JPH0442943Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a hybrid integrated circuit having a wiring structure that allows easy positioning of mounted components and reduces heat generation.

(Prior Art) The problems of a hybrid integrated circuit including a power circuit section such as a power transistor chip will be explained with reference to the circuit. FIG. 1 is a schematic diagram of a circuit including a power circuit section, where 1 is a ground terminal, 2 is a power terminal, and a control circuit section 5 and a power circuit section 6 are connected in series between an input terminal 3 and an output terminal 4. connected. The control circuit section 5 outputs a required control signal based on the input signal, and the power circuit section 6 outputs a drive signal to the output terminal 4 based on this control signal. Usually, a load such as a solenoid or a lamp is connected to the output terminal 4, and a required drive current is supplied to these loads.

FIGS. 2 and 3 show conventional examples in which the above circuit is constructed from a hybrid integrated circuit. The second is a plan view, and FIG. 3 is a sectional view taken along the line A--A in FIG. In this figure,
5 is a control circuit section, and 6 is a power circuit section. In the power circuit section 6, a ceramic substrate 9 is provided on a heat sink 7 with a solder layer 8 interposed therebetween, and the power circuit section is constructed on this. First, a heat sink 12 and a bonding post 13 are placed on a ceramic substrate 9 via a printed and fired conductor 10 made of, for example, Ag--Pd and a solder layer 11. The heat sink 12 serves as a heat dissipation conductor for the power transistor chip 14, and the bonding post 13 is used to take out the collector electrode of the power transistor. Before forming the printed solder layer 11, an over glass 15 for positioning the bonding post 13 is printed and fired. A power transistor chip 1 is placed on the heat sink 12 via a high temperature solder layer 16.
4 is mounted, and this power transistor chip 1
The emitter and base of No. 4 are connected to the control circuit section 5 with aluminum wires 17, 17. On the other hand, the bonding post 13 is also connected to the control circuit section 5 with an aluminum wire 17.

In the above, a current flows in the power circuit section 6 as shown by the broken line _I1 in FIG. Therefore, a large current flows through the printed and fired conductor 10, and it is necessary to widen the pattern width of this conductor in accordance with the amount of current. Furthermore, since it is necessary to print and bake the over glass 15 in order to position the bonding post 13, there is a drawback that the cost of the power circuit section 6 increases. In addition, the printed fired conductor 10
When using Ag-Pd, the conductor resistance increases, so when viewed from the output terminal side, the saturation voltage of the power transistor increases by the voltage drop due to the conductor resistance, which increases the amount of heat generated by the hybrid integrated circuit. It had the following drawback.

(Purpose of the invention) The present invention was made to solve the above-mentioned problems, and the width of the wiring pattern of the printed fired conductor for carrying electricity in the power circuit section etc. is kept almost constant regardless of the amount of current, and the printed It is an object of the present invention to facilitate positioning of electrodes when attaching them by forming a fired conductor, and to reduce heat generation by reducing the resistance value of the printed fired conductor.

(Structure of the invention) The hybrid integrated circuit according to the invention includes a plurality of mounting lands and wiring sections between these mounting lands made of printed and fired conductors, and a single electrode component such as a bonding post on each mounting land. In a hybrid integrated circuit in which circuit components are fixed by soldering, the mounting land on which the single electrode component is fixed has approximately the same shape as the end face shape of the single electrode component, and At least two wiring parts should be placed in a symmetrical positional relationship between the wiring parts, and the wiring parts should be arranged radially from the center of the mounting land on which the single electrode component is fixed, and the wiring parts formed by the adjacent wiring parts. They are formed so that the angles are equal, and printed solder for fixing the single electrode component is applied onto the mounting land and these wiring parts after being melted in a reflow oven.

(Embodiment) A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 4 is a plan view of a hybrid integrated circuit according to the present invention;
FIG. 5 is a sectional view taken along the line BB in FIG. 4.

Reference numeral 18 denotes a heat sink, which is made of, for example, a nickel-plated copper plate. A solder layer 19 is printed on the upper surface of this heat sink 18, and a ceramic substrate 20 is further provided on the solder layer 19. On the ceramic substrate 20, a thickness having a predetermined shape is formed.
A printed fired conductor 21 of 20μ is formed. For example, Ag-Pd is used for this printed and fired conductor 21.
The planar shape of the printed and fired conductor 21 is as shown in FIG. 6, and consists of a land 21a on which a power transistor chip is placed and a land 21b on which a collector bonding post is placed, and between these 21a and 21b. are the two wiring sections 2 in symmetrical positions.
1c and 21c in a divided state. A heat sink 23 made of a 1 mm thick copper plate is provided on the land 21a via a 200 μ thick solder layer 22, and a power transistor chip 25 is mounted on the heat sink 23 via a high temperature solder layer 24 by printing or coating. It is placed. on the other hand,
The land 21b has a solder layer 26 similar to that described above.
Attach the bonding post 27 via the.
This bonding post 27 constitutes a collector electrode. In this case, the soldering land 21b of the bonding post 27 has the same cross-sectional shape as the bonding post, and has a larger diameter by about 0.5 to 1 mm. In this way, the power circuit section 6 is formed.

Next, the manufacturing procedure will be described. First, the power transistor chip 25 is placed on the heat sink 23 on which the high-temperature solder layer 24 is placed, and the chip is integrated by passing it through a high-temperature reflow oven. After that, the heat sink 23 and the bonding post 27 are
It is placed on a ceramic substrate 20 having a printed fired conductor 21 and solder layers 22 and 26, and is integrated by passing it through a reflow oven again. Further, the integrated product is placed on the heat sink 18 via the solder layer 19, and passed through a reflow oven. In this way, the power circuit portion of the hybrid integrated circuit is formed.

On the other hand, on the other part of the heat sink 18, a controller ceramic substrate 28, on which various control elements and parts are soldered, is fixed with adhesive.
For example, aluminum wires 30, 31, 32 with a diameter of 0.3 mm are connected between the emitter, base electrodes and collector bonding posts 27 of the power transistor chip 25 and the bonding posts 29 of the control circuit section. Ru.

In the above, in the power circuit section 6 of the hybrid integrated circuit, as shown by the broken line _I2 , collector aluminum wire 32 → bonding post 27 → printed fired conductor 21 and printed solder layers 22, 26 → heat sink 23 → high temperature solder layer 24 → Emitter of power transistor chip 25 → Aluminum wire for emitter 3
0 and current flows. In such current route _I2 , bonding post 27 is connected as shown in FIG.
The wiring between the bonding post 27 and the heat sink 23 consists of lands 21b and 21a on which the bonding post 27 and the heat sink 23 are placed, respectively, and two wiring parts 21c and 21c that connect these and are divided symmetrically about the axis C. It was formed by a printed fired conductor 21. As a result, the current flowing through the current route I ₂ flows through the printed and fired conductor 21 and the solder layers 22 and 26 while being divided at the wiring portions 21c and 21c.

In the above, the width of the wiring portions 21c, 21c is smaller than the diameter of the bonding post 27. As described above, the wiring between the bonding post 27 and the heat sink 23 is divided into two parts, and the printed solder layers 22 and 26 are formed on the printed fired conductor 21, so that the width of the wiring part can be reduced and The resistance of the current-carrying section as a whole can be reduced. Also bonding post 27
In the conductor portion 21b on which the bonding post 27 is placed, the wiring portions 21c, 21c are pulled out symmetrically in opposite directions, so that the surface tension of the solder layer 26 can be evenly distributed when it is melted. can be done accurately.

FIG. 7 shows a second embodiment of the invention. In this embodiment, wiring portions 33c are symmetrically drawn out in four directions between a land 33a on which the heat sink 23 is placed on the printed fired conductor 33 and a land 33b on which the bonding post 27 is placed. Connect with... With such a wiring structure, the bonding post 27 can be accurately positioned by the same effect as described above, and the resistance of the current-carrying portion between the bonding post 27 and the power transistor chip 25 can be reduced. can.

Note that the number of the above-mentioned wiring portions can also be further increased.

The wiring structure of the power circuit section of the hybrid integrated circuit according to the present invention can be applied not only to power circuit components but also as a method for locating small signal circuit components.

(Effect of the invention) As is clear from the above explanation, according to the invention,
The positioning of the mounted components can be easily performed by the shape of the wiring part formed by the printed and fired conductor, which reduces the need for conventional positioning components.
Simplification of the manufacturing process can be achieved. Furthermore, since the resistance of current-carrying parts including wiring parts can be reduced, the overall heat generation amount can be reduced.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of a circuit including a power circuit, etc., Figure 2 is a plan view of a conventional hybrid integrated circuit that realizes the circuit in Figure 1, and Figure 3 is a cross-sectional view taken along line A-A in Figure 2. , FIG. 4 is a plan view of the hybrid integrated circuit according to the present invention, FIG. 5 is a sectional view taken along line B-B in FIG. 4, FIG. 6 is a diagram showing the shape of the printed and fired conductor, and FIG. 7 is a diagram similar to FIG. 6 according to a second embodiment of the invention; FIG. 5... Control circuit section, 6... Power circuit section, 7,
18... Heat sink, 8, 10, 11, 16, 19,
22, 24, 26... Solder, 9, 20... Ceramic substrate, 10, 21, 33... Printed fired conductor,
12, 23... Heat sink, 13, 27... Bonding post, 14, 25... Power transistor chip, 21a, 21b, 33a, 33b...
...Land, 21c, 33c...Wiring section.

Claims (1)

[Scope of utility model registration request] A hybrid structure in which multiple mounting lands and the wiring between these mounting lands are formed of printed and fired conductors, and single electrode parts such as bonding posts and circuit components are fixed to each of the mounting lands by soldering. In the integrated circuit, the shape of the mounting land on which the single electrode component is fixedly mounted is substantially the same as the end face shape of the single electrode component, and at least two wiring portions are symmetrically arranged between the mounting land and the mounting land. In addition, the wiring portions are formed so as to radiate out from the center of the mounting land on which the single electrode component is fixed, and the angles formed by adjacent wiring portions are equal. 1. A hybrid integrated circuit characterized in that a printed solder for fixing the single electrode component is applied onto the mounting land and the wiring portion thereof after being melted in a reflow oven.