example embodiments will now be described more fully with reference to the accompanying drawings . example embodiments may , however , be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein ; rather , these embodiments are provided so that this disclosure will be thorough and complete , and will fully convey the concept of example embodiments to those of ordinary skill in the art . it will be understood that when an element is referred to as being “ connected ” or “ coupled ” to another element , it can be directly connected or coupled to the other element or intervening elements may be present . in contrast , when an element is referred to as being “ directly connected ” or “ directly coupled ” to another element , there are no intervening elements present . as used herein the term “ and / or ” includes any and all combinations of one or more of the associated listed items . other words used to describe the relationship between elements or layers should be interpreted in a like fashion ( e . g ., “ between ” versus “ directly between ,” “ adjacent ” versus “ directly adjacent ,” “ on ” versus “ directly on ”). it will be understood that , although the terms “ first ”, “ second ”, etc . may be used herein to describe various elements , components , regions , layers and / or sections , these elements , components , regions , layers and / or sections should not be limited by these terms . these terms are only used to distinguish one element , component , region , layer or section from another element , component , region , layer or section . thus , a first element , component , region , layer or section discussed below could be termed a second element , component , region , layer or section without departing from the teachings of example embodiments . spatially relative terms , such as “ beneath ,” “ below ,” “ lower ,” “ above ,” “ upper ” and the like , may be used herein for ease of description to describe one element or feature &# 39 ; s relationship to another element ( s ) or feature ( s ) as illustrated in the figures . it will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures . for example , if the device in the figures is turned over , elements described as “ below ” or “ beneath ” other elements or features would then be oriented “ above ” the other elements or features . thus , the exemplary term “ below ” can encompass both an orientation of above and below . the device may be otherwise oriented ( rotated 90 degrees or at other orientations ) and the spatially relative descriptors used herein interpreted accordingly . the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments . as used herein , the singular forms “ a ,” “ an ” and “ the ” are intended to include the plural forms as well , unless the context clearly indicates otherwise . it will be further understood that the terms “ comprises ”, “ comprising ”, “ includes ” and / or “ including ,” if used herein , specify the presence of stated features , integers , steps , operations , elements and / or components , but do not preclude the presence or addition of one or more other features , integers , steps , operations , elements , components and / or groups thereof . example embodiments are described herein with reference to cross - sectional illustrations that are schematic illustrations of idealized embodiments ( and intermediate structures ) of example embodiments . as such , variations from the shapes of the illustrations as a result , for example , of manufacturing techniques and / or tolerances , are to be expected . thus , example embodiments should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result , for example , from manufacturing . for example , an implanted region illustrated as a rectangle may have rounded or curved features and / or a gradient of implant concentration at its edges rather than a binary change from implanted to non - implanted region . likewise , a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation takes place . thus , the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of example embodiments . it should also be noted that in some alternative implementations , the functions / acts noted may occur out of the order noted in the figures . for example , two figures shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order , depending upon the functionality / acts involved . unless otherwise defined , all terms ( including technical and scientific terms ) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong . it will be further understood that terms , such as those defined in commonly - used dictionaries , should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein . hereinafter , example embodiments of the inventive concepts will be described with reference to the accompanying drawings . referring to fig1 and 2 , a heat treatment apparatus 1 for liquid crystal display ( lcd ) cells according to an example embodiment is illustrated . the heat treatment apparatus 1 may include a liquid bath 10 , in which a liquid as a heat transfer medium is contained , a loading device 20 to load / unload a plurality of lcd cells l into / from the liquid bath 10 , and heaters 30 installed in the liquid bath 10 , which heat the liquid contained in the liquid bath 10 . the heat treatment apparatus 1 may also include sound wave transmitters 40 installed in the liquid bath 10 , which transmit sound waves to liquid crystals in the lcd cells l loaded in the liquid bath 10 . in each lcd cell l , liquid crystals may be sealed between two glass sheets . in order to reduce or prevent a portion of the lcd cell l , in which the liquid crystals are contained , from being physically damaged , and to prevent the heat transfer medium , for example , the liquid , from entering the lcd cell , the peripheral edges of the two glass sheets are watertight - treated using a sealant . a liquid supply tube 13 may be connected to a lower portion of a side wall of the liquid bath 10 , to supply the liquid to the interior of the liquid bath 10 . water may be used as the liquid to be supplied to the interior of the liquid bath 10 . a cover 11 may be installed at a top of the liquid bath 10 , to seal the liquid bath 10 when a plurality of lcd cells l has been loaded in the liquid bath 10 . a base 50 may be installed beneath the liquid bath 10 , to support the liquid bath 10 . in the base 50 , a power supplier 51 to supply electric power to the heaters 30 may be disposed . sound wave generators 53 , which generate sound waves , may also be disposed in the base 50 , to supply sound waves to the sound wave transmitters 40 . a plurality of lcd cells l may be loaded or unloaded into / from the liquid bath 10 by the loading device 20 . the loading device 20 may include support plates 23 to support lcd cells l to be loaded or unloaded , and a lever 21 to vertically move the support plates 23 . although the loading device 20 is illustrated as loading 4 lcd cells l into the liquid bath 10 , it may be configured to load more than 4 lcd cells l or less than 4 lcd cells l into the liquid bath 10 , without being limited to the illustrated example embodiment . the loading device 20 may adjust vertical levels of lcd cells l supported by the support plates 23 by rotating the lever 21 , and thus vertically moving the support plates 23 . as the vertical levels of lcd cells l are adjusted by the loading device 20 , it may be possible to adjust the spacing between each lcd cell l and the sound wave transmitters 40 installed at the bottom of the liquid bath 10 . although not shown , a spacing adjuster ( not shown ) may be separately installed to adjust the vertical levels of lcd cells supported by the support plates 23 , and thus to adjust the spacing between each of the lcd cells l and the sound wave transmitters 40 . the heaters 30 , which heat the liquid supplied to the liquid bath 10 , may be installed at left and right walls of the liquid bath 10 within the liquid bath 10 , respectively . although the heaters 30 are illustrated as being installed at the left and right walls of the liquid bath 10 , they may be installed at other portions of the liquid bath 10 within the liquid bath 10 , without being limited to the example embodiment . the heaters 30 disposed within the liquid bath 10 may receive electric power from the power supplier 51 installed in the base 50 , thereby heating the liquid supplied to the interior of the liquid bath 10 to a desirable ( or alternatively , predetermined ) temperature at which the lcd cells l loaded in the liquid bath 10 are effectively heat - treated , and maintaining the liquid at the desirable ( or alternatively , predetermined ) temperature . heat is transferred to the liquid crystals in the lcd cells l via a medium , for example , the liquid , which is maintained at the desirable ( or alternatively , predetermined ) temperature by the heater 30 . as the liquid crystals receive heat , they may be diffused to have a more uniform distribution . in order to more effectively diffuse the liquid crystals in the lcd cells l , which receive heat when being loaded in the liquid bath 10 , the sound wave transmitters 40 may be installed in the liquid bath 10 , to transmit sound waves to the liquid crystals . although the sound wave transmitters 40 are illustrated as being installed at front , rear , and bottom walls of the liquid bath 10 , they may be installed at other portions of the liquid bath 10 within the liquid bath 10 , without being limited to the example embodiment . the sound wave transmitters 40 installed in the liquid bath 10 may receive sound waves from the sound wave generators 53 installed in the base 50 . after receiving sound waves from the sound wave generator 53 , the sound wave transmitters 40 may transmit the received sound waves to the liquid crystals in the lcd cells l via the medium , for example , the liquid in the liquid bath 10 . as the liquid crystals receive sound waves , they may be diffused to have a more uniform distribution . the intensity of the sound waves artificially promoting diffusion of the liquid crystals in the lcd cells l may be adjusted such that the sound waves do not damage the watertight - treated sealing portions of the peripheral edges of the two glass sheets and thin film transistor ( tft ) circuits . as sound waves are transmitted to the liquid crystals in the lcd cells l , along with heat , the liquid crystals may be effectively diffused within a relatively short time . fig3 and 4 illustrate a heat treatment apparatus for lcd cells according to an example embodiment . as shown in fig3 and 4 , the heat treatment apparatus , which is designated by reference numeral “ 1 ′”, may include a liquid bath 10 ′, in which a liquid as a heat transfer medium is contained , a loading device 20 ′ to load / unload a plurality of lcd cells l into / from the liquid bath 10 ′, and heaters 30 ′ installed in the liquid bath 10 ′, to heat the liquid contained in the liquid bath 10 ′. the heat treatment apparatus 1 ′ may also include sound wave transmitters 40 ′ installed in the liquid bath 10 ′, to transmit sound waves to liquid crystals in the lcd cells l loaded in the liquid bath 10 ′, and at least one spacing adjuster 50 ′ to adjust the spacing between a corresponding one of the lcd cells l and the sound wave transmitter 40 ′, which is arranged adjacent to the corresponding lcd cell l . a liquid supply tube 13 may be connected to a lower portion of a side wall of the liquid bath 10 ′, to supply the liquid to the interior of the liquid bath 10 ′. water may be used as the liquid to be supplied to the interior of the liquid bath 10 ′. a cover 11 ′ may be installed at a top of the liquid bath 10 ′, to seal the liquid bath 10 ′ in a state in which a plurality of lcd cells l has been loaded in the liquid bath 10 ′. a base 60 may be installed beneath the liquid bath 10 ′, to support the liquid bath 10 . lcd cell holders 17 ′ may be mounted on a bottom wall of the liquid bath 10 ′ within the liquid bath 10 ′, to firmly hold the lcd cells l loaded in the liquid bath 10 ′. sound wave transmitter holders 19 ′ also may be mounted on the bottom wall of the liquid bath 10 ′ within the liquid bath 10 ′, to firmly hold the sound wave transmitters 40 ′. the lcd cell holders 17 ′ and sound wave transmitter holders 19 ′ are attached to a bottom plate 15 ′ mounted on the bottom wall of the liquid bath 10 ′ within the liquid bath 10 ′. the spacing adjuster 50 ′ may adjust the spacing between the corresponding lcd cell l held by the corresponding lcd cell holders 17 ′ and the corresponding sound wave transmitter 40 ′ held by the corresponding sound wave transmitter holder 19 ′. a plurality of lcd cells l may be loaded or unloaded into / from the liquid bath 10 ′ by the loading device 20 ′. the heaters 30 ′, which heat the liquid supplied to the liquid bath 10 ′, may be installed at front , rear , left and right walls of the liquid bath 10 ′ within the liquid bath 10 ′, respectively . although the heaters 30 ′ are illustrated as being installed at the front , rear , left and right walls of the liquid bath 10 ′, they may be installed at other portions of the liquid bath 10 ′ within the liquid bath 10 ′, without being limited to the example embodiment . the heaters 30 ′ disposed within the liquid bath 10 ′ may externally receive electric power , thereby heating the liquid supplied to the interior of the liquid bath 10 ′ to a desirable ( or alternatively , predetermined ) temperature at which the lcd cells l loaded in the liquid bath 10 ′ are effectively heat - treated , and maintaining the liquid at the desirable ( or alternatively , predetermined ) temperature . heat may be transferred to the liquid crystals in the lcd cells l via a medium , for example , the liquid , which is maintained at the desirable ( or alternatively , predetermined ) temperature by the heater 30 ′. as the liquid crystals receive heat , they may be diffused to have a more uniform distribution . in order to more effectively diffuse the liquid crystals in the lcd cells l , which receive heat in a state of being loaded in the liquid bath 10 ′, the sound wave transmitters 40 ′ may be installed in the liquid bath 10 ′, to transmit sound waves to the liquid crystals . the sound wave transmitters 40 ′ may be arranged within the liquid bath 10 ′ such that they are adjacent to the lcd cells l loaded in the liquid bath 10 ′, respectively . the sound wave transmitters 40 ′ may externally receive sound waves . after receiving sound waves , the sound wave transmitters 40 may transmit the received sound waves to the liquid crystals in the lcd cells l via the medium , for example , the liquid in the liquid bath 10 ′. as the liquid crystals receive sound waves , they may be diffused to have a more uniform distribution . next , a heat treatment method for lcd cells according to an example embodiment will be described with reference to fig1 and 2 . first , a liquid , which is a medium to transmit heat and sound waves , may be supplied to the interior of the liquid bath 10 through the liquid supply tube 13 connected to the liquid bath 10 . the liquid supplied to the interior of the liquid bath 10 may be heated by the heater 30 and maintained at a desirable ( or alternatively , predetermined ) temperature , at which the lcd cells l to be loaded in the liquid bath 10 will be effectively heat - treated . when the liquid in the liquid bath 10 is maintained at the desirable ( or alternatively , predetermined ) temperature in accordance with the heating operation , lcd cells l may be loaded . for example , the cover 11 installed at the top of the liquid bath 10 may be opened and a plurality of lcd cells l may be loaded into the liquid bath 10 . after the lcd cells l are loaded into the liquid bath 10 , the cover 11 may be closed to seal the interior of the liquid bath 10 . liquid crystals of the lcd cells l loaded in the liquid bath 10 may receive heat from the liquid contained in the liquid bath 10 . accordingly , the lcd cells l may be effectively heat - treated and thereby diffuse liquid crystals therein to have a more uniform distribution . when the lcd cells l loaded in the liquid bath 10 , the vertical levels of the support plates 23 supporting the lcd cells l may adjust the spacing between each lcd cell l and the sound wave transmitters 40 installed at the bottom wall of the liquid bath 10 . accordingly , the liquid crystals in the lcd cells l , which have been diffused to have a more uniform distribution by receiving heat from the liquid , may additionally receive sound waves from the sound wave transmitters 40 . for example , the sound wave transmitters 40 may transmit sound waves to the liquid crystals in the lcd cells l via the liquid as a medium . accordingly , the liquid crystals receiving the sound waves may be further diffuse the liquid crystals that have not been sufficiently diffused by heat . thus , the liquid crystals in the lcd cells may have a more uniform distribution . after heat treating for the lcd cells l using heat and sound waves , the cover 11 installed at the top of the liquid bath 10 may be opened , and the lcd cells l may be unloaded from the liquid bath 10 by the loading device 20 . according to example embodiments of the inventive concepts , it may be possible to effectively heat - treat lcd cells within a relatively short time such that liquid crystals in the lcd cells have a more uniform distribution , and thus securing enhanced performance of reducing or removing heat treatment defects such as spot defects . because the inventive concepts reduce processing time per lcd cell , it may also be possible to achieve an improvement in the quality of lcd cells and an enhancement in productivity . although example embodiments of the inventive concept have been shown and described in this specification and figures , it would be appreciated by those skilled in the art that changes may be made in the illustrated embodiments without departing from the principles and spirit of the inventive concepts , the scope of which is defined in the claims and their equivalents .