Abstract: Various carrier ring designs and configurations to control an amount of deposition at a wafer's front side and bevel edge are provided. The carrier ring designs can control the amount of deposition at various locations of the wafer while deposition is performed on the wafer's back side, with no deposition desired on the front side of the wafer. These locations include front side, edge, and back side of bevel; and front and back side of the wafer. Edge profiles of the carrier rings are designed to control flow of process gases, flow of front side purge gas, and plasma effects. In some designs, through holes are added to the carrier rings to control gas flows. The edge profiles and added features can reduce or eliminate deposition at the wafer's front side and bevel edge.

Abstract: A container for storing a powder mixture during heat treatment in a furnace, a furnace and a method for heat treatment of a powder mixture. The aim of the invention is to specify a container by means of which in particular the throughput per unit of time can be increased and an automatic removal of the container is simplified. This aim is achieved by a plurality of receptacles for releasable fastening of spacers which in the installed state allow contactless stacking of a plurality of containers one above the other.

Abstract: A manufacturing device for mask unit having a mask frame and a mask fixed to the mask frame includes a stage including a frame holding stage, and an alignment stage arranged with a plurality of lift-pins, a holding part for holding a reference plate arranged facing the stage, a mask holding unit, the mask holding unit being arranged between the stage and the reference plate, and a camera for imaging a direction of the stage passing through the reference plate, wherein the mask holding unit holds the mask at a surface on the frame side, the mask holding unit rises and falls above the alignment stage by the plurality of the lift-pins, the plurality of lift-pins includes a plurality of first lift-pins capable of contacting the mask holding unit, and the camera images a first reference marker on the mask and a second reference marker on the reference plate.

Abstract: A multi-part support element for spacing carrier elements, includes an upper part and a lower part, wherein the upper part can be detachably axially connected to the lower part by a rotary connection in order to fix a carrier element between the upper part and the lower part, the rotary connection is formed by a stud provided on the lower part and an opening provided on the upper part, into which the stud can be screwed, and the rotary connection is implemented such that the rotary connection is released again after defined screwing of the stud into the opening, such that the stud is locked in the opening with axial play, and wherein the lower part has a disk-shaped attachment, whose layer thickness decreases toward the edge.

Abstract: An alignment tool that is easy to use during the installation and fastening of storage rack is disclosed herein. The alignment tool comprises a first end having a conical shape and a second end defining an opening therein, and the opening extending into said cylindrical body along the longitudinal axis. Once the storage rack is installed, the alignment tool can be easily removed with a removal tool through a hole in the alignment tool.

Abstract: A setter for firing in a plate which is used for firing a honeycomb formed body and interposed between the honeycomb formed body and a shelf plate, wherein the setter for firing has a setter lower surface section facing the shelf plate, the setter lower surface section including: a central region part formed by a region including a lower surface center of the setter lower surface section; and a peripheral region part formed by a peripheral region of the central region part, and the peripheral region part has at least four or more setter groove parts each having a recessed cross sectional shape and extending radially from the lower surface center respectively in a direction from a boundary with the central region part toward a setter outer circumferential section.

Abstract: A wafer producing apparatus includes: an ingot grinding unit configured to grind and planarize an upper surface of an ingot held by a first holding table; a laser applying unit configured to apply a laser beam of such a wavelength as to be transmitted through the ingot to the ingot, with a focal point of the laser beam positioned at a depth corresponding to the thickness of a wafer to be produced from an upper surface of the ingot held by a second holding table, to form a peel-off layer; a wafer peeling unit configured to hold the upper surface of the ingot held by a third holding table and peel off the wafer from the peel-off layer; and a carrying tray having an ingot support section configured to support the ingot and a wafer support section configured to support the wafer.

Abstract: A refractory article can include a socket including a cavity that is configured to receive a post, a particulate material, and a binder. The binder is configured to bond the post to the socket. The refractory article can include a sleeve coupled to the socket and configured to bond the post to the socket. In an embodiment, the sleeve can bond to the binder. In another embodiment, a collar can be placed between the sleeve and the binder. The collar can be configured to bond the post to the socket. A method of forming a refractory article can include disposing a particulate material within a cavity of a socket and placing a binder material overlying the particulate material.

Abstract: The present disclosure provides a dental bridge intermediary structure comprising a superstructure (203) and a reference plate (200), with distance pins (202) connecting the two. A method for producing a dental bridge superstructure (203) is also provided.

Abstract: An apparatus for drying sporting equipment has at least two hangers removably positionable in a spaced-apart configuration on a substantially horizontal hanger support. Each hanger has one or more hanger protrusions and/or hanger apertures for hanging sporting equipment. At least one flexible connector mounted on each of the hangers connects a shelf to the hangers so that the shelf is suspended below the hangers when the hangers are positioned on the horizontal hanger support. The shelf has a plurality of interior through apertures through which sporting equipment may hang supported by the shelf and the shelf further has one or more shelf protrusions for hanging sporting equipment. A system for drying sporting equipment has a free-standing base, spaced-apart telescoping struts connected to and extending upwardly from the base, a substantially horizontal hanger support connecting the telescoping struts and an apparatus as described above configured to hang from the hanger support.

Abstract: A rectangular thin panel conveyance unit includes a plurality of sets of four corner modules, and vibration suppressing bodies for rectangular thin panels in a fixed shape. The corner module has a support surface to support each corner portion of the rectangular thin panel from a lower side. At each corner portion, stacking the corner modules in a vertical direction stacks a plurality of rectangular thin panels in the vertical direction. The vibration suppressing bodies have a thickness equal to or less than the distance between the support surfaces of the corner modules vertically adjacent to one another; and are disposed on each of a top surface and an inferior surface of the rectangular thin panel such that the vibration suppressing body faces a planar portion of each rectangular thin panel to restrict vertical amplitude of vibration of the rectangular thin panel within a predetermined range.

Abstract: A wafer boat for accommodating semiconductor wafers comprises two side rods and at least one back rod, the rods being vertically oriented and extending between a top member and a bottom member. The rods comprise vertically spaced recesses formed at corresponding heights, recesses at the same height defining a wafer accommodation for receiving and supporting a wafer in a substantially horizontal orientation, the recesses having an improved shape. The upwardly facing surfaces of the recesses comprise a first flat surface in an inward region of the recess which is horizontal or inclined upward in an outward direction of the recess and a second flat surface in an outer region of the recess which is inclined downward in an outward direction of the recess. The intersection of the first and second surface forming an edge for supporting the wafer. The recesses are easy to machine and prevent damage to the wafer.

Abstract: A platform shipping rack cart for shipping rack(s) supporting glass sheets is provided. The cart may include a plurality of upwardly extending locator projections (e.g., pins) for engaging L-frame racks that hold glass sheets, so as to allow the L-frame rack(s) to be positioned and securely mounted on the cart for shipping and the like. The locator projections are arranged so that first and second L-frame racks may be provided on the cart either facing each other, or in back-to-back position, as desired. The cart advantageously allows multiple L-shaped glass racks to be stabilized on the cart and moved at a given time, and allows for loading the glass in either lengthwise or sideways orientations into vans or the like.

Abstract: A wafer boat is provided for holding a plurality of wafers in a vertically stacked and spaced relationship. The wafer boat comprises a top member; a bottom member facing the top member; and at least three vertical members extending between the top member and the bottom member. The vertical members are provided with a plurality of protrusions, the protrusions configured to form a plurality of wafer accommodations at different vertical heights, the protrusions configured to be arranged in groups of at least two protrusions. A pitch of protrusions within a group has a first value and a pitch of two adjacent protrusions that belong to different groups has a second value larger than the first value.

Abstract: A substrate holder has two holder constituting bodies, each having a plurality of columns arranged on an imaginary circle, and substrate holding sections that hold circumferential portions of respective substrates. The holder constituting bodies hold the substrates so that either their front surfaces or their back surfaces face upward with a substrate having an upward facing front and a substrate having an upward facing rear being alternately arranged in a vertical direction. At least one of the holder constituting bodies moves in the vertical direction to change the positions of the holder constituting bodies relative to each other. A distance between a first pair of vertically adjacent substrates with their respective front surfaces facing each other is set to ensure treatment uniformity, and to be larger than a distance between a second pair of vertically adjacent substrates with their respective back surfaces facing each other.

Abstract: A disclosed substrate processing apparatus comprises a heat exchange plate configured to heat and/or cool the substrate; plural protrusions provided on the heat exchange plate so as to allow the substrate to be placed on the plural protrusions, leaving a gap between the substrate and the heat exchange plate; a suction portion configured to attract the substrate onto the plural protrusion by suction through plural holes formed in the heat exchange plate; and a partition member that is provided on the heat exchange plate and lower than the plural protrusions, wherein the partition member is configured to divide the gap into two or more regions including at least one of the holes so that at least one of the two or more regions is two-dimensionally closed by the partition member.

Abstract: A substrate heat treatment apparatus includes a heat-treating plate having a flat upper surface, support devices formed of a heat-resistant resin for contacting and supporting a substrate, a seal device disposed annularly for rendering gastight a space formed between the substrate and heat-treating plate, and exhaust bores for exhausting gas from the space. The support devices are formed of resin, and the upper surface of the heat-treating plate is made flat, whereby a reduced difference in the rate of heat transfer occurs between contact parts and non-contact parts on the surface of the substrate. Consequently, the substrate is heat-treated effectively while suppressing variations in heat history over the surface of the substrate.

Abstract: A substrate treatment apparatus and a supporting unit are provided. The substrate treatment apparatus includes a chamber in which a substrate is processed; a supporting unit that is disposed in the chamber and is configured to support the substrate; and a heating member that is configured to apply heat to the substrate supported by the supporting unit. The supporting unit includes a plate; a plurality of supporting pins upwardly protruding from the plate; and at least one auxiliary pin upwardly protruding from the plate. A distance between a central point of the plate and the at least one auxiliary pin is different from a distance between the central point of the plate and the supporting pins.

Abstract: The present invention relates to a device for supporting, stacking, and transporting kiln run, in particular for firing ceramic products, comprising an assembly of supports and support beams, like carrier beams and cross beams, on which, in particular one or several supports for placing the kiln run are provided. Thus, for supporting at least one support beam, at least one loose bearing is provided, comprising a support body, moveably disposed, substantially in the direction of the support beam.

Abstract: A heat treatment apparatus includes a support sheet placed on an upper surface of a heat-treating plate. The support sheet has, formed on an upper surface thereof, projections for contacting and supporting a substrate, and a lip for contacting edge regions of the substrate. The support sheet is formed by an etching process, and therefore areas of the sheet around the projections are recessed, rather than being perforated as in the case of laser processing. These heat-treating plate and support sheet constitute a substrate support structure capable of supporting the substrate properly.

Abstract: Heat treatment apparatus and a method of manufacturing a substrate are provided, in which drop of particles produced by a rubbing action between a support strip and a support member can be prevented. Heat treatment apparatus 10 has a reactor 40 for treating a substrate, and a support tool 30 for supporting the substrate 54 in the reactor 40. The support tool 30 has a support part 57 to be contacted to the substrate 54, and a support strip 67 for supporting the support part 57. A back of the support part 57 has a convex portion or a concave portion, and the back of the support part 54 is configured to be not contacted to an edge of the support strip 67, and contacted to a top of the support strip 67 at inner than the edge of the support strip 67.

Abstract: Disclosed are devices and methods for supporting glass sheets during a thermal treatment process, such as heat treating, to maintain the physical geometry of the glass sheets. The device can comprise means for separating adjacent glass sheets to prevent them from touching. The separating means can comprise a separation comb having projections and channels configured for receiving the glass sheets, separating rods configured to be positioned between the glass sheets, or a combination of separation combs and separating rods.

Abstract: This invention provides a heat treatment jig for semiconductor silicon substrates, which, in respective heat treatment of hydrogen annealing or argon annealing, can handle enlargement of the diameter of wafers to be treated and can also prevent slipping and dislocations that occur as a result of the stress caused by the weight of the wafer itself or the deflection of the heat treatment jig itself.

Abstract: The present invention provides a wafer support tool for heat treatment easy in working and capable of realizing reduction in cost without generating damages or slip dislocations that would be otherwise caused by high temperature heat treatment and a heat treatment apparatus. The present invention is directed to a wafer support tool for heat treatment comprising: a plurality of wafer support members for supporting a wafer to be heat treated; and a support member holder for holding the wafer support members, wherein the wafer support members each has a contact portion with the wafer, at least one of the contact portions being movable relative to the support member holder.

Abstract: A vertical wafer boat for supporting at least one semiconductor wafer, formed by a process includes forming a plurality of angled support grooves into a plurality of support members with a groove-making machine. Each support member extends along a longitudinal axis and each of the support grooves is spaced apart from one another and extend generally obliquely into the respective support member with respect to the longitudinal axis. The groove-making machine is positioned at a nonperpendicular angle with respect to the longitudinal axis, and thus defines an angled tooth between adjoining support grooves to support at least one wafer, and each support groove includes top and bottom corners inside a base portion that are generally supplementary with respect to each other. Top and bottom portions of the plurality of members are joined to top and bottom end plates that oppose each other respectively, to form the wafer boat.

Abstract: There is provided a vertical heat treatment system capable of simplifying the structure of various mechanisms in the vicinity of an opening which is formed in a partition wall separating a housing-box transfer area from a treating-object transfer area (a wafer transfer area), and of contributing to space saving, when an object to be treated is carried in the vertical heat treatment system through the opening to carry out a predetermined treatment.

Abstract: The present invention provides a wafer holder, a wafer support member, a wafer boat and a heat treatment furnace, which are capable of sufficiently suppressing slip dislocations, without lowering productivity and at low cost, in the high temperature heat treatment of silicon wafers, and said wafer holder is characterized in that: the wafer holder is composed of a wafer support plate and three or more wafer support members mounted on said wafer support plate, each of the wafer support members having a wafer support portion or more; at least one of said wafer support members is a tilting wafer support member which has a plurality of upward-convex wafer support portions on the upper surface and is tiltable with respect to said wafer support plate; and the wafer is supported by at least four wafer support portions.

Abstract: This invention provides a heat treatment jig for semiconductor silicon substrates, which, in respective heat treatment of hydrogen annealing or argon annealing, can handle enlargement of the diameter of wafers to be treated and can also prevent slipping and dislocations that occur as a result of the stress caused by the weight of the wafer itself or the deflection of the heat treatment jig itself.

Abstract: The aim of the invention is to reduce the formation of scratches in a device for the thermal treatment of substrates, in particular, semiconductor substrates, in a chamber in which the substrate is placed upon support elements. According to the invention, said aim is achieved by means of displaceable support elements.

Abstract: A support slug (2) used for the heat treatment of a part (3), particularly for the hardening of a steel part, comprises a guide element (221) that is used to guide the part (3) towards a supporting surface (230) of the support slug (2) when said part is being positioned on the support slug. A ceramic element (23) including the supporting surface (230) is embedded in the metal body (20) of the support slug.

Abstract: A support for a material to be fired for a ceramic dental prosthesis, having a support plate dimensionally stable when heat is applied and having a plurality of passages which are arranged perpendicularly relative to the support plate surface. A bundle of several pins, which in an undeformed state extend parallel with each other, can be introduced into each one of the passages for placing the dental prosthesis to be fired on them.

Abstract: A method and device for producing shaped ceramic bodies, particularly ceramic sheets or multilayer hybrids provided with printed circuit traces, switching elements and/or plated-through holes. The shaped ceramic bodies are initially present as green bodies and also contain organic auxiliary agents, for example as a binder. During sintering and/or removal of the binder from the shaped ceramic bodies, they are compressed between porous setter plates in whose pores a catalytically active substance is introduced, so that the gaseous, organic, bake-out products of the green bodies, these products developing during sintering and/or binder removal, are catalytically converted when escaping through the porous setter plates. The setter plates be provided with separating layers that likewise may contain the catalytically active substance. The method should provide a considerable time savings when sintering and/or removing binder from the shaped ceramic bodies.

Abstract: A sealing box for a chamber for continuously treating a thin strip product, in particular for a furnace for continuously carbonizing a fiber substrate. The sealing box comprises: a longitudinal passage (12) opening out from the box via a first end (12b) for connection to an inlet or an outlet of a treatment chamber (2) and via a second end (12a), opposite from the first; a support surface (14a) inside the passage, on which a strip product (T) can travel between the ends of the box; and static sealing means (30) acting by making contact with the strip product travelling along the passage on the support surface. The static sealing means comprise at least one inflatable gasket (32) placed across the passage (12) above the support surface (14a), and dynamic sealing means (40) are also provided in the passage between the second end (12a) of the box and the static sealing means, the dynamic sealing means comprising means (52, 56) for injecting gas into at least one chamber (42, 46) formed in the passage.

Abstract: A ceramic heater (1) includes a ceramic substrate (2) having a heating surface (2a) for supporting and heating an object to be processed, a hearing element (6) provided in the substrate (2), and embossed portions (4) on the heating surface (2a) which contact the object. The number of the embossed portions (4) per unit area on the heat spot (3) is less than that on the rest of the heating surface (2a). When the average temperature of the heating surface (2a) is raised to reach a target temperature, the heat spot (3) having relatively high surface temperatures exists on the heating surface (2a).

Abstract: An apparatus and method to position a wafer onto a wafer holder and to maintain a uniform wafer temperature is disclosed. The wafer holder or susceptor comprises a recess or pocket whose surface is concave and includes a grid containing a plurality of grid grooves separating protrusions. The concavity and grid grooves define an enclosed flow volume between a supported wafer and the susceptor surface, as well as an escape area, or total cross-sectional area of the grid grooves opening out from under the periphery of the wafer. These are chosen to reduce the wafer slide and curl during wafer drop-off and wafer stick during wafer pick-up, while improving thermal uniformity and reducing particle problems. In another embodiment, centering locators in the form of thin, radially placed protrusions are provided around the edge of the susceptor pocket to reduce further the possibility of contact between the wafer and the outer edge of the susceptor.

Abstract: A heating apparatus comprises a central hot plate for heating the center portion of a substrate, a plurality of segment hot plates for heating the peripheral portion of the substrate, a hot plate support member supporting the central hot plate and the segment hot plates, support pins for supporting the substrate so as to face the central hot plate and the segment hot plates in a close proximity without being in contact with the central hot plate and the segment hot plates, and a power supply for supplying electricity to the central hot plate and the segment hot plates.

Abstract: The present invention relates generally to an improved ladder boat for supporting semiconductor wafers during thermal treatments which comprises top and bottom plates vertically opposing each other and support rods secured to said plates. Said support rods are provided with dividers for supporting a plurality of wafers one above another in a parallel arrangement. The dividers have a special profile to include a ramp portion so that the wafer is seated at a sharp corner thereof. Therefore, the contact surface between the wafer backside at its periphery and the dividers is segmental or punctual. This contact is preferably performed outside the contact area between the wafer backside and the wafer support zones of the electrostatic chuck of the photolithography tool to be subsequently used in the course of the wafer manufacturing.

Abstract: An apparatus for semiconductor processing includes: a) at least one support member comprising an upper surface for supporting a semiconductor wafer; b) a component through which the support member extends, the component comprising a front surface and a back surface, at least one of the support member and the component being movable relative to the other of the support member and the component such that the support member can support a wafer in an elevated position above the front surface and can be withdrawn into the component to lower the wafer relative to the front surface of the component; and c) a block joined to the support member below the component back surface, the block engaging the component back surface when the support member upper surface extends above the component to a predetermined distance, the block preventing the support member upper surface from extending beyond the front surface by more than the predetermined distance.

Abstract: A substrate support, such as an edge ring, includes an inner portion, and an outer portion contiguous with the inner portion and extending radially outward therefrom. The inner portion has a raised annular extension forming a ridge for supporting a substrate.

Abstract: A clamp holds a semiconductor wafer during an Al reflow process. The clamp is made of a ceramic material, and thereby clamp surface roughening which damages semiconductor wafers and other damaging of the wafer caused by the deformation of the clamp are avoided. A sloped surface of the clamp pad can also reduce the damage on the wafer by reducing the contact area between the clamp pad and the wafer. In addition, the clamp has several features that can reduce heat dissipation from the wafer to outside during the Al reflow. Slots formed on the pad reduce the amount of heat conduction through the clamp, and the polished inner surface of the clamp cap reflects the heat radiated from the wafer back to the wafer.

Abstract: A boat for semiconductor wafers has reduced contact surface area with the wafer, thereby preventing distortion of the wafer during heating. The boat has an upper member; a lower member, a plurality of wafers being loaded between the upper member and the lower member; and a plurality of support members vertically extended between and connecting the upper member to the lower member for supporting the wafers. A plurality of slots are successively and horizontally formed in each of the support members, and the peripheral edge of the wafer is inserted therein, wherein a hemisphere-shaped protrusion is formed inside the slot, and the bottom surface of the wafer contacts and is supported by each hemisphere-shaped protrusion at a single contact point.

Abstract: A substrate heat-treating apparatus includes a heat-treating plate, and support pins extending through the heat-treating plate to be vertically movable relative thereto. The support pins support each substrate at a lower surface thereof such that edges of the substrate are at a higher level than a central region of the substrate. This construction facilitates air flows into and out of a space between the lower surface of the substrate and the upper surface of the heat-treating plate when the substrate is vertically moved.

Abstract: The present invention is designed to provide an annealing method for silicon single crystal wafers, which makes it possible to increase the number of silicon single crystal wafers processed during a single annealing process under a variety of annealing performed on silicon single crystal wafers, such as oxygen outer diffusion annealing for forming a DZ layer, annealing that generates and controls BMD for providing IG functions, and annealing that endeavors to improve and enhance GOI characteristics by eliminating wafer surface layer COP, and internal grown-in defects, and also enables the suppression of dislocation and slip in elevated temperature annealing environments. It calls for annealing to be performed by stacking up around 10 wafers, treating this group as a unit, placing this group, either horizontally or slightly inclined at an angle of roughly 0.5.about.5.degree.

Abstract: An annular-shaped edge ring support for a semiconductor wafer has an innermost radial portion for supporting the semiconductor wafer and an outermost radial portion contiguous with the inner portion. The inner portion has a graded thermal mass that generally increases with increasing radius.

Abstract: The invention relates to a structure for a firing table to accept ceramic items to be fired.

Abstract: A tray for heat treatment furnace including a tray base which comprises a plate and a lattice part being fixed on the plate, said lattice part having a plurality of cylindrical reinforcements formed at cross portions thereof; a fixing device having a plurality of paired barrels being connected to each other by a plurality of connecting members, each of said paired barrels being provided with a plurality of cutting grooves on an upper surface thereof, one of the connecting members having a pair of coupling jaws for engagement with a portion of the lattice part; a plurality of spacers each being engageable with one of a respective said plurality of cutting grooves.

Abstract: A substrate holding assembly for horizontally holding a substrate to be treated is provided in a heat treatment chamber of a heat treatment apparatus. The substrate holding assembly has an annular base, and a plurality of fixed support projections provided on the annular base, for holding the underside of the substrate to be treated. A flexible beam portion is fixed to the annular base, or to a vertical support rod, and a flexible support projection is provided on the beam portion, for flexibly supporting a portion of the substrate to be treated which tends to flex downward under its own weight. Flexure caused by the own weight of the substrate to be treated held in the substrate holding assembly is thus corrected by the flexible holding portions. Accordingly, stresses caused in the substrates to be treated can be decreased or removed, and occurrence of slips in the substrate to be treated can be precluded in a high-temperature heat treatment. Accordingly, high yields can be obtained.

Abstract: A boat carrier for accommodating multiple width integrated circuit (IC) boats is provided. The boat carrier comprises a base member and opposed guide faces which abut side surfaces of IC boats of multiple widths. In a first embodiment, the boat carrier includes a first guide having a first guide face affixed to the base member, and a movable guide having a movable guide face releasably affixed to the base member. The movable guide face has a first position and a second position, whereby a narrower IC boat is receivable in the first position and a wider IC boat is receivable in the second position. In a further embodiment, the boat carrier comprises a base member, a fixed guide assembly having a fixed guide face, and an opposed guide assembly having an inner and outer guide face, whereby a boat having a first or second width is receivable.

Abstract: A supporting shaft 11 that can be inserted through a center hole 5a in each of cured resin disks 5 and which has a bottom plate in a disk form at an end, as well as a plurality of spacer disks 12 each having a center hole through which the supporting shaft 11 can be inserted are used in the process of manufacturing GC (glass-like carbon) by baking to carbonize the cured resin disks 5. The cured resin disks 5 are stacked alternately with the spacer disks 12 on the supporting shaft 11 in an erect position that is inserted through the center holes in each of the cured resin and spacer disks. The stack is then baked in a baking furnace. By so doing, the cured resin disks can be set up easily and the baking furnace can be operated to its full capacity.

Abstract: A firing underlying board having a long use life free from thermal expansion and which does not cause twisting of ribs, deformation of an end face, color change or cracking in a honeycomb structural body fired on the underlying board. The firing underlying board is composed mainly of 55-85 wt % of cordierite and 15-45 wt % of mullite. The firing underlying board is used to fire green ceramic honeycomb structural bodies placed thereon.