JPS61230363A - Semiconductor integrated device - Google Patents

Abstract

PURPOSE:To form the titled device in a small mounting area without requiring the external attaching of a resistor isolating a circuit input section or output section for a semiconductor chip, in which a predetermined circuit is integrated, and an external terminal in a high-frequency manner by connecting the resistor in series between both the circuit input section or output section and the external terminal. CONSTITUTION:One parts of a lead frame 11 for an input (output) section required are cut, and resistors R are inserted to the cut sections. Consequently, suitability to an electromagnetic environment can be improved on the IC side, thus increasing the degree of freedom in the design, then eliminating the need for a countermeasure to the electromagnetic environment in a system into which an IC is incorporated. A mounting area is not made wider than the countermeasure of improvement by external attaching parts, high-density mounting is enabled, and these effects are effective for not only the case when an analog IC malfunctions by an electromagnetic field from the outside but also the case when an IC into which a clock source is incorporated leaks out a clock component to the outside as seen in a microprocessor, a successive comparison A/D converter, etc. and other apparatus are malfunctioned.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor integrated device with improved electromagnetic environment compatibility.

[Conventional technology]

As electronic devices become more diverse and universal, the environments in which they are used are also becoming more diverse. Among these, in-vehicle equipment can be cited as an example of equipment used under poor electromagnetic environment conditions. There are two cases for this. One is a case in which in-vehicle electronic equipment is affected by the ignition noise of the car or electromagnetic waves emitted by an on-board wireless communication device. In this case, if the device is used to control the running of a car, such as engine control, it is dangerous because its malfunction could endanger human life. In other cases, in-vehicle electronic equipment becomes a source of electromagnetic waves, and the noise components it generates (clock frequency electromagnetic waves, etc.) have an adverse effect on other in-vehicle equipment (for example, radio receivers) installed in the same vehicle interior. This is a case where

Conventionally, in order to increase the electromagnetic compatibility of electronic equipment used in such an electromagnetic environment, an insertion resistor R is sometimes used as shown in FIG. 4. This resistance R is comparator 1
The impedance is selected to be sufficiently small compared to the input impedance of an analog IC such as the A/D converter 2 (the circuit input part is generally the base of a PNP transistor) and can be ignored in terms of circuit operation (for example, IKΩ or less). The function of this resistor R has not been fully elucidated theoretically, but it has been empirically confirmed that it has a high-frequency blocking function similar to a low-pass filter in high frequency bands (for example, 100 MHz or higher). It may also be used in input (output) terminals of processors.

It is used at the input of a comparator or A/D converter to block external influences, and at the output of a microprocessor to prevent clock components from leaking to the outside.

[Problem that the invention seeks to solve]

However, if the above-mentioned resistor R is externally attached to the outside of the IC, the mounting area will be expanded by the resistor R, and
There is a drawback that if the wiring 3 between the IC 1 and the IC 2 becomes long, the effect will be lost. The present invention attempts to improve this point.

[Means for solving problems]

The present invention is characterized in that a resistor is connected in series between a circuit input section or an output section of a semiconductor chip in which a predetermined circuit is integrated and an external terminal to isolate the two in terms of high frequency. be.

[Effect]

If the IC configuration is such that a resistor R is inserted between the circuit input section or output section of a semiconductor chip that integrates a predetermined circuit and an external terminal to isolate the two in terms of high frequency, it is not necessary to connect the resistor R externally. Since there is no wiring, the mounting area is small, and the wiring 3 between the resistor and rc shown in FIG. 4 is not a problem at all.This will be explained in detail below with reference to the illustrated embodiment.

〔Example〕

FIG. 1 shows an embodiment of the present invention, where 10 is an IC chip, 11 is an IC chip, and 11 is an IC chip.
1 is a lead frame (external terminal), and 12 is a bonding wire connecting therebetween. Up to this point, it is a general IC.
However, in this example, a part of the lead frame 11 of the required input (output) blade part is cut and the above-mentioned resistor R is installed there.
Insert.

The resistor R in this example is of a chip type and is connected to the cut portion of the lead frame 11 by soldering.

FIG. 2 shows another embodiment of the invention. In this example, NiCr is used instead of the normal bonding wire 12.

Resistor R using high resistance bonding wire such as T1Ni
This has been realized. This high resistance bonding wire R is also provided from the lead frame 11 to the input (output) pad of the IC chip 10 in the same way as the normal bonding wire 12.

FIG. 3 shows an embodiment in which a resistor R is formed on the IC chip 10. In FIG. In the figure, 13 is the 5102nd layer on the front surface, 14 is a pad connected to a lead frame (not shown) with a bonding wire, and 15 is an A1 wire that connects the pad to the circuit board inside the IC chip. It is a layer. In this example, this AI wiring layer 15 is partially cut and a thin film resistor R is formed there. This i1m resistance resistance, NiCr, 'ra
It is formed by depositing 15n02 or the like by vapor deposition, sputtering, or the like.

〔Effect of the invention〕

As described above, according to the present invention, electromagnetic environment compatibility is
Since improvements can be made on the c side, the degree of freedom in design increases, and the
This has the advantage of eliminating the need for electromagnetic environment countermeasures in systems that incorporate Furthermore, external mounting does not increase the mounting area compared to improvement measures using parts (as shown in FIG. 4 as an example), and high-density mounting is possible.

These effects occur not only when analog ICs malfunction due to external electromagnetic fields, but also when ICs with built-in clock sources such as microprocessors, successive approximation A/D converters, etc. It is also effective in cases where other equipment malfunctions due to leakage (including waves).

[Brief explanation of the drawing]

1 to 3 are configuration diagrams showing different embodiments of the present invention,
FIG. 4 is a circuit diagram showing an example of conventional electromagnetic environment countermeasures. In the figure, 10 is an IC chip, 11 is an external terminal, 12 is a bonding wire, 14 is a pad, 15 is a wiring layer, and R is a high frequency blocking resistor. Applicant Fujitsu Ten Ltd. Representative Patent Attorney Minoru Aoyagi 2 Tojinai Tohiguchi's *1t item 11 Figure 1 Hoyo 60 Oshiborori 2 Figure 2 n 1lfl *柁' column 3 13 Figure 1 Enrollment 19 e1 Establishment 6H Ri Figure 4

Claims (1)

[Claims] 1. A semiconductor integrated device comprising a resistor connected in series between a circuit input section or an output section of a semiconductor chip on which a predetermined circuit is integrated and an external terminal to isolate the two in terms of high frequency.