JPH02216895A - Semiconductor porcelain board with built-in capacitor - Google Patents

Abstract

PURPOSE:To prevent a decrease in capacitance of a built-in capacitor, an increase in dielectric loss and an increase in process capacity change by forming the capacitor of an electrode material in which predetermined amounts of sintering agent made of glass powder and metal oxide having specific melting point are added to conductive metal component. CONSTITUTION:A capacitor is formed of an electrode material in which 0.05-1.5wt.% of sintering agent made of glass power and metal oxide having 850 deg.C or lower of melting point are added to conductor metal component. Thus, a predetermined part of a semiconductor porcelain board with built-in capacitors to be used as a capacitor is coated with paste for electrodes made of metal component to become conductor, glass powder, low melting point metal oxide and organic vehicle, dried, and baked at 850-950 deg.C to form electrodes 3 for the capacitor. In order to avoid contact of an electrode except as desired with upper base wirings, it is coated with dielectric paste made of glass, and in order to connect the electrode to desired conductor wirings 9, it is coated with paste made of conductor. Then, it is baked at approx. 850 deg.C to form the dielectric glass and the conductor as an insulating layer 4 and viahole 5, and the steps are repeated predetermined times.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a capacitor-embedded semiconductor ceramic substrate that can be used as an electronic material such as a dielectric ceramic substrate.

[Conventional technology]

In recent years, grain boundary insulated substrates with built-in capacitors have been developed, and are expected to help miniaturize electronic devices. In this board, the capacitance of the built-in capacitor section was taken out using a conductive paste conventionally used for conductor wiring for alumina boards.

[Problem to be solved by the invention]

However, the conductor paste conventionally used for conductor wiring for alumina substrates contains a large amount of a sintering agent made of glass powder and a low melting point metal oxide compared to its conductor metal components, and Semiconductor with built-in capacitor°
When used as an electrode for the capacitor part of a ceramic substrate,
Even if the built-in capacitor is adjusted to the specified capacity by trimming, etc., after the subsequent insulation layer formation process,
The more the capacitance changes from a predetermined value, and the larger the rate of change, the more
The variation has also increased, and it has been found that the semiconductor ceramic substrate with a built-in capacitor has a problem that cannot be ignored in terms of the yield rate.

[Means to solve the problem]

The present inventors have completed the present invention as a result of extensive research in search of an electrode material that can reduce process changes in capacitance. That is, the present invention forms a capacitor using an electrode material in which 0.05 to 1.5% by weight of a sintering agent made of glass powder and a metal oxide having a melting point of 850° C. or lower are added to the conductor metal component. This is a semiconductor ceramic substrate with a built-in capacitor.

In the semiconductor ceramic substrate with a built-in capacitor, the reason why the sintering agent made of glass powder and the metal oxide with a melting point of 850°C or less are limited to 0.05 to 1.5% by weight based on the conductor metal component is as follows. It is as follows.

If the additive component is less than 0.05% by weight, the adhesion strength between the capacitor portion of the capacitor built-in ceramic substrate and the electrode will be weak. Moreover, if it exceeds 1.5% by weight, process changes in capacitor capacity and dielectric loss (tan δ) will worsen. Furthermore, the capacitance itself before the change also decreases.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

l) An electrode paste consisting of a metal component to be a conductor, glass powder, a low melting point metal oxide, and an organic vehicle is applied to a predetermined portion of a semiconductor ceramic substrate with a built-in capacitor (Fig. 1) to be used as a capacitor, and after drying, 850-950
The electrodes for the built-in capacitor are formed by firing at a temperature range of 10°C (Fig. 2). The reference numeral l in FIG. 1 is a capacitor functional part, the reference numeral 2 is a part separating each capacitor function, and the reference numeral 3 in FIG. 2 is an electrode. Further, the electrode 3 may be trimmed to fit within a predetermined capacitance range.

2) Applying a dielectric paste made of glass in order to avoid contact between the above-mentioned electrodes other than those desired and the upper substrate wiring,
Further, a paste made of a conductor is applied for the purpose of connecting the electrode to a desired conductor wiring. Next, it is fired at about 850° C. to form the dielectric glass and the conductor into an insulating layer and a via hole, respectively (FIG. 3). However, each may be fired separately.

In addition, reference numeral 4 in FIG. 3 is an insulating layer made of dielectric glass, and reference numeral 5 is a via hole made of a conductor.

3) Next, repeat the step 2) a predetermined number of times (FIG. 4). However, FIG. 3 is an example in which the process is repeated three times.

In addition, the difference between the capacitor capacitance at the time of forming the capacitor electrode and the capacitor capacitance at the time of forming the final insulating layer and the peer hole,
That is, the process capacity change rate is expressed by the following equation.

A: Capacitance of capacitor when forming capacitor electrode B: Capacitance of capacitor when forming final insulating layer and via hole FIG. 5 shows an example of an electronic circuit board using the semiconductor substrate with a built-in capacitor of the present invention. In FIG. 5, reference numeral 6 indicates an IC, 7 indicates a chip component, 8 indicates a resistor, and 9 indicates a conductor wiring.

Metal components too, o that become conductors in the electrode material for extracting the capacitor capacity of the semiconductor ceramic substrate with a built-in capacitor
If the glass powder as a sintering agent and the low melting point metal oxide with a melting point of 850°C or less exceed 5.0 parts by weight, the built-in capacitor capacity will decrease, dielectric loss will increase, and process capacity will change. This is undesirable as an increase in

Further, examples of the present invention will be explained in comparison with comparative examples.

A semiconductor ceramic substrate with a built-in capacitor shown in FIG. 6 was prepared. In Figure 6, 1 is the capacitor function part, 2 is the part that separates the capacitor function, and the area of 1 is 16m5"
, the thickness of the substrate is 0.635 mm. A paste consisting of metal powder, glass powder, metal oxide powder, ethyl cellulose, and solvent, which will become a conductor, adjusted to the ratio shown in the "Electrode Composition" column of Table 1 is applied to both sides of this capacitor functional part. Coated. After that, it was dried at 850℃ and 900℃.
°C, fired at 950 °C. Next, measure the capacitance (μF) and tanδ (%) as the built-in capacitor characteristics.
This capacitance was taken as the capacitor capacitance at the time of capacitor electrode formation in the process capacitance change rate formula. Next, glass paste as an insulating layer and conductive paste as a via hole were printed, dried and fired at 850°C. This operation was repeated three times to form an insulating layer with a thickness of about 45 μm. Next, as built-in capacitor characteristics, capacitance (μF) and tan δ (%) were measured, and this capacitance was used as the capacitance at the time of forming the final insulating layer and via hole in the formula for process capacitance change rate. Next, the process capacity change rate was calculated according to the process capacity change rate formula. The results of these measurements are shown in Table 1. In Table 1, * marks indicate comparative examples, and others indicate examples.

The adhesion strength test method (see Figure 7) is as follows.

An electrode 11 of 2 mm x 2 mm was formed on the substrate 10, and a lead wire 13 with a diameter of 0.65111 mφ was provided by soldering 12 as shown in the figure, and an L-shaped tensile test was conducted.

〔Effect of the invention〕

According to the present invention, a capacitor-embedded semiconductor ceramic substrate having a built-in capacitor with little process capacitance change and low dielectric loss could be obtained at a high yield rate.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of height measurement according to the present invention, and FIG. 2 is a cross-sectional view showing an example of the height measurement shown in FIG. FIG. 3 is a sectional view showing an example of the height measurement according to the present invention in which an insulating layer and a via hole are formed, and FIG. 4 is a sectional view showing an example of the height measurement according to the present invention in which an insulating layer and a via hole are formed in three layers. FIG. 5 is a cross-sectional view showing an example of an electronic circuit board using one embodiment of the height measurement method of the present invention, and FIG. 6 is a perspective view of a semiconductor ceramic board with a built-in capacitor used in the example. Furthermore, FIG. 7 is a schematic explanatory diagram showing the adhesion strength testing method according to the present invention. 1... Capacitor functional part 2... Part separating each capacitor function 3... Electrode 4... Insulating layer made of dielectric glass 5... Via hole made of conductor 6... IC7... Chip parts 8...Resistor 9...Conductor wiring lO...
・Substrate 11... Electrode 12... Soldering 13... Lead wire Patent applicant Nippon Oil & Fats Co., Ltd. Figure 5 Figure 6

Claims (1)

[Claims] 1. In a semiconductor ceramic substrate with a built-in capacitor, a sintering agent made of glass powder and a metal oxide having a melting point of 850°C or less are added in an amount of 0.05 to 1.5% by weight based on the good conductor metal component.
A semiconductor ceramic substrate with a built-in capacitor, characterized in that a capacitor is formed using an added electrode material.