JPS61260603A - Electronic component - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to electronic components such as thermal heads,
In particular, it relates to improvements in electrical connection structures between dissimilar conductor metal layers.

[Conventional technology]

In recent years, electronic components have been trending toward smaller sizes and lower prices, and thin-film and thick-film technologies are playing a role in this trend. For example, thermal heads as main parts used in facsimiles, printers, and the like are formed using thin film technology, thick film technology, and the like.

By the way, this thermal head is a device in which a pulse voltage is applied to dots made by arranging multiple heating resistors on an insulating substrate, and the heat generated by each dot is used to print characters, symbols, etc. on thermal paper. This enables continuous printing by generating heat from each dot and transporting the thermal paper.

FIG. 5 is a cross-sectional view schematically showing this type of conventional thermal head. In the figure, (1) is an insulating substrate, and (2) is a resistive film layer deposited on this insulating substrate (1). ,(3)
(4) is the second conductive metal layer deposited on the first conductive metal layer (3), and (6) is the first conductive metal layer deposited on the resistive film layer (2). This heating resistor is formed by removing a part of the conductive metal layer (3) and exposing the resistive film layer (2).

A conventional thermal head is constructed as described above, and in order to manufacture it using thin film technology, a few hundred to several thousand angstroms of cermet film, which will become the resistive film layer (2), is deposited on an insulating substrate (1) by sputtering. , then Al, Cu,
Metals such as Ni and Cr are used as the 14th metal layer (3)
A layer of several microns is deposited by sputtering, and then a conductor pattern and heating resistor (6) are formed by photolithography.
etc. will be formed.

Here, if it is necessary to lower the pattern resistance of the formed conductor pattern, or if you want the conductor pattern to be a solderable pattern, due to various process constraints, the M1 conductor metal N (3) Au, which is different from metal,
A second conductive metal layer (4) such as Cu is deposited by plating, sputtering, printing, etc. to obtain the desired characteristics. For example, when the first conductive metal layer (3) is Cu and the second conductive metal layer (4) is Au,
If the manufacturing process includes a heating step, metal diffusion progresses at the contact interface between Cu and Au to form an alloy, increasing contact resistance and making it impossible to obtain desired characteristics.

Further, the first conductive metal layer (3) is the hem 24th body metal layer (
If 4) is made of Au, battery cell action occurs at the contact interface between A71 and Au, resulting in poor reliability. Furthermore, if an IC mounting process or the like is included, the first conductive metal layer (3) and the second conductive metal layer (4) will be more limited.

In this way, in the conventional method, it is necessary to select a combination of the first conductive metal layer (3) and the second conductive metal layer (4), which results in an increase in the price of electronic components. There were problems such as not being able to obtain high reliability at the contact interface between the conductive metal layers (3) and (4).

This invention was made to solve these problems, and aims to provide an electronic component that can prevent diffusion and battery action at the contact interface of an unusual conductor metal layer, and can be manufactured at low cost. 0 [Means for Solving the Problems] The electronic component according to the present invention is characterized in that a first conductive metal layer and a second conductive metal layer made of different metals are interconnected with a resistive film layer interposed therebetween. It is designed to conduct electricity.

[Effect]

In this invention, since the resistive film layer is interposed between the different types of conductor metal layers, there is no need to consider the combination of both conductor metal layers, and the cost can be reduced. 0 [Example] Figure 1 shows an example of the present invention.
The same reference numerals as in the figures indicate the same or corresponding parts.

In this example, the first conductive metal layer (3) and the insulating substrate (1
), for example, a resistive film layer (2) is interposed between the second conductive metal layer (4), which is formed by printing and firing an Au paste, and both the conductive metal layers (81, (41) are connected to this resistive film layer ( 2).

In the electronic component configured as described above, Au paste is printed and fired at required positions on the insulating substrate (1) to form the second conductive metal layer (4), and on top of that, Ta, T
A resistive film layer (2) mainly composed of a mixture of metal powders such as No. 1 and insulators such as EliO, O, N, etc. is deposited by sputtering to a thickness of several to several thousand angstroms, and then The first conductive metal layer (3
) is deposited by sputtering, and a part of the first conductive metal layer (3) other than the conductive part with the second conductive metal layer (4) is removed to expose the resistive film layer (2) and form a heating resistor. It is manufactured by making the body (6).

Here, metal powder such as Ta, Ti and 5in2.0
．． The resistive film layer mainly composed of a mixture with an insulator such as N is made of relatively stable metals such as Ta and Ti, and is made of relatively stable metals such as Al and Cu sputtered on the resistive film layer (2).
It serves as an intervening metal that buffers the contact potential difference with the first conductive metal layer (3) and prevents diffusion. This resistive film layer (2) has a thickness of several hundred to several thousand angstroms and a sheet resistance value of several tens to several thousand angstroms.
Since it is several hundred ohms, the conduction resistance between both conductive metal layers (81, (41) is as follows: the area of the resistive film layer (2) between them is 0.1
Even if it is, it will be as small as tens of thousands to hundreds of thousands of times, and sufficient conduction can be obtained.

1. Low-cost metals can be used without selecting the combination of metal layers, and manufacturing processes such as heating processes can be used.

In the above embodiment, the first conductive metal layer (3) and the second conductive metal layer (4) are electrically connected through the resistive film layer (2), but as shown in FIG. conductive metal layer (6
) and the second conductive metal layer (4) may be electrically connected via the resistive film layer (2),
Similar effects can be expected.

〔Effect of the invention〕

As explained above, this invention interposes a resistive film layer between different types of conductor metal layers, so it is possible to lower the cost of electronic components such as thermal heads, and it also prevents diffusion and battery action at the contact interface between different types of conductive metal layers. This has the effect of improving reliability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view schematically showing a thermal head according to an embodiment of the present invention, FIG. 2 is a view corresponding to FIG. 1 showing another embodiment of the invention, and FIG. 3 is a diagram showing a conventional thermal head. This is a diagram corresponding to FIG. 1 shown as a model. (1): Insulating substrate (2): Resistive film layer (3): First conductive metal layer (4): Second conductive metal layer (5): Heat generating resistor Note that the same symbols in each figure are the same or equivalent. shall indicate the part.

Claims (4)

[Claims] (1) A first conductive metal layer and a second conductive metal layer made of different metals.
and a conductive metal layer formed on an insulating substrate, wherein both the conductive metal layers are electrically connected to each other with a resistive film layer interposed therebetween. (2) The electronic component according to claim 1, wherein the resistive film layer contains conductive metal powder and an insulator. (3) The electronic component according to claim 1, wherein the resistive film layer is a cermet resistive film layer whose main component is a mixture of powdered metal and ceramic powder. (4) Claims 1 to 3, characterized in that the resistive film layer forms a heating resistor at a location other than the conductive portion between the first conductive metal layer and the second conductive metal layer. Electronic components described in any of the paragraphs.