JPS60261108A - Method of producing thick film positive temperature coefficient semiconductor element - 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 Field of Industrial Application The present invention relates to a method for manufacturing a thick-film positive temperature coefficient semiconductor element that does not require glass frit, among planar heating elements used for heat insulation and heating of equipment, etc. It is.

Conventional configuration and its problems.

Elements made of BaTiO3-based semiconductors have switching characteristics in which the resistance value increases rapidly above a certain temperature and self-heating characteristics after switching, and have fast temperature rise characteristics and self-temperature control functions, requiring an external control circuit. It is widely used because it does not.

Conventional positive temperature coefficient thermistor heating elements were obtained by press-molding BaTi○3 semiconductor powder and then firing it, but it was considered difficult to obtain a practical thick film positive temperature coefficient thermistor heating element. was.

Conventionally, the following method is known as a method for processing a B a T 10s semiconductor into a film.

■ After forming into a disk shape, the fired product is polished into thin pieces.

■ Form a thin film on the substrate by vacuum evaporation.

(2) A conductive additive and glass frit are added to B a T 103 semiconductor powder to form a paste, which is screen printed on a substrate and then fired.

However, in the method (2) above, since the crystal grain size of the BaTlO3-based semiconductor is large and brittle, it is necessary to polish it to a film shape.
It is extremely difficult. Furthermore, the method (2) is cumbersome to operate, and it is difficult to obtain a large amount of power suitable for the heating element. Furthermore, method (2) above tends to have a high sheet resistance and is difficult to control, and is not suitable for heating elements.The glass frit must be prepared and fired beforehand, which is troublesome and difficult to control. BaT depending on the material
It deteriorates the switching characteristics and self-heating characteristics of iO3-based semiconductors. Then, by adding glass frit, it is susceptible to thermal shock due to the difference in heat resistance and coefficient of thermal expansion between BaTzOs semiconductor and glass frit, and heat conduction is hindered. Furthermore, it is difficult to uniformly mix conductive additives and glass frit, which is one of the causes of variations in properties.

Purpose of the Invention Therefore, the present invention solves the drawback of the prior art, which is the complexity of manufacturing, and creates a film with excellent thermal shock resistance, thermal conductivity, and uniformity by forming a thick film without using glass frit. It is an object of the present invention to provide a method for easily manufacturing a thick film type positive characteristic semiconductor element having such characteristics.

Structure of the Invention The method for manufacturing a thick film type positive temperature semiconductor device of the present invention comprises B a
N 13S l+N i to T 103 semiconductor powder
s S 121 N i 3S 12 .

i, at least one type of Ni2Si, NiSi.

The purpose is to obtain a thick film type positive characteristic semiconductor element by applying a mixture made into a paste by adding ~60.0 weight coefficient onto a substrate to form a thick film, and then firing it. 1 With the method using conventional conductive additives and glass frit -
A conductive additive is required to electrically connect the B a T 103-based semiconductor powders, and a glass frit is necessary to physically connect the B a T IO3-based powders.

However, according to the present invention, Ni3Si, Ni6
Si2. Ni2Si 捷、Ni2Si idaha NiSi
It is characterized by its use of wo. These Ni3Si
.

Ni5Si2. Ni3Si2. Ni2Si, NiSi
is a conductor at room temperature, and when the temperature exceeds 1000 to 1100°C, a part of it decomposes and 8102 is precipitated on the particle surface, but inside the particle, the 8102 film on the surface causes only a slight decomposition of IU-1tl. It will be done. Follow-), B a T
z O33-based semiconductor powder Kichi, Ni3Si, Ni5Si2
．． Ni3Si2. When Ni2Si i or NiSi powder is mixed and fired, Ni3Si, Ni, Si2
．． S102 precipitated on the surface of Ni3Si2゜Ni2Si or NiSi plays the same role as glass frit, and the inside of the particle plays the role of a conductive additive, so N'i
3Si, Ni6St2°N z 3S 12,
A thick-film type positive characteristic semiconductor element that does not require a glass frit can be obtained by simply adding 1 ounce of N 12 S or N i Si.

In fact, by adding a conductive metal, thermal conductivity becomes better than glass frit, which has poor thermal conductivity, and thermal shock resistance also improves.

DESCRIPTION OF EMBODIMENTS Below, embodiments of the present invention will be specifically explained with reference to FIG.

Example 1 1.0 mol % (7) Nb2O was added to BaTiO3 and fired at 1300°C, followed by pulverization to obtain a BaTiO3-based semiconductor powder. A paste-like mixture 1 is prepared by adding 15.0% by weight of Ni3St powder to the BaT 103-based semiconductor powder and mixing uniformly, and then adding α-terpineol.

On the other hand, a pair of rough electrodes 3.4 made of a conductive material such as Aq are provided on a substrate 2 made of Al2O3, etc., and a part of the electrodes 3.4 is left on the electrodes 3, 4. The paste mixture 1 is applied by screen printing or the like, heated from room temperature to 10"C'/mm at a heating rate of 1350'C, held for 1 hour, and left to cool in the furnace. In this way, a thick film type positive characteristic semiconductor device was obtained.

Example 2 In the same manner as in Example 1, 3.0 mol of La2O2 was added to B a T IO3 and fired at 1250°C, followed by pulverization to obtain a B a T IO3 based semiconductor powder. Said B
a T 103-based semiconductor powder with 5.0% by weight of N isS 12 powder and 5.0% by weight of Ni
3S i2 powder and 10.0% by weight NiSi powder are added and mixed uniformly, and a-terpineol is further added to form paste mixture 1.

Next, as in Example 1, the electrodes 3 and 4 are provided on the substrate 2 in advance, and the paste mixture 1 is applied by screen printing or the like so that a portion of the electrodes 3 and 4 remain. , 1 at a heating rate of 10°C/mm from room temperature
The temperature was raised to 000°C7, held for 3°, and then allowed to cool in the furnace. In this way, a thick film semiconductor element was obtained.

The sheet resistance of the thick-film semiconductor device obtained in this way at room temperature is 5.1KQfi,.l in the case of Example 1, and 2.0KQ〆i in the case of Example 2, depending on the temperature and resistance value. The relationship was as shown in Figure 2. In FIG. 2, A shows the characteristics of the device obtained in Example 1, and B shows the characteristics in Example 2.

However, even when Nl2S1 powder is added as a conductive metal, properties equivalent to those described above can be obtained;
'i 3S i , Ni5Si2. Ni3Si2. N1
It has been confirmed through experiments that 2St and NiSi have similar effects when added alone or in combination.

Effects of the Invention As described above, according to the manufacturing method of the present invention, Ni3Si
, Ni6Si2. Ni3St2. Ni2Si or Ni
Si powder plays the role of both a conventional conductive additive and a glass frit, has sufficient effects for electrical connection and physical connection, and thick film positive characteristic semiconductor devices can be obtained without glass 7 litho. becomes.

There is still a glue called glass frit, which has poor thermal conductivity.
) N 13 S 1rNi, a conductive metal with good thermal conductivity
5S12. N13Si2. By using Ni2Si and Nl5l, heat conduction is improved and thermal shock resistance is also improved.

Furthermore, since it can be manufactured by screen printing or the like, the work is easy and mass production is possible.

In addition, in the present invention, as BaTiO3-based semiconductor powder,
Any material may be used as long as it is made into a semiconductor by adding various additives to N', B a T 103. That's right, N13
Si.

Ni5Si2. Ni3Si2. N'12St, NiS
Although the amount of I powder to be added is specified as 1 to 6 o weight ratio for all heavy equipment, if it is less than 1 weight ratio, the area resistance becomes too large and it is unsuitable for a heating element, and it is impossible to physically fix BaT103 powder together. On the other hand, if the weight coefficient exceeds 60, the area resistance becomes too small, and the self-control characteristics (PTC characteristics) become small, making it unsuitable for a heating element.

Furthermore, BaTiO3-based semiconductor powder, Ni3St, N
13Si2.

Ni3Si2. An organic solvent (α-terpineol in the example) was used to make the Ni2Si and NiSi powder into a paste, but any solvent may be used as long as it can be made into a paste.

As described above, according to the present invention, it is possible to easily manufacture a thick film type positive characteristic semiconductor device that does not require a glass frit.
Its practical effects are significant.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view showing a thick film positive temperature coefficient semiconductor device obtained by the method of the present invention, and FIG. 2 is a diagram showing the relationship between temperature and resistance value of the device according to an embodiment of the present invention. 1 paste-like mixture, 2... substrate, 3.4...
electrode. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3 t4 Figure 2 part Y 21 d'c)

Claims (1)

[Claims] BaTi○3-based semiconductor powder with Ni3Si and Ni5Si
2゜Ni3Si2. A thick film characterized by adding 1.0 to 60.0% by weight of at least one of Ni2Si and NiSi and applying a paste-like mixture onto a substrate to form a thick film, followed by firing. A method for manufacturing a film type positive characteristic semiconductor device.