DE1646752A1 - Semiconducting components - Google Patents

Description

IiLEGTKIC IHDÜSTEIAL CO., LTD. Osaka, Japan

Me 3rfindung relates to semiconducting components and in particular to those conductive components that are electrical Represent v / ideratände with excellent properties.

The invention has for its object semiconducting components to create, which consist of a vitreous material and one or more semiconductor materials and in the semiconductor field have a specific concept to which a specific concept of lO ^ bic It) ohmzontimeter is based.

Another object of the invention is to provide an appropriate3 Process for the production of the pre-designated semiconducting components to create ·.

The conductive glasses known to the state of the art, the au η a Gfjmirjoh uines glaoartigon material with a metal

109815/1583 bad original

powders are made in order to obtain glasses that come very close to a conductor in terms of their specific resistance or at least come as close as possible, or to obtain semiconducting glasses with a directed specific resistance zj. obtained whose specific resistance is in the order of magnitude of 10 to 10 ohm centimeters and is therefore in the semiconductor range, but is not influenced by an electric field. In the manufacture of the known semiconducting glasses, cumbersome gate precautionary measures have to be taken in order to ensure a suitable working atmosphere so that the metal powder or other oxidizing due to the high temperatures during the

■ fc cases

Degradation phenomena caused by the process can be prevented .. Since the metals are also very generally mechanically resistant to a high degree, they are extremely difficult to pulverize beyond a certain limit with the current state of comminution or granulation technology. In the case of the known conductive glasses, it is also very difficult to precisely maintain a predetermined value of the specific Y / resistance, since the specific resistance of the metals per se is quite low. "

Another group of semiconducting devices comprises those in which a conductive powder is embedded in an organic resin or a plastic, the former serving as a binder for the particles of the latter. However, as a result of the imperfect contact between the conductive particles and the binder and the state of the surface layer of the conductive particles, such arrangements have an at non-linear voltage-current characteristic. With arrangements of this type, therefore, the desired Ohmaohe resistivity is not obtained. The temperature will also rise due to the donation

109815/1583

BATH ORIGINAL

temperature rise due to the power linearity of the resistance to be returned "overcurrent is caused, which is called Resin used as a binder, which has only a low level of heat resistance has, degraded, whereby the life of the component in question is shortened. .

According to the invention, novel semi-conducting components which are very resistant against external influences and a specific ohmic have resistance in the semiconductor region (Lue ^J to 10 ohm-cm), obtained by using as the semiconductive LIaterial a powdered Ketalloxyd that at considerably high temperature in is resistant to an atmospheric environment and which can be pulverized relatively easily.

The request calculation should now be based on the enclosed drawings are explained in detail. In the drawings seigenj

Figure 1 is a sectional view of one embodying the invention semiconducting component;

FIG. 2 shows a diagram of the current-voltage characteristic of the semiconducting component shown in FIG.

FIG. 3 shows a section of another that. invention embodied arrangement *

Figure 4 is a top view of another, the invention embodied. Arrangement;

Figure 5 is a sectional view of yet another that Invention embodying arrangement; .

Figure 6 is a diagram of "the current-voltage characteristic of the Component shown in Figure 5 »

Fi.jur 7 a Gchnit tan sees another, the invention

.10 9 8 15/1583 ...

■. '"' dung

BAD OfUGlNAL

embodiment embodying arrangement * and

Figure 8 is a top view of another, the invention personifying arrangement.

Reference is first made to FIG. Particles of a substance 103, which is powdered tin dioxide (SnO ₉ ), are embedded in a vitreous binder 102 as a semiconducting material. This semiconducting layer is formed by applying the mixture of semiconducting material 103 with the material consisting of a vitreous powder to the surface of an iron plate 104 and then drying it by heating. The glazed sheet iron plate 104 serves both as an electrode and as a heat-resistant substrate surface. An electrode 101 consisting of an electrically conductive coating is applied to the aforementioned semiconducting layer.

The following is an example of the production process for the above-described arrangement embodying the invention will. The composition of a powdered frit material (hereinafter referred to as A) as a binder and of powdered tin dioxide (hereinafter referred to as B) as the semiconducting material is shown in the following list: ■

Material volume percentage

powdered frit materiali A 85

powdered SnO ₂ ϊ Β 15

The percentage of the metal oxide can vary as desired The resistivity value may vary in the range of 10 to 35 percent. The average grain size of A

109815/1583

■ ORIGINAL BATHROOM

"is preferably about 1 micron and that of B is qtono c tr α 5 Ilikron. A grain size larger than this "impairs the dispersibility of the particles and leads to difficulties in the formation of the layer because the layer is in it If it becomes porous »On the other hand, a smaller grain size is desirable, since this improves the dispersibility, a more stable one electrical resistance is achieved and the molding is facilitated. However, it must be ensured that the condition · is met is to choose the grain size of A smaller than that of B. If namely the grain size of. Ä is larger than Von B, so cover it the particles of the frit material with metal oxide particles and can no longer touch each other «It comes from this with Then do not heat to form a coherent layer.

Next are those brought together in this ratio Powder A and B in a suitable machine or cutter thoroughly mixed »In the context of this exemplary embodiment the amount of A and B to which a volatile liquid such as Diacetone alcohol or an equivalent amount of octyl alcohol was added and mixed in a ball mill for twelve hours. as suitable period of time for this mixing process comes a half until a full day into consideration. For a shorter period of time, the particles are not sufficiently dispersed, while for a longer time span the differences between the grain size of A and that of B blur, so that the condition is no longer met is that the grain size of substance A is larger than that of B. Dae in this way mixed and dispersed powder In essence, I am in a solar-like state, with the Liquid serves as a diaper aid. The mixture is after

- Seidonrasterverfahron

109815/1583

. BADORiQINAL

- 6 - J646752

Silk screen process applied to the surface of the heat-resistant substrate, this procedure, although this procedure represents a preferred method of applying the substance, but this circumstance is not to be understood in a limiting sense of the invention. The purpose of the heating is to fuse the particles of the vitreous binder together without, however, dissolving the particles of the metal oxide in the vitreous material, and also to cause the binder to adhere to the substrate to form a smooth-surfaced layer. In this way, the metal oxide particles go at least on their surface in a solid solution in the vitreous binder, whereby the hand layer effect of the surfaces of the metal oxide particles is reduced Layer a uniform specific ohmic resistance. The lowest possible heating temperature is preferred. Accordingly, a frit material is to be selected that is less viscous even at a low temperature, that is to say a frit material. which has a low softening point. The following table 1 shows the composition of the vitreous material used in the tap of this exemplary embodiment »

Table 1

Components Weight percent Components Weight percent SiO ₂ 20.01 Fa ₂ O 10.84 B ₂ O ₅ . 28.58 K ₂ C 4.05 ZnO 18.33 TiO _? 2.31 BaO 14.34 Al ₂ O ₃ 0.41 CaO 0.74 Fe ₁₁ O ₅ C, 00 ° MeO 0.016 PbO U, 01 '?

10 9 8 15/1583

BATH ORIGINAL

-7- '16Λ67b2

The softening point of this Prittenramaterials was "about 600 Ms 64O ⁰ G. A sheet iron plate with approximately the same thermal expansion coefficient as the vitreous substance was used as the substrate can take place in a normal room atmosphere without special measures being necessary, since the tin dioxide (SnO ₂ ) used as a semiconducting material is very stable in the air at temperatures around 640 ⁰ C and since the substrate used has the same coefficient of thermal expansion as the glass-like material The solar-like mixture of A and B is applied to the substrate and within a period of about 20 minutes after "~

heated to 650 C after placing in an electric furnace, whereby the liquid component evaporates and the powder mixture remains on the substrate. The mixture applied to the substrate is kept at this temperature (65Ο C) for about five minutes, followed by a cooling time of about 20 minutes, after which the entire operation is finished. If to sift out the powder with a grain size of about 1 micron, use a silk screen 150 meshes per inch (130 mesh) is used, a layer with

a thickness of about 20 microns within one heating cycle ™

be shaped. In addition, a further layer can be applied to the already formed layer, if this should be desired for certain purposes. Since das.Glas is of considerable thickness, there is no fear that while the first layer of the glass melt at the temperature of 65O ⁰ C during the short period of time of 5 minutes or could change their strength. Figure 2 shows the current-voltage characteristic of the semiconducting layer formed in this way, the direct voltage across the electrical

1098 15/1583

BAB

the 101 and 104 is applied. From the excellent straightness of the characteristic curve it can be seen that, the ohmic layer has a XIi having standing. This layer had a current carrying capacity of considerable height and is readily heat-resistant. ■ _a ·.

FIG. 3 shows another arrangement embodying the invention, in which instead of the tin dioxide of the previous embodiment, titanium dioxide (TiO ₂ ) is used. In the illustration in FIG. 3, the binder 301 is a vitreous material with a softening point of 55 ° to 580 ° C. in which the powdered TiO 2 is dispersed. Transparent electrodes 303 and 304 are provided separately from each other on a glass substrate whose softening point is 680 to 700 ° C. A semiconducting layer consisting of the binding agent 301 and the particles of the semiconducting substance 302 is formed over the electrodes and over the substrate including the space between the two electrodes. The. The embodiment shown in FIG. 1 is intended as a Y / x resistance in the direction of the layer thickness, whereas in the embodiment according to FIG. 3, the electric current is intended to flow in the viewing direction of the figure in the lateral direction. Another feature of this embodiment is that the vitreous layer is formed on the surface of a glass or a vitreous substrate. The procedure in the preparation of this component and the requirements of the particle size are the same as with respect to genes in the voraufgegah- ⁼ embodiment.

- As for the substrate, come as materials for it in the first example described, only sheet iron

: 109815/1583 ...

i'- _: ., Λ-ι, Λν * ··. BATH ORIGINAL

plates, ceramic or similar materials can be considered while in the context of the last exemplary embodiment, glass can also be used. Two requirements must be met in order for a glass to be used as a substrate Can be used. One of these is that the softening point of the binder is lower than that of the substrate. This is an essential precondition as it is impossible to shape if the substrate softens rather than the binder when heated. The other requirement concerns the cubic expansion coefficient of the substrate, which must be approximately the same as that of the vitreous binder, namely the expansion coefficients Both materials differ significantly from one another, "cracks form in the substrate as a result of the tension forces occurring during cooling, or at least the electrodes 303 and 303 lose 304 as a result of the deforming mechanical tension 'their conductivity * speed. In Table 2, the cubic expansion coefficients are and the softening spunk te in the context of this embodiment binder and substrate used.

Table 2

Expansion coefficient softening point

Binder 2? 0 χ 10 approximately 58O ⁰ C-

Sheet glass (substrate) (270-300) X ΙΟ " ⁷ 650-700 ° C

In this embodiment, was heated to 63O ⁰ C. The transparent electrodes * 303 and 304 do not lose their conductivity when heated.

Figure 4 shows a further embodiment of the invention, in which the component has a shape as it would be for a potentiometer suitable. Transparent electrodes 401 and 402 are on one

* Giesfi-'slek electrodes) 1 η 9 8 1 5/1 5 8 3 Mtz-resistant

- ίο - 1648752

heat-resistant (made of glass or ceramic material) substrate 403 formed. The semiconducting rail 404, ^{which consists of a} binder containing a powdered metal oxide, is applied to the substrate and to the electrodes. In the arrangements embodying the invention, not only tin dioxide (SnO ₂ ) or titanium dioxide (TiO _p ) are considered as semiconducting material as it was used in the above embodiments, but it can also be another semiconducting metal oxide, for example Qy Sb ₃ Cv, CrpO ,, Fe ₂ O ,, YO _1. or Bi ₂ O, as well as Deletion of any two or more of these oxides.

It does not need to be particularly emphasized that the invention is not restricted to the embodiments described above is, but also embodied in manifold modified arrangements, can be, as it is the respective purpose requires.

As already stated above, the invention creates semiconducting components in which the particles of a semiconducting metal oxide are embedded in a vitreous binder. Thanks to the fact that there are those Substance component that gives the component the conductivity to If a metal oxide is involved, this component has a high degree of resistance in the case of heavy use by external influences and is resistant to ambient temperatures of considerable height, so that no complicated and expensive operating equipment or special measures are required during manufacture. Thus, semiconducting components are used within the scope of the invention with an ohmic resistance, to which a specific resistance "

10 9 815/1583

_w ^. _{Λ;) ί 4} j ^ BAD ORIGINAL

16467S2

stood in the semiconductor sector (namely in the range from IO ^ to 10 Ohm centimeter) is based, created in each individual case The specific resistance obtained depends on the relative volume fraction of the metal oxide compared to the binder.

In a nutshell, the semiconducting components according to the invention can easily be produced by a process whose individual process steps are as follows: a process step in which a powdered glass with an average grain size of less than 1 micron is mixed with a powdered semiconducting metal oxide, whose average grain size is less than 5 microns, but larger than that of the glass, the proportion of the letalloxyds ffaganfihpr dem dee Slaceo being 10 to 35 percent by volume and the mixture together with an additive in the form of a volatile liquid until it reaches one is carried out in a solar-like state; a process step in which this mixture is applied in the form of a layer to the surface of a heat-resistant substrate, the melting or softening point of which is higher than the softening point of the glass; and a step of heating that layer of the mixture to a temperature higher than the softening point of the glass but lower than the melting or softening point of the refractory substrate. According to the method according to the invention, the heating can be carried out in a room atmosphere without special precautionary measures having to be taken with regard to the external conditions. Also, due to the fact that the grain size of the glass powder is selected to be smaller than that of the ketal oxide powder, a smooth and firmly set layer is obtained. The fact that the grain size of the glass and of the tallow oxide powder is less than 1 hikron

109 8 15/158 3 "

relationally ^; ■ "BAD ORIGINAL

or J micron, prevents the layer from becoming porous and ensures adequate dispersion of the metal oxide particles in the glass serving as a binder, thus enabling the production of resistors with uniform and constant Properties enables and at the same time the layer formation is very much facilitated. This means that semiconducting can be achieved in a very simple manner Components with a specific resistance in the semiconductor range (Kr up to 10 ohm centimeters) are produced.

The semiconducting components according to the invention are themselves Resistant to temperatures of considerable height and to moisture and other external influences very resistant.

In the following, in the context of further exemplary embodiments another aspect of the invention will be discussed.

According to this aspect of the invention, a powdered insulating material or several such insulating materials are admixed with the metal oxide powder described above in order to facilitate the dispersion of the metal oxide particles. In the context of these embodiments of the invention, extremely durable semiconducting components with uniform properties, which have an ohmic resistance in the semiconductor range (10 to 10 ohm centimeters) and increased dielectric strength, are obtained. With regard to the insulating material to be admixed, the only requirement is that it be thermally stable, since this material only serves to ^{prevent incomplete dispersion or maldistribution of the Uetalloxydpartikel 1} and in no way contributes to the conductivity of the building element. In this case, too, the grain size of the glass powder should be selected to be smaller than that of the luetal oxide powder and also that of the insulating material. When mixing, applying and creating

1098 15/158 3 ' heat

BATH ORIGINAL

the powder is essentially the same way, as in the preceding in connection with other embodiments of the invention has been described.

An embodiment of such an arrangement embodying the invention will be explained below with reference to the accompanying drawings. In the illustration of FIG. 5, a vitreous binder designated by the reference number 102 contains, as semiconducting material, particles of a powdered mass 103 of tin dioxide (SnO) and particles of a powdered mass 104? M.

which is BaTiO, and which is mixed in to facilitate the dispersion and distribution of the semiconducting material 105 and to increase the dielectric strength of the component. The mixture consisting of the powders 1Ö2V, 103 and 104 is applied in the form of a layer to the surface of an iron plate 105 and dried by heating. The glazable iron plate 105 serves as an electrode and at the same time as a heat-resistant substrate. An electrode 101 consisting of an electrically conductive coating is applied to the aforementioned semiconducting layer. The composition of the mixture consisting of the powdered frit material (hereinafter referred to as A), of the powdered tin dioxide (hereinafter referred to as B) and of the powdered BaTiQ ₃₅ (hereinafter referred to as G) is shown in the list below.

Material · volume percentage

powdered frit material: A ",. = 65

powdered SnO ₃ SB 15

powdered BaTiO 'ί C 20

Of the

109815/15 8 3. _;

BATH

'-U- 1_6 46.7 S / 2

The percentage SmG iaim depending on the desired v / ert the resistivity in favor of or at the expense of the percentage of the material in the range of 10 ibis 35 percent. . vary. With regard to the grain sizes of B and G in proportion to 'car from A, the same preconditions must be met as for the Play previous lead leadership. Also the procedure at home mixing and churning the game, the se were parts of the irittonmaterials and the process of retrieval are essential here the same as in the previous exemplary embodiments . Figure 6 shows the current-voltage characteristic curve of the = molded semiconducting. Layer, with the DC voltage across the Electrodes 101 and 105 is applied. The straightness of the characteristic indicates that the layer has a Gfamian resistance. This The layer also has a considerable current carrying capacity Height. ■. .

FIG. 7 shows a further embodiment which is essentially the same as the arrangement of the Hgai J, but with the! PiO _? -Particles or powdered AIpO- is added. In particular, the binder 301 is usually a glass-like material with a: a softening point of 550 Ms 58O ° G, the semiconducting material 302 TiO _{2 powdered as the semiconducting material 302 and Al 0} O powdered as the dispersant 303 , contains. Electrodes 304 and 305 made of SnO ₃ are arranged in a separate arrangement on the surface of the glass substrate 306 in Russian: -cforat ,. the softening point of which is 6 ° C to 700 ° C. The hall-conducting layer consisting of the powders 301, 302 and 303 also fills the space between the two electrodes. In its other structural features, this type of carrion is essentially the same as the

under

109815/1583 ~~ 7 ~

BATH ORIGINAL

described with reference to FIG.

^In Figure 8 a 'further arrangement embodying the invention is shown. This arrangement is essentially the same as the embodiment of FIG. 4, but a dispersant has been added to the mixture. In the illustration of FIG. 8, transparent electrodes 401 and

402 provided. "Then that's over the substrate and the electrodes Semiconducting layer formed, denoted by the reference number 404 is.

In these embodiments, too, not only tin dioxide (SnO ₂ ) or titanium dioxide (TiO ₂ ) come into consideration as semiconducting material, but also, as has already been explained above, a semiconducting metal oxide such as 7/0 ,, Sb _n O ,, Cr ₀ O-, Fe_0 ,, T ^ O ^ or Bi ₀ O, as well as any mixtures of such metal oxides. Furthermore, the selection of the insulating or dispersing agent is by no means limited to BaTiGL or AlpO, but can also include any other substances (such as SiOp) that have a significantly higher value of electrical resistance than the aforementioned metal oxides and a higher melting point than that have vitreous binders.

As explained above, according to the second aspect of the invention, semiconducting components are created in which Particles of an introductory metal oxide and Particles of an oxide with a higher specific field level than that of that metal oxide are contained in a vitreous binder. These components show other than the iia context of the first aspect of the invention with the previous embodiments described

1Q98 15/158 3 features

- i6 - 1846752

Features increased dielectric strength and an even more uniform specific resistance on what is sufficient fine dispersion of the semiconducting particles is due.

Semiconducting components of this type can be produced without difficulty by a process, the individual process steps of which are as follows: a process step in which a powdered glass with an average pore size of less than 1 micron with a powdered semiconducting metal oxide and with a powdered, a higher specific Resistance than the oxide having metallic oxide is mixed, the average grain sizes of the metal oxide and that of the oxide having a higher specific resistance than the metal oxide being smaller than 5 microns, but larger than that of the glass, the proportion of the metal oxide being equal to '^ fl * - rtxnm ^ -Λαρ m γ ^ q _r amounts to 10 to 35 percent by volume and the mixture is stirred together with an additive in the form of a volatile liquid until a solar-like state of the art is reached, a process step in which this mixture is applied in the form of a layer Surface of a hitζebest ändigen substrate is applied, whose melting or softening point higher than the softening point of the ölasesi and a step _t in which this layer is heated to a temperature of the mixture j which is high as the softening point of the glass ,, but lower than the melting or Softening effect of the heat-resistant substrate. The advantages that can be achieved by this method have already been explained in the context of the first aspect of the invention and will therefore not be repeated here *

, Bat en tan spray ehe

BATH ORIGINAL

Claims (1)

P a t e η t a η s ρ r ü c h e 1. Hello 1 extsndes component, characterized in that one particle powdered semiconducting metal oxide (lOj) in a vitreous Binder (lO2) are dispersed. '■ 2. Semiconducting component according to claim 1, characterized in that the semiconducting ketal oxide is SnOg-, TiO ₂ , Sb ₃ O ^,? / O ", Cr _? 0 ,, Fe ₂ O ₇ , YpO ₁ - or Bi ₉ O, or several of these substances. '■ "" - J. A method for the production of the claimed in claim 1 semiconducting the component, characterized in that a glass powder with a (| is a powder halbleiteiiden Zetalloxyds whose grain size is larger, mixes than the grain size of the glass powder ", the particles of the .etallox ~ ^r äpulvers be well dispersed in the glass powder and the above-emenge is heated. - ■ 4. Process for the production of the semiconducting material claimed in claim 1 Component, characterized by a process step, at the cd η powdered glass with an average grain size of less 3.1s 1 micron with a powdered semiconducting metal oxide is mixed, the average grain size of which is less than 5 Mi- * kran, but is larger than the grain size of the glass, where the proportion of He tall oxy ds ^^ ΐ "" ^ ° τ> λ _? ™ α,., _Ff ^ l-ic ^ j; amounts to 10 to 3! 3 percent by volume and the mixture is stirred together with an addition of a volatile liquid until a solar-like state is reached; a process step in which this mixture is applied in the form of a layer to the surface of a heat-resistant solid substrate, the melting or softening point of which is higher than the softening point of the glass »and a 109815/1583 SA © a process step in which this layer de r ki schung on a Temperature is heated to the. higher than the softening point of the Glass, but lower than the melting or softening point of the heat-resistant substrate, the layer being bonded to the substrate will. 5. Semiconducting component according to claim 1, characterized in that particles of a powdered semiconducting metal oxide (iCj?) ^U e £ of a powdered oxide (IO4) j whose specific resistance is higher than that of the semiconducting metal oxide (lOjj), in a vitreous binder ( lO2) are dispersed. 6. Semiconducting component according to claim 5> characterized, . that the semiconducting iletal oxide is SnO _n , TiO ₀ , Sb CV, W ^, Cr 0, Pe Oj or Bi ₉ O, or several of these substances. 7. Semiconducting component according to claim 5, characterized in that the oxide is BaTiO, Al ₀ O ₇ or SiO ₀ or a number of these substances. 8. A process for the production of the light-conducting material claimed in claim 5 Component, characterized in that a glass powder with a powder of a semiconducting metal oxide and with a powder of a Oxide, the specific resistance of which is higher than that of the semiconducting metal oxide, is mixed, the grain sizes of the lethal oxide powder and that has a higher specific resistance than that semiconducting metal oxyd'aufweisenden oxide powder are larger than that of the glass powder * the particles of the ketal oxide and the one higher specific resistance than the semiconducting metal oxide pointing " Oxyds are well dispersed in the glass powder? and heat the mixture will. 109815/1583 ^ ; h ..; V-, ..i BAPORrQINAL 9. Method for the production of the semiconducting component claimed in claim 5, characterized by a process step in which a powdered glass with an average grain size of less than 1 micron with a powdered semiconducting metal oxide and with a powdered, a higher specific resistance than that Oxide containing metal oxide is mixed, the average grain sizes of the metal oxide and that of the oxide having a higher specific resistance than the oxide of metal being smaller than 5 Llikron, but larger than that of the glass, the proportion of the lethal oxide being ¹ ^ """ ^Ar > ™ ^ ⁰⁰ ^ f ⁰⁰ ? Amounts to 10 to 35 percent by volume and the mixture is stirred together with an additive in the form of a" volatile liquid until a sol-like state is reached; " a process step in which this mixture is applied in the form of a layer to the surface of a heat-resistant substrate whose melting or softening point is higher than the softening point of the glass and a process step in which this layer of the mixture is heated to a temperature which is higher than the softening point of the glass but lower M is connected as the melting or softening point of the heat resistant substrate, the layer with the substrate comparable. 109815 / 158-3 BAD QRtGlNM.