/n. Further, the variation in voltage can be absorbed by providing a capacitance between the power supply lines between the internal circuit regions.
A second exemplary embodiment of the present invention will be described with reference to the drawings.
Referring to
The semiconductor device 10 has four semiconductor chips (10-A, 10-B, 10-C, 10-D) mounted thereon. It is assumed here that these semiconductor chips operate with an operating voltage of 1.8 V and a power consumption of 0.9 W (electric current of 0.5 A).
The semiconductor chips (10-A, 10-B, 10-C, 10-D) each include a low-potential side wiring line and a high-potential side wiring line. The low-potential side wiring line (6-1) of the semiconductor chip (10-A) is connected to the high-potential side wiring line (7-2) of the semiconductor chip (10-B). An inter-connecting wiring line (9-2) is led out from the connecting point between these lines. Likewise, the low-potential side wiring line (6-2) of the semiconductor chip (10-B) is connected to the high-potential side wiring line (7-3) of the semiconductor chip (10-C), and an inter-connecting wiring line (9-3) is led out from the connecting point between these lines. The low-potential side wiring line (6-3) of the semiconductor chip (10-C) is connected to the high-potential side wiring line (7-4) of the semiconductor chip (10-D), and an inter-connecting wiring line (9-4) is led out from the connecting point between these lines. Further, the high-potential side wiring line (7-1) of the semiconductor chip (10-A) is connected to a power supply terminal via a lead line. A power supply voltage VDD of 7.2 V is supplied to the power supply terminal from a power supply. On the other hand, the low-potential side wiring line (6-4) of the semiconductor chip (10-D) is connected to a ground terminal, via a lead line, to be supplied with ground potential from the power supply.
Accordingly, the semiconductor chips are connected in series with respect to the power supply, and the low-potential side and high-potential side wiring lines are connected in series to the electric current supply paths connected in series to the power supply of the semiconductor device 1.
The inter-connecting wiring lines are each supplied with an intermediate voltage between the ground and the power supply voltage VDD. The intermediate voltage is set such that the differential voltage between the high-potential side wiring line and the low-potential side wiring line of each of the semiconductor chips (10-A, 10-B, 10-C, 10-D) becomes a predetermined operating voltage (for example, 1.8 V) for the chip. Specifically, the inter-connecting wiring lines (9-4, 9-3, 9-2) are supplied with a voltage of 1.8 V, 3.6 V, and 5.4V, respectively.
Further, a capacitor is connected to form capacitance between the ground and the inter-connecting wiring line (9-4), between the inter-connecting wiring lines, and between the inter-connecting wiring line (9-2) and the power supply line.
Each of the semiconductor chips (10-A, 10-B, 10-C, 10-D) is activated by being supplied with a voltage such that the differential voltage between the high-potential side and low-potential side wiring lines thereof becomes a predetermined operating voltage (1.8 V). In this case, an electric current of 0.5 A flows through the semiconductor chips. The electric current flowing through the semiconductor chips is reduced to a quarter, namely 0.5 A according to present invention, whereas electric current flowing through semiconductor chips is 2 A when the power supply is connected in parallel as shown in
As described above, when the power supply line is connected in series, any variation in power consumption among the internal circuit regions will lead to variation in voltage supplied to the internal circuit regions. According to the second exemplary embodiment of present invention, the power supply lines mutually connecting the internal circuit regions in series are led out as intermediate power supply lines and an intermediate voltage is supplied to each of them, whereby variation in voltage caused by variation in power can be absorbed. These intermediate power supply lines only have to be supplied with electric current corresponding to the variation in power between the internal circuit regions, and hence very low resistance may not always be required of the power supply lines. Further, as for the variation in power occurring in a short period of time, the variation in voltage associated thereto can be absorbed by connecting a capacitor.
As shown in
A capacitance element is formed each between the low-potential side through electrode 331 and the high-potential side through electrode 341, between the high-potential side through electrode 341 and the through electrode 351, between the through electrodes 351 and 352, and between the through electrode 352 and the through electrode 353. Accordingly, in this semiconductor device, including from the lowermost semiconductor chip to the uppermost semiconductor chip, a serial connection is established between the ground and the power supply voltage VDD in terms of the supply of power supply voltage. The low-potential side wiring lines and high-potential side wiring line in the chips are also connected in series as a power supply path. The high-potential side through electrodes of the chips except for the uppermost chip, specifically those of the lowermost chip, the second from the lowermost chip, and the third from the lowermost chip are supplied with an intermediate voltage of 1.8 V, 3.6 V, and 5.4 V, respectively.
The through electrodes to be used in the semiconductor chip according to the present invention may be, for example, those disclosed in Japanese Laid-Open Patent Publication No. 2002-305283.
Each of the semiconductor chips (30-A, 30-B, 30-C, 30-D) is activated by being supplied with a predetermined operating voltage (1.8 V) between the high-potential side wiring line and the low-potential side wiring line thereof. In this case, electric current of 0.5 A flows through the semiconductor chips. When the power supply is connected in parallel as shown in
In the exemplary embodiments described above, the internal circuit regions or the semiconductor chips operate with a same operating voltage and power. However, the present invention is not limited to this and is also applicable to a case in which the internal circuit regions or the semiconductor chips operate with different operating voltages but with a substantially same operating current. In the exemplary embodiment shown in
In this case, it will suffice to supply a voltage, as an intermediate voltage to the respective semiconductor chips, obtained by sequentially adding the respective operating voltages in the power supply direction from the ground GND. Specifically, intermediate voltages of 1.5 V, 3.3 V and 5.1 V, and a power supply voltage VDD of 6.9 V are supplied to the semiconductor chips, respectively. The supply of the voltage obtained by adding respective operating voltages enables each of the semiconductor chips to be supplied with the predetermined operating voltage of 1.5V or 1.8V through the low-potential side and high-potential side wiring lines.
According to the present invention, the low-potential side and high-potential side wiring lines of the n components forming the semiconductor device are connected in series between the ground voltage GND and power supply VDD, so that a predetermined operating voltage is supplied to each of the components. If the semiconductor device is composed of a single chip, the internal circuit is divided into a plurality of regions as the components such that the current consumption is the same among the components. If the semiconductor device is composed of a plurality of semiconductor chips, these semiconductor chips are the components, each of which is supplied with a voltage obtained by adding the predetermined operating voltages as the intermediate power supply or the power supply VDD. The voltage is supplied such that the differential voltage between the low-potential side and high-potential side wiring lines of each internal component is equal to the predetermined operating voltage. This configuration reduces the electric current flowing through the semiconductor device to 1/n, which enables the reduction of the drop of the power supply voltage to 1/n. Further, the provision of a capacitance between the power supply lines of the respective internal components makes it possible to absorb variation in voltage.
Having described exemplary embodiments of the present invention in a rather specific manner, the present invention is not limited to these exemplary embodiments. It should be understood that various modifications can be made without departing from the spirit and scope of the invention, and all such modifications are also covered by the appended claims.
Number | Date | Country | Kind |
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2006-345439 | Dec 2006 | JP | national |