JPH07321433A - Thick film circuit board device - Google Patents

Abstract

(57) [Abstract] [Purpose] In the cross wiring of conductors on thick film circuit board,
An object of the present invention is to make it possible to flexibly cope with the length of cross wiring without complicating the structure. A hybrid integrated circuit device in which circuit elements formed on a single-layer thick film substrate 1 are electrically connected by conductors,
Between the conductors 2a and 2b where the conductor 2c intersects, the conductor 2
The bonding wires 3 directly bonded to a and 2b are used for cross wiring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thick film circuit board device in which circuit elements formed on a thick film board are electrically connected by conductors.

[0002]

2. Description of the Related Art Conventionally, in a thick film circuit board device of this type, in order to make a cross wiring at a place where conductors cross each other, FIG.
As shown in, the insulators 11a and 11b are formed on the thick film substrate 10.
The conductors 12a and 12b are cross-wired through the conductors, or the conductors 21a and 21b on the thick film substrate 20 are connected as shown in FIG.
A bridge component 22 is provided on the above to perform cross wiring with respect to the conductor 21c.

[0003]

However, the former one has a problem that the structure is complicated due to the multi-layer structure, and the latter one has a bridge component having a shape corresponding to the length of the cross wiring. Since a large number of types must be prepared in advance and they must be handled in the same way as parts in terms of mounting, there is a problem that the cost is high and it is difficult to flexibly deal with them.

The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to flexibly cope with the length and the like of intersecting wirings without complicating the structure.

[0005]

In order to achieve the above-mentioned object, the present invention provides a thick film in which circuit elements formed on a thick film substrate are electrically connected by a conductor. The circuit board device is characterized in that the conductors at the locations intersecting with other conductors of the conductors are cross-wired by bonding wires directly bonded to the conductors.

Further, in the invention described in claim 2, in the invention described in claim 1, the thick film substrate is a single layer substrate.

[0007]

In the invention described in claim 1,
Since the cross-wiring is done with the bonding wires directly bonded to the conductors, cross-wiring can be realized without complicating the structure, and even if the distance between the conductors is different, You can respond flexibly.

Further, as in the second aspect of the invention, even if the thick film substrate is a single layer substrate, it is possible to realize cross wiring similar to a multilayer substrate.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial cross-sectional perspective view showing a part of a hybrid integrated circuit device as a thick film circuit board device. In FIG. 1, conductors 2a and 2b and a conductor 2c wired between them are formed on the surface of a single-layer thick film substrate 1. In addition,
A plurality of conductors for electrically connecting circuit elements are formed on the thick film substrate 1, and FIG. 1 shows a part thereof.

Here, the feature of this embodiment is that
This is the point that the conductor 2c is cross-wired between the conductors 2a and 2b by the bonding wire 3. The bonding wire 3 is connected to the conductors 2a and 2b by direct wire bonding. In order to perform such direct wire bonding, the conductors 2a to 2c in the present embodiment are formed by print-applying palladium-coated silver powder obtained by coating the surface of silver powder with palladium on the thick film substrate 1 and firing. I am using Further, not only such a silver-based conductor but also a copper-based conductor may be used for direct wire bonding in the same manner, or a gold-plated conductor may be used for direct wire bonding.

This type of bonding is usually performed by forming a bonding pad of aluminum or the like on the conductor, but by directly bonding on the conductor as in the present embodiment, such a dedicated pad is formed. Bonding can be easily performed without providing. As the thick film substrate 1, not only a low temperature baked thick film substrate but also a high temperature baked thick film substrate can be used.

As described above, since the conductors 2a and 2b are directly wire-bonded to each other by the bonding wires 3 to form the cross wiring, the structure is simple and the length of the bonding wires 3 can be adjusted to adjust the cross wiring. It is possible to flexibly deal with the length of the. Further, by such cross-wiring by wire bonding, even a single-layer substrate can be wired as a multi-layer substrate. Since the bonding wire 3 may sag when the distance between the conductors 2a and 2b becomes long, it is necessary to adjust the height of the bonding wire 3 so as to keep it at a certain level.

At the same time when a bonding wire is formed between the thick film substrate 1 and the metal leads of the housing (not shown), or when a bare chip or the like is mounted on the thick film substrate 1 and the bonding wire is formed on them. The above-mentioned cross wiring bonding can also be performed, and it is not necessary to add an additional step for that.
Equipment can be shared. FIG. 2 shows an embodiment in which the lengths of the cross wirings are different. Even if the distances between the conductors are different as described above, the bonding wires 3a, 3
By using b, the cross wiring can be flexibly performed.

FIG. 3 shows an embodiment in which the bonding wires are crossed with each other. Also in this case, by maintaining the height at which the bonding wire 3c does not sag, the bonding wires 3c and 3d can cross each other, and a more flexible cross wiring can be realized. Note that FIG.
In FIG. 3, 2d to 2n indicate conductors.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional perspective view of a hybrid integrated circuit device showing an embodiment of the present invention.

FIG. 2 is a plan view showing another embodiment of the present invention.

FIG. 3 is a side view showing still another embodiment of the present invention.

FIG. 4 is a partial cross-sectional perspective view showing a conventional configuration.

FIG. 5 is a partial cross-sectional perspective view showing another conventional configuration.

[Explanation of symbols]

 1 Thick film substrate 2a to 2b Conductor 3 Bonding wire

Claims (2)

[Claims] 1. A thick-film circuit board device in which circuit elements formed on a thick-film board are electrically connected by conductors, and a conductor is directly connected to a conductor at a portion of the conductor that intersects with another conductor. A thick film circuit board device, characterized in that cross-wiring is performed with bonded bonding wires. 2. The thick film circuit board device according to claim 1, wherein the thick film substrate is a single layer substrate.