JPH0452002B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to, for example, microwave transmission lines,
This article relates to so-called triplate strip lines used in filters or MICs (microwave integrated circuits) using them.

[Conventional technology]

FIG. 5 is a sectional view partially showing an example of a conventional stripline. This stripline is of a so-called triplate type, and consists of two dielectric substrates 2a, each having ground electrodes 4a, 4b formed on one main surface and one or more line electrodes 6a, 6b formed on the other main surface. , 2b are stacked one on top of the other so that the respective line electrodes 6a and 6b face each other and are electrically conductive.

Specifically, the dielectric substrates 2a and 2b are bonded together using an inorganic adhesive 10 such as glass glaze, and the line electrodes 6a and 6b are bonded together using a conductive bonding agent 8, such as silver paste. Conductive bonding (bonding in a conductive state) is done by baking or soldering using solder cream or the like.

[Problem that the invention seeks to solve]

However, in the above-mentioned stripline, unless the amount and position of the conductive bonding agent 8 applied are very strictly controlled, the conductivity will be lost after the upper and lower dielectric substrates 2a, 2b and line electrodes 6a, 6b are bonded together. The bonding agent 8 is the line electrode 6
The electrode area may change by protruding from the a and 6b portions, or there may be a portion where the conductive bonding agent 8 is not attached, and the condition may vary among individual striplines, so the characteristics of the stripline may vary easily. Therefore, there were problems in mass production, such as a decrease in the quality of products when mass-produced.

Furthermore, since the conductive bonding agent 8 is sandwiched between the line electrodes 6a and 6b, the gap A between both dielectric substrates 2a and 2b is large, and it tends to vary, so the characteristics tend to vary from this point as well. was.

Therefore, an object of the present invention is to provide a stripline that has stable characteristics and is highly mass-producible.

[Means for solving problems]

The stripline of this invention consists of two dielectric substrates each having a ground electrode formed on one main surface and a line electrode formed on the other main surface, which are stacked so that the line electrodes face each other and are electrically conductive. In the strip line, a recess is provided in at least one of the opposing line electrodes, and a conductive bonding agent is placed in the recess to connect the opposing line electrodes to each other in the recess. It is characterized by being joined.

[Effect]

Conductive bonding between line electrodes that face each other is performed in the recessed area, and the recess has a so-called escape space for the conductive bonding agent when bonding the electrodes, so the amount and position of the conductive bonding agent may vary. Even if there is some variation, there is almost no protrusion of the conductive bonding agent after electrode bonding, and as a result, variations in the characteristics of the stripline can be suppressed to a small level.

〔Example〕

1 and 2 are respectively partially sectional views showing a stripline according to an embodiment of the present invention. Components equivalent to those in FIG. 5 are designated by the same reference numerals and their explanations will be omitted.

In the embodiment shown in FIG. 1, a recess 18 is provided in one of the opposing line electrodes 16a and 16b, in this example the line electrode 16b. In the embodiment shown in FIG. 2, a similar recess 18 is also provided on the line electrode 16a side.

The shape of the recess 18 is not limited to a specific shape, and various shapes can be adopted. For example, taking the line electrode 16b side as an example, as shown in FIG. 3, the recess 18 may be in the form of a long and narrow groove running in the longitudinal direction of the line electrode 16b, or as shown in FIG. Several partial recesses 18 may be provided at various locations along the length of the electrode 16b. The same applies to the line electrode 16a side.

When bonding both dielectric substrates 2a and 2b together, a conductive bonding agent 8 such as silver paste or solder cream is placed in the recess 18 to electrically bond the line electrodes 16a and 16b to each other only in the recess 18. I try to do that.

Therefore, in the above stripline, there is a so-called escape space in the recess 18 when the conductive bonding agent 8, for example, silver paste, is baked or solder cream is melted. Even if there is some variation in the amount and position of the adhesive 8 applied, the protrusion of the conductive adhesive 8 from the electrode after electrode bonding and the occurrence of areas where the conductive adhesive 8 is not attached, as in the conventional case, are almost eliminated. . As a result, variations in the characteristics of the stripline are suppressed to a small extent, and the yield rate in mass production is improved. In other words, mass productivity is improved.

In addition, as in the conventional line electrodes 16a, 16b,
Since the conductive adhesive 8 is not sandwiched between the two dielectric substrates 2a and 2b, the gap B between the two dielectric substrates 2a and 2b becomes small, and the size of the gap B after bonding is approximately equal to the thickness of the line electrodes 16a and 16b. Since the characteristics are defined, variations are small, and from this point of view as well, a stripline with stable characteristics can be obtained.

Incidentally, when the recess 18 is as shown in FIG. 4, the joining points between the line electrodes 16a and 16b will be partially scattered, but the positions will not vary as in the conventional case, so this In this case, as in the case of FIG. 3, a stripline with stable characteristics can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, a stripline with stable characteristics and high productivity can be obtained. As a result, it is also possible to reduce the cost of the stripline.

[Brief explanation of the drawing]

1 and 2 are respectively partially sectional views showing a stripline according to an embodiment of the present invention. Figures 3 and 4 are, respectively,
FIG. 2 is a perspective view partially showing an example of one dielectric substrate. FIG. 5 is a sectional view partially showing an example of a conventional stripline. 2a, 2b...dielectric substrate, 4a, 4b...earth electrode, 8...conductive bonding agent, 16a, 16b
... Line electrode, 18 ... recess.

Claims (1)

[Claims] 1. In a strip line formed by overlapping two dielectric substrates each having a ground electrode formed on one main surface and a line electrode formed on the other main surface so that the respective line electrodes face each other and are electrically conductive, A recess is provided in at least one of the opposing line electrodes, a conductive bonding agent is placed in the recess, and the opposing line electrodes are conductively bonded to each other in the recess. Strip line.