JP2004107203A - Electronic component firing tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic component firing tool which is obtained by an inexpensive thick-film forming method and excellent in anti-exfoliation property and wear resistance of a zirconia layer. <P>SOLUTION: In the electronic component firing tool having a base material and the coated zirconia layer on the surface of the base material, at least one kind of metal oxide forming a liquid phase is incorporated for improving the anti-exfoliation property and the wear resistance at the time of firing the zirconia layer, and after sintering, the liquid phase crystallizes. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a jig for firing electronic parts such as setters, shelf boards, and mortars, which are used when firing electronic parts such as dielectrics, multilayer capacitors, ceramic capacitors, piezoelectric elements, and thermistors.

The performance required as a jig for firing electronic parts is required not to react with ceramic electronic parts to be fired in addition to heat resistance and mechanical strength. When an electronic component workpiece such as a dielectric contacts and reacts with the firing jig, there are problems such as fusion or deterioration of characteristics due to variation in the composition of the workpiece.

Usually, as a base material for jigs for firing these electronic components, alumina material, aluminalite material, alumina zirconia material, alumina magnesia spinel material, aluminalite cordierite material, or a combination thereof Materials are used (see Patent Documents 1 and 2).
JP 2001-213666 A JP-A-8-253381

In order to prevent reaction with the workpiece, a method of covering the surface layer with zirconia (zirconium oxide) is employed. Zirconia has low reactivity with the base material, but due to the large difference in thermal expansion coefficient with the base material, there is a problem that the coating of the jig is cracked or peeled off under the usage environment in which repeated thermal cycling occurs. . Further, when the jig is used repeatedly, if the anti-granulation resistance and abrasion resistance at which particles contained in the zirconia layer on the surface drop off are low, fine particles are mixed into the electronic component, which causes a significant problem.

Furthermore, zirconia undergoes a phase change from monoclinic to tetragonal at about 1100 ° C. As a result, there is a problem that the coating layer of zirconia is easily detached due to a change in the thermal expansion coefficient accompanying the phase transformation due to repeated thermal cycling. When unstabilized zirconia is used, pulverization associated with phase transformation is likely to occur, and the anti-degranulation property is lowered.

There are a coating method, a dip coating method, a spray coating method, and the like as a method for forming a zirconia layer on the surface of a base material of an electronic component firing jig. These methods are relatively inexpensive and suitable for industrial production, but the formed zirconia layer may not have sufficient peel resistance and wear resistance.

In particular, in an environment in which a repeated thermal cycle is applied to the electronic component firing jig, the zirconia layer may be peeled off from the base material or degranulation may occur.
An object of the zirconia layer of the present invention is to provide a jig for firing an electronic component that is excellent in the peel resistance and wear resistance of the zirconia layer even when such an inexpensive thick film forming method is used.

The present invention includes one or more metal oxides that form a liquid phase in order to improve peel resistance and wear resistance when a zirconia layer is formed on a substrate surface and then fired. In addition, the present invention provides a method for forming a zirconia layer having excellent peeling resistance and abrasion resistance on the surface of a substrate by crystallizing these liquid phases after sintering.

That is, in a jig for firing an electronic component comprising a substrate and a zirconia layer coated on the surface of the substrate, a liquid phase is formed in order to improve peeling resistance and wear resistance when firing the zirconia layer. An electronic component firing jig characterized by comprising a metal oxide of at least a seed and crystallizing these liquid phases after sintering.

In addition, the metal oxide contained in the zirconia layer includes one or more metal oxides selected from rare earth oxides, alkaline earth oxides, and transition metal oxides, or aluminum oxide. The electronic component firing jig described above.

In the electronic component firing jig described above, a composite oxide selected from the oxide group described above is used as the metal oxide contained in the zirconia layer.

Further, in the electronic component firing jig described above, the impurity contained in the zirconia layer is 5 wt% or less.

In the electronic component firing jig described above, the zirconia as a main component forming the zirconia layer is stabilized, partially stabilized or unstabilized zirconia.

As described above, the zirconia layer of the present invention is based on an inexpensive thick film forming method, and can provide a jig for firing an electronic component that is excellent in the peel resistance and wear resistance of the zirconia layer.

  The present invention will be described in detail below. The present invention provides a metal oxide forming a liquid phase contained in the zirconia layer, rare earth oxides such as yttrium oxide and lanthanum oxide, alkaline earth oxides such as calcium oxide and barium oxide, and titanium oxide and niobium oxide. Providing a jig for firing electronic parts including a zirconia layer excellent in peeling resistance and wear resistance by selecting one or more metal oxides or aluminum oxide selected from transition metal oxides such as manganese oxide it can.

In the present invention, by selecting one or more kinds of metal oxides or aluminum oxides, a reaction occurs between two or more kinds of oxides including the zirconia layer containing the main component, and some of them are melted. Forms a liquid phase and strengthens the bond between zirconia particles. Furthermore, it is desirable that these reaction products crystallize after sintering to form a liquid phase. The durability of the zirconia layer at a temperature at which the electronic component is baked by crystallization, for example, 1300 ° C., is kept good.

The metal oxide contained in these zirconia layers can be added in the form of composite oxide j. For example, when two kinds of metal oxides of barium oxide and titanium oxide are added, they can be added as an appropriate amount of barium titanate composite oxide.

In addition to the above metal oxides, impurities contained in the zirconia layer, such as zinc oxide, bismuth oxide, sodium oxide, silicon oxide, etc. are more preferably 1 wt% when promoting the reaction with the above metal oxides. The maximum is preferably 5 wt% or less. If these impurities exceed 5 wt%, the liquid phase formation temperature decreases, a liquid phase is formed even at the firing temperature of the electronic component, for example, 1300 ° C., and a reaction occurs with the electronic component fired on the surface of the zirconia layer. The peelability is reduced. In addition, when the amount of impurities exceeds 5 wt%, a glass phase is easily formed after the zirconia layer is sintered, which causes the zirconia layer to be deformed and the bond strength to be significantly reduced.

The particle size of the metal oxide particles added to the zirconia layer can be selected from 0.1 μm to 100 μm, but when added as a component forming a liquid phase, it is preferably 10 μm or less. Unstabilized, partially stabilized, and stabilized zirconia can be used as the main component zirconia particles forming the zirconia layer, and these particle sizes can be variously selected in consideration of the surface roughness and pore size of the zirconia layer. For example, the average particle size is 100 μm.

Further, fine particles having an average particle size of 1 μm and coarse particles having an average particle size of 100 μm can be combined as the main component zirconia particles. In such a case, the fine zirconia and the added metal oxide react to form a liquid phase to increase the bonding strength of the zirconia layer.
The amount of the metal oxide added to the zirconia layer is preferably 0.1 wt% to 20 wt%, and if the added amount is further increased, a reaction with the electronic component work occurs, or a glass phase is formed and the peeling resistance is improved. Problems such as lowering occur.

Formation of the zirconia layer on the surface of the substrate is performed by applying a zirconium compound solution and pyrolysis, spray coating a zirconia compound solution or zirconia powder and a solution of a selected metal oxide, and immersing the substrate in these solutions. Then, it may be carried out according to a conventional method such as a method of thermally decomposing and converting the compound into zirconia. The base material to be used may be the same as the conventional one. For example, an alumina-based material, an alumina-mullite-based material, an alumina-magnesia-based spinel material, an alumina-mullite-cordierite-based material, or a combination thereof is used.

The firing temperature of an electronic component firing jig including such a base material and a zirconia layer is fired at a temperature higher than the temperature at which the electronic component is actually fired, and the electronic component firing jig of the present invention does not deteriorate during use. It is desirable to do so. Accordingly, since the normal electronic component firing temperature is 1200 to 1400 ° C., the zirconia layer firing temperature is preferably about 1300 to 1600 ° C.

FIG. 1 shows a schematic diagram of the microstructure of the zirconia layer in order to better understand the jig for firing electronic parts having improved peel resistance and wear resistance according to the present invention. As shown in FIG. 1, zirconia particles are partially bonded to each other via a liquid phase, and partly a base material and a zirconia layer are bonded to each other via a liquid phase. It is considered that the peel resistance and the wear resistance are remarkably improved.

Examples relating to the production of the electronic component firing jig of the present invention will be described, but the examples do not limit the present invention.

Example 1
As the substrate, an alumite substrate having a silica component of about 10 wt% was used. As the main component of the zirconia layer, yttria stabilized zirconia having an average particle size of 80 μm, 70 wt% of yttria stabilized zirconia having an average particle size of 3 μm, and 7 wt% of calcia stabilized zirconia are used as an average metal oxide. A mixture to which 3 wt% of aluminum oxide having a particle size of 1 μm was added was prepared.

Further, 0.5 wt% SnO2 was added as an impurity to the above powder. These were uniformly mixed with a ball mill, and water and polyvinyl alcohol as a binder were added to form a slurry. This slurry was spray coated on the substrate surface. The thickness of the obtained zirconia layer was about 150 μm. The spray-coated substrate was dried at 100 ° C., held at 1400 to 1600 ° C. for 2 hours, and a baked zirconia layer was produced to obtain an electronic component firing jig.

In order to examine the peel resistance and wear resistance of the zirconia layer of this electronic component firing jig, the electronic component firing jig was rapidly heated from 500 ° C. to 1300 ° C. over 3 hours, and then 1300 over 3 hours. The thermal cycle of rapid cooling from 500C to 500C was repeated 30 times. When the heat cycle was repeated 30 times, an abrasion resistance test was performed on the zirconia layer that did not peel.

In the abrasion resistance test, a constant load was applied to a sample of an electronic component firing jig on a SiC abrasive paper, the coating surface was polished (performed a fixed number of times at a fixed distance), and the weight loss of the sample was measured. The amount of wear is expressed as a relative value when the amount of wear in Comparative Example 2 is 1. For example, when the wear amount is half that of Comparative Example 2, it is 0.5. These results are shown in Table 1.

(Example 2)
As the main component of the zirconia layer, 90 wt% of yttria stabilized zirconia having an average particle diameter of 70 μm, 5 wt% of calcia stabilized zirconia having an average particle diameter of 3 μm, and 2 wt. Of lanthanum oxide having an average particle diameter of 1 μm as a metal oxide. %, And barium oxide was added in the same manner as in Example 1 except that 3 wt% of barium oxide was added. These were uniformly mixed with a ball mill, water and polyvinyl alcohol as a binder were added to form a slurry, and this slurry was spray-coated on the substrate surface. The spray-coated substrate was dried at 100 ° C., held at 1400 to 1600 ° C. for 2 hours, and a baked zirconia layer was produced to obtain an electronic component firing jig. The peel resistance and wear resistance of the zirconia layer of the obtained electronic component firing jig were examined. These results are shown in Table 1.

(Example 3)
As main components of the zirconia layer, 70 wt% of yttria stabilized zirconia having an average particle diameter of 100 μm, 26 wt% of yttria stabilized zirconia having an average particle diameter of 1 μm, and 1 wt% of calcium oxide having an average particle diameter of 1 μm as a metal oxide. % And titanium oxide was added in the same manner as in Example 1 except that 3 wt% of titanium oxide was added. These were uniformly mixed with a ball mill, water and polyvinyl alcohol as a binder were added to form a slurry, and this slurry was spray-coated on the substrate surface. The spray-coated substrate was dried at 100 ° C., held at 1400 to 1600 ° C. for 2 hours, and a baked zirconia layer was produced to obtain an electronic component firing jig. The peel resistance and wear resistance of the zirconia layer of the obtained electronic component firing jig were examined. These results are shown in Table 1.

Example 4
As main components of the zirconia layer, 80 wt% of yttria stabilized zirconia having an average particle diameter of 150 μm, 15 wt% of unstabilized zirconia having an average particle diameter of 1 μm, and 2 wt% of calcium oxide having an average particle diameter of 1 μm as a metal oxide. %, 2 wt% of yttrium oxide, and 1 wt% of niobium oxide were added in the same manner as in Example 1 to obtain a mixture. These were uniformly mixed with a ball mill, and water and polyvinyl alcohol as a binder were added to form a slurry. The slurry is spray-coated on the surface of the base material, and the spray-coated base material is dried at 100 ° C. and then held at 1400 to 1600 ° C. for 2 hours to produce a baked zirconia layer to produce an electronic component firing jig. It was. The peel resistance and wear resistance of the zirconia layer of the obtained electronic component firing jig were examined. These results are shown in Table 1.

(Example 5)
As main components of the zirconia layer, 60 wt% of yttria-stabilized zirconia having an average particle diameter of 100 μm, 35 wt% of yttria-stabilized zirconia having an average particle diameter of 5 μm, and 2 wt. Of strontium oxide having an average particle diameter of 1 μm as a metal oxide are used. A mixture was obtained in the same manner as in Example 1 except that 0.5 wt% Bi2O3 was added as an impurity to the mixture to which 3 wt% of barium titanate was added. These were uniformly mixed with a ball mill, water and polyvinyl alcohol as a binder were added to form a slurry, and this slurry was spray-coated on the substrate surface. The spray-coated substrate was dried at 100 ° C. and held at 1400 to 1600 ° C. for 2 hours to produce a baked zirconia layer, which was used as an electronic component firing jig. The peel resistance and wear resistance of the zirconia layer of the obtained electronic component firing jig were examined. These results are shown in Table 1.

(Comparative Example 1)
As main components of the zirconia layer, 20 wt% of yttria stabilized zirconia having an average particle diameter of 150 μm, 50 wt% of unstabilized zirconia having an average particle diameter of 5 μm, and 30 wt. Of barium oxide having an average particle diameter of 1 μm as a metal oxide. A mixture was obtained in the same manner as in Example 1, except that% was added. These were uniformly mixed with a ball mill, water and polyvinyl alcohol as a binder were added to form a slurry, and this slurry was spray-coated on the substrate surface. The spray-coated substrate was dried at 100 ° C. and held at 1400 to 1600 ° C. for 2 hours to produce a baked zirconia layer, which was used as an electronic component firing jig. The peel resistance and wear resistance of the zirconia layer of the obtained electronic component firing jig were examined. These results are shown in Table 1.

(Comparative Example 2)
A mixture was obtained in the same manner as in Example 1 except that 70 wt% of yttria-stabilized zirconia having an average particle diameter of 100 μm and 30 wt% of yttria-stabilized zirconia having an average particle diameter of 1 μm were used as the main component of the zirconia layer. It was. These were uniformly mixed with a ball mill, water and polyvinyl alcohol as a binder were added to form a slurry, and this slurry was spray-coated on the substrate surface. The spray-coated substrate was dried at 100 ° C., held at 1400 to 1600 ° C. for 2 hours, and a baked zirconia layer was produced to obtain an electronic component firing jig. The peel resistance and wear resistance of the zirconia layer of the obtained electronic component firing jig were examined. These results are shown in Table 1.

(Comparative Example 3)
Implemented except that 50 wt% yttria stabilized zirconia with an average particle size of 100 μm and 50 wt% unstabilized zirconia with an average particle size of 1 μm were used as the main component of the zirconia layer, and 8% silicon oxide was added as an impurity. In the same manner as in Example 1, a mixture was obtained. These were uniformly mixed with a ball mill, water and polyvinyl alcohol as a binder were added to form a slurry, and this slurry was spray-coated on the substrate surface. The spray-coated substrate was dried at 100 ° C., held at 1400 to 1600 ° C. for 2 hours, and a baked zirconia layer was produced to obtain an electronic component firing jig. The peel resistance and wear resistance of the zirconia layer of the obtained electronic component firing jig were examined. These results are shown in Table 1.

It is a schematic diagram of the fine structure of the zirconia layer regarding this invention.

Claims (5)

1 or more types which form a liquid phase in order to improve peeling resistance and abrasion resistance in the baking of a zirconia layer in the jig | tool for electronic component baking which comprises the base material and the zirconia layer coat | covered on the base-material surface A jig for firing electronic parts, characterized in that the liquid phase is crystallized after sintering. The metal oxide contained in the zirconia layer comprises one or more metal oxides selected from rare earth oxides, alkaline earth oxides, and transition metal oxides, or aluminum oxide. 1. A jig for firing electronic components according to 1. The electronic component firing jig according to claim 1, wherein a composite oxide selected from the oxide group according to claim 2 is used as the metal oxide contained in the zirconia layer. The electronic component firing jig according to claim 1, wherein, in addition to claim 2, impurities contained in the zirconia layer are 5 wt% or less. The electronic component firing jig according to claim 1, wherein the main component zirconia forming the zirconia layer is stabilized, partially stabilized or unstabilized zirconia.

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