JP2001284762A - Electronic circuit device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic circuit device whose mounting area can be reduced and which can be miniaturized and made low-cost. SOLUTION: An FET 17 and a thick-film printed resistance 18 are arranged so as to be adjacent on a ceramic substrate 11. The printed resistance 18 is formed by a printing method by using a palladium-silver (Pd-Ag) alloy so as to cross over interconnections 12, 13 which are arranged so as to be faced with each other. A copper (Cu) layer 19 as a low-impedance conductive material layer is laminated on the printed resistance 18 by a printing method in the same manner. When the printed resistance 18 is used as a shunt resistance, the mounting area of the electronic circuit device 10 can be reduced, and the circuit device can be miniaturized and made low-cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit device, and more particularly, to an electronic circuit device in which a field effect transistor (hereinafter referred to as FET) and a resistance element are mounted on a ceramic substrate.

[0002]

2. Description of the Related Art As a conventional electronic circuit device, there is an electronic circuit device having a shunt resistor 2 for monitoring a current flowing to a load FET 1 as shown in FIG. In such an electronic circuit device, a semiconductor relay system as shown in FIG. 4 is mounted on a printed wiring board. In the figure, reference numeral 3 indicates a semiconductor integrated circuit (IC). When a hybrid IC substrate is assembled in this manner, the FET 1 is mounted on a bare chip, and the shunt resistor 2 is mounted on a printed wiring board in a chip type package as shown in FIG.

The shunt resistor 2 is preferably arranged near the FET 1, but has a heat generation property,
It is arranged at a position relatively distant from ET1. As shown in FIG. 4, the mounting method of the shunt resistor 2 is such that the terminals 7 and 8 of the shunt resistor 2 are arranged so as to straddle between the wirings 5 and 6 patterned on the printed wiring board 4.
6 is connected and fixed using solder 9.

[0004]

However, in such a conventional electronic circuit device, when the allowable power becomes large, the package of the shunt resistor 2 becomes large, so that the area required for mounting becomes large and the printed wiring board becomes large. Therefore, there is a problem that the cost increases.

In order to mount such a shunt resistor 2, soldering is performed as shown in FIG. 5, but the resistance value is shifted due to a misalignment with the patterns of the wirings 5 and 6 on the printed wiring board 4. However, there is a problem that the position is greatly shifted.

Further, the shunt resistor 2 itself is, for example, 1
Although it has an accuracy of about ± 10% at 0 mΩ, there is a problem that the value is largely shifted depending on the method of soldering.

Accordingly, an object of the present invention is to provide an electronic circuit device capable of reducing the mounting area and reducing the cost.

[0008]

According to the first aspect of the present invention,
An electronic circuit device in which a shunt resistor for monitoring a current flowing to a load is mounted on a ceramic substrate, wherein the shunt resistor is a thick-film printed resistor.

According to the first aspect of the present invention, the shunt resistor is a thick-film printed resistor formed by thick-film printing, so that the mounting area can be reduced. In addition, the use of the thick-film printed resistor eliminates the need for soldering, thereby avoiding the occurrence of a large resistance value shift due to a positional shift during soldering.

According to a second aspect of the present invention, there is provided the electronic circuit device according to the first aspect, wherein the thick-film printed resistor is printed across a wiring pattern formed on the ceramic substrate, and A conductive material layer having low impedance is laminated on the thick-film printed resistor on the pattern.

Therefore, according to the second aspect of the present invention, in addition to the operation of the first aspect of the invention, a three-layer structure of a wiring pattern, a thick-film printed resistor, and a low-impedance conductive material layer is employed, for example. A minimum trimming error can be achieved when resistance adjustment processing such as laser trimming is performed.

Further, the invention according to claim 3 is the invention according to claim 1.
3. The electronic circuit device according to claim 2, wherein the thick-film printing resistor is made of Pd-Ag, and the wiring pattern is made of Pt-Ag.
The conductive material layer is made of Ag, and the conductive material layer is made of Cu.

Therefore, according to the third aspect of the present invention, in addition to the effects of the first and second aspects of the present invention, since the wiring pattern is a low impedance conductive material,
The resistance setting value can be made more accurate.

According to a fourth aspect of the present invention, there is provided the electronic circuit device according to any one of the first to third aspects, wherein:
The thick-film printing resistor transfers heat to a heat sink structure provided on a back surface side of the ceramic substrate via a thermovia.

Therefore, according to the fourth aspect of the present invention, in addition to the functions of the first to third aspects of the present invention, the thick-film printed resistor is connected to the heat sink structure provided on the back surface side of the ceramic substrate via the thermovia. As a result, the heat dissipation of the thick-film printed resistor can be enhanced, and the distance between the weak-electric component, which is easily affected by temperature, and the thick-film printed resistor can be reduced. As described above, since the length of the wiring pattern from the weak electrical component to the thick-film printed resistor can be set short, the power loss can be suppressed low.

Further, the invention according to claim 5 is the invention according to claim 1.
5. The electronic circuit device according to claim 4, wherein the load is a field effect transistor (FET) mounted on the ceramic substrate with a bare chip. 6.

Therefore, according to the fifth aspect of the present invention, in addition to the functions of the first to fourth aspects of the present invention, an FET is provided.
Since the distance between the shunt resistor and the thick-film printed resistor can be reduced, the mounting area can be reduced and the measurement accuracy of the monitor current can be improved.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electronic circuit device according to the present invention will be described in detail based on an embodiment shown in the drawings. FIG.
FIG. 2 is a plan view showing an example of the electronic circuit device of the present embodiment, and FIG.
1 is a plan view of a main part in which a part of FIG. 1 is enlarged, and FIG. 3 is a cross-sectional view of the main part of the present embodiment.

In the electronic circuit device 10 of this embodiment, FIG.
And as shown in FIG. 2, for example, an alumina-based ceramic,
Wirings 12 to 1 of a predetermined pattern are formed on a rectangular ceramic substrate 11 made of a ceramic material such as a glass ceramic.
6 are formed. The wirings 12 to 16 are formed on the surface of the ceramic substrate 11 by printing platinum-silver (Pt-Ag) having a low impedance by a printing method.

In this embodiment, as shown in FIGS. 1 and 2, the FET 17 and the thick-film printed resistor 18 are arranged in the vicinity. The thick-film printed resistor 18 is formed by printing palladium-silver (Pd-Ag) so as to straddle between the wirings 12 and 13 which are arranged and formed to face each other. Further, a copper (Cu) layer 19 as a conductive material layer having a low impedance is laminated on the thick film printed resistor 18 by the printing method.

In the electronic circuit device 10 of the present embodiment, on the ceramic substrate 11, for example, electronic components having a relatively small calorific value such as a driver IC, a FET with a built-in overheat cutoff circuit, and a temperature sensor IC, and components other than the shunt resistor are provided. A heat-generating component such as a resistance element, a relay element (including a mechanical relay), and a capacitance element that generates a relatively large amount of heat is mounted. In addition, the code | symbol 20 in a figure has shown the relay.

As shown in FIG. 3, a thermovia 21 is formed on the ceramic substrate 11 so as to be connected to at least one of the wirings 12, 13 over which the thick-film printed resistor 18 straddles and to reach the back side. Also, it has a function of efficiently transmitting the heat generated by the thick-film printing resistor 18 to the radiation fins 22.

In this embodiment, since the shunt resistor is a thick film printed resistor 18 formed by printing a thick film, the mounting area can be reduced. Also,
The use of the thick-film printed resistor 18 eliminates the need for soldering as in the related art, and prevents a large shift in resistance value due to a positional shift during soldering.

In the present embodiment, a three-layer structure of the wirings 12 and 13, the thick film printed resistor 18 and the copper layer 19 is adopted.
For example, a minimum trimming error can be achieved when a resistance adjustment process such as laser trimming is performed. Further, since the wirings 12 and 13 used in the present embodiment are also low-impedance conductive materials (Pt-Ag),
The resistance setting value can be made more accurate.

Further, in the present embodiment, since the thick-film printed resistor 18 conducts good heat transfer through the thermo-via 21 to the radiating fins 22 as a heat sink structure provided on the back side of the ceramic substrate 11, The heat radiation of the printed resistor 18 can be improved, and the distance between the weak film component such as the FET 17 and the thick film printed resistor that are easily affected by the temperature can be reduced. As described above, since the length of the wiring pattern from the weak electrical component to the thick-film printed resistor can be set short, the power loss can be suppressed low.

Further, since the distance between the FET and the shunt resistor, which is a thick-film printed resistor, can be reduced, the mounting area can be reduced and the monitor current measurement accuracy can be increased.

As described above, the electronic circuit device 1 of the present embodiment
0, the thick-film printed resistor 18 can be used as the shunt resistor, so that the mounting area can be reduced and the cost can be reduced.
8 can be immediately radiated by the radiation fins 22. For this reason, the thermal adverse effect in the electronic circuit device 10 can be significantly suppressed.

Although the embodiments have been described above, the present invention is not limited to these embodiments, and various changes accompanying the gist of the configuration are possible. For example, in the above-described embodiment, the present invention can be applied to a case where the thick film printed resistor 18 is arranged near the FET 17 and is arranged near another weak electric component as described above. Further, the copper layer 19 is laminated on the thick-film printed resistor 18 as a low-impedance conductive material, but it is of course possible to use another low-impedance conductive material.

[0029]

As is apparent from the above description, according to the first aspect of the present invention, the shunt resistor is a thick-film printed resistor formed by thick-film printing, so that the mounting area can be reduced. According to the first aspect of the present invention, the use of the thick-film printed resistor eliminates the need for soldering, and has the effect of avoiding the occurrence of a large resistance value shift due to a positional shift during soldering.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, for example, by adopting a three-layer structure of a wiring pattern, a thick-film printed resistor, and a low-impedance conductive material layer, A minimum trimming error can be achieved when resistance adjustment processing such as laser trimming is performed.

According to the third aspect of the present invention, in addition to the effects of the first and second aspects of the present invention, since the wiring pattern is made of a low-impedance conductive material, the resistance set value can be more precisely adjusted. It has the effect of raising it.

According to the invention described in claim 4, claims 1 to 1 are provided.
In addition to the effect of the third aspect of the present invention, the heat sink structure provided on the back surface side of the ceramic substrate performs good heat transfer with the thick film printed resistor through the thermovia, so that the heat dissipation of the thick film printed resistor is achieved. And the arrangement distance between the weak electric component which is easily affected by the temperature and the thick-film printing resistor can be reduced. As described above, since the length of the wiring pattern from the weak electric component to the thick-film printed resistor can be set short, there is an effect of suppressing the power loss.

According to the invention described in claim 5, claims 1 to 5
In addition to the effect of the fourth aspect of the present invention, the distance between the FET and the shunt resistor, which is a thick-film printed resistor, can be reduced, so that the mounting area can be reduced and the monitor current measurement accuracy can be increased.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of an electronic circuit device according to the present invention.

FIG. 2 is an enlarged plan view of a main part of the electric circuit device shown in FIG. 1;

FIG. 3 is a sectional view of a main part of the embodiment.

FIG. 4 is an equivalent circuit diagram showing a semiconductor relay system mounted on the electronic circuit device.

FIG. 5 is a cross-sectional view illustrating a mounting structure of a shunt resistor in a conventional electronic circuit device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 electronic circuit device 11 ceramic substrate 12, 13 wiring 17 FET 18 thick film printed resistor 19 copper layer 21 thermovia 22 radiating fin

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 3/34 H05K 3/34 7/20 7/20 F (72) Inventor Hiroaki Ito Washizu, Kosai City, Shizuoka Prefecture 2464-48 Yazaki Parts Co., Ltd. (72) Inventor Shigeru Kamiya 206-1 Nunobikihara, Haibara-cho, Haibara-gun, Shizuoka Prefecture Yazaki Parts Co., Ltd. (72) Inventor Toshihiko Arai Nichicon Co., Ltd. (72) Inventor Takayuki Yamamoto 4th Uehara Bldg. 3rd floor, Nichicon Co., Ltd. 72) Inventor Shuichi Murayama First floor of Uehara Bldg. 3F, 191 Nakaboricho, Ichidori-Karasuma Higashi-iri, Nakagyo-ku, Kyoto-shi, Kyoto Pref. ) 4E351 AA01 AA07 BB01 BB05 BB23 BB24 BB31 BB35 DD04 DD05 DD20 DD22 GG06 GG20 5E028 AA04 BA07 BB01 GA02 5E033 AA23 BA01 BB09 BG02 BH03 5E319 AA03 AA07 AB05 AC04 CC22 5E322 AA01 FA04

Claims (5)

[Claims] 1. An electronic circuit device having a shunt resistor for monitoring a current flowing to a load mounted on a ceramic substrate, wherein the shunt resistor is a thick-film printed resistor. apparatus. 2. The electronic circuit device according to claim 1, wherein the thick-film printed resistor is printed across a wiring pattern formed on the ceramic substrate, and the thick-film printed resistor on the wiring pattern is provided. An electronic circuit device, wherein a conductive material layer having a low impedance is laminated on the substrate. 3. The electronic circuit device according to claim 1, wherein the thick-film printed resistance is made of Pd-Ag, the wiring pattern is made of Pt-Ag, and the conductive material layer is made of Pt-Ag. An electronic circuit device comprising Cu. 4. The electronic circuit device according to claim 1, wherein the thick-film printed resistor is connected to a heat sink structure provided on a back side of the ceramic substrate via a thermovia. An electronic circuit device that performs transmission. 5. The electronic circuit device according to claim 1, wherein the load is a field effect transistor mounted on the ceramic substrate with a bare chip. .