JPH08159671A - Jig for baking electronic component - Google Patents

Abstract

PURPOSE: To provide a jig for baking which enables production of electronic components by automating the baking thereof industrially with an excellent yield. CONSTITUTION: A jig for baking electronic components which is formed of a refractory layer of an SiC material and a refractory layer of an alumina- mullite material surrounding the refractory layer of the SiC material and which is a vessel with an opening. It is preferable that the refractory of the SiC material contains 90-100wt.% SiC and that the refractory of the alumina-mullite material contains 75-100wt.% alumina and 0-25wt.% mullite.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jig for firing electronic parts, and more particularly to a jig for firing electronic parts which is used for firing treatment of electronic parts, has excellent durability and does not contaminate electronic parts.

[0002]

Ceramics are widely used for electronic parts such as oxide magnetic ferrites, capacitors, piezoelectric elements, crystal oscillators, varistors, carbon-based resistors, magnetic heads, high-frequency filters, and various sensors. Variously used. In particular, with the rapid development of electronics in recent years, the range and manner of use as electronic parts have expanded, and automation that enables smooth and high-yield production is demanded. As is well known, ceramics, regardless of whether they are for electronic parts or not, must be sintered in a firing step after forming raw material powders of the constituents. 2. Description of the Related Art Conventionally, in the firing treatment of industrial ceramics, generally, a method of stacking so-called sheaths of firing shelves or firing containers in multiple stages and firing a large number of objects to be fired simultaneously in a firing furnace has been adopted. For example, FIG. 4 shows a perspective explanatory view of an example in which shelf boards made of refractory are used in multiple stages. In FIG.
The shelf board 20 is supported by columns 21 to form a multi-stage structure. In addition, the container-shaped sheath is usually a box type with an open upper part, and is formed of a refractory material like the shelf board and sequentially loaded,
It has a structure in which the uppermost part is sealed with a lid or the like.

Conventionally, the above-mentioned shelves and sheaths have generally been made of a refractory material such as alumina or silicon carbide (SiC). Alumina refractory has excellent resistance to reaction with the material to be fired, but has low strength at high temperature, and when high temperature firing is required, SiC refractory is used. However, SiC refractories have extremely high hardness and poor workability, and correction processing is not easy when deformation or the like occurs during long-term use. In addition, ferrites and the like are silicons (Si, S
It may react with iO ₂ ) and should not come into direct contact with the material to be fired. So, for example,
Japanese Unexamined Patent Publication (Kokai) No. 4-273989 proposes a shelf board having a sandwich structure in which both sides of a SiC refractory layer are sandwiched by refractory layers such as alumina. This shelf board has high temperature strength and surface contact by utilizing the characteristics of SiC such as bend resistance and spalling resistance, and the characteristics of alumina having excellent resistance to reaction with the material to be fired. In addition to preventing the reactivity due to, the warpage generated in the manufacturing process is small, and the correction process of the warpage generated during firing is facilitated.

[0004]

However, the shelf board proposed in JP-A-4-273989 has a structure in which both sides of a SiC-based refractory layer are sandwiched between refractory layers such as alumina and the like. The SiC-based refractory layer is exposed to the firing atmosphere, the SiC-based refractory layer is oxidized, and the SiC bend resistance, spalling resistance, and other S
The iC refractory property may be impaired, the high temperature strength may be reduced, and a large warp may occur on the shelf board. In addition, SiC
The Si component in the high-quality refractory layer may scatter and react with the object to be fired, which may cause a problem of contamination of the object to be fired, which must be particularly prevented in electronic parts. Further, it is necessary to arrange the above-mentioned baking shelves in combination with columns, and in industrial production, when attempting to automate the baking process, automatic loading is difficult. The inventors of the present invention have diligently studied to make the ceramic firing tool according to the above-mentioned conventional method applicable to firing of ceramics for electronic parts, in particular, and to make it automatable in order to improve production efficiency. It came to eggplant. That is, in comparison with the shelf method and the sheath method at the time of firing, in the sheath method, automatic loading is possible and automation is easy, and in terms of firing atmosphere adjustment required for performance of electronic components. Based on the finding that the sheath method is superior, we adopted a sheath container as a jig for firing, reduced weight in response to automation, and reduced deformation during long-term use. An object is to provide a jig for firing an electronic component that does not deteriorate the electronic component that is the object and can further improve its performance.

[0005]

According to the present invention, SiC
A jig for firing electronic parts is provided which is an open container formed of a high-quality refractory layer and an alumina-mullite refractory layer surrounding the SiC-type refractory layer. In the electronic component firing jig of the present invention, the SiC refractory layer surrounded by the alumina-mullite refractory layer is continuously formed on substantially the entire bottom surface of the container or from the entire bottom surface to the peripheral wall surface portion. It is preferable to arrange them. Also,
At the bottom of the container, the total thickness is 15 mm or less, S
It is preferable that the thickness of the iC-based refractory layer is 2 to 11 mm and the thickness of the alumina-mullite refractory layer is 2 to 5 mm. Further, the SiC refractory constituting the jig for firing electronic parts of the present invention contains 90 to 100% by weight of SiC, and the alumina-mullite refractory contains 75 to 100% by weight of alumina and 0% by weight of silica. It is preferably contained in an amount of up to 25% by weight.

[0006]

The jig for firing electronic parts of the present invention is constructed as described above, and since the SiC refractory layer is surrounded by the alumina / mullite refractory, the SiC refractory layer is exposed to the outside air. It is possible to prevent the oxidation of the SiC refractory layer without being exposed to
It does not deteriorate the properties such as C-bend resistance and spalling resistance. In addition, since the outer surface layer of the container is formed of alumina / mullite, it has excellent reaction resistance and is used together with the SiC layer surrounded by the mechanical strength of mullite for long-term high temperature use. Deformation is suppressed, and the product yield that can prevent defective products of electronic parts to be fired is improved. Further, since the SiC-based refractory layer is surrounded by the alumina-mullite refractory layer, the scattering of the Si component is prevented, and there is no possibility that the object to be fired is contaminated. Furthermore, in the present invention, the firing jig structure has a sheath structure, and the weight is increased by setting the respective thicknesses of the SiC refractory layer and the alumina-mullite refractory layer on the bottom surface of the container. In addition, it is lighter in weight, can be automatically loaded, is easy to automate, has good bend resistance, improves product yield, and smoothly improves productivity and workability. Also, by selecting the shape of the sheath and the size of the notch for gas release, for example, the firing atmosphere can be adjusted by controlling the gas concentration generated from the electronic components to be fired so as to improve the characteristics of the electronic components. Therefore, the characteristics of the electronic component can be improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a jig for firing electronic parts of the present invention will be described in detail below with reference to the drawings. However,
The present invention is not limited to the examples below. FIG.
FIG. 3 is a cross-sectional explanatory view showing a jig for firing an electronic component of an embodiment of the present invention. In FIG. 1, an electronic component firing jig 1 of the present invention has an outer shape of 300 mm in length, 300 mm in width, and 1 in height.
A rectangular parallelepiped container 2 with a diameter of 00 mm without a gas vent in the upper opening
It consists of. The bottom of the container is 15 mm as a whole
The bottom layer X of the SiC-based refractory material, which is formed of a flat plate made of the SiC-based refractory material having a large thickness over the entire area so as to have the following thickness.
And a surface layer portion surrounding the alumina-mullite refractory layer Y. That is,
A SiC-based refractory bottom surface layer X is arranged inside the middle of the bottom surface portion. If the bottom part thickness exceeds 15 mm,
It is not preferable because the weight is remarkably increased and the workability such as transportation is deteriorated. The peripheral side surface portion is formed so that the bottom surface layer X of SiC-based refractory material and the layer Y of alumina-mullite refractory material are continuous. The thickness of the peripheral side surface portion is not particularly limited as long as it is designed to support the weight of the containers of the plurality of firing jigs loaded on the upper portion. Usually, it is formed to have the same thickness as the bottom portion. The SiC-based refractory bottom surface layer X has a thickness of about 2 to
It is preferably formed to have a thickness of 11 mm. This is because if the thickness is less than 2 mm, the characteristics of SiC such as bend resistance and spalling resistance are not utilized, and the high temperature strength is lowered and the occurrence of warpage cannot be prevented. The SiC refractory layer X is
Depending on the molding process, the end portion is thinned to about 1 mm, but if the central portion is 2 to 11 mm, the bend resistance does not decrease. It is preferable that the alumina-mullite refractory layer Y surrounding the SiC refractory layer X has a bottom portion having a thickness of about 2 to 5 mm above and below the bottom portion layer X. When it is less than 2 mm, the Si component in the SiC refractory layer X penetrates the alumina-mullite refractory layer Y and reacts with the object to be fired to contaminate the object to be fired, which is not preferable. On the other hand, if it exceeds 5 mm, the weight increases and the workability deteriorates. In addition, the SiC-based refractory layer X is relatively thin and the bend resistance is lowered.

FIG. 2 is a perspective view showing another embodiment of the jig for firing electronic parts of the present invention, and FIG. 3 is a sectional view taken along the line AA of FIG. In FIG. 2 and FIG. 3, the electronic component firing jig 10 has a long side of 200 m at the top of each peripheral side surface.
m, a short side 170 mm, and a height 20 mm of trapezoidal gas vents 3 and 4 are cut out and surrounded by the alumina-mullite refractory layer Y of the surface layer, and the SiC refractory layer is a bottom layer. The same as FIG. 1 except that a side surface layer X ′ that is continuous from X to the inside of the peripheral side surface portion is formed continuously. The thickness of the SiC refractory side surface layer X ′ disposed inside the peripheral side surface portion may be 1 mm or more, and can be formed to be thinner than the bottom surface portion layer X. This is because the bend resistance is not directly affected. Usually, in the case of continuous molding, the thickness is the same as that of the bottom layer X. In the present invention, the continuity of the bottom surface layer X and the side surface layer X ′ is not critical and may be close to each other. Gas vents 13 and 14
Is mixed with the gas generated during firing and the atmospheric gas outside the vessel due to the constituent components of the electronic component to be fired, etc.
The size of the electronic component can be appropriately selected and adjusted so as to create a gas atmosphere in which the characteristics of the electronic component can be maximized. For example, when debinding is required, each side surface has a gap of about 10 to 20 mm so that a gas atmosphere can flow in and out of the container. In addition, in the case of an electronic component to which an element that damages the firing furnace is added, it is possible to keep the inside of the container airtight without providing a degassing part and fire it in a state where there is no alternating current inside and outside the container. preferable.

In the electronic part firing jig of the present invention, since the surface layer portion is formed of the reaction-resistant alumina-mullite refractory as described above, the reactivity with the object to be fired can be prevented. The defective rate of is significantly reduced. In the present invention,
The alumina-mullite refractory that constitutes the surface layer of the container of the electronic component firing jig is preferably alumina (Al
₂ O ₃ ) about 75 to 100% by weight, more preferably 90%
˜100 wt%, silica (SiO ₂ ) about 0-2
5% by weight, more preferably 0 to 10% by weight. This is because if the amount of alumina is less than 75% by weight, the reaction resistance, which is a characteristic of aluminum, cannot be utilized. Further, as the SiC material of the present invention, one having a SiC purity of 90 to 100% by weight can be preferably used. Further, in the present invention, particularly when the electronic component to be fired has remarkable reactivity such as ferrite, the mounting surface of the electronic component to be fired, which is the bottom surface of the container in the firing jig, is made of alumina or zirconia. It is possible to use by further coating with, and further improving the reaction resistance.

Example 1 In a manner similar to that shown in FIG. 1, each of the peripheral side surface portion and the bottom surface portion has a thickness of 10 mm, a length of 300 mm and a width of 30.
A container 2 having a rectangular parallelepiped outer shape with an opening of the firing jig was manufactured as a rectangular parallelepiped body having a height of 0 mm and a height of 30 mm. S on the bottom
The thickness of the iC refractory layer X is 2 mm, 290 × 29
A container 2 was formed by using a flat plate of 0 (mm) such that the alumina / mullite refractory material Y had a thickness of 4 mm above and below the flat plate. The SiC-based refractory layer X on the bottom surface
Is 99.5 wt% of SiC purity, and A of the alumina-mullite refractory Y forming the peripheral side surface portion and the bottom surface portion surface layer portion.
The contents of l ₂ O ₃ and SiO ₂ were 76% by weight and 24% by weight, respectively. Container 2 formed as described above
Inside, a box made of alumina refractory was placed on the uppermost container, and three rectangular parallelepiped bodies on which 50 Ni-Zn-based ferrites to be fired were placed were stacked in a multi-tiered manner. A baking process was performed at 1200 ° C. for 60 minutes in a baking furnace in an atmosphere.
The above baking treatment was repeated 30 times using the same sheath body, and as a result, the bottom portion of the sheath body was not deformed, the material to be fired was not contaminated, and the yield was 98%. It was

Comparative Example 1 A SiC refractory bottom layer X has a thickness of 1 mm, and alumina and mullite refractory Y is 4.5 on each of the upper and lower surfaces thereof.
A rectangular sheath body was formed in the same manner as in Example 1 except that the thickness was set to mm. The obtained sheath body was loaded in three stages in the same manner as in Example 1, and ferrite was similarly fired. As a result, the bottom surface of the rectangular parallelepiped body was deformed into a concave shape after the 8th firing process, and was not suitable for use.

Comparative Example 2 The same as Example 1 except that the peripheral side surface portion and the bottom surface portion had a thickness of 20 mm and the upper and lower alumina / mullite refractory materials Y at the bottom surface portion had a thickness of 9 mm in order to impart bend resistance. Then, a rectangular parallelepiped body was formed. Using the obtained sheath, Example 1
In the same manner as above, three layers were stacked and ferrite was similarly fired 30 times. As a result, the bottom surface portion was not deformed, but the obtained sheath body weighed 5200 g, which was about 1.7 times the weight of the sheath body formed in Example 1, and the automatic loading device was used. It was unsuitable due to the weight limit to load it.

Comparative Example 3 The bottom layer X of SiC refractory has a thickness of 5 mm, and alumina and mullite refractory Y has a thickness of 1 mm on each of the upper and lower surfaces thereof.
A rectangular sheath body was formed in the same manner as in Example 1 except that the above was adopted. The obtained sheath was loaded in three stages in the same manner as in Example 1, and ferrite was similarly fired 5 times. As a result, the fired product was contaminated with Si and an abnormal crystal state was observed on the bottom surface in 50% of defective products.

From the above-mentioned Examples and Comparative Examples, the firing jig for electronic parts of the present invention has a SiC material surrounded by an alumina-mullite refractory material, has no Si component contamination in the material to be fired, and has good reactivity resistance, and It turns out that it is excellent in bend resistance. Further, it can be seen that the weight is reduced and the automatic loading and the like can be automated. On the other hand, the SiC quality refractory layer is less than 2 mm 1 m
It is also apparent that the bottom surface portion is deformed at m. In addition, the alumina / mullite refractory layer is less than 2 mm, 1 m
It can be seen that when the value is m, it may react with the bottom surface of the object to be burned in long-term use.

Examples 2-5 and Comparative Examples 3-4 A container 10 similar to that shown in FIGS. 2 and 3 is provided with gas vents 13 and 14 each having a height of 20 mm and a long side 200.
mm, short side 170 mm trapezoidal notch, SiC refractory layer is continuously formed up to the peripheral side surface, SiC purity 99.5
% Of SiC refractory bottom X layer is 3mm, X'layer is 1
It was formed in the same manner as in Example 1 except that the content ratio of Al ₂ O ₃ and SiO ₂ of the alumina-mullite refractory which forms the surface layer portion in mm is shown in Table 1. Ferrite was placed as an object to be fired on the inner bottom surface of each of the rectangular parallelepiped bodies and fired at 1200 ° C. for 1 hour in a firing furnace in an air atmosphere to contaminate the Si component of the fired object ( Reaction resistance) was observed by mineral identification by X-ray. Regarding the peelability due to the difference in thermal expansion among the SiC refractory bottom layer X, the side layer X ′, and the alumina-mullite refractory layer Y, heating and cooling between room temperature and 1400 ° C. were repeated repeatedly. Observed. The results are shown in Table 1. In the table, regarding the reaction resistance evaluation, ⊚ indicates that it can be used (suitable), ○ indicates that some can be used (appropriate), and Δ indicates that few can be used (impossible). Regarding the evaluation of releasability, ⊚ indicates that there is no peeling (suitable), and ◯ indicates that there is no peeling and cracks occur on the surface, but it is sufficiently usable (suitable).

[0016]

[Table 1]

From the above Examples and Comparative Examples, when the silica content of the alumina-mullite layer is 30% by weight or more, S
Although the difference in thermal expansion from the iC material was small and almost no exfoliation occurred, the alumina content was low, so the reaction resistance characteristic of the alumina material could not be utilized, and the Si in the SiC material refractory layer could not be utilized. It was found that the components were leached to the surface and the material to be fired was contaminated. On the other hand, when the alumina content is 75% by weight or more, although some cracks occur on the surface, it does not lead to the destruction of the firing jig sheath body, and it can be sufficiently used without peeling, and it can be used for ferrite firing. It is obvious that a product to be fired can be obtained with a high yield without producing a defective product suitable for. Therefore, the firing jig having the alumina-mullite layer having an alumina content of 75 to 90% by weight and a silica content of 25 to 10% by weight shown in the above-mentioned examples has both desired reaction resistance and peelability. It can be seen that it is fully suitable for use as a jig for firing electronic parts, as it fully retains the function described above.

[0018]

EFFECT OF THE INVENTION The jig for firing electronic parts of the present invention adopts a container-shaped sheath structure and is different from the conventional one in that the SiC refractory layer is surrounded by alumina / mullite refractory. Therefore, the SiC refractory layer is not exposed to the outside air, oxidation is prevented, and characteristics such as bend resistance and spalling resistance of SiC are not deteriorated. Therefore, it has excellent high-temperature strength, does not deform even after long-term use, and has excellent durability. Further, since the surface layer portion is formed by the alumina-mullite layer and surrounds the SiC refractory layer, the Si component does not scatter, the material to be fired is not contaminated, the reactivity is excellent, and the yield is high. It is possible to smoothly obtain high-quality electronic components. In addition, due to the sheath structure, automatic loading is easy, and if necessary, a gas vent is formed to adjust the atmosphere inside and outside the sheath to control the gas concentration generated from the electronic components and to determine the characteristics of the electronic components. It can be controlled so as to raise the temperature, and the quality of electronic components to be fired can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory cross-sectional view of an embodiment of a jig for firing an electronic component of the present invention.

FIG. 2 is a perspective explanatory view of another embodiment of the jig for firing an electronic component of the present invention.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a perspective explanatory view of an example in which shelf plates of a conventional firing jig are used in multiple stages.

[Explanation of symbols]

 X, X'SiC refractory layer Y Alumina-mullite refractory layer 1, 10 Electronic component firing jig 2, 12 Container 13, 14 Degassing part 20 Refractory shelf 21 Strut

Claims (5)

[Claims] 1. A jig for firing electronic parts, comprising an open container formed of a SiC refractory layer and an alumina / mullite refractory layer surrounding the SiC refractory layer. . 2. The jig for firing electronic components according to claim 1, wherein the SiC refractory layer is arranged on the bottom surface of the container. 3. The jig for firing electronic components according to claim 1, wherein the SiC refractory layer is continuously arranged from the bottom surface portion of the container to the peripheral side surface portion. 4. The container bottom has a thickness of 15 m.
m or less, the thickness of the SiC refractory layer is 2 to 11 mm, and the thickness of the alumina-mullite refractory layer is 2 to 5
The jig for firing electronic components according to any one of claims 1 to 3, which has a size of mm. 5. The SiC refractory contains 90 to 1 SiC.
The jig for firing electronic parts according to any one of claims 1 to 4, wherein the jig contains 100 wt% of alumina, and the alumina-mullite refractory contains 75 to 100 wt% of alumina and 0 to 25 wt% of silica.