A boron nitride boat for sintering ceramic substrates

Abstract

The application discloses a boron nitride supporting furnace for sintering ceramic substrates, which comprises one or more ceramic substrate supporting assemblies which are sequentially nested and stacked from bottom to top; each of the ceramic substrate supporting assemblies comprises a groove type supporting plate and a pressing plate arranged in the groove type supporting plate; the middle part of the groove type supporting plate is a first groove part for placing a ceramic substrate; and the shape and size of the pressing plate are matched with those of the first groove part, and the pressing plate is arranged on the ceramic substrate in the first groove part. The application provides the boron nitride supporting furnace which can greatly improve the yield of the ceramic substrates.

Description

Technical Field

[0001] This invention belongs to the field of ceramic substrate production technology, specifically referring to a boron nitride firing furnace for sintering ceramic substrates, used in the debinding and sintering processes of ceramic substrate preparation. Background Technology

[0002] Ceramic substrates refer to ultra-large thermally conductive ceramic sheets made by mixing ceramic powders such as aluminum nitride, alumina, and silicon nitride with sintering aids, forming large-size thin green blanks through processes such as molding, casting, and injection molding, and then stacking them in multiple layers in a firing furnace for high-temperature debinding, assembly, and atmosphere sintering.

[0003] Chinese invention patent (publication number CN101333114A) discloses a method for preparing a high thermal conductivity aluminum nitride ceramic substrate. The sintering method for the ceramic substrate involves: applying boron nitride powder between aluminum nitride green blanks of the same size, stacking multiple blanks, placing them on a boron nitride plate, removing the binder, transferring them to a boron nitride crucible, and sintering them in a furnace to obtain the aluminum nitride ceramic substrate. This method requires a large number of boron nitride crucibles, resulting in high costs; the large number of ceramic substrate layers makes them prone to slippage and breakage; uneven temperature between substrate layers causes substrate bending, edge curling, and cracking; the boron nitride crucible must be a highly permeable porous ceramic with a density of approximately 1.40-1.45 g / cm³. 3 This method, intended to facilitate the removal of binders and impurities during sintering, is detrimental to improving crucible strength and thermal conductivity, resulting in problems such as short lifespan and poor temperature uniformity. Currently, similar methods are commonly used in the market for sintering ceramic substrates. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a boron nitride firing furnace that can significantly improve the yield of ceramic substrates.

[0005] This invention is implemented as follows:

[0006] A boron nitride firing furnace for sintering ceramic substrates includes: one or more ceramic substrate firing components nested and stacked from bottom to top;

[0007] Each of the ceramic substrate firing components includes: a groove-type support plate and a pressure plate placed within the groove-type support plate;

[0008] The middle part of the groove-type support plate is the first sink groove, which is used to place the ceramic substrate;

[0009] The shape and size of the pressure plate match the shape and size of the first sink, and it is placed on the ceramic substrate inside the first sink.

[0010] The first groove portion of the trough-type support plate has a first outer edge portion around its periphery, and a first protrusion portion is provided on the first outer edge portion; the bottom periphery of the trough-type support plate has a first groove portion.

[0011] When the number of ceramic substrate firing components is two or more, the first groove portion at the bottom periphery of the upper groove-type support plate is precisely fitted into the first protrusion portion at the periphery of the lower groove-type support plate to form a nested assembly mode.

[0012] The bottom of the one or more ceramic substrate firing assemblies that are nested and stacked in sequence is also provided with a bottom support plate;

[0013] The bottom support plate includes: a second outer edge portion and a second sink portion in the middle, wherein a second protrusion portion is provided on the second outer edge portion;

[0014] The first groove on the bottom periphery of the bottom of the bottom support plate located at the bottom is precisely fitted into the second protrusion on the second outer edge of the bottom support plate located below, forming a nested assembly pattern.

[0015] A top sealing plate is provided above the ceramic substrate firing assembly located at the topmost point. The bottom periphery of the top sealing plate has a second groove. The top sealing plate covers the first outer edge of the periphery of the uppermost groove-type support plate. The second groove at the bottom periphery of the top sealing plate fits into the first protrusion of the first outer edge of the periphery of the groove-type support plate to form a nested assembly.

[0016] Furthermore, the periphery of the first sinking section of the trough-type bearing plate is provided with multiple first ventilation holes.

[0017] Furthermore, the pressure plate is provided with multiple second vent holes.

[0018] Furthermore, the periphery of the first recessed portion of the trough-type support plate has a first outer edge portion, and the bottom center of the trough-type support plate has a third protrusion portion; the height of the third protrusion portion is less than the depth of the first recessed portion;

[0019] When there are two or more ceramic substrate firing assemblies, the third protrusion at the bottom center of the upper grooved support plate is placed in the first recessed groove in the middle of the lower grooved support plate to form a nested assembly pattern.

[0020] Furthermore, a bottom support plate is provided at the bottom of one or more ceramic substrate firing assemblies that are nested and stacked in sequence;

[0021] The bottom support plate includes: a second outer edge portion and a second sinking portion in the middle;

[0022] The bottom third protrusion of the bottom of the lowest grooved support plate fits precisely into the second recessed part of the bottom support plate below, forming a nested assembly pattern.

[0023] Furthermore, a top sealing plate is provided above the uppermost ceramic substrate firing assembly, and the bottom center of the top sealing plate has a fourth protrusion; the top sealing plate covers the uppermost groove-type support plate, and the fourth protrusion is exactly placed in the first recessed groove in the middle of the groove-type support plate to form a nested assembly mode; the height of the fourth protrusion is less than the depth of the first recessed groove.

[0024] Furthermore, the first sink groove of the trough-type bearing plate is provided with multiple third ventilation holes.

[0025] The advantages of this invention are:

[0026] 1. The stacked porous grooved support plate has a wide heat-conducting outer edge that surrounds the grooved support plate and makes full contact with the upper and lower grooved support plates. This allows heat to be evenly transferred to the grooved support plate after being homogenized by the surrounding outer edge, and the heat transfer through the stacked wide outer edge achieves the same temperature for the upper and lower grooved support plates.

[0027] 2. Each set of firing components contains a single or double ceramic substrate green body, which allows the green body to make surface contact with the boron nitride carrier plate and pressure plate with high thermal conductivity. This results in more uniform, rapid and direct heat transfer, and the shrinkage resistance of the green body is consistent during sintering.

[0028] 3. With fewer stacked layers and limited by the wide outer edge of the structure, the probability of the ceramic substrate green body breaking due to slippage in subsequent processes is almost zero.

[0029] 4. Before the green blank is degummed, the ceramic substrate green blank is placed and the sintering furnace is stacked and assembled. This avoids the thin sheet blank, which has no strength after degumming, from cracking due to multiple assembly processes. The subsequent simple transfer process is extremely conducive to the realization of automated production.

[0030] 5. By artificially creating ventilation holes on the trough-type bearing plate and pressure plate, the size and number of the pores can be precisely matched to the porosity required in the process, which is conducive to the discharge of colloids in the ceramic substrate green body after high-temperature vaporization and the volatilization and removal of impurity phases during sintering.

[0031] 6. The furnace body can be made of high-density, non-permeable boron nitride ceramic. Increasing the density can significantly improve the structural strength and thermal conductivity of the furnace, extend the service life of the furnace, further homogenize the temperature inside the furnace, and facilitate the optimization of the furnace structure, increase the number of groove-type support plates per unit space, increase the number of substrate sintering, and reduce production costs. Attached Figure Description

[0032] The present invention will now be further described with reference to the accompanying drawings and embodiments.

[0033] Figure 1 This is a top-view three-dimensional structural diagram of the trough-type bearing plate in the first embodiment of the present invention.

[0034] Figure 2 This is a bottom-view three-dimensional structural diagram of the grooved bearing plate in the first embodiment of the present invention.

[0035] Figure 3 This is a longitudinal cross-sectional view of the trough-type bearing plate in the first embodiment of the present invention.

[0036] Figure 4 yes Figure 3 A magnified schematic diagram of a portion (part A).

[0037] Figure 5 This is a schematic diagram of the pressure plate structure in the first embodiment of the present invention.

[0038] Figure 6 This is a front view of the bottom tray in the first embodiment of the present invention.

[0039] Figure 7 This is a front view of the top sealing plate in the first embodiment of the present invention.

[0040] Figure 8 This is a cross-sectional view of the boron nitride furnace according to the first embodiment of the present invention after assembly.

[0041] Figure 9 yes Figure 8 Enlarged schematic diagram of a portion (part B).

[0042] Figure 10 This is a top-view three-dimensional structural diagram of the trough-type bearing plate in the second embodiment of the present invention.

[0043] Figure 11 This is a bottom-view three-dimensional structural diagram of the grooved bearing plate in the second embodiment of the present invention.

[0044] Figure 12 This is a longitudinal cross-sectional view of the trough-type bearing plate in the second embodiment of the present invention.

[0045] Figure 13 yes Figure 12 Enlarged schematic diagram of a portion (section C).

[0046] Figure 14 This is a front view of the bottom tray in the second embodiment of the present invention.

[0047] Figure 15 This is a front view of the top sealing plate in the second embodiment of the present invention.

[0048] Figure 16 This is a cross-sectional view of the boron nitride furnace according to the second embodiment of the present invention after assembly.

[0049] Figure 17 yes Figure 16 Enlarged schematic diagram of a portion (part D). Detailed Implementation

[0050] First embodiment:

[0051] Please see Figures 1 to 9 As shown, a boron nitride firing furnace for sintering ceramic substrates includes: one or more ceramic substrate firing assemblies 1 that are nested and stacked from bottom to top;

[0052] Each of the ceramic substrate firing assembly 1 includes: a groove-type support plate 11 and a pressure plate 12 placed inside the groove-type support plate 11;

[0053] The middle part of the trough-type support plate 11 is the first sink 111 for placing the ceramic substrate 100;

[0054] The shape and size of the pressure plate 12 match the shape and size of the first sink 111, and it is placed on the ceramic substrate 100 inside the first sink 111.

[0055] The first recessed portion 111 of the trough-type support plate 11 has a first outer edge portion 112 around its periphery, and a first protrusion 113 is provided on the first outer edge portion 112; the bottom periphery of the trough-type support plate 11 has a first groove portion 114; the periphery of the first recessed portion 111 has a plurality of first ventilation holes 1121.

[0056] The pressure plate 12 is provided with a plurality of second ventilation holes 121, and the shape and size of the pressure plate 12 match the shape and size of the central first sink 111. The pressure plate 12 is placed on the ceramic substrate 100 and together placed in the central first sink 111 of the trough-type support plate 11.

[0057] Each ceramic substrate firing assembly 1 contains one or two ceramic substrates 100.

[0058] When there are two or more ceramic substrate bearing assemblies 1, the first groove portion 114 at the bottom periphery of the upper groove-type bearing plate 11 fits into the first protrusion portion 113 at the periphery of the lower groove-type bearing plate 11, forming a nested assembly mode.

[0059] This embodiment also includes a bottom support plate 2, which is disposed at the bottom of one or more ceramic substrate firing assemblies 1 that are nested and stacked sequentially.

[0060] The bottom support plate 2 includes: a second outer edge portion 21 and a second sink portion 22 in the middle, wherein a second protrusion 23 is provided on the second outer edge portion 21.

[0061] The first groove 114 at the bottom periphery of the bottom of the bottom support plate 11 fits into the second protrusion 23 at the second outer edge 21 of the bottom support plate 2 located below, forming a nested assembly.

[0062] A top sealing plate 3 is provided above the uppermost ceramic substrate firing assembly 1. The bottom periphery of the top sealing plate 3 has a second groove 31. The top sealing plate 3 covers the first outer edge 112 of the uppermost grooved support plate 11. The second groove 31 of the bottom periphery of the top sealing plate fits into the first protrusion 113 of the first outer edge 112 of the grooved support plate 11, forming a nested assembly.

[0063] It should be noted that the nesting and stacking method between the upper and lower grooved support plates 11 of the ceramic substrate firing assembly 1 is not limited to the structure and form in this embodiment. In practice, the nesting and stacking method between the upper and lower grooved support plates 11 can also be other structures or other forms of groove protrusion matching method.

[0064] Second embodiment:

[0065] Please see Figures 10 to 17 As shown, a boron nitride firing furnace for sintering ceramic substrates includes: one or more ceramic substrate firing assemblies 1 that are nested and stacked from bottom to top;

[0066] Each of the ceramic substrate firing assembly 1 includes: a groove-type support plate 11 and a pressure plate 12 placed inside the groove-type support plate 11;

[0067] The middle part of the trough-type support plate 11 is the first sink 111 for placing the ceramic substrate 100;

[0068] The shape and size of the pressure plate 12 match the shape and size of the first sink 111, and it is placed on the ceramic substrate 100 inside the first sink 111.

[0069] The first sink 111 of the trough-type support plate 11 has a first outer edge 112 around its periphery, and a third protrusion 115 is provided at the bottom center of the trough-type support plate 11; the height of the third protrusion 115 is less than the depth of the first sink 111.

[0070] The first settling tank 111 is provided with multiple third ventilation holes 1111.

[0071] The pressure plate 12 in this embodiment is the same as that in the first embodiment. The pressure plate 12 is provided with a plurality of second vent holes 121. The shape and size of the pressure plate 12 match the shape and size of the first recessed section 111 in the middle. The pressure plate 12 is placed on the ceramic substrate 100 and placed together in the first recessed section 111 in the middle of the grooved support plate 11.

[0072] Each ceramic substrate firing assembly 1 contains one or two ceramic substrates 100.

[0073] When there are two or more ceramic substrate bearing assemblies 1, the third protrusion 115 at the bottom center of the upper groove bearing plate 11 fits into the first recessed groove 111 of the lower groove bearing plate 11 to form a nested assembly.

[0074] This embodiment also includes a bottom support plate 2, which is disposed at the bottom of one or more ceramic substrate firing assemblies 1 that are nested and stacked sequentially.

[0075] The bottom support plate 2 includes: a second outer edge portion 21 and a second sink trough portion 22 in the middle;

[0076] The third protrusion 115 at the bottom center of the bottom of the bottom-type support plate located at the bottom is precisely fitted into the second recessed part 22 of the bottom support plate located below, forming a nested assembly mode.

[0077] Above the uppermost ceramic substrate firing assembly 1, there is a top sealing plate 3. The bottom center of the top sealing plate 3 has a fourth protrusion 32. The top sealing plate 3 covers the uppermost groove-type support plate 11. The fourth protrusion 32 is placed exactly in the middle of the first recessed groove 111 of the groove-type support plate 11 to form a nested assembly mode. The height of the fourth protrusion 32 is less than the depth of the first recessed groove 111.

[0078] To facilitate the manual placement of the ceramic substrate 100 and the pressure plate 12 within the first sink 111, notches 1122 are designed at the center of both sides of the first outer edge portion 112 of the trough-type support plate 11, and notches 211 are designed at the center of both sides of the second outer edge portion 21 of the bottom support plate 2. If machine placement is used, no notches are required. Similarly, in the first embodiment, notches can be designed if manual placement is used.

[0079] In both of the above embodiments, the boron nitride density of the trough-type bearing plate 11 and the pressure plate 12 is between 1.45 and 2.05 g / cm³. 3 .

[0080] In the two embodiments described above, the ceramic substrate firing assembly 1 is square in shape, which is adapted to the shape of the square ceramic substrate. In practice, the shape of the ceramic substrate firing assembly 1 can be adjusted according to the shape of the ceramic substrate in the specific situation.

[0081] In practice, the specific dimensions of each component of a boron nitride furnace can be adjusted according to the actual situation.

[0082] The boron nitride firing furnace described in the above two embodiments is used in the debinding process of ceramic substrate preparation. After the debinding is completed, it needs to be placed in a boron nitride protective box for sintering.

[0083] This invention employs stacked porous grooved support plates with wide, heat-conducting outer edges surrounding the grooved support plates and ensuring full contact with the upper and lower grooved support plates. This allows heat to be homogenized around the outer edges and then evenly transferred to the grooved support plates. The wide outer edges also contribute to heat transfer, achieving uniform temperature distribution between the upper and lower plates. Each firing assembly contains one or two ceramic substrate green bodies, allowing for surface contact between the green bodies and the highly thermally conductive boron nitride support plate and pressure plate. This results in more uniform, rapid, and direct heat transfer, and consistent shrinkage resistance of the green bodies during sintering. The fewer stacked layers and the constraint of the wide outer edges of the structure virtually eliminate the probability of the ceramic substrate green bodies breaking due to slippage in subsequent processes. Before the green bodies are debinded, the placement of the ceramic substrate green bodies and the stacking and assembly of the sintering furnace are completed. This design avoids the cracking of thin sheet blanks with no strength after debinding due to repeated assembly processes, and the subsequent simple transfer process is extremely conducive to the realization of automated production. The artificially created vent holes on the slotted support plate and pressure plate can precisely match the porosity required in the process by controlling the size and number of the pores, which is conducive to the discharge of the colloid in the ceramic substrate green blank after high-temperature vaporization and the volatilization and removal of impurity phases during sintering. The furnace body can be made of high-density, non-permeable boron nitride ceramic. Increasing the density can significantly improve the structural strength and thermal conductivity of the furnace, extend the service life of the furnace, further homogenize the temperature inside the furnace, and facilitate the optimization of the furnace structure, increase the number of slotted support plates per unit space, increase the number of substrates sintered, and reduce production costs.

[0084] The above embodiments and figures are not intended to limit the form and style of the present invention. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of the present invention.

Claims

1. A boron nitride firing furnace for sintering ceramic substrates, characterized in that: include: One or more ceramic substrate firing components are nested and stacked from bottom to top; Each of the ceramic substrate firing components includes: a groove-type support plate and a pressure plate placed within the groove-type support plate; The middle part of the groove-type support plate is the first sink groove, which is used to place the ceramic substrate; The shape and size of the pressure plate match the shape and size of the first sink, and it is placed on the ceramic substrate inside the first sink. The first groove portion of the trough-type support plate has a first outer edge portion around its periphery, and a first protrusion portion is provided on the first outer edge portion; the bottom periphery of the trough-type support plate has a first groove portion. When the number of ceramic substrate firing components is two or more, the first groove portion at the bottom periphery of the upper groove-type support plate is precisely fitted into the first protrusion portion at the first outer edge of the periphery of the lower groove-type support plate to form a nested assembly mode. The bottom of the one or more ceramic substrate firing assemblies that are nested and stacked in sequence is also provided with a bottom support plate; The bottom support plate includes: a second outer edge portion and a second sink portion in the middle, wherein a second protrusion portion is provided on the second outer edge portion; The first groove on the bottom periphery of the bottom of the bottom support plate located at the bottom is precisely fitted into the second protrusion on the second outer edge of the bottom support plate located below, forming a nested assembly pattern. A top sealing plate is provided above the ceramic substrate firing assembly located at the topmost point. The bottom periphery of the top sealing plate has a second groove. The top sealing plate covers the first outer edge of the periphery of the uppermost groove-type support plate. The second groove at the bottom periphery of the top sealing plate fits into the first protrusion of the first outer edge of the periphery of the groove-type support plate to form a nested assembly.

2. The boron nitride firing furnace for sintering ceramic substrates as described in claim 1, characterized in that: The periphery of the first sinkhole of the trough-type bearing plate is provided with multiple first ventilation holes.

3. The boron nitride firing furnace for sintering ceramic substrates as described in claim 1, characterized in that: The pressure plate is provided with multiple second ventilation holes.

4. The boron nitride firing furnace for sintering ceramic substrates as described in claim 1, characterized in that: The first recessed portion of the trough-type support plate has a first outer edge portion around its perimeter, and the bottom center of the trough-type support plate has a third protrusion portion; the height of the third protrusion portion is less than the depth of the first recessed portion. When there are two or more ceramic substrate firing assemblies, the third protrusion at the bottom center of the upper grooved support plate is placed in the first recessed groove in the middle of the lower grooved support plate to form a nested assembly pattern.

5. A boron nitride firing furnace for sintering ceramic substrates as described in claim 4, characterized in that: The bottom of the one or more ceramic substrate firing assemblies that are nested and stacked in sequence is also provided with a bottom support plate; The bottom support plate includes: a second outer edge portion and a second sinking portion in the middle; The bottom third protrusion of the bottom of the lowest grooved support plate fits precisely into the second recessed part of the bottom support plate below, forming a nested assembly pattern.

6. A boron nitride firing furnace for sintering ceramic substrates as described in claim 4, characterized in that: Above the uppermost ceramic substrate firing assembly, there is a top sealing plate with a fourth protrusion at the bottom center. The top sealing plate covers the uppermost groove-type support plate, and the fourth protrusion is positioned exactly in the middle of the first recessed groove of the groove-type support plate to form a nested assembly. The height of the fourth protrusion is less than the depth of the first recessed groove.

7. A boron nitride firing furnace for sintering ceramic substrates as described in claim 4, characterized in that: The first groove of the trough-type bearing plate is provided with multiple third ventilation holes.

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