JPS6347955A - Laminated substrate for electronic component - Google Patents

Abstract

PURPOSE:To obtain a laminated substrate which has a small difference in thermal expansion coefficient of a high melting point glass layer from that of a silicon semiconductor placed on a substrate, excellent heat resistance strength and easy manufacture by covering at least one main surface of a sealed alloy plate containing Cr with the glass layer through a priority oxide film made mainly of Cr2O3. CONSTITUTION:A high melting point glass layer 3 is covered through a priority oxide film 2 made mainly of Cr2O3. Or, one of both main surfaces of a sealed alloy plate 1 containing Cr is covered with the layer 3 through the film 2 made mainly of Cr2O3, and the other main surface is covered with a frit layer 4. For example, the substrate 1 containing Cr is interposed between flat ceramic plates, heated to 1000-1300 deg.C in wet H2 gas while pressurizing it to form the film 2 mainly made of Cr2O3, a high melting point glass plate having 550 deg.C or higher of melting point is disposed thereon, heated to the melting point or higher of the glass plate, and pressurized, and a laminated substrate on which the layer 3 is covered through the film 2 is obtained on the substrate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application This invention relates to a laminated substrate having an insulating film for mounting various electronic components, and particularly to a multilayer substrate having a small difference in coefficient of thermal expansion from a silicon semiconductor placed on the substrate ( The present invention relates to a multilayer substrate for a hybrid LIC that has excellent heat resistance and strength and is easy to manufacture.

Background technology As a board for mounting and loading hybrid ICs,
BACKGROUND ART Conventionally, a so-called copper-clad glass epoxy substrate is well known, which has a laminated structure in which a Cu plate is adhered to a substrate made of an epoxy resin plate reinforced with glass fiber.

In addition, a so-called polymer insulating film-forming metal with a laminated structure in which an insulating film made of resin is coated on an alumina-based substrate or a sealing alloy plate such as a 40% Ni Fe alloy plate or a Cu alloy plate,
Furthermore, enameled iron substrates with a laminated structure consisting of an enameled insulating film on a steel plate are known.

The above-mentioned copper-clad glass epoxy substrate has low thermal conductivity and heat resistance, and has a large difference in thermal expansion coefficient from the silicon semiconductor on which it is placed, so there is a problem of cracking, and alumina-based substrates have poor thermal conductivity. On the other hand, it has a weak impact resistance.

In addition, the polymer insulating film-formed metal plate has a working temperature of 45
There are problems with poor durability at 0°C and poor IjJ5 properties, and waxed iron substrates require firing at 1000°C or higher for installation, which poses various problems in terms of the number of steps and cost.

Purpose of the Invention In view of the current state of laminated substrates having an insulating film for hybrid ICs, the present invention has been made to provide a multilayer substrate that has a small difference in coefficient of thermal expansion from a silicon semiconductor placed on the substrate, has excellent heat resistance strength, and is easy to manufacture. It is aimed at laminated substrates.

Structure and Effects of the Invention The present invention has excellent heat resistance and thermal conductivity at an operating temperature of 450°C, is high in strength, has a small difference in coefficient of thermal expansion from the silicon semiconductor placed on the substrate, and is resistant to scratching. As a result of various studies aimed at producing a laminated substrate with an insulating film that is less likely to generate and is easy to manufacture, we decided to form an oxide film mainly composed of Cr2O3 on the main surface of a Cr-containing sealing alloy plate by heat treatment. discovered that by providing a glass layer or a frit layer, which is an insulating film, on the oxide film, the adhesion between the sealing alloy plate and the insulating film was improved, and the above object was achieved, and the invention was completed. It is something.

That is, this invention provides Cr2O on at least one main surface of a Cr-containing sealing alloy plate.
This is a multilayer substrate for electronic components, which is characterized in that it is coated with a high melting point glass layer with an oxide film interposed therebetween, and further includes Cr2O3 on both sides of the Cr-containing sealing alloy plate. This is a multilayer substrate for electronic components, characterized in that one principal surface is coated with a high melting point glass layer and the other principal surface is coated with a frit layer, with a preferential oxide film mainly consisting of:

DISCLOSURE OF THE INVENTION BASED ON DRAWINGS FIGS. 1a, b, and c are cross-sectional explanatory views of a laminated substrate according to the present invention.

To explain the manufacturing process of the laminated board according to the present invention, for example, as shown in figure a, a Ni40 to 50w plate with a board thickness of 2 mm or less is used.
t%-Cr4~8wt%-Fe alloy plate or Cr
A Cr-containing sealing alloy substrate (1) made of a 15-30 wt%-Fe alloy plate is sandwiched between flat shellac plates and heated to 1000°C in a humid H2 gas with a dew point of 10-50°C while applying pressure.
A preferential oxide film (2) mainly composed of Cr2O3 with a thickness of 10 μm or less, preferably 1 to 5 pm is formed on one main surface of the alloy substrate (1) by heating to ~1300°C. A high melting point glass plate with a thickness of 0.4 mm to 1.0 mm and a melting point of 550°C or higher is placed on the f-emitting oxide film (2) of the deposited alloy substrate (1), and heated to a temperature higher than the melting temperature of the high melting point glass plate. , by applying pressure to form a preferential oxide film (
2) A laminated substrate is obtained on which a high melting point glass layer (3), which is an insulating film, is adhered via a layer (3) of high melting point glass.

In addition, as shown in Figure b, a preferential oxide film (2) mainly composed of Cr2O3 is formed on the amphibatic surface of the alloy substrate (1),
The above-mentioned high melting point glass plate is placed on both sides of the sealing alloy substrate (1), and heated and pressurized to a temperature higher than the melting temperature of the high melting point glass plate to form a preferential oxide film ( 2
) A laminated substrate can be obtained on which a high-melting point glass layer (3), which is an insulating film, is adhered via a layer (3) of high melting point glass.

Furthermore, as shown in Figure C, a high melting point glass layer (3
) on the other main surface of the laminated substrate coated with
A sealing alloy substrate (1
) is coated with a frit layer (4) which is an insulating film via a preferential oxide film (2), and a high melting point glass layer (3) is applied to one main surface of the sealing alloy substrate (1) and a high melting point glass layer (3) is applied to the other main surface. A laminated substrate provided with a frit layer (4) is obtained.

Preferred Embodiment of the Invention In this invention, the Fe of the sealing alloy substrate containing Cr is
-Cr-Ni alloys are undesirable if the Ni content is less than 40%, the coefficient of thermal expansion becomes too small and the difference in coefficient of thermal expansion with the high melting point glass plate becomes large, and if it exceeds 50%, the coefficient of thermal expansion becomes too small. Since the difference in expansion coefficient becomes too large, Ni is limited to 40 to 50%.

Further, if Cr is less than 4%, dense oxide particles will not be formed after heat treatment, which is undesirable, and if it exceeds 8%, the difference in the ripe expansion coefficient will become too large, so Cr should be 4 to 4%.
Limited to 8%.

C needs to be kept at 0.05% or less in order to prevent foaming caused by reaction with the insulating film.

In addition, in order to deoxidize the sealing alloy during melting, generate a surface oxide film, and improve the adhesion between the alloy substrate and the oxide film layer, the sealing alloy contains 0.1 to 0.5% Mn, 5iO11 to 0.5%,
It is preferable to contain at least one of 0.1 to 0.5% of AI, and if necessary, 0.3% of at least one of Ti, Zr, RE, and AI to improve film adhesion. The following may be contained.

In addition, in the present invention, the Fe-Cr alloy for the sealing alloy substrate containing Cr is undesirable if the Cr content is less than 15% because the coefficient of thermal expansion becomes too large, and if it exceeds 30%, the processability of the alloy substrate becomes difficult. Cr deteriorates, so Cr is 15~
Limited to 30%.

C needs to be kept at 0.05% or less in order to prevent foaming caused by reaction with the insulating film.

In addition, Mn
0.1-0.5%, SiO, 1-0.5%, AIo
, 1 to 0.5%, and if necessary, to improve film adhesion, Ti
, Zr, RE, and AI at 0.6%
The following may be contained.

In this invention, the high melting point glass has a plate thickness of 0.4 mm to
High melting point glass such as 1.0 mm soda glass or borosilicate glass is preferable, and the melting temperature is preferably 50° C. or more higher than the melting temperature of the frit layer and 550° C. or more. Further, the thermal expansion coefficient is preferably smaller than the thermal expansion coefficient of the alloy substrate (90 to 110 x 10-7/'C) and larger than 70 x 10-77'C.

In addition, the frit layer has a particle size of 100mesh to 30mesh.
0mesh PbO-B2O3 system, PbO-B2O3-
Glass powder such as 8i02 series is preferable, and the melting temperature is
The temperature is preferably 500°C or lower, and the thermal expansion coefficient is the thermal expansion coefficient of the alloy substrate (90 to 110 x 10-7/'
C) and preferably larger than 70 x 10-7/°C.

When providing the frit layer on the sealing alloy substrate, the maximum thickness of the frit film by screen printing is 0.15 mm,
To provide a thick insulating layer, form it with a high melting point glass layer,
In order to form it thinly, it is preferable to form it with 7 lit layers.

In the laminated substrate according to the present invention, a sealing alloy substrate (A)
The layer thickness ratio between and the high melting point glass layer (B) adhered to the entire surface of the substrate is preferably 1010.5 to 5, and when the layer thickness ratio exceeds 1010.5, the dielectric breakdown voltage is low. Become,
The capacitance increases, which is undesirable, and the layer thickness ratio is 1.
If it is less than 0.015, thermal stress caused by the difference in thermal expansion causes problems such as warping, glass cracking, and a decrease in thermal conductivity.

Further, when a high melting point glass layer is provided on both surfaces of the sealing alloy substrate, the layer thickness ratio is preferably B/AfB = 0.5-5/1010.5-5.

In addition, when a high melting point glass layer is provided on one main surface of the sealing alloy substrate and a frit layer (C) is provided on the other main surface, the layer thickness ratio is B/A/
C=0.5-5/1010.5-5 is preferred. A/
If the layer thickness ratio of C exceeds 1010.5, the dielectric strength will decrease and the electrostatic field will increase, which is undesirable.
If the layer thickness ratio is less than 1015, it is not preferable because problems such as warpage, glass cracks, etc., and a decrease in thermal conductivity occur due to thermal stress due to the difference in thermal expansion.

Examples Example I CO, 01 wt%, Si 0.2 wt%, Mn 0.2
wt%, Cr 6.0wt%, Ni 42.5wt%,
A sealing alloy substrate consisting of 0.25 wt% AI, 05 wt% ZrO, and the balance Fe, has a mature expansion coefficient of 95 x 10-7°C, and has dimensions of 100 mm in diameter, 1.0 mm in thickness, and 300 mm in length. After cleaning the surface by alkaline degreasing, the alloy substrate was sandwiched between flat alumina ceramic plates and heated to a dew point of 4 with a pressure of 10 g/cm2.
It was heated to 1200° C. in moist H2 at 0° C. to form a preferential oxide film layer mainly composed of Cr2O3 with a thickness of 3 pm on the surface of the alloy substrate.

Second, the melting temperature is 760°C and the coefficient of thermal expansion is 8? X 10-7/'C properties, width 95mm x plate thickness 0.7mm x length 280m
Place soda-based glass of m size, 30 g/cm
Bonding was carried out by heating and pressing at a pressure of 2 and a heating temperature of 900°C.

The layer thickness ratio between the four alloy base layers and the high melting point glass layer during this lamination was 1010.6.

The heat resistance, coefficient of thermal expansion, thermal conductivity, and strength of the obtained laminated substrate according to the present invention were evaluated. The results are shown in Table 1.

The evaluation methods for heat resistance, thermal expansion coefficient, conductivity and strength are as follows.

Heat resistance: 30°C x 30 minutes, 500°C x 30 minutes, 30°C
Repeat the heat pattern for 30 minutes three times to check for changes in the overall shape and for defects such as cracks and chips in the glass and frit.

Coefficient of thermal expansion; elongation from 30°C to 500°C was measured.

Thermal conductivity: Measured at 30°C. The 11th place is c
Displayed in al/cm-s-deg.

Strength: 71 on a circular arc surface with a radius 100 times the plate thickness
The evaluation was based on whether or not bending was possible. In the table, the ○ mark indicates that no cracking occurred, the △ mark indicates that minute cracks occurred, and the X mark indicates that cracking occurred completely.

Note that the sample dimensions of the copper-clad glass epoxy substrate, alumina-based substrate, and enameled iron substrate of the comparative examples shown in Table 1 were 100 mm wide x tFi, 1 mm thick x 300 mm long.

Example 2 CO, 01wt%, SiO, 2wt%, Mn 0.2
wt%, Cr 6.0wt%, Ni 42.5wt%,
Consists of 0.25 wt% Al, 05 wt% ZrO, balance Fe, has a thermal expansion coefficient of 95 x 10-7/''C, width 100 mm x plate thickness 1.0 mm x length 300 mm
After cleaning both sides of the sealing alloy substrate by alkaline degreasing, the alloy substrate was sandwiched between flat alumina ceramic plates and heated to a dew point of 40°C under a pressure of 10 g/cm2. It was heated to 1150° C. in wet H2 to form a 31.1 m thick preferential oxide film layer mainly composed of Cr2O3 on the surface of the alloy substrate.

A melting temperature of 7 is applied on the preferential oxide film layer on both sides of the alloy substrate.
60℃, mature expansion coefficient 87 x 10-7/'C, width 95mm x plate thickness 0.55mm x length 280mm
A laminated substrate with a high melting point glass layer on both sides of the sealing alloy substrate was created by placing soda glass of the following dimensions on the substrate and bonding it by heating and pressing at a pressure of 25 g/cm2 and a heating temperature of 880°C. Obtained.

The layer thickness ratio between the alloy substrate and the high melting point glass layer during this lamination is 0.
．． It was 5/1010.5.

The heat resistance, coefficient of thermal expansion, thermal conductivity, and strength of the laminated substrate according to the present invention were evaluated. The results are shown in Table 1.

Actual toughness example 3 CO, 01 wt%, Si O, 2 wt%, Mn O, 2
wt%, Cr 18.0wt%, Ti 0.5wt
%, AI 0.25 wt%, Zr O, 05 wt
%, balance Fe, mature expansion coefficient 105 x 10-
7/”C, width 100mm x plate thickness 1mm x length 30
The entire surface of a sealing alloy substrate with a size of 0 mm was coated with Alka 1
After cleaning with 11L fat, the alloy substrate was sandwiched between flat alumina ceramic plates and heated to 1200°C in humid H2 with a dew point of 40°C under a pressure of 20g/cm2.])11 3 μm thick Cr2 on the surface of the polymerized substrate.
A pre-oxidized membrane layer consisting mainly of O3 was formed.

This alloy substrate has a preferential oxide film layer on its entire surface, has a melting temperature of 760°C, a mature expansion coefficient of 87 x 10-7/°C, and has dimensions of 95 mm width x 0.7 mm thickness x 280 mm length. Soda glass was placed on it, and it was bonded by heating and pressing at a pressure of 30 g/cm2 and a heating temperature of 900°C.

Furthermore, on the other main surface of the alloy substrate, the first oxide film layer was printed with a melting temperature of 760°C and a mature expansion coefficient of 8.
Particle size 300mesh with properties of 7X10-7/″C
PbO-based glass powder with a width of 95 mm and a length of 280 mm.
After adhering to the dimensions, drying, and removing the binder, the frit is heated to a temperature higher than the softening point of the frit and melted, thereby adhering the frit layer to the sealing alloy substrate via a preferential oxide film, thereby forming a sealing alloy substrate. A laminated substrate was obtained in which a high melting point glass layer was provided on one main surface and a frit layer was provided on the other main surface.

The layer thickness ratio of the high melting point glass layer, alloy substrate, and frit layer during this lamination was 0.6/1010.10.

The heat resistance, coefficient of thermal expansion, thermal conductivity and strength of the obtained laminated substrate according to the present invention were rated 9. The results are shown in Table 1.

Table 1

[Brief explanation of the drawing]

FIGS. 1A, 1B, and 1C are cross-sectional explanatory views of a laminated substrate according to the present invention. DESCRIPTION OF SYMBOLS 1...Sealing alloy substrate, 2...Priority oxide film layer, 3...
...High melting point glass layer, 4...Frit layer. Figure 1 (a) (b) (C)

Claims (1)

[Claims] 1. Cr_2 on at least one main surface of the Cr-containing sealing alloy plate.
A multilayer substrate for electronic components, characterized in that it is coated with a high melting point glass layer with a preferential oxide film mainly composed of O_3. 2 A preferential oxide film mainly composed of Cr_2O_3 is interposed on both main surfaces of a Cr-containing sealing alloy plate, and one main surface is coated with a high melting point glass layer and the other main surface is coated with a frit layer. Characteristic multilayer substrate for electronic components.