JPH11222664A - Metal mask, formation of resistor by using this metal mask and production of resistor using this metal mask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the incident limitation of sputter particles in the corner parts of aperture flanks and to form a thin-film resistor which is thick in the film thickness at ends and has excellent electrical characteristics by forming a taper increased in a hole diameter toward a sputter vapor deposition source in the aperture of the metal mask. SOLUTION: A pair of electrodes 64, 64 are formed on a heat resistant and insulative substrate 61 mainly composed of Al2 O3 and a pair of the opposite flanks of the metal masks 62 made of iron, etc., having the square aperture 63 are placed thereon. The metal masks are in close contact with the electrodes so as to be overlapped and one aligned. The sputter particles from the sputter vapor deposition source are supplied to the aperture 63 of the metal mask 62 to deposit the thin-film resistor of Ni-Cr, etc., across the electrodes 64, 64 on the substrate 61. At this time, the other pair of the opposite flanks of the metal mask 62 are provided with the taper 65 increases in the hole diameter toward the sputter vapor deposition source of the aperture 63. The angle of inclination of the taper 65 is preferably set at about 15 to 80 deg., more particularly about 30 to 65 deg. with the surface of the metal mask 62.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal mask, a method for forming a resistor using the metal mask, and a method for manufacturing a resistor using the metal mask.

[0002]

2. Description of the Related Art In recent years, with the miniaturization of electronic devices, there has been an increasing demand for miniaturization in order to increase the mounting density of electronic components used for circuit boards. For resistors, there is an increasing demand for resistors that are small and have a high tolerance in resistance value in order to eliminate the need for adjustment of electronic circuits.

Hereinafter, a conventional metal mask, a method of forming a resistor using the conventional metal mask, and a method of manufacturing a resistor using the conventional metal mask will be described with reference to the drawings.

FIG. 7 is a sectional view of a conventional metal mask. 1 is a metal mask made of a metal or a magnetic material, and 2 is an opening. Here, in the metal mask, the opening 2 is formed on a metal or magnetic plate by using a photolithography method.
At this time, the angle of the side surface of the opening 2 with respect to the mask surface is substantially a right angle.

Hereinafter, a conventional method of forming a resistor using a metal mask will be described with reference to the drawings.

FIG. 8A is a plan view showing mounting of a metal mask when forming a resistor using a conventional metal mask. (B) is an XX sectional view of the same, and (c) is a YY sectional view of the same. FIG. 9 is a view showing FIG. 8 when a resistor is formed by a sputtering method.
It is a YY sectional view in (a), and the arrow in a figure shows the incidence direction of sputtered particles.

The rectangular opening 13 of the metal mask 12
Positioning is performed in close contact with a pair of electrodes 14 formed on the substrate 11 so as to overlap. At this time, the side surface of the opening 13 of the metal mask is substantially perpendicular to the surface of the metal mask. In this state, a thin film resistor 15 is formed on the substrate 11 of the mask opening 13 by a sputtering method using a sputter deposition source such as Ni-Cr as a resistor.

Hereinafter, a method of manufacturing a resistor using a conventional metal mask will be described with reference to the drawings.

FIG. 10 is a process chart showing a conventional method for manufacturing a resistor using a metal mask. First, FIG.
As shown in the figure, a substrate 31 containing 96% alumina
An electrode paste made of a metal organic substance or the like is screen-printed and dried on the upper and lower sides of the substrate. Thereafter, by heating in a firing furnace, only the organic components of the electrode paste are skipped, and only the metal components are baked on the substrate 31 to form the upper electrode layer 32 and the lower electrode layer (not shown).

Next, as shown in FIG. 10B, the conventional metal mask shown in FIG. 8 is brought into close contact with the upper surface of the substrate 31 on which the upper electrode layer 32 has been formed, and put into a sputtering apparatus to form a resistor layer 33. Is formed by sputtering. At this time, the side surface of the opening of the metal mask is substantially perpendicular.

Next, heat treatment is performed to make the resistor layer 33 a stable resistor. Next, as shown in FIG. 10C, a trimming groove 34 is formed by laser trimming or the like to correct the resistance value of the resistor layer 33 to a predetermined value, and the resistance value is corrected.

Next, as shown in FIG. 10D, a resin paste is applied to the resistor layer 33 (not shown in FIG. 1) to protect the resistor layer 33 (not shown in the drawing) whose resistance has been corrected by forming a trimming groove 34. Screen printing is performed so as to cover 33, and heat curing is performed to form a protective layer 35.

Next, as shown in FIG.
The upper electrode layer 32 and / or the resistor layer 33 on one side surface
Side electrode layer 3 made of a thin film of Ni-Cr or the like by a sputtering method so as to connect the lower electrode layer (not shown) to the lower electrode layer.
6 is formed.

Finally, if necessary, the exposed upper electrode layer 32, lower electrode layer (not shown), and side electrode layer 36 are exposed.
A Ni plating layer (not shown) by electroplating;
A resistor was manufactured by forming a solder plating layer (not shown).

[0015]

However, when a thin-film resistor is formed by a sputtering method using the above-described conventional metal mask, the incident direction of the sputtered particles varies as shown in FIG. (Indicated by an arrow in the drawing), the incidence of sputtered particles on the end of the opening 13 of the metal mask 12 is limited by the side surface of the metal mask 12, and the thickness of the end of the thin film resistor 15 on the substrate Becomes thinner.
Therefore, if the resistance is corrected by removing part of the resistor by laser trimming, etc., the load will concentrate near the end of the resistor, and the electrical characteristics such as the pulse characteristics of the resistor will deteriorate. There was a problem to do.

The present invention has been made to solve the above problems, and has as its object to provide a metal mask for forming a thin film resistor having excellent electric characteristics.

[0017]

In order to achieve the above object, a metal mask according to the present invention is provided with a taper whose hole diameter increases in the direction of a sputter deposition source.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a metal mask characterized in that the opening has a taper whose hole diameter increases in the direction of the sputter deposition source.

The invention described in claim 2 is the first invention.
The described opening is a resistor-forming metal mask having a taper in which the hole diameter is increased only on a pair of sides.

According to a third aspect of the present invention, there is provided a resistor for forming a thin film resistor by a sputtering method using a metal mask having a tapered hole having a hole diameter increased in the direction of a sputter deposition source in an opening. It is a forming method.

Further, the invention according to claim 4 is a method for forming a thin film resistor, wherein the opening portion uses a tapered metal mask in which only a pair of sides has a larger hole diameter.

The invention described in claim 5 is the same as the invention in claim 4.
Using a metal mask on the substrate on which the electrodes described above are formed, aligning the electrodes so that the sides adjacent to the side having a larger hole diameter with respect to the pair of electrodes are connected to the electrodes, and the thin film resistance is adjusted. It forms the body.

The invention described in claim 6 is the same as the invention in claim 5
The electrode described is a method for forming a resistor made of a thin film or a thick film of Au, Cu, Ni, or Ag.

According to a seventh aspect of the present invention, a metal mask having a tapered hole whose diameter is increased in the direction of the sputter deposition source is formed on the substrate on which the electrode is formed. And forming a thin-film resistor by positioning the electrode so that the side adjacent to the side having the larger hole diameter is connected to the electrode.

(Embodiment 1) A metal mask, a method for forming a resistor using the metal mask, and a method for manufacturing a resistor using the metal mask according to Embodiment 1 of the present invention will be described below. It will be described with reference to FIG.

FIG. 1 is a sectional view of a metal mask according to the first embodiment of the present invention. In the drawing, 51 is a metal mask made of a metal or a magnetic material, preferably iron, 52 is an opening, 53 is an opening formed at an angle of 15 to 80 degrees, preferably 30 to 65 degrees with respect to the mask surface. The side surface is tapered.

A method for forming a resistor using a metal mask according to the first embodiment of the present invention will be described below with reference to the drawings.

FIG. 2A is a plan view showing the mounting of a metal mask when a resistor is formed using the metal mask according to the first embodiment of the present invention, and FIG. 2
(C) is a sectional view taken along the line YY. FIG. 3 is a sectional view taken along line YY in FIG.

First, the rectangular opening 6 of the metal mask 62 is formed.
3 is brought into close contact with a pair of electrodes 64 formed on the substrate 61 and aligned. At this time, a pair of side surfaces facing the rectangular opening of the metal mask 62 are, as shown in FIG.
It has a taper 65 angled from 80 to 80 degrees, preferably from 30 to 65 degrees. Positioning is performed so that a side adjacent to this side is connected to the pair of electrodes 64.

Thereafter, the substrate 61 and the metal mask 62
Into a sputtering device, and a resistor material such as Ni-Cr
A resistor 66 is formed on the substrate 61 in the mask opening 63 by a sputtering method. At this time, as shown in FIG. 3, a taper 65 provided on a pair of side surfaces of the opening portion of the metal mask is provided.
As a result, the incidence of sputtered particles on the side surface of the opening becomes less likely to be restricted, and the film thickness at the end of the resistor becomes thicker than when a resistor is formed using a conventional metal mask, and the electrical characteristics of the resistor are reduced. improves.

A method for manufacturing a resistor using a metal mask according to the first embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 is a process chart showing a method of manufacturing the resistor according to the first embodiment of the present invention. First, as shown in FIG. 4A, on the upper and lower sides of a substrate 81 containing 96% alumina having excellent heat resistance and insulation properties,
An electrode paste made of a metal organic material or the like containing Au as a main component is screen-printed and dried. Next, in order to skip only the organic component and burn only the metal component on the substrate 81,
At a temperature of about 850 ° C., 45
Baking is performed according to a minute profile to form an upper electrode layer 82 and a lower electrode layer (not shown).

Next, as shown in FIG. 4B, the metal mask of the present invention shown in FIG. 1 is adhered to the upper surface of the substrate 81 on which the upper electrode layer 82 is formed, and a resistor layer such as Ni--Cr is formed. 8
3 is formed by a sputtering method. At this time, in the metal mask of the present invention, since the side surface of the opening has a taper, the incidence of sputtered particles is not interrupted, and the resistance layer 8
The thickness of the end portion 3 becomes thicker than when a resistor is formed using a conventional metal mask, and the electrical characteristics of the resistor are improved.

Next, in order to make the resistor layer 83 a stable resistor, a heat treatment is performed in an atmosphere of about 300 to 400 ° C.

Next, as shown in FIG. 4C, in order to correct the resistance value of the resistor layer 83 to a predetermined value, a trimming groove 84 is formed by laser trimming or the like to correct the resistance value.

Next, as shown in FIG. 4D, an epoxy-based resin paste is applied to protect the resistor layer 83 (not shown in FIG. 4) whose resistance has been corrected by forming a trimming groove 84. Screen printing is performed, and thermosetting is performed at about 200 ° C. for 30 minutes to form a protective layer 85.

Next, as shown in FIG.
Side electrode layer 86 made of a thin film of Ni-Cr or the like by a sputtering method so that upper electrode layer 82 and / or resistor layer 83 and the lower electrode layer (not shown) are connected to the side surfaces of
To form

Finally, prevention of electrode erosion during soldering of the exposed upper electrode layer 82, lower electrode layer (not shown), and side electrode layer 86, as required, and reliability during soldering. For the purpose of securing, a Ni plating layer (not shown) and a solder plating layer (not shown) are formed by electroplating to manufacture a resistor.

In the resistor according to the first embodiment of the present invention constructed and manufactured as described above, the thickness of the end portion of the resistor layer is larger than that formed using a conventional metal mask. . Thus, it becomes possible to manufacture a thin film resistor having excellent electric characteristics.

Hereinafter, a resistor manufactured using the conventional metal mask and a resistor manufactured using the metal mask of the first embodiment of the present invention were compared by the following experimental method.

As an experimental method, in order to evaluate the pulse characteristics, the resistance value change rate after repeating a cycle of applying a load three times the rated voltage for 1 second and applying no load for 25 seconds 10,000 times is shown in FIG. 11 is shown.

As is apparent from FIG. 11, the resistance in the resistor according to the first embodiment of the present invention is smaller than that of the conventional resistor, and the electrical characteristics are improved.

(Embodiment 2) A metal mask, a method of forming a resistor using the metal mask, and a method of manufacturing a resistor using the metal mask according to a second embodiment of the present invention will be described below. It will be described with reference to FIG.

For the formation of the resistor, the section shown in FIG.
A metal mask having a stepped taper 93 on the side surface of the opening 92 is used. At this time, the angle 94 between the plane surrounded by the upper end and the lower end of the metal mask 91 on the side surface of the opening 92 and the metal mask surface is 15 degrees to 80 degrees, preferably 3 degrees.
0 to 65 degrees.

The method of forming the resistor and the method of manufacturing the resistor using this metal mask are the same as those of the first embodiment, and the effects are the same.

(Embodiment 3) A metal mask, a method of forming a resistor using the metal mask, and a method of manufacturing a resistor using the metal mask according to a third embodiment of the present invention will be described below. It will be described with reference to FIG.

For the formation of the resistor, the section shown in FIG.
A metal mask having a tapered surface 103 having a curvature on the side surface of the opening 102 is used. At this time, the angle 104 between the plane surrounded by the upper and lower edges of the metal mask 101 on the side surface of the opening 102 and the metal mask surface is 15 degrees to 80 degrees.
Degrees, preferably 30 to 65 degrees.

The method for forming the resistor and the method for manufacturing the resistor using this metal mask are the same as those in the first embodiment, and the effects are the same.

[0049]

As described above, if a thin film resistor is formed by the sputtering method using the metal mask according to the present invention, the sputter on the side surface of the opening is formed by the taper provided on the pair of side surfaces of the opening. Particle incidence is less likely to be restricted,
The thickness of the end portion of the resistor becomes thicker than when the resistor is formed using a conventional metal mask, and the electrical characteristics of the resistor are improved.

Therefore, if a thin film resistor is formed by a sputtering method using the metal mask according to the present invention,
A resistor excellent in electric characteristics can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a metal mask according to a first embodiment of the present invention.

FIG. 2 is a schematic view for explaining formation of a resistor using a metal mask which is a main part of the same.

FIG. 3 is a cross-sectional view showing a state when a resistor is formed using a metal mask, which is a main part of the same.

FIG. 4 is a process chart of a method for manufacturing a resistor using a metal mask, which is a main part of the method.

FIG. 5 is a sectional view of a metal mask according to a second embodiment of the present invention.

FIG. 6 is a sectional view of a metal mask according to a third embodiment of the present invention.

FIG. 7 is a sectional view of a conventional metal mask.

FIG. 8 is a schematic diagram for explaining formation of a resistor using a metal mask as a main part of the same.

FIG. 9 is a cross-sectional view showing a state when a resistor is formed using a metal mask, which is a main part of the same.

FIG. 10 is a process chart of a method for manufacturing a resistor using a metal mask, which is an essential part of the method.

FIG. 11 is a diagram comparing characteristics between a conventional resistor and the resistor according to the first embodiment of the present invention.

[Explanation of symbols]

 51 metal mask 52 opening 53 taper

Claims (7)

[Claims] 1. A metal mask having a tapered opening having a hole diameter increased in the direction of a sputter deposition source. 2. The metal mask according to claim 1, wherein the opening has a taper in which only a pair of sides has a larger diameter. 3. A method of forming a thin-film resistor by a sputtering method using a metal mask having a tapered hole whose diameter increases in the direction of a sputter deposition source on a substrate. 4. The method for forming a resistor according to claim 3, wherein the opening portion of the substrate is formed by using a metal mask having a tapered hole having only one pair of sides and having a larger diameter. 5. A substrate on which an electrode is formed is positioned using a metal mask such that the electrode is formed such that a side adjacent to a side having a larger hole diameter with respect to the pair of electrodes is connected to the electrode. 5. The method for forming a resistor according to claim 4, wherein the thin film resistor is formed. 6. The electrode is made of Au-based, Cu-based, Ni-based, Ag
6. The method for forming a resistor according to claim 5, comprising a thin film or a thick film. 7. A substrate on which electrodes are formed, a metal mask having a tapered hole whose diameter is increased in the direction of the sputter deposition source in an opening portion, and adjacent to a side having a larger hole diameter for a pair of the electrodes. A method for manufacturing a resistor, comprising the steps of forming a thin-film resistor by aligning the electrode so that a side is connected to the electrode.