JPS5925206A - Method of producing thin film condenser - 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 The present invention provides a method for producing Ta2NXOY and Ta on an insulating substrate such as glass.
The present invention relates to a method of manufacturing a thin film capacitor having a dielectric thin film such as 2O5.

When manufacturing a thin film capacitor, it is difficult to obtain a desired capacitance without adjusting the capacitance value. For this reason,
Conventionally, a lower electrode made of Ta2N or Ta is provided on a glass substrate with the electrode divided into a first part and a second part.
By anodizing this lower electrode, TaNXOY
Alternatively, a dielectric thin film such as TA2O5 is provided, an upper electrode for main capacitance is provided on the dielectric thin film of the first portion, and a plurality of upper electrodes for capacitance adjustment are provided on the dielectric thin film of the second portion, and at this stage. A meter is connected to the lower electrode and the upper electrode for main capacitance to measure the static capacitance, and if the desired capacitance value cannot be obtained, a laser beam is used to measure the capacitance between the upper electrode for main capacitance and multiple upper electrodes for capacitance adjustment. was selectively cut to obtain the desired capacitance value.

However, since the capacitance is measured and the laser beam is projected before forming the protective insulating layer, there is a possibility that the characteristics of the capacitor may deteriorate or be damaged during this process. Furthermore, even if the capacitance is adjusted, if a protective insulating layer is subsequently provided or soldered to the circuit board, the capacitance will change due to thermal effects, mechanical effects such as stress, etc., and the desired capacitance value will not be obtained. There were times when it was difficult.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for manufacturing a thin film capacitor that can easily obtain a desired capacitance value.

To achieve the above object, the present invention includes a step of forming a lower electrode comprising at least a first portion and a second portion continuous to the first portion on a light-transmitting insulating substrate, and an oxidation treatment. forming a dielectric thin film on a portion of the first portion and the second portion; and providing an upper electrode for main capacitance on the dielectric thin film on the first portion; A plurality of capacitance adjustment upper electrodes are provided on the dielectric thin film on the portion, and a plurality of connection portions are provided to electrically connect the main capacitance adjustment upper electrode and the plurality of capacitance adjustment upper electrodes, respectively. a step of providing the main capacitance upper electrode, the plurality of capacitance adjustment upper electrodes, the plurality of connection parts, the exposed surface of the dielectric thin film, and at least the insulating substrate near the connection part on the insulating substrate; a step of providing a protective insulating layer rather than covering it; and a step of measuring capacitance by connecting a capacitance measuring instrument to the lower electrode and the upper electrode for main capacitance after providing the protective insulating layer; The capacitance is reduced by projecting a laser beam onto one or more of the plurality of connection parts from the back side opposite to the surface on which the lower electrode of the insulating substrate is provided, and cutting the connection part. The present invention relates to a method of manufacturing a thin film capacitor, characterized by comprising a step of adjusting the value of .

According to the above invention, since the capacitance is adjusted by projecting a laser beam from the back surface of the glass substrate after forming the protective insulating layer, it is also possible to correct the change in capacitance due to the formation of the protective insulating layer. Furthermore, since capacitance measurement and laser beam projection are performed after forming the protective insulating layer, deterioration or damage to characteristics in this process can be prevented.

Next, a method for manufacturing a thin film capacitor according to an embodiment of the present invention will be described with reference to FIGS. 1 and 217.

FIGS. 1A to 1E are plan views showing the thin film capacitor in order of process, and FIGS. 2A to 2E are sectional views of each part of FIG. 1. First, a Ta2N film is formed to a thickness of about 6000 Å on a transparent glass substrate (1) of about 0.5 mm by sputtering or vapor deposition, and this is photoetched into a predetermined pattern. As shown in (A) of the figure, a lower electrode (2) consisting of a first part (2a) and a second part (2b) is formed. Furthermore, the second part (
2b) are connected to the first portion (2a) and are arranged opposite to each other via the separation region (3).

Next, by partially anodizing the lower electrode (2), as shown in FIGS. 1 and 2 (B), TaNXO
A dielectric thin film (4) made of Y and having a thickness of about 3000 Å is formed.

Next, by sputtering or vapor depositing Ni-Cr to a thickness of 50 Å and Au to a thickness of 1000 Å, and etching this into a desired pattern, (C) in FIGS. 1 and 2 is formed.
As shown, the upper electrode (5) for main capacitance corresponds to the first part (2a) of the lower electrode (2), and the plurality of capacitors correspond to the second part (2b) of the lower electrode (2). Upper electrode for adjustment (6), upper electrode for main capacitance (5) and upper electrode for adjustment (
6) is provided. At this time, a lower electrode terminal portion (8) and an upper electrode terminal portion (9) are provided at the same time using the same metal. As is clear from FIG. 1(C), a plurality of capacitance adjustment upper electrodes (6) and connection parts (7)
are provided in a comb-like shape protruding from the main capacitance upper electrode (5).

Next, the exposed surface of the main capacitance upper electrode (5), the plurality of capacitance adjustment upper electrodes (6), the plurality of connection parts (7), the dielectric thin film (4), and at least the vicinity of the connection part (7) A protective insulating layer (10) made of epoxy resin is provided to cover the glass substrate (1) as shown in FIGS. 1 and 2 (D).

Note that this insulating layer (10) is formed to a thickness of about 12 μm by applying an epoxy resin and heating it in air at 150° C.

Next, a capacitance measuring instrument (not shown) is connected to the lower electrode (2) and the upper electrode for main capacitance (5) via the terminal portions (8) and (9) to measure the capacitance. Thereby, the capacitance between the first part (2a) of the lower electrode (2) and the main capacitance upper electrode (5), and the capacitance between the second part (2b) of the lower electrode (2) and the capacitance adjusting upper electrode (6) and the sum of the capacitances are measured.

Next, since this embodiment is designed to obtain a larger capacity than the desired capacity, some of the plurality of connection parts (7) are shown in the partially cutaway plan view of FIG. Figure 2 (
It is cut with a laser beam as shown in the cross-sectional view of E), and the capacitance value is adjusted to a desired value.

At this time, taking advantage of the fact that the glass substrate (1) is transparent,
As shown by the arrow (11) in FIG. 2(D), the glass substrate (1
) from the back side of the Nd:YAG laser beam to the connecting part (
7) and connect the connection part (7) with the energy of the laser beam.
cut.

Next, the circuit board (
(not shown), the elements shown in FIG. 1 and FIG.
The terminal portions (8) and (9) are connected to the circuit board by the solder reflow method. This allows the glass substrate (
1) Since the mounting state is such that the connection part (7) can be seen from the side, after mounting the element on the circuit board, measure the capacitance and connect the connection part (7) with a laser beam to obtain the desired capacitance.
7) can be cut to adjust the capacity.

As is clear from the above, this embodiment has the following advantages.

(a) When the protective insulating layer (10) is formed, the capacitance value becomes 0.
Although it increases by 5 to 2.5%, since the capacitance is adjusted after forming the protective insulating layer (10), the capacitance is adjusted to eliminate the ratio and variation in capacitance due to the formation of the protective insulating layer (10). Is possible.

(b) Since measurement and capacitance adjustment using a laser beam are performed after providing the protective insulating layer (10), custom-made deterioration and damage during these steps can be prevented.

(c) Capacity can be adjusted even after phase-down bonding, so it is also possible to correct periodic changes due to heat during solder bonding.

Although the embodiments of the present invention have been described above, the present invention is not limited thereto and can be further modified.

For example, the lower electrode (2) is made of Ta and the dielectric thin film (4) is made of T.
It may also be a2O5 or the like. In addition, the insulating layer (10) is made of Si
It may be formed of O2, silicone resin, or the like.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a thin film capacitor according to an embodiment of the present invention in order of process, and FIG.
) are cross-sectional views taken along lines a, b, c, d, and e in FIG. In addition, in the symbols used in the drawings, (1) is the glass substrate, (2) is the lower electrode, (2a) is the first part, (
2b) is the second part, (4) is the dielectric thin film, (5) is the upper electrode for main capacitance, (6) is the upper electrode for capacitance adjustment, (7)
is a connection part, and (10) is a protective insulating layer. Agent Norihiro Takano Figure 1-5 to Figure 2 (A) (B) (C) (o) (E)

Claims (1)

[Claims] (1) forming a lower electrode consisting of at least a first portion and a second portion continuous to the first portion on a light-transmitting insulating substrate; and performing an oxidation treatment to remove the first portion and the second portion. a step of forming a dielectric thin film on a part of the second portion, and providing an upper electrode for main capacitance on the dielectric thin film on the first portion and on the dielectric thin film on the second portion; a step of providing a plurality of capacitance adjustment upper electrodes on the insulating substrate, and further providing a plurality of connecting portions on the insulating substrate so as to electrically connect the main capacitance upper electrode and the plurality of capacitance adjustment upper electrodes, respectively; , the main capacitance upper electrode, the plurality of container adjustment upper electrodes,
providing a protective insulating layer to cover the plurality of connection parts, the exposed surface of the dielectric thin film, and at least the insulating substrate near the connection parts; and after providing the protective insulating layer,
measuring the capacitance by connecting a capacitance measuring instrument to the lower electrode and the upper electrode for main capacitance; The method is characterized by comprising a step of projecting a laser beam onto one or more of the plurality of connection parts and cutting the connection part to adjust the value of the capacitance to a desired value. Method of manufacturing thin film capacitors.