CN102341214B - Glass substrate and method for manufacturing same - Google Patents

Abstract

Provided is a glass substrate (1) having the front surface (2a), the rear surface (2b), and the edge surface (3b) between the outer circumferential ends of the both surfaces (2a, 2b). A chamfered surface (4) is formed on the boundary section between the front surface (2a) and/or the rear surface (2b) and the edge surface (3b), the ten-point average roughness (Rz2) of the chamfered surface (4) is smaller than the ten-point average roughness (Rz1) of the edge surface (3b), and the average length (RSm2) of the roughness curve elements of the chamfered surface (4) is longer than the average length (RSm1) of the roughness curve elements of the edge surface. Preferably, the ten-point average roughness (Rz2) of the chamfered surface (4) and the ten-point average roughness (Rz1) of the edge surface (3b) satisfy the inequalities of Rz1=1.5 and 1.5<=Rz1/Rz2<=10.0.

Description

Glass substrate and manufacture method thereof

Technical field

The present invention relates to glass substrate and the manufacture method thereof of the surface texture optimization making surface and the boundary portion between the back side and end face, wherein, this end face is present in the outer circumference end on above-mentioned surface and this two sides, the back side each other.

Background technology

As everyone knows, in image (image) display unit in recent years, become main flow with the flat-panel monitor (FPD) that liquid crystal display (LCD), plasma display (PDP), electroluminescent display (FED), organic el display (OLED) etc. are representative.In addition, organic EL does not make fine three primary colors flicker by TFT as OLED, and only makes monochrome (such as, white) luminous, thus is constantly utilized as the planar light source such as the backlight of LCD or the light source of room lighting.

Above-mentioned FPD or illumination are all passed through to carry out setting up etc. and combining and form to the various works comprising each element or distribution on the surface of glass substrate.Especially, from the view point of productivity ratio high efficiency, the glass substrate of a large type forms multiple FPD panel components etc., the most at last their suitably segmentations and carry out being formed that the what is called of each FPD face glass is multiple chooses.The plurality of choose along with glass substrate maximize and efficiency improve, the length therefore even used is more than the glass substrate of 3m.Further, in recent years, because the maximization of FPD self develops, therefore in order to respond the requirement preventing its weight from increasing, as glass substrate, more thin-walled property was needed.In addition, this kind of glass substrate, except above-mentioned FPD or organic EL illuminating, even utilizes the glass substrate as solar cell.

Further, in the manufacturing process of above-mentioned FPD, organic EL illuminating and solar cell, there is the operation such as lifted from platform by glass substrate or the operation of heat-treating, in these operations, when lifting glass substrate, producing problem as follows.

That is, if the thin-walled property of glass substrate and size-enlargement development, then can produce great flexure when lifting, because of this flexure, on the face of protruding, effect has tensile stress, and effect has compression stress on the face of depression.In this case, although glass substrate has its surface and the back side and the outer circumference end being present in above-mentioned two sides end face each other respectively via the form that boundary portion is connected, when glass substrate occurs to bend, this stress concentrates on above-mentioned boundary portion.Therefore, when flexure occurs glass substrate, the boundary portion periphery of the end face be connected with this face on the surface of protruding or the back side produces large tensile stress.Therefore, damage if exist on the table back of the body two sides of glass substrate and the respective boundary portion periphery of end face, the tiny flaw such as crackle or foreign matter, then when flexure occurs glass substrate, large tensile stress is produced near this defect, and concentrate at this fault location generation stress, tiny flaw expands and makes glass substrate breakage at one stroke.

In the heat treatment step of above-mentioned glass substrate, also produce problem identical therewith.Namely, glass substrate expands with temperature rises, and shrinks with temperature reduces, but in heat treatment step, when producing irrational Temperature Distribution on the glass substrate, producing in a glass substrate and expanding and shrink and be mixed with tensile stress and compression stress.In this case, if there is tiny flaw on the table back of the body two sides of glass substrate and the boundary portion periphery of end face and produce tensile stress in this boundary portion, then produce stress at this tiny flaw place and concentrate, until make glass substrate breakage.

But, this kind of glass substrate is by being split to form as desired size, but as its dividing method, the so-called bending segmentation of usual employing, quarter is established line by utilizing diamond chip etc. on the surface of glass substrate in this bending segmentation, and apply power, make to act on tensile stress in this line, thus cut off glass substrate.In such dividing method, the boundary portion of the table of glass substrate after singulation back of the body two sides and end face produces countless tiny flaws, therefore as described above, when the flexure of glass substrate or heat treatment time this glass substrate breakage probability uprise.

In order to tackle such problem, according to patent document 1,2, disclose following method, that is, the table back of the body two sides of glass substrate and the boundary portion of end face are implemented to milled processed and formed fillet surface, and make the fillet surface after grinding more level and smooth than end face.In detail, according to patent document 1, record following situation: the end face of preferred glass substrate is rectangular relative to table back of the body two sides, the surface of this end face maximum concavo-convex be below 0.05mm and the surface of fillet surface maximum concavo-convex be below 0.007mm.In addition, according to patent document 2, record following situation: the end face of preferred glass substrate is bending and give prominence to outward from the outer circumference end on table back of the body two sides, the surface of this end face maximum concavo-convex be below 0.04mm and the surface of fillet surface maximum concavo-convex be below 0.007mm.

[patent document 1] Japanese Unexamined Patent Publication 9-278466 publication

[patent document 2] Japanese Unexamined Patent Publication 9-278467 publication

But, because glass substrate disclosed in patent document 1,2 is tempered glass, even if therefore carry out to the glass substrate not implementing intensive treatment the process forming fillet surface in the same manner as above-mentioned each document, when producing flexure or unsuitable Temperature Distribution on the glass substrate, also cannot reliably avoid the breakage causing glass substrate.That is, the fillet surface recorded in above-mentioned each document can say it is not which type of glass substrate comprising the glass substrate being used in the above-mentioned purposes enumerated all is applicable to applicable surface texture.

Further, the surface texture of the fillet surface of the glass substrate recorded in above-mentioned each document is maximum concavo-convex for parameter and the proterties that specifies with surface, for the surface texture based on regulation like this, reliably cannot prevent the breakage of glass substrate as described above.Namely, not inherently be applicable to the most with the maximum concavo-convex situation for parameter in surface, even if therefore the surface texture of fillet surface meets the regulation that above-mentioned each document is recorded, the breakage of the glass substrate that the flexure of substrate or unsuitable Temperature Distribution cause also reliably cannot be tackled.

Further, if the surface texture of the fillet surface specified in above-mentioned each document, then in matting, also cause to produce during the grinding of end face and the glass granules etc. be attached on the surface of glass substrate is easily trapped in the unfavorable condition on fillet surface.Further, for above-mentioned reasons, also cause in drying process, to form glass granules etc. be attached to state on the surface of glass substrate, and cause the quality of glass substrate to reduce so fatal defect.

It should be noted that, problem so is above split except the situation of carrying out by the bending described except the segmentation of glass substrate, such as cutting off as laser etc., using laser to carry out the glass substrate split, can produce too when its boundary portion forms the fillet surface obtained by grinding.

Further, although do not deny likely producing above such problem, in the past for the concrete method for this surface texture being defined as the best, actual conditions do not find best method.

Summary of the invention

The present invention in view of the foregoing, its technical problem is, by make glass substrate from surface and the back side to the surface texture optimization of the boundary face (fillet surface) of end face, no matter whether implement intensive treatment, the generation of the breakage that can reliably prevent flexure or unsuitable Temperature Distribution because of glass substrate from causing, and the problem of glass granules can be eliminated.

The first technical scheme of the present invention proposed to solve above-mentioned technical problem relates to a kind of glass substrate, there is surface and the back side and be present in the end face each other of outer circumference end on this two sides, it is characterized in that, boundary portion in described surface and the back side between the face of at least one party and described end face is formed with fillet surface, 10 mean roughness Rz of this fillet surface ₂be less than 10 mean roughness Rz of described end face ₁, and the average length RSm of the roughness curve key element of this fillet surface ₂be greater than the average length RSm of the roughness curve key element of described end face ₁.It should be noted that, use Tokyo accurate society SURFCOM590A effects on surface roughness to carry out measuring (following, identical).In addition, at this, 10 mean roughness Rzjis (Rz ₁, Rz ₂) and the average length RSm (RSm of roughness curve key element ₁, RSm ₂) according to JIS B0601:2001 (following, identical).Further, " fillet surface " represents the surface (following, identical) of the chamfered section obtained this boundary portion enforcement chamfer machining.

According to such structure, 10 mean roughness being not only the fillet surface that the boundary portion between the face of at least one party in the surface and the back side of glass substrate and end face is formed are less than 10 mean roughness of end face, and the average length of the roughness curve key element of this fillet surface is also greater than the average length of the roughness curve key element of end face.Like this, by carrying out the relation of the surface texture of regulation fillet surface and the surface texture of end face with the average length RSm of 10 mean roughness Rzjis and roughness curve key element for parameter, can effectively avoid peeling off the situation of removing, matting glass granules etc. from this boundary portion with this boundary portion and being trapped in glass granules in the situation of this boundary portion and drying process etc. for the situation of shortcoming or crackle and glass substrate generation defect or breakage, sheet glass or glass granules occur starting point and being attached to the surface of glass substrate and causing the unfavorable condition of quality reduction etc.Further, intensive treatment (hot intensive treatment) is implemented or do not implemented to the glass substrate that this first technical scheme relates to no matter, can both obtain advantage as described above.

In this first technical scheme, 10 mean roughness Rz of preferred described fillet surface ₂and ten of described end face mean roughness Rz ₁meet Rz ₂≤ 1.5 μm and 1.5≤Rz ₁/ Rz ₂the relation of≤10.0.

If like this, by making 10 mean roughness Rz of the fillet surface formed in above-mentioned boundary portion ₂be less than 1.5 μm, and can suppress more reliably, with the breakage etc. of this boundary portion glass substrate that is starting point, to make the breakdown strength of end face periphery increase, and more effectively can avoid the problem such as generation or delay of the glass granules of this boundary portion.Further, as 10 mean roughness Rz of end face ₁divided by the value (Rz after 10 mean roughness of fillet surface ₁/ Rz ₂) when being less than 1.5, the upper ascending effect forming the breakdown strength of the end face periphery that fillet surface produces reduces.On the other hand, Rz is worked as ₁/ Rz ₂during more than 10.0, the difference of the roughness of fillet surface and end face becomes greatly, may bring out because new stress concentrates the breakage caused on the border on this two sides.Therefore, Rz ₁/ Rz ₂preferably in above-mentioned number range.

In addition, in the first technical scheme, the average length RSm of the roughness curve key element in preferred described particular abrasive face ₂meet RSm ₂the relation of>=100 μm.

If like this, then can effectively avoid further with breakage of this boundary portion glass substrate that is starting point etc. and the problem such as generation or delay at the glass granules of this boundary portion.Particularly by RSm ₂>=100 μm, the concavo-convex interval (cycle) of the fluctuating of fillet surface becomes large, and surface area is suppressed, therefore can effectively avoid glass granules to be attached to significant surface (surface) this unfavorable condition.In this case, the ratio of the average length of preferred roughness curve key element and RSm ₁/ RSm ₂be more than 0.1 and less than 0.7.That is, RSm is worked as ₁/ RSm ₂when being less than 0.1, the difference at the concavo-convex interval of the fluctuating of end face and fillet surface becomes greatly, thus the surface texture on the border of both occurs sharply to change, and therefore can produce new damaged starting point on this border.On the other hand, RSm is worked as ₁/ RSm ₂during more than 0.7, between end face and chamfered section, the difference at the concavo-convex interval of fluctuating diminishes, and conclusion is failed effectively to remove concavo-convex, and the upper ascending effect of breakdown strength is insufficient.Therefore, preferred RSm ₁/ RSm ₂in above-mentioned number range.

The second technical scheme of the present invention proposed to solve above-mentioned technical problem relates to a kind of glass substrate, there is surface and the back side and be present in the end face each other of outer circumference end on this two sides, it is characterized in that, boundary portion in described surface and the back side between the face of at least one party and described end face is formed with fillet surface, and the outstanding valley degree of depth Rvk in this fillet surface meets the relation of Rvk≤0.95 μm.At this, outstanding valley degree of depth Rvk is according to JIS B0671-2:2002 (following, identical).

According to such structure, owing to being the glass substrate of the fillet surface had as follows, namely, the surface texture of the fillet surface formed in the boundary portion of glass substrate is except using except outstanding valley degree of depth Rvk specifies as parameter, also specify that this Rvk is less than 0.95 μm, therefore, it is possible to the problem that the quality that the breakage suppressing the flexure of this glass substrate or unsuitable Temperature Distribution to cause as much as possible and glass granules cause reduces.That is, outstanding valley degree of depth Rvk represents that the average concavo-convex part deeply of specific surface is that the conduct of which kind of degree refers to target value, if this value is large, then there is abnormal dark valley and divides.And, if boundary portion is have the surface texture that so abnormal valley divides, then when producing tensile stress because of flexure or unsuitable Temperature Distribution in this boundary portion, generation stress is divided to concentrate in abnormal dark valley, therefore easily cause breakage, and divide easy remaining delay glass granules in the valley that this exception is dark.But, if the outstanding valley degree of depth Rvk of fillet surface formed in boundary portion is as described above less than 0.95 μm, then there is not abnormal dark valley in boundary portion to divide, concentrate even if therefore have tensile stress to be difficult to produce stress in boundary portion effect yet, and be difficult to remaining delay glass granules yet.It should be noted that, from such a viewpoint, the outstanding valley degree of depth Rvk of fillet surface preferably formed in boundary portion is less than 0.20 μm.In addition, the situation that the outstanding valley degree of depth Rvk in the boundary portion of glass substrate is less than the outstanding valley degree of depth Rvk of the end face be connected with the fillet surface of this boundary portion is effective.That is, when producing stress in the inside of this glass substrate because the flexure of glass substrate or unsuitable Temperature Distribution cause, known described stress easily becomes the strongest near boundary portion.Therefore, if the outstanding valley degree of depth Rvk of boundary portion is less than the outstanding valley degree of depth Rvk of end face, then becomes the dark valley of the exception of the reason that stress is concentrated and divide and reduce from easily producing the boundary portion that this stress concentrates.Consequently, the breakage that the flexure of glass substrate or unsuitable Temperature Distribution cause can be reduced as much as possible, in addition, also can avoid the problem of the remaining delay of glass granules.It should be noted that, even if the outstanding valley degree of depth Rvk of the end face of glass substrate is less than the outstanding valley degree of depth Rvk of the fillet surface of boundary portion, from the view point of surface texture, be also only extra quality requirement, and can not obstruction be become in the problem of damaged or glass granules.Further, no matter implement in the glass substrate that this second technical scheme relates to or do not implement intensive treatment (hot intensive treatment), advantage as described above can both be obtained.

The 3rd technical scheme of the present invention proposed to solve above-mentioned technical problem relates to a kind of glass substrate, there is surface and the back side and be present in the end face each other of outer circumference end on this two sides, it is characterized in that, boundary portion in described surface and the back side between the face of at least one party and described end face is formed with fillet surface, and the root mean square slope R Δ q of the roughness curve in this fillet surface meets the relation of R Δ q≤0.10.At this, the root mean square slope R Δ q of roughness curve is according to JIS B0601-2001 (following, identical).

According to such structure, owing to being the glass substrate of the fillet surface had as follows, namely, the surface texture of the fillet surface formed in the boundary portion of glass substrate is except using except the root mean square slope R Δ q of roughness curve specifies as parameter, also specify that this R Δ q is less than 0.10, therefore, it is possible to the problem that the quality that the breakage suppressing the flexure of this glass substrate or unsuitable Temperature Distribution to cause as much as possible and glass granules cause reduces.That is, the root mean square slope R Δ q of roughness curve be each recess in roughness curve and each protuberance relative to the mean value of the slope of the normal in this face, if therefore this value is large, then represent that concavo-convex slope is large, namely the lowest point is that the recess of sharp keen shape is many.And, if boundary portion is the fillet surface of such proterties, then when producing tensile stress because of flexure or unsuitable Temperature Distribution in this boundary portion, be that the recess of sharp keen shape can produce stress and concentrates in the lowest point, therefore apt to cause breakage, and at the easy remaining delay glass granules of this recess.But, if the root mean square slope R Δ q of the roughness curve as described above in the fillet surface of boundary portion formation is less than 0.10, the recess then with sharp keen the lowest point arrives the degree that can not become problem less in boundary portion, even if therefore have tensile stress to be also difficult to produce stress in boundary portion effect to concentrate, and glass granules is difficult to remaining delay.It should be noted that, from such a viewpoint, the root mean square slope R Δ q of the roughness curve more preferably in the fillet surface of boundary portion formation is less than 0.05.In addition, the root mean square slope R Δ q of the roughness curve of the boundary face of glass substrate is less than the situation of the root mean square slope R Δ q of the roughness curve of the end face be connected with this boundary face is effective.That is, when producing stress in the inside of this glass substrate because the flexure of glass substrate or unsuitable Temperature Distribution cause, known described stress easily becomes the strongest near boundary portion.Therefore, if the root mean square slope R Δ q of the roughness curve of boundary portion is less than the root mean square slope R Δ q of the roughness curve of end face, then becomes the sharp keen recess in the lowest point of the reason that stress is concentrated and reduce from easily producing the boundary portion that this stress concentrates.Consequently, the breakage that the flexure of glass substrate or unsuitable Temperature Distribution cause can be reduced as much as possible, in addition, the problem of the remaining delay of glass granules can also be avoided.It should be noted that, even if the root mean square slope R Δ q of the roughness curve of the end face of glass substrate is less than the root mean square slope R Δ q of the roughness curve of the fillet surface of boundary portion, from the view point of surface texture, also be only extra quality requirement, and can not obstruction be become in the problem of damaged or glass granules.Further, no matter implement in the glass substrate that the 3rd technical scheme relates to or do not implement intensive treatment (hot intensive treatment), advantage as described above can both be obtained.

The 4th technical scheme of the present invention proposed to solve above-mentioned technical problem relates to a kind of glass substrate, there is surface and the back side and be present in the end face each other of outer circumference end on this two sides, it is characterized in that, boundary portion in described surface and the back side between the face of at least one party and described end face is formed with fillet surface, and the maximum valley degree of depth Rv in this fillet surface meets the relation of Rv≤2.0 μm.At this, maximum valley degree of depth Rv is according to JIS B0601-2001 (following, identical).

According to such structure, owing to being the glass substrate of the fillet surface had as follows, namely, the surface texture of the fillet surface formed in the boundary portion of glass substrate is except using except maximum valley degree of depth Rv specifies as parameter, also specify that this Rv is less than 2.0 μm, therefore, it is possible to the problem that the quality that the breakage suppressing the flexure of this glass substrate or unsuitable Temperature Distribution to cause as much as possible and glass granules cause reduces.

Namely, peak portion and valley is there is in the roughness curve of the proterties of the fillet surface notationally stated, and when valley is dark, if the tensile stress that bending or heat causes acts on fillet surface, then produce stress to concentrate in this lowest point, and valley is torn, thus, valley tear development, until make glass substrate breakage.But, if make the maximum valley degree of depth Rv of fillet surface be less than 2.0 μm as described above, then do not exist because heat or the bending tensile stress produced cause and tear the valley of the such degree of depth of development at fillet surface, not only be difficult to the breakage causing glass substrate, and be also difficult to remaining delay glass granules in valley.It should be noted that, from such a viewpoint, the maximum valley degree of depth Rv of fillet surface preferably formed in boundary portion is less than 1.5 μm.In addition, the maximum valley degree of depth Rv of the fillet surface of glass substrate is less than the situation of the maximum valley degree of depth Rv of the end face be connected with this fillet surface is effective.That is, when producing stress in the inside of this glass substrate because the flexure of glass substrate or unsuitable Temperature Distribution cause, known described stress easily becomes the strongest near boundary portion.Therefore, if the maximum valley degree of depth Rv of boundary portion (fillet surface) is less than the maximum valley degree of depth Rv of end face, then the dark valley becoming the reason that stress is concentrated reduces from easily producing the concentrated boundary portion of this stress or disappears.Consequently, the breakage that the flexure of glass substrate or unsuitable Temperature Distribution cause can be reduced as much as possible, in addition, the problem of the remaining delay of glass granules can also be avoided.It should be noted that, even if the maximum valley degree of depth Rv of the end face of glass substrate is less than the maximum valley degree of depth Rv of the fillet surface of boundary portion, from the view point of surface texture, be also only extra quality requirement, and can not obstruction be become in the problem of damaged or glass granules.Further, no matter implement in the glass substrate that the 4th technical scheme relates to or do not implement intensive treatment (hot intensive treatment), advantage as described above can both be obtained.

In arbitrary technical scheme in first to fourth above technical scheme, preferred described fillet surface is formed by milled processed.

Namely, if form the fillet surface based on milled processed in this boundary portion of glass substrate, the surface texture of this fillet surface then just can be made (to be Rzjis and RSm in the first technical scheme by implementing same milled processed, be Rvk in the second technical scheme, be R Δ q in the 3rd technical scheme, be Rv in the 4th technical scheme) homogenising, therefore, it is possible to form in the boundary portion of single glass substrate the fillet surface that whole length direction total length has uniform surface texture.In addition, for multiple glass substrate, no matter whether glass substrate is variant, can both form the fillet surface with equal surface texture, and can reduce the variation in quality in respective boundary portion.

Further, preferred described fillet surface is formed by the milled processed after the milled processed of described end face.

Namely, first, the surface texture moderately optimizing this end face in advance by grinding the end face of glass substrate (reduces Rzjis and increases RSm in the first technical scheme, Rvk is reduced in the second technical scheme, R Δ q is reduced in the 3rd technical scheme, Rv is reduced) in the 4th technical scheme, afterwards, if form fillet surface by grinding and make the surface texture of this fillet surface be better than the surface texture of described end face, then can form the surface texture can eliminating the breakage of glass substrate or the problem of particulate expeditiously.Therefore, from the view point of surface texture, become efficient process.

In such a configuration, described end face can be formed in the outer circumference end at described surface and the back side each other as tabular surface.

So, each boundary portion between the face of surface and these both sides of the back side and end face becomes the state having corner angle, and therefore from the view point of mitigation tensile stress, the meaning forming fillet surface in this boundary portion increases.In this case, the end face of glass substrate can implement milled processed, or uses laser to carry out the situation of the segmentation of glass substrate for cutting off as laser etc., also can not implement milled processed.Namely, when to be cut off by laser etc. carry out the segmentation of glass substrate, be formed as close and surperficial and that the back side is the roughly equal face of surface texture of the end face of the glass substrate of tabular surface, therefore end face do not ground, and only formed based on the fillet surface ground just enough in boundary portion.

In addition, described end face also can be formed as from the outer circumference end at described surface and the back side to the outstanding outward gradually flexure plane of thickness of slab central portion.

If so, then via mild bend, the connecting portion of fillet surface and end face and fillet surface can be connected with the connecting portion on surface (or back side), therefore reduce tensile stress that fillet surface periphery produces or stress concentrate in favourable.

When such end surface shape, preferably in orthogonal with the length direction of described end face and orthogonal with described surface and back side cross section, the tangent line towards rear side of the described fillet surface that the boundary portion of the tangent line towards face side of the described fillet surface formed in the boundary portion of face side and described surperficial angulation α and overleaf side is formed and described back side angulation β meet the relation of 10 °≤α≤30 ° and 10 °≤β≤30 ° respectively.

Namely, such as, as shown in Fig. 7 top view, after only grinding having been carried out to the end face 3b1 of the cross section arc-shaped outstanding outward gradually to thickness of slab central portion, this end face 3b1 becomes concaveconvex shape with the boundary portion z1 of surface (or back side) 2a1, and this boundary portion z1 was present in the position represented by straight line zx originally, but the center side of abutment surface (or back side) 2a1 exists in fact partially.Such phenomenon is when the end face 3b1 of grinding glass substrate 11, and the engaging-in ratio of the abrasive grains due to emery wheel should become the position of straight line zx abutment surface (or back side) 2a1 side on border and the abrasive grains of emery wheel makes surface (or back side) 2a1 side part stripping etc. and produces.But, as shown in longitudinal cross-section in Fig. 8, if the grinding face 6b1 of emery wheel is with near the slope of about 45 ° contact surface (or back side) 2a1 of the glass substrate 11 and above-mentioned straight line zx that should become border of end face 3b1, then the grinding face 6b1 of emery wheel becomes noncontact with actual boundary portion z1.Therefore, emery wheel cannot grind this concavo-convex boundary portion z1, or can only grind a part etc. of boundary portion z1, and result does not grind concavo-convex boundary portion z completely, thus can cause cannot forming in this boundary portion the fillet surface be made up of specific abradant surface.Therefore, although preferably above-mentioned angle [alpha], β are less than 45 °, but when this angle [alpha], β are less than 10 °, narrowed by the abrasive areas of end face side during grinding formation fillet surface, remain in this end face and the chips of glass of respective boundary portion on surface (or back side) or the removing of shortcoming, crackle etc. insufficient, therefore in order to avoid this situation, and need by abrasive areas to face side (or rear side) expansion, thus become not preferred form as boundary portion.On the other hand, when above-mentioned angle [alpha], β are more than 30 °, if then the abrasive areas of the end face side when being formed fillet surface by grinding is not expanded inadequately, then cannot form this fillet surface, and cause the deterioration of productivity ratio.Therefore, if this angle [alpha], β are in above-mentioned number range, then above-mentioned unfavorable condition can not be produced.From such a viewpoint, more preferably above-mentioned angle [alpha], the lower limit of β are 15 °, and higher limit is 20 °.

In above structure, preferred thickness of slab T meets the relation of 0.05mm≤T≤1.1mm.

Namely, when the thickness of slab T of glass substrate is more than 1.1mm, the thickness of slab T of glass substrate becomes large to the impact of the intensity of this glass substrate, possibly cannot play the present invention's (first to fourth technical scheme) the distinctive effect for resisting the stress that the flexure that associates with the breakage of above-mentioned glass substrate or unsuitable Temperature Distribution produce fully.On the other hand, if the thickness of slab T of glass substrate is less than 0.05mm, then may be difficult to effects on surface and this two sides, the back side and end face respective between boundary portion apply suitable milled processed.Therefore, if the thickness of slab T of glass substrate is in above-mentioned number range, then such unfavorable condition can be avoided.It should be noted that, from the view point of above-mentioned, more preferably the lower limit of the thickness of slab T of glass substrate is 0.1mm, and higher limit is 0.7mm.

In addition, the width W in the direction orthogonal to the longitudinal direction of preferred thickness of slab T and described fillet surface meets the relation of 0.07≤W/T≤0.30.

That is, if W/T is less than 0.07, then the forming region of fillet surface is insufficient, and the upper ascending effect of the end face strength caused by the existence of fillet surface diminishes.On the other hand, if W/T is more than 0.30, then the time required for formation of fillet surface is elongated, and productivity ratio reduces.Therefore, if W/T is in above-mentioned number range, then such unfavorable condition can be avoided.It should be noted that, from the view point of above-mentioned, more preferably meet the relation of 0.10≤W/T≤0.20.

It should be noted that, the fillet surface preferably possessing the glass substrate of above structure is formed in the whole length on limit, but for the glass substrate etc. that thickness of slab is thin, consider the adjacent corner under top view to be removed the difficulty that fillet surface is formed by grinding from the forming part of fillet surface.

On the other hand, in order to the technical scheme solving the method that above-mentioned technical problem proposes relates to a kind of method that manufacture is formed with the glass substrate of above-mentioned fillet surface, it is characterized in that, as the milling tool ground described fillet surface, use and there is the rotating polishing tool with the abradant surface of rotating shaft direct cross, and the roughness of the peripheral part of described abradant surface is formed less than the roughness of inner peripheral portion, and relative to the boundary portion between the end face behind the face of at least one party in the surface of glass substrate and the back side and milled processed, described rotating polishing tool is made relatively to carry out rectilinear movement along this boundary portion length direction and rotate around described rotating shaft simultaneously, thus form described fillet surface by the peripheral part of described abradant surface and these both sides of inner peripheral portion.

According to such method, due to rotating polishing tool abradant surface (grinding face) and rotating shaft direct cross and the roughness of the roughness ratio inner peripheral portion of the peripheral part of this abradant surface is little, when therefore rotating the milled processed of carrying out this boundary portion around rotating shaft while the boundary portion making this rotating polishing tool relative to above-mentioned glass substrate relatively carries out moving linearly along its length, first carry out the fine grinding (fine ground) of this boundary portion by the peripheral part that the roughness of abradant surface is little and obtain so-called " fine grinding processing " effect.Thus, the boundary portion of glass substrate is being formed to the starting stage of fillet surface, unsuitable stress can be suppressed to concentrate, and the generation of the shortcoming that the inequality of glass substrate can be suppressed to cause (initial chip) or crackle etc., on this basis, the fillet surface being equivalent to the starting stage is formed in this boundary portion.As next stage, by making rotating polishing tool relatively move linearly, and the large inner peripheral portion of the roughness in abradant surface is abutted with the fillet surface being equivalent to above-mentioned initial stage, thus carry out relative rough lapping.By the rough lapping that this is relative, that can improve grinding carries out speed, therefore fillet surface formation time is shortened, and when relative rough lapping starts, fine ground carried out to this boundary portion and carried out above-mentioned " fine grinding processing ", therefore can not cause generation or their development of shortcoming or crackle etc., successfully make relative rough lapping start to carry out.As terminal stage, by making rotating polishing tool relatively move linearly again, and the little peripheral part of the above-mentioned roughness in abradant surface is made to abut with the fillet surface implementing relative rough lapping and carry out smooth grinding.Thus, can suppress because the vibration of rotating polishing tool to act on the generation of the shortcoming to the back-end of this fillet surface that fillet surface causes or crackle etc. from the moving direction rear end of abradant surface, and small grinding powder or the glass dust removing of fillet surface can be residued in because relative rough lapping causes.Like this, with the relative rectilinear movement of single rotating polishing tool, the boundary portion of glass substrate is implemented successively to a series of milled processed be made up of fine ground (fine grinding processing), relative rough lapping, smooth grinding, thus the generation of shortcoming or crackle etc. can be suppressed also can to carry out the formation processing of fillet surface at short notice simultaneously, therefore, on the basis of the good quality of the simplification and fillet surface periphery of guaranteeing device, the raising of significantly productivity ratio is realized.It should be noted that, either one or both of rotating polishing tool and glass substrate carries out moving linearly, and when the length direction of the boundary portion of glass substrate is of a size of the large-scale like this glass substrate of more than 1000mm, being fixed on by glass substrate, under the first-class state of operation post, rotating polishing tool is moved relative to the length direction of its boundary portion be favourable, contrary to small-sized glass substrate, it is favourable for being fixedly installed rotating polishing tool and making glass substrate carry out moving linearly in the mode of crosscut abradant surface.Further, preferably under the elastomers such as use spring carry out flexibly mounted state to rotating polishing tool, make rotating polishing tool and the boundary portion of above-mentioned glass substrate carry out pressure and contact, thus the surface texture of fillet surface can be made more suitable.

And, in order to the technical scheme solving the method that above-mentioned technical problem proposes relate to a kind of be manufactured on the milled processed of above-mentioned end face after form the method for the glass substrate of fillet surface, it is characterized in that, smooth grinding process is implemented again after rough lapping process is implemented to the end face of glass substrate, then the milling tool had than described smooth grinding process fine size is utilized, particular abrasive process is implemented to the boundary portion between the face of at least one party in the surface of glass substrate and the back side and described end face, thus forms described fillet surface.

According to such method, can by rough lapping and smooth grinding efficiently and at short notice by the end surface grinding precedent of glass substrate as cross section roughly arc-shaped etc., and as grinding afterwards, not, further by more fine-grained milling tool, this end surface grinding is become similar shape, and form fillet surface by more fine-grained milling tool in this boundary portion.Therefore, make end face, fillet surface, these three kinds of surface texture the bests of the table back side, thus effectively can improve end face strength.And, preferably in advance by carrying out the milling tool of the rough lapping process of end face, the milling tool carrying out the smooth grinding process of end face, the milling tool that carries out particular abrasive process be disposed on same path, thus, each milling tool can carry out relative rectilinear continuously and moves and carry out each milled processed simultaneously, compared with carrying out the situation of each process respectively, significantly can shorten the processing time and realize the raising of productivity ratio.Further, preferably under use the elastomer such as spring state that elastic bearing carries out the milling tool of particular abrasive process, make milling tool and the boundary portion of above-mentioned glass substrate carry out pressure and contact, thus the surface texture of fillet surface can be made more suitable.

[invention effect]

As previously discussed, according to the present invention, the boundary portion existed between the face of at least one party in the surface and the back side of glass substrate and end face forms fillet surface, the surface texture of this fillet surface is defined as optimum value by using suitable parameter, even if therefore when producing tensile stress because of the flexure of glass substrate or unsuitable Temperature Distribution at this fillet surface, also be difficult to the stress produced as the reason of breaking or lacking of glass substrate concentrate, sharply reduce damaged probability of happening, and glass granules is difficult to remaining delay and realizes the quality raising of product.

Accompanying drawing explanation

Fig. 1 be the glass substrate that relates to of embodiments of the present invention amplifying longitudinal sectional view with the major part of end face cut off on the length direction orthogonal direction of side edge part.

Fig. 2 represents to cut off glass raw sheet and the glass substrate that obtains and the sketch to the milling tool that the end face portion of this glass substrate is ground.

Fig. 3 is the longitudinal sectional view of the major part representing the glass substrate only having carried out end surface grinding process.

Fig. 4 represents that the glass substrate after to end face processing carries out the concise and to the point front view of the state of the formation processing of fillet surface.

Fig. 5 represents that the glass substrate after to end face processing carries out the schematic top of the state of the formation processing of fillet surface.

Fig. 6 is the schematic top of the major part of glass substrate after the formation representing fillet surface.

Fig. 7 is the schematic top of the major part of the glass substrate of the problem points represented in the past.

Fig. 8 is the longitudinal sectional view of the major part of the glass substrate of the problem points represented in the past.

Symbol description:

1 glass substrate

2a surface

The 2b back side

3 end faces

4 fillet surfaces

5 milling tools (first, second milling tool)

6 the 3rd milling tools

The rotating shaft of 6a the 3rd milling tool

The abradant surface (grinding face) of 6b the 3rd milling tool

The inner peripheral portion of the abradant surface (grinding face) of 6ba the 3rd milling tool

The peripheral part of the abradant surface (grinding face) of 6bb the 3rd milling tool

The tangent line towards face side of A fillet surface

Z boundary portion

α tangent line and surperficial angulation

Detailed description of the invention

Below, with reference to accompanying drawing, embodiments of the present invention are described.It should be noted that, in the following embodiments, with LCD with the glass substrate of representative FPD for object.

Fig. 1 is the longitudinal sectional view after the major part of glass substrate 1 of the present embodiment being amplified.It should be noted that, this figure only illustrates the form of the surperficial 2a side part of glass substrate 1, and rear side part is across the substantially symmetrical form of thickness of slab direction center line X.As shown in the drawing, this glass substrate 1 has plane surperficial 2a, the end face 3 of longitudinal section circular shape convexly, the plane fillet surface 4 that formed between surperficial 2a and end face 3.In other words, in glass substrate 1, surperficial 2a and the back side are connected via fillet surface 4 respectively with end face 3, and wherein end face 3 is present in the outer circumference end at surperficial 2a and the back side each other.It should be noted that, intensive treatment (hot intensive treatment etc.) do not implemented by this glass substrate 1, but can implement this process yet.

The end face 3 of this glass substrate 1 is in the present embodiment for implementing again the abradant surface of smooth grinding process after implementing rough lapping process, and surperficial 2a is forming face and unfocused surface, and fillet surface 4 is the particular abrasive faces implementing particular abrasive process after the smooth grinding process of end face 3.

10 mean roughness Rz of the fillet surface 4 of this glass substrate 1 ₂be less than 10 mean roughness Rz of end face 3 ₁, and the average length RSm of the roughness curve key element of fillet surface 4 ₂be greater than the average length RSm of the roughness curve key element of end face 3 ₁.It should be noted that, because surperficial 2a is minute surface, therefore its 10 mean roughness are less than 10 mean roughness Rz of fillet surface 4 ₂, and the average length of its roughness curve key element is greater than the average length RSm of the roughness curve key element of fillet surface 4 ₂.In this case, 10 mean roughness Rz of fillet surface 4 ₂be less than 1.5 μm, and ten of the abradant surface of end face 3 mean roughness Rz ₁with 10 mean roughness Rz of fillet surface 4 ₂ratio and Rz ₁/ Rz ₂be more than 1.5 and less than 10.0.In addition, the average length RSm of the roughness curve key element of fillet surface 4 ₂be more than 100 μm, and the average length RSm of the roughness curve key element of end face 3 ₁with the average length RSm of the roughness curve key element of fillet surface 4 ₂ratio and RSm ₁/ RSm ₂be more than 0.1 and less than 0.7.

In addition, the outstanding valley degree of depth Rvk of the fillet surface 4 of this glass substrate 1 is less than 0.95 (being preferably less than 0.20).It should be noted that, because surperficial 2a is minute surface, therefore its outstanding valley degree of depth Rvk is less than the outstanding valley degree of depth Rvk of fillet surface 4.

Further, the root mean square slope R Δ q of the roughness curve of the fillet surface 4 of this glass substrate 1 is less than 0.10 (being preferably less than 0.05).It should be noted that, because surperficial 2a is minute surface, therefore the root mean square slope R Δ q of its roughness curve is less than the root mean square slope R Δ q of the roughness curve of fillet surface 4.

In addition, the maximum valley degree of depth Rv of the fillet surface 4 of this glass substrate 1 is less than 2.0 μm (being preferably less than 1.5 μm).It should be noted that, because surperficial 2a is minute surface, therefore its maximum valley degree of depth Rv is less than the maximum valley degree of depth Rv of fillet surface 4.

On the other hand, in cross section (orthogonal with the length direction of end face 3 and orthogonal with surperficial 2a and back side cross section) shown in Fig. 1, the tangent line A towards surperficial 2a side of fillet surface 4 and surperficial 2a angulation α is more than 10 ° and less than 30 ° (present embodiment is 18 °), although and it is not shown, but in the fillet surface of side overleaf, be more than 10 ° and less than 30 ° (being 18 ° in the present embodiment) towards the tangent line of this rear side and back side angulation.

In this case, fillet surface 4 is removed and the face formed by the periphery (periphery at position shown in dotted lines in Figure 1) becoming the original boundary portion z of waveform of particular abrasive process by the surperficial 2a under the state of only having carried out the milled processed of end face 3 and end face 3, and this removing unit is that the width W 1 from original boundary portion z to end face 3 side is 70 μm and from original boundary portion z to the region that the width W 2 of surperficial 2a side is 30 μm.It should be noted that, the tangent line B of this original boundary portion z and surperficial 2a angulation γ is 25 ° in present embodiment.

And, the thickness of slab T of this glass substrate 1 is below 1.1mm and more than 0.05mm, and the ratio of the width W of fillet surface 4 (size in the direction orthogonal and parallel with surperficial 2a and the back side with the length direction (direction along limit) of fillet surface 4) and thickness of slab T and W/T are set to more than 0.07 and less than 0.30.

The glass substrate 1 possessing above such structure manufactures as follows.

Fig. 2 exemplifies substantially rectangular glass substrate 1 and carries out to this glass substrate 1 milling tool 5 that the end face portion 3a after bending segmentation carries out milled processed, this glass substrate 1 is by obtaining as follows, namely, four positions on the surface of the glass raw sheet after being shaped by glass tube down-drawing or float glass process etc. are carved into line, to obtain describing the region that substantially rectangular quarter establishes line, further, with this line trace for starting point is by glass raw sheet bending segmentation, thus this glass substrate 1 is obtained.First the end face portion 3a of this glass substrate 1 carries out rough lapping process by the first milling tool, then carries out smooth grinding process by the second milling tool.As shown in Figure 2, the first milling tool be roughly circular shape concavely under front is observed outer peripheral face on the diamond abrasive particles layer kept by metallic bond and the rough lapping revolving wheel (metal anchoring agent diamond wheel) formed are installed.And, under the state that this first milling tool is pressed into the end face portion 3a of glass substrate 1, carry out relative movement by making the first milling tool relative to the length direction (direction along limit) of the end face portion 3a of glass substrate 1 and carry out rough lapping process.Second milling tool in the shape identical with the first milling tool, and is combined with the smooth grinding revolving wheel (resin bond wheel) of the thin abrasive grains such as carborundum at its outer peripheral face by polyurethane resin etc.Under the state of the end face portion of this second milling tool after the rough lapping process being pressed against glass substrate 1, smooth grinding process is carried out by carrying out relative movement as described above, consequently, as shown in Figure 3, glass substrate 1 is formed end face 3b, this end face 3b is that 10 mean roughness Rzjis are about 1 ~ 3 μm, outstanding valley degree of depth Rvk is about 1.0 ~ 1.5, the root mean square slope R Δ q of roughness curve is about 0.12 ~ 0.20, the end face of cross section that maximum valley degree of depth Rv is about 3.0 ~ 5.0 μm roughly arc-shaped.It should be noted that, the formation of the end face 3b of glass substrate 1 is not limited to the milled processed of above-mentioned such two-stage, also can be undertaken by milled processed more than three stages.

As described above, on glass substrate 1 during the end face 3b of Formation cross-section roughly arc-shaped, use the 3rd milling tool 6 to implement particular abrasive process to the boundary portion z of this end face 3b and surperficial 2a and the boundary portion z of end face 3b and back side 2b, form fillet surface 4 thus.As shown in Figure 4, the 3rd milling tool 6 has plane abradant surface (grinding face) 6b orthogonal with rotating shaft 6a, and this abradant surface 6b is formed by the abrasive grains thinner than above-mentioned second milling tool.It should be noted that, glass substrate 1 is placed in the upper surface of operation post (platform) 7 with the state that the periphery of end face 3b is outstanding.

Afterwards, the abradant surface 6b of two the 3rd milling tools 6 be pressed into the boundary portion z of surperficial 2a side of the glass substrate 1 and boundary portion z of 2b side, the back side simultaneously and make it rotate, making the 3rd milling tool 6 carry out relative movement to carry out particular abrasive process relative to the length direction of the boundary portion z of glass substrate 1 simultaneously.Thus, a large amount of chips of glass etc. remained on the boundary portion z of glass substrate 1 is removed.In this case, the abradant surface 6b of two the 3rd milling tools 6 and surperficial 2a of glass substrate 1 and back side 2b angulation are set as more than 10 ° and less than 30 ° (be 18 ° in present embodiment) respectively.Preferably the 3rd milling tool 6 is that central portion is circular recess as shown in Figure 5, be arranged with the relatively large inner circumferential side grind section 6ba of roughness little outer circumferential side grind section 6bb relative to roughness in the mode of surrounding this recess, by grind section 6ba, the 6bb of these both sides, particular abrasive process carried out to the boundary portion z of glass substrate 1.It should be noted that, two the 3rd milling tools 6 are relative to relative movement direction configured separate.

Further, by completing this particular abrasive process, as shown in Fig. 6 (and Fig. 1), between the surperficial 2a and end face 3 of glass substrate 1, the fillet surface 4 removed completely by boundary portion z is formed.By forming this fillet surface 4; even if the tensile stress caused because of flexure or the unsuitable Temperature Distribution of glass substrate 1 acts on this fillet surface 4; this fillet surface 4 also can not produce stress concentrate; the breakdown strength of end face 3 (comprising fillet surface 4) rises, and also can avoid the problem of the remaining delay such as glass granules or chips of glass.

It should be noted that, in the above-described embodiment, to bend to outward the glass substrate 1 of convex from the outer circumference end of surperficial 2a and back side 2b at end face 3 and be suitable for the present invention, but the glass substrate of (tabular surface preferably at a right angle with the table back side) can be suitable for the present invention too in tabular surface for end face 3.

In addition, in the above-described embodiment, the present invention is applicable to the glass substrate of the end face be formed with in flexure plane, this flexure plane is given prominence to from the outer circumference end at surface and the back side gradually outward to thickness of slab central portion, but equally also the present invention can be applicable to the glass substrate of the end face be formed with in tabular surface, this tabular surface surface and the back side outer circumference end each other with surface and the back side at a right angle.

And, in the above-described embodiment, the present invention is applicable to utilize bending to split the glass substrate that is split to form glass raw sheet, but equally also the present invention can be applicable to laser and the glass substrate using laser or thermal stress to be split to form glass raw sheet like that such as cuts off.In this case, milled processed is not carried out to the end face in tabular surface, and only the fillet surface based on milled processed is formed to boundary portion.

In addition, in the above-described embodiment, the present invention is applicable to the glass substrate of FPD, but equally also the present invention can be applicable to such as organic EL illuminating use or glass substrate used for solar batteries.

[embodiment 1]

The present inventors, in order to confirm the effect of the average length RSm about 10 mean roughness Rzjis and roughness curve key element on the fillet surface of the glass substrate exemplified in above-mentioned Fig. 1, carry out the contrast of embodiments of the invention 1a ~ 1e and comparative example 1a ~ 1c as shown in the following.Above-described embodiment and comparative example all use the Nippon Electric Glass Co., Ltd OA-10 be shaped by overflow downdraw to be used as glass raw sheet.

As the test portion used in the embodiments of the invention 1a ~ 1c shown in following table 1 and comparative example 1a, 1b, by by thickness of slab be the glass raw sheet of 700 μm along line trace bending segmentation, and to obtain width dimensions be 1500mm and length dimension is the glass substrate of 1800mm.In addition, equally as the test portion used in embodiment 1d, 1e and comparative example 1c, by by thickness of slab be the glass raw sheet of 500 μm along line trace bending segmentation, and to obtain width dimensions be 550mm and length dimension is the glass substrate of 670mm.Further, according to order shown below, the end face portion of above-mentioned glass substrate is carried out to the milled processed of the end face for the formation of cross section circular shape convexly, formed the particular abrasive process of fillet surface for the respective boundary portion of the end face behind surface and the back side and this grinding.

For embodiments of the invention 1a ~ 1c and comparative example 1a, 1b, first glass substrate to be loaded and under adsorbing the state be fixed on platform, make the outer peripheral face of the rough lapping revolving wheel as the first milling tool (abrasive grains #400) in the form shown in Fig. 2 carry out pressure with the end face portion of glass substrate to contact, and make it move linearly with the grinding speed shown in table 1, thus the Formation cross-section roughly matsurface of circular shape and end face portion.Then, similarly make the outer peripheral face of the smooth grinding revolving wheel as the second milling tool (abrasive grains #1000) in the form shown in Fig. 2 carry out pressure with the end face portion after the rough lapping of glass substrate to contact, and make its with shown in table 1 grinding speed rectilinear movement, thus formed by lappingout wear into cross section roughly circular shape end face.In addition, for embodiments of the invention 1d, 1e and comparative example 1c, first glass substrate is made to move linearly with the grinding speed shown in table 2, and the outer peripheral face making to be fixedly arranged on the rough lapping revolving wheel as the first milling tool (abrasive grains #400) in the form shown in Fig. 2 on fixed position carries out pressure with the end face portion of glass substrate contacts simultaneously, thus the Formation cross-section roughly matsurface of circular shape and end face portion.Then, glass substrate is made to move linearly with the grinding speed shown in table 2 equally, and the outer peripheral face making to be fixedly installed on the smooth grinding revolving wheel as the second milling tool (abrasive grains #1000) in the form shown in Fig. 2 on fixed position carries out pressure with the end face portion after the rough lapping of glass substrate contacts simultaneously, thus formation is worn into the end face of cross section roughly circular shape by lappingout.

Afterwards, particular abrasive process is carried out by the respective boundary portion of the end face of the 3rd milling tool effects on surface and the back side and glass substrate.As the 3rd milling tool, be used in the milling tool circular base securing flat diamond lap plate, this diamond lap plate obtains by making diamond abrasive particles be scattered in resin material.It should be noted that, the size of the size of above-mentioned abrasive grains and the abrasive grains shown in table 1,2 is according to JIS R6001:1998.

When performing particular abrasive process, the angle of suitable adjustment the 3rd milling tool, to make the tangent line on the surface of glass substrate and the back side and fillet surface difference angulation (angle [alpha] of Fig. 1: rear side too) be 18 ° ~ 22 °, on this basis, the contact surface to the 3rd milling tool and glass substrate supplies grinding fluid (grinding water).And, in order to obtain desired chamfer dimesion, 3rd milling tool (abrasive sheet) is rotated with circumferential speed 2000m/min, and make it move linearly with the different grinding speed shown in table 1,2, particular abrasive process is carried out to the whole periphery of the glass substrate except adjacent corner.Thus, the glass substrate of embodiment 1a ~ 1c and embodiment 1d, 1e is obtained.

In embodiment 1a, 1b, 1d, the abrasive grains of the 3rd milling tool is #3000, in embodiment 1c, 1e, the abrasive grains of the 3rd milling tool is #2000, on the other hand, in comparative example 1a ~ 1c, do not carry out the particular abrasive process based on the 3rd milling tool, and the rough lapping process based on the first milling tool and the smooth grinding process based on the second milling tool are only carried out to the end face portion of glass substrate.In addition, in whole embodiments, with the translational speed, the grinding condition that make chamfer dimesion (chamfering width) mode become in the scope of 60 ~ 200 μm carry out selected 3rd milling tool, test portion and glass substrate whole end faces form the fillet surface of general planar with the boundary portion at surface and the back side.

It should be noted that, in above embodiment, employ following method, namely, form the abradant surface of roughly arc-shaped in the end face portion of glass substrate after, the 3rd milling tool is utilized to form the method for fillet surface at end face with surface and the boundary portion at the back side, but also can under the state that glass substrate absorption is fixed on platform, same moving track arranges the first milling tool, the second milling tool and the 3rd milling tool, make these three kinds of milling tools move along this moving track simultaneously, complete abrasive action continuously thus.Like this, within the shorter time, complete whole milled processed, therefore, it is possible to make working (machining) efficiency significantly rise, and be of a size of in the milled processed operation of the glass substrate of the big size of more than 1000mm on each limit, this operation becomes easy.In addition, for the glass substrate that size is little, can make with the following method, that is, three kinds of milling tools are arranged to parallel with the limit of glass substrate, use the conveying mechanism conveying glass substrates such as conveyer belt, and carry out the method for each milled processed continuously simultaneously.

On the other hand, for each glass substrate of embodiment 1a ~ 1e and comparative example 1a ~ 1c, use the accurate society SURFCOM590A in Tokyo, under measured length 5.0mm, carry out roughness mensuration, calculate the end face of glass substrate and 10 mean roughness Rzjis (Rz of fillet surface according to JIS B0601:2001 ₁, Rz ₂) and the average length RSm (RSm of roughness curve key element ₁, RSm ₂) each roughness parameter of value.For these 10 mean roughness Rz ₁, Rz ₂and the average length RSm of roughness curve key element ₁, RSm ₂, implement 10 glass substrates, on the basis of chamfered, to measure 10 times respectively to each glass substrate, calculate its mean value to evaluate under identical conditions.Its result shown in following table 1,2.

For the intensity of the glass substrate after grinding, measure breakdown strength by using the three point bending test method of Orientec society Tensilon RTA-250.The sample of bend test uses and to be cut out by the central portion on the limit of the end face portion of glass substrate is the test film that the size of 80 × 15mm obtains, and then with the summit of end face portion the summit of circular arc (cross section roughly) mode imposed load upward, measure load during its breakage, and calculated by the formula shown in following formula 1, thus determine bursting stress (end face strength) σ.

[formula 1]

$\mathrm{\&sigma;}=\frac{3\mathrm{PL}}{2B{h}^2}$

It should be noted that, in the above-mentioned formula shown in formula 1, P is breaking load, and L is distance between the fulcrum, and B is Sample Width, and h is thickness of glass.

In following table 1,2, describe the bursting stress of glass substrate, but these measure 10 respectively to the respective bursting stress of each embodiment and each comparative example, represents the bursting stress of its minimum of a value (intensity is minimum).And, in order to evaluate the attachment characteristic adhering to or remain in the glass granules on the surface of glass substrate, the respective glass substrate of each embodiment and each comparative example is being cleaned and after drying, is determining the particulate value on the surface of each sheet glass remained on the surface of glass substrate.Particulate value utilizes high and new technology company of Hitachi fine particle measuring device GI-7200 to carry out the mensuration of the population of more than 1 μm, and its numerical value is converted into the number of every square metre.Its result shown in following table 1,2.In addition, for the respective glass substrate of each embodiment and each comparative example, the Restzustand of the difference of height that the chip by microscope amplifying observation in the boundary member on surface and the back side and end face causes.Its result shown in following table 1,2.In this case, in table 1,2, "○" represents the existence not observing chip difference of height, and the residual of small difference of height is observed in " △ " expression, and "×" represents observes the residual of large difference of height.

[table 1]

[table 2]

It should be noted that, the surface of the glass substrate during particular abrasive process of fillet surface shown in following table 3 and the tangent line angulation α towards face side (with reference to Fig. 1) of fillet surface be adjacent and the back side of glass substrate and the fillet surface that is adjacent towards rear side tangent line formed by the measured value of angle β, the width W of fillet surface measured value.

[table 3]

According to above-mentioned table 1,2, confirm the end face of the glass substrate in embodiments of the invention 1a ~ 1e with surface and the boundary portion at the back side be all formed 10 mean roughness little close to minute surface there is the fillet surface of sufficient width, compared with not forming the glass substrate of fillet surface like that with the situation of comparative example 1a ~ 1c, there is significantly high breakdown strength (namely end face strength is more than 160MPa).In addition, confirm in the fillet surface of each embodiment, the difference of height of the grinding boundary portion caused to chip unconfirmed or fine crack, and confirm and all show well or extremely good result in the attachment etc. of glass granules.

Therefore, the glass substrate that various embodiments of the present invention relate to is difficult to the breakage caused in subsequent handling, be formed as the glass substrate of extremely high strength, and the generation of the glass granules that end face causes is extremely few, even if when being used in the display of such high-resolution such as liquid crystal display, plasma display and organic EL, the unfavorable condition etc. of the broken string occurred when forming display element or equipment on the glass substrate also effectively can be suppressed.

In addition, when various embodiments of the present invention, even if grinding speed is increased to 400mm/min from 100mm/min, as long as suitably select the abrasive sheet of milling tool and suitably set grinding condition, then just can obtain same fillet surface efficiently, the high efficiency of operation can be realized.

On the other hand, in each comparative example, not only when the translational speed of milling tool is 200mm/sec or 400mm/sec, even if be reduced to 100mm/sec, the minimum breakdown strength of end face portion is also lower, likely can concentrate to the contact of the low end face portion of intensity or thermal stress and bring out breakage because of conveying mechanism.In addition, the particulate value of arbitrary comparative example is all higher, and the chip difference of height of boundary portion is large, therefore when such as cleaning and time dry, during conveying and bale packing time etc. operation in, glass granules is peeled off from the chip portion of boundary portion and adheres on the glass substrate, thus when forming display element or equipment, the unfavorable condition of broken string likely can occur.Therefore, confirm compared with glass substrate that glass substrate that various embodiments of the present invention relate to and above-mentioned comparative example relate to, all extremely excellent in the either side of breakdown strength and glass granules.

[embodiment 2]

The present inventors, in order to confirm the effect of the outstanding valley degree of depth Rvk in the fillet surface of illustrative glass substrate in above-mentioned Fig. 1, have carried out the contrast of embodiments of the invention 2a ~ 2d and comparative example as shown in the following.The Nippon Electric Glass Co., Ltd OA-10 (not implementing intensive treatment) be shaped by overflow downdraw is all used to be used as glass raw sheet in above-described embodiment and comparative example.

As the test portion used in the embodiments of the invention 2a ~ 2d shown in following table 4 and comparative example, by being the glass raw sheet of 700 μm is carved into rule and carry out bending segmentation at thickness of slab, thus obtaining width dimensions and be 1500mm and length dimension is the glass substrate of 1800mm.The dividing method of concrete glass raw sheet is carved into line by utilizing diamond chip on the surface of glass raw sheet, and to glass raw sheet effect bending moment, makes to produce tensile stress in this line place, thus carry out bending segmentation.It should be noted that, as other dividing method, also initial damage (initial crack) can be partially formed by skive etc. at glass raw sheet, and irradiate laser to this position and carry out local heat, quick refrigeration is carried out in ejector refrigeration agent afterwards, thus, initial crack is developed, thus cut off glass raw sheet.But when cutting off based on such laser, the end face due to glass substrate is tabular surface, be therefore formed as the end surface shape different from the glass substrate of this embodiment and comparative example.

Make outer peripheral face by barrel surface (in this embodiment and comparative example, outer peripheral face caves in into roughly arc-shaped) the columned emery wheel that forms rotates being arranged under its rotating shaft state parallel with the normal to a surface direction of glass substrate, and be pressed on the end face of the above-mentioned glass substrate obtained like that, make its length direction along the end face of glass substrate relatively move linearly simultaneously, thus carry out the milled processed of this end face.In this case; as the emery wheel ground the end face of glass substrate; prepare abrasive grains or the different multiple emery wheel of adhesive in advance, first thick from abrasive grains and the emery wheel that adhesive is hard, change to the thin and emery wheel of adhesive softness of abrasive grains gradually.

Next, for the glass substrate of milled processed finishing end face, form the fillet surface of roughly planar by grinding at end face and the boundary portion on surface (back side).In this case, the emery wheel used in the grinding of fillet surface is compared with the abradant emery wheel of above-mentioned end face, and abrasive grains is thin and adhesive softness is necessary important document.The abradant emery wheel face be pressed on fillet surface of fillet surface can be barrel surface or taper seat, and also can be circular end face or the annulus end face of roughly planar, can also be the surface of the abrasive cloth being fixed with abrasive grains on tape.Further, above-mentioned emery wheel (or abrasive cloth) relatively moves linearly relative to the length direction of the fillet surface of glass substrate.

Specifically describe the embodiment 2a shown in following table 4, first, glass substrate after segmentation to be loaded and under adsorbing the state be fixed on platform, by the outer peripheral face of the rough lapping revolving wheel as the first milling tool (abrasive grains of #400 is fixed by metallic bond) in the form shown in Fig. 2 being pressed into the end face portion of glass substrate and making it move linearly simultaneously, thus the Formation cross-section roughly matsurface of circular shape and end face portion.Then, equally make it move linearly the end face portion after the outer peripheral face of the smooth grinding revolving wheel as the second milling tool (abrasive grains of #1000 is fixed by resinoid bond) in the form shown in Fig. 2 is pressed into the rough lapping of glass substrate simultaneously, thus form the end face being worn into cross section roughly circular shape by lappingout.Afterwards, the 3rd milling tool is utilized to carry out particular abrasive process respectively to the end face of glass substrate and each boundary portion at surface and the back side.As the 3rd milling tool, be used in the milling tool circular base securing flat diamond lap plate, this flat diamond lap plate obtains by making diamond abrasive particles (abrasive grains of #3000) be scattered in resin material.When performing particular abrasive process, suitably adjust the angle of the 3rd milling tool, it is 18 ° ~ 22 ° with the angle making the tangent line of the surface of glass substrate and the back side and fillet surface be formed respectively (angle [alpha] of Fig. 1: rear side too), on this basis, the contact surface to the 3rd milling tool and glass substrate supplies grinding fluid (grinding water).And, in order to obtain the width dimensions of desired fillet surface, and the 3rd milling tool (abrasive sheet) is rotated with circumferential speed 2000m/min, and particular abrasive process has been carried out to the whole periphery except adjacent corner under the top view of glass substrate simultaneously.Thus, the glass substrate of embodiment 2a is obtained.It should be noted that, the size of above-mentioned abrasive grains is according to JIS R6001:1998.In this case, for embodiment 2b, 2c, 2d and comparative example, the abrasive grains of first, second, third milling tool is different from embodiment 2a respectively.

The outstanding valley degree of depth Rvk of the fillet surface of the glass substrate shown in following the table 4 and outstanding valley degree of depth Rvk of end face utilizes the accurate society SURFCOM590A in Tokyo, in the scope of measured length 5.0mm, carry out roughness mensuration, and calculate the value of each Rvk according to JIS B0601:2001.These two kinds outstanding valley degree of depth Rvk implement fillet surface respectively by under identical conditions to 10 glass substrates, measure 10 times afterwards, calculate its mean value to evaluate to them.Further, meanwhile, the maximum cross-section height Pt of the end face of glass substrate and the maximum cross-section height Pt of fillet surface is obtained.In addition, the end face strength obtaining glass substrate is used as the standard of the cracky degree that the flexure of glass substrate or thermal stress cause.For the end face strength of glass substrate, measure breakdown strength by the three point bending test method employing Orientec society Tensilon RTA-250, and it can be used as end face strength.The sample of bend test uses the size central portion on the limit of the end face portion of glass substrate being cut out 80 × 15mm and the test film obtained, and with the summit of end face portion the summit of circular arc (cross section roughly) for upper mode imposed load, measure its damaged time load, and measure bursting stress (end face strength) σ by utilizing the formula shown in the formula 1 that describes to carry out calculating.

The outstanding valley degree of depth Rvk of the fillet surface obtained as described above shown in following table 4, end face strength, the maximum cross-section height Pt of fillet surface and the maximum cross-section height Pt of end face.

[table 4]

	Embodiment 2a	Embodiment 2b	Embodiment 2c	Embodiment 2d	Comparative example
						Rvk[μm]	0.11	0.68	0.55	0.94	0.97
End face strength [MPa]	181	168	166	162	155
						The Pt [μm] of fillet surface	1.07	5.00	3.55	5.30	5.57
The Pt [μm] of end face	2.26	8.06	3.96	6.53	7.44

In above-mentioned table 4, be equivalent to the maximum height Rmax in JIS B0601:1982 due to the maximum cross-section height Pt of end face and the maximum cross-section height Pt of fillet surface, therefore can think that the surface being equivalent to the patent document 1,2 described is maximum concavo-convex.And, the maximum height Pt of the fillet surface of the glass substrate of comparative example is 5.57 μm, at 7 μm (0.007mm) below, and the maximum height Pt of end face is 7.44 μm, at 40 μm (0.04mm) below, the condition of the number range recorded in the patent document 1,2 described therefore is met.But breakage can be there is continually in the glass substrate that the present inventors confirm this comparative example in the manufacturing process of FPD, organic EL and solar cell etc.This represents that the end face strength of the glass substrate of comparative example is insufficient.If consider this situation, then can fully understand that end face strength needs for 160MPa.Further, can fully understand embodiments of the invention 2a ~ 2d by make the outstanding valley degree of depth Rvk of fillet surface be less than 0.95 and end face strength more than 160MPa, there is sufficient end face strength.Therefore, confirmed the generation in the tensile stress suppressing the flexure of glass substrate or unsuitable Temperature Distribution to cause and reduce as much as possible stress concentrate and prevent glass substrate breakage on, the situation that the outstanding valley degree of depth Rvk of the fillet surface of glass substrate is defined as less than 0.95 is significant.

In addition, to glass raw sheet carry out laser cut off and the surface texture of splitting the end face in tabular surface of the glass substrate obtained with show in the same manner as the back side close to minute surface, even if therefore, it is possible to be estimated as described above when this boundary portion of this glass substrate forms fillet surface, as long as the outstanding valley degree of depth Rvk of this fillet surface is less than 0.95, or its above result equal with the good result shown in above-mentioned table 4 just can be obtained.

[embodiment 3]

The present inventors, in order to confirm the effect of the root mean square slope R Δ q of the relevant roughness curve in the fillet surface of illustrative glass substrate in above-mentioned Fig. 1, have carried out the contrast of embodiments of the invention 3a ~ 3d and comparative example as shown in the following.The Nippon Electric Glass Co., Ltd OA-10 (not implementing intensive treatment) be shaped by overflow downdraw is all used to be used as glass raw sheet in above-described embodiment and comparative example.

As the test portion used in the embodiments of the invention 3a ~ 3d shown in following table 5 and comparative example, by being the glass raw sheet of 700 μm is carved into rule and carry out bending segmentation at thickness of slab, and obtaining width dimensions and be 1500mm and length dimension is the glass substrate of 1800mm.The dividing method of concrete glass raw sheet is carved into line by utilizing diamond chip on the surface of glass raw sheet, and to glass raw sheet effect bending moment, to produce tensile stress in this line place, thus carries out bending segmentation.It should be noted that, as other dividing method, also initial damage (initial crack) can be partially formed by skive etc. at glass raw sheet, and irradiate laser to this position and carry out local heat, quick refrigeration is carried out in ejector refrigeration agent afterwards, thus, initial crack is developed, thus cut off glass raw sheet.But when cutting off based on such laser, the end face due to glass substrate is tabular surface, be therefore formed as the end surface shape different from the glass substrate of this embodiment and comparative example.

Make outer peripheral face by barrel surface (in this embodiment and comparative example, outer peripheral face caves in into roughly arc-shaped) the columned emery wheel that forms rotates being arranged under its rotating shaft state parallel with the normal to a surface direction of glass substrate, and be pressed on the end face of the above-mentioned glass substrate obtained like that, make its length direction along the end face of glass substrate relatively move linearly simultaneously, thus carry out the milled processed of this end face.In this case; as the emery wheel ground the end face of glass substrate; prepare abrasive grains or the different multiple emery wheel of adhesive in advance, first thick from abrasive grains and the emery wheel that adhesive is hard, change to the thin and emery wheel of adhesive softness of abrasive grains gradually.

Then, for the glass substrate of milled processed finishing end face, the fillet surface of roughly planar is formed by grinding at end face and the boundary portion on surface (back side).In this case, the emery wheel used in the grinding of fillet surface is compared with the abradant emery wheel of above-mentioned end face, and abrasive grains is thin and adhesive softness is necessary important document.The face be pressed on fillet surface of the abradant emery wheel of fillet surface can be barrel surface or taper seat, and also can be circular end face or the annulus end face of roughly planar, can also be the surface of the abrasive cloth being fixed with abrasive grains on tape.Further, above-mentioned emery wheel (or abrasive cloth) relatively moves linearly relative to the length direction of the fillet surface of glass substrate.

Specifically describe the embodiment 3a shown in following table 5, first, glass substrate after segmentation to be loaded and under adsorbing the state be fixed on platform, by the outer peripheral face of the rough lapping revolving wheel as the first milling tool (abrasive grains of #400 is fixed by metallic bond) in the form shown in Fig. 2 being pressed into the end face portion of glass substrate and making it move linearly simultaneously, thus the Formation cross-section roughly matsurface of circular shape and end face portion.Then, similarly make it move linearly the end face portion after the outer peripheral face of the smooth grinding revolving wheel as the second milling tool (abrasive grains of #1000 is fixed by resinoid bond) in the form shown in Fig. 2 is pressed into the rough lapping of glass substrate simultaneously, thus formed by lappingout wear into cross section roughly circular shape end face.Afterwards, the 3rd milling tool is utilized to carry out particular abrasive process to the end face of glass substrate and the respective boundary portion at surface and the back side.As the 3rd milling tool, be used in the milling tool circular base securing flat diamond lap plate, this flat diamond lap plate obtains by making diamond abrasive particles (abrasive grains of #3000) be scattered in resin material.When performing particular abrasive process, suitably adjust the angle of the 3rd milling tool, it is 18 ° ~ 22 ° with the angle making the tangent line of the surface of glass substrate and the back side and fillet surface be formed respectively (angle [alpha] of Fig. 1: rear side too), on this basis, the contact surface to the 3rd milling tool and glass substrate supplies grinding fluid (grinding water).And, in order to obtain the width dimensions of desired fillet surface, 3rd milling tool (abrasive sheet) is rotated with circumferential speed 2000m/min, and particular abrasive process is carried out to the whole periphery except adjacent corner under the top view of glass substrate simultaneously.Thus, the glass substrate of embodiment 3a is obtained.It should be noted that, the size of above-mentioned abrasive grains is according to JIS R6001:1998.In this case, for embodiment 3b, 3c, 3d and comparative example, the abrasive grains of first, second, third milling tool is different from embodiment 3a respectively.

The root mean square slope R Δ q of the root mean square slope R Δ q of the roughness curve of the fillet surface of the glass substrate shown in following table 5 and the roughness curve of end face utilizes the accurate society SURFCOM590A in Tokyo, in the scope of measured length 5.0mm, carry out roughness mensuration, and calculate the value of each R Δ q according to JIS B0601:2001.Above-mentioned two kinds of root mean square slope R Δ q pass through to implement fillet surface respectively to 10 glass substrates under identical conditions, measure 10 times afterwards, calculate its mean value to evaluate to them.Further, meanwhile, the maximum cross-section height Pt of the end face of glass substrate and the maximum cross-section height Pt of fillet surface is obtained.In addition, the end face strength obtaining glass substrate is used as the standard of the cracky degree that the flexure of glass substrate or thermal stress cause.For the end face strength of glass substrate, measure breakdown strength by the three point bending test method employing Orientec society Tensilon RTA-250, and it can be used as end face strength.The sample of bend test uses the size central portion on the limit of the end face portion of glass substrate being cut out 80 × 15mm and the test film obtained, and with the summit of end face portion the summit of circular arc (cross section roughly) for upper mode imposed load, measure its damaged time load, and measure bursting stress (end face strength) σ by utilizing the formula shown in the formula 1 that describes to carry out calculating.

The root mean square slope R Δ q of the fillet surface obtained as described above shown in following table 5, end face strength, the maximum cross-section height Pt of fillet surface and the maximum cross-section height Pt of end face.

[table 5]

	Embodiment 3a	Embodiment 3b	Embodiment 3c	Embodiment 3d	Comparative example
						RΔq[-]	0.038	0.083	0.076	0.096	0.105
End face strength [MPa]	181	168	166	162	155
						The Pt [μm] of fillet surface	1.07	5.00	3.55	5.30	5.57
The Pt [μm] of end face	2.26	8.06	3.96	6.53	7.44

In above-mentioned table 5, be equivalent to the maximum height Rmax in JIS B0601:1982 due to the maximum cross-section height Pt of end face and the maximum cross-section height Pt of fillet surface, therefore can think that the surface being equivalent to the patent document 1,2 described is maximum concavo-convex.And, the maximum height Pt of the fillet surface of the glass substrate of comparative example is 5.57 μm, at 7 μm (0.007mm) below, and the maximum height Pt of end face is 7.44 μm, at 40 μm (0.04mm) below, the condition of the number range recorded in the patent document 1,2 described therefore is met.But the present inventors confirm and continually breakage can occur at the glass substrate of this comparative example in the manufacturing process of FPD, organic EL and solar cell etc.This represents that the end face strength of the glass substrate of comparative example is insufficient.If consider this situation, then can fully understand that end face strength needs for 160MPa.Further, can fully understand embodiments of the invention 3a ~ 3d by make the root mean square slope R Δ q of fillet surface be less than 0.10 and end face strength more than 160MPa, there is sufficient end face strength.Therefore, confirmed the generation in the tensile stress suppressing the flexure of glass substrate or unsuitable Temperature Distribution to cause and reduce as much as possible stress concentrate and prevent the breakage of glass substrate on, the root mean square slope R Δ q of the fillet surface of glass substrate is defined as less than 0.10 and is significant.

In addition, to glass raw sheet carry out laser cut off and the surface texture of splitting the end face in tabular surface of the glass substrate obtained with show in the same manner as the back side close to minute surface, even if therefore, it is possible to be estimated as described above when this boundary portion of this glass substrate forms fillet surface, as long as the root mean square slope R Δ q of this fillet surface is less than 0.10, or its above result equal with the good result shown in above-mentioned table 5 just can be obtained.

[embodiment 4]

The present inventors, in order to confirm the effect of the relevant maximum valley degree of depth Rv in the fillet surface of illustrative glass substrate in above-mentioned Fig. 1, have carried out the contrast of embodiments of the invention 4a ~ 4d and comparative example as shown in the following.The Nippon Electric Glass Co., Ltd OA-10 (not implementing intensive treatment) be shaped by overflow downdraw is all used to be used as glass raw sheet in above-described embodiment and comparative example.

As the test portion used in the embodiments of the invention 4a ~ 4d shown in following table 6 and comparative example, by being the glass raw sheet of 700 μm is carved into rule and carry out bending segmentation at thickness of slab, and obtaining width dimensions and be 1500mm and length dimension is the glass substrate of 1800mm.The dividing method of concrete glass raw sheet is carved into line by utilizing diamond chip on the surface of glass raw sheet, and to glass raw sheet effect bending moment, makes to produce tensile stress in this line place, thus carry out bending segmentation.It should be noted that, as other dividing method, also initial damage (initial crack) can be partially formed by skive etc. at glass raw sheet, and irradiate laser to this position and carry out local heat, quick refrigeration is carried out in ejector refrigeration agent afterwards, thus, initial crack is developed, thus cut off glass raw sheet.But when cutting off based on such laser, the end face due to glass substrate is tabular surface, is therefore formed as the end surface shape different from the glass substrate that this embodiment and comparative example relate to.

Make outer peripheral face by barrel surface (in this embodiment and comparative example, outer peripheral face caves in into roughly arc-shaped) the columned emery wheel that forms rotates being arranged under its rotating shaft state parallel with the normal to a surface direction of glass substrate, and be pressed into the end face of the above-mentioned glass substrate obtained like that, make its length direction along the end face of glass substrate relatively move linearly simultaneously, thus carry out the milled processed of this end face.In this case; as the emery wheel ground the end face of glass substrate; prepare abrasive grains or the different multiple emery wheel of adhesive in advance, first thick from abrasive grains and the emery wheel that adhesive is hard, change to the thin and emery wheel of adhesive softness of abrasive grains gradually.

Then, for the glass substrate after the milled processed finishing end face, the fillet surface of roughly planar is formed by grinding at end face and the boundary portion on surface (back side).In this case, the emery wheel used in the grinding of fillet surface is compared with the abradant emery wheel of above-mentioned end face, and abrasive grains is thin and adhesive softness is necessary important document.The face be pressed on fillet surface of the abradant emery wheel of fillet surface can be barrel surface or taper seat, and also can be circular end face or the annulus end face of roughly planar, can also be the surface of the abrasive cloth being fixed with abrasive grains on tape.Further, above-mentioned emery wheel (or abrasive cloth) relatively moves linearly relative to the length direction of the fillet surface of glass substrate.

Specifically describe the embodiment 4a shown in following table 6, first, glass substrate after segmentation to be loaded and under adsorbing the state be fixed on platform, by the outer peripheral face of the rough lapping revolving wheel as the first milling tool (abrasive grains of #400 is fixed by metallic bond) in the form shown in Fig. 2 being pressed into the end face portion of glass substrate and making it move linearly simultaneously, thus the Formation cross-section roughly matsurface of circular shape and end face portion.Then, equally make it move linearly the end face portion after the outer peripheral face of the smooth grinding revolving wheel as the second milling tool (abrasive grains of #1000 is fixed by resinoid bond) in the form shown in Fig. 2 is pressed into the rough lapping of glass substrate simultaneously, thus form the end face being worn into cross section roughly circular shape by lappingout.Afterwards, the 3rd milling tool is utilized to carry out particular abrasive process to the end face of glass substrate and the respective boundary portion at surface and the back side.As the 3rd milling tool, be used in the milling tool circular base securing flat diamond lap plate, this flat diamond lap plate obtains by making diamond abrasive particles (abrasive grains of #3000) be scattered in resin material.When performing particular abrasive process, suitably adjust the angle of the 3rd milling tool, it is 18 ° ~ 22 ° with the angle making the tangent line of the surface of glass substrate and the back side and fillet surface be formed respectively (angle [alpha] of Fig. 1: rear side too), on this basis, the contact surface to the 3rd milling tool and glass substrate supplies grinding fluid (grinding water).And, in order to obtain the width dimensions of desired fillet surface, and the 3rd milling tool (abrasive sheet) is rotated with circumferential speed 2000m/min, and particular abrasive process is carried out to the whole periphery except adjacent corner under the top view of glass substrate simultaneously.Thus, the glass substrate of embodiment 4a is obtained.It should be noted that, the size of above-mentioned abrasive grains is according to JIS R6001:1998.In this case, for embodiment 4b, 4c, 4d and comparative example, the abrasive grains of first, second, third milling tool is different from embodiment 4a respectively.

The maximum valley degree of depth Rv of the fillet surface of the glass substrate shown in following table 6 utilizes the accurate society SURFCOM590A in Tokyo, carries out roughness mensuration, and calculate its value according to JIS B0601:2001 in the scope of measured length 5.0mm.This maximum valley degree of depth Rv, by implementing fillet surface to 10 glass substrates under identical conditions, measures 10 times them afterwards, calculates its mean value to evaluate.Further, meanwhile, the maximum cross-section height Pt of the end face of glass substrate and the maximum cross-section height Pt of fillet surface has been obtained.In addition, the standard of the cracky degree that the end face strength obtaining glass substrate causes as flexure or the thermal stress of glass substrate.For the end face strength of glass substrate, measure breakdown strength by the three point bending test method employing Orientec society Tensilon RTA-250, and it can be used as end face strength.The sample of bend test uses the size central portion on the limit of the end face portion of glass substrate being cut out 80 × 15mm and the test film obtained, and with the summit of end face portion the summit of circular arc (cross section roughly) for upper mode imposed load, measure its damaged time load, and measure bursting stress (end face strength) σ by utilizing the formula shown in the formula 1 that describes to carry out calculating.

The maximum cross-section height Pt of maximum valley degree of depth Rv, the end face strength σ of the fillet surface obtained as described above shown in following table 6, the maximum cross-section height Pt of fillet surface and end face.

[table 6]

	Embodiment 4a	Embodiment 4b	Embodiment 4c	Embodiment 4d	Comparative example
						Rv[μm]	1.96	1.62	0.76	0.44	3.15
End face strength [MPa]	161	164	170	180	134
						The Pt [μm] of fillet surface	1.07	5.00	3.55	5.30	5.57
The Pt [μm] of end face	2.26	8.06	3.96	6.53	7.44

In above-mentioned table 6, be equivalent to the maximum height Rmax in JIS B0601:1982 due to the maximum cross-section height Pt of end face and the maximum cross-section height Pt of fillet surface, therefore can think that the surface being equivalent to the patent document 1,2 described is maximum concavo-convex.And, the maximum height Pt of the fillet surface of the glass substrate of comparative example is 5.57 μm, at 7 μm (0.007mm) below, and the maximum height Pt of end face is 7.44 μm, at 40 μm (0.04mm) below, the condition of the number range recorded in the patent document 1,2 described therefore is met.But the present inventors confirm and continually breakage can occur at the glass substrate of this comparative example in the manufacturing process of FPD, organic EL and solar cell etc.This represents that the end face strength of the glass substrate of comparative example is insufficient.If consider this situation, then can fully understand that end face strength needs for 160MPa.Further, can fully understand embodiments of the invention 4a ~ 4d by make the maximum valley degree of depth Rv of fillet surface be less than 2.0 μm and end face strength more than 160MPa, there is sufficient end face strength.Therefore, confirmed the generation in the tensile stress suppressing the flexure of glass substrate or unsuitable Temperature Distribution to cause and reduce as much as possible stress concentrate and prevent the breakage of glass substrate on, the maximum valley degree of depth Rv of the fillet surface of glass substrate is defined as less than 2.0 μm and is significant.

In addition, to glass raw sheet carry out laser cut off and the surface texture of splitting the end face in tabular surface of the glass substrate obtained with show in the same manner as the back side close to minute surface, even if therefore, it is possible to be estimated as described above when this boundary portion of this glass substrate forms fillet surface, as long as the maximum valley degree of depth Rv of this fillet surface is less than 2.0 μm, or its above result equal with the good result shown in above-mentioned table 6 just can be obtained.

Claims (13)

1. a glass substrate, has surface and the back side and is present in the end face each other of outer circumference end on this two sides, it is characterized in that,

Boundary portion in described surface and the back side between the face of at least one party and described end face is formed with fillet surface, 10 mean roughness Rz of this fillet surface ₂be less than 10 mean roughness Rz of described end face ₁, and the average length RSm of the roughness curve key element of this fillet surface ₂be greater than the average length RSm of the roughness curve key element of described end face ₁,

And, 10 mean roughness Rz of described fillet surface ₂and ten of described end face mean roughness Rz ₁meet Rz ₂≤ 1.5 μm and 1.5≤Rz ₁/ Rz ₂the relation of≤10.0.

2. glass substrate according to claim 1, is characterized in that,

The average length RSm of the roughness curve key element of described fillet surface ₂meet RSm ₂the relation of>=100 μm.

3. a glass substrate, has surface and the back side and is present in the end face each other of outer circumference end on this two sides, it is characterized in that,

Boundary portion in the position except adjacent corner under top view and described surface and the back side between the face of at least one party and described end face is formed with fillet surface, outstanding valley degree of depth Rvk in this fillet surface meets the relation of Rvk≤0.95 μm, and thickness of slab T meets the relation of 0.1mm≤T≤0.7mm.

4. a glass substrate, has surface and the back side and is present in the end face each other of outer circumference end on this two sides, it is characterized in that,

Boundary portion in the position except adjacent corner under top view and described surface and the back side between the face of at least one party and described end face is formed with fillet surface, the root mean square slope R Δ q of the roughness curve in this fillet surface meets the relation of R Δ q≤0.10, and thickness of slab T meets the relation of 0.1mm≤T≤0.7mm.

5. a glass substrate, has surface and the back side and is present in the end face each other of outer circumference end on this two sides, it is characterized in that,

Boundary portion in the position except adjacent corner under top view and described surface and the back side between the face of at least one party and described end face is formed with fillet surface, maximum valley degree of depth Rv in this fillet surface meets the relation of Rv≤2.0 μm, and thickness of slab T meets the relation of 0.1mm≤T≤0.7mm.

6. the glass substrate according to any one of Claims 1 to 5, is characterized in that,

Described fillet surface is formed by milled processed.

7. glass substrate according to claim 6, is characterized in that,

Described fillet surface is formed by the milled processed after the milled processed of described end face.

8. glass substrate according to claim 7, is characterized in that,

Described end face is formed in the outer circumference end at described surface and the back side each other as tabular surface.

9. glass substrate according to claim 7, is characterized in that,

Described end face is formed as from the outer circumference end at described surface and the back side to the outstanding outward gradually flexure plane of thickness of slab central portion.

10. glass substrate according to claim 9, is characterized in that,

In orthogonal with the length direction of described end face and orthogonal with described surface and back side cross section, the tangent line towards rear side of the described fillet surface that the boundary portion of the tangent line towards face side of the described fillet surface formed in the boundary portion of face side and described surperficial angulation α and overleaf side is formed and described back side angulation β meet the relation of 10 °≤α≤30 ° and 10 °≤β≤30 ° respectively.

11. glass substrates according to any one of claim 3 ~ 5, is characterized in that,

The width W in the direction orthogonal to the longitudinal direction of thickness of slab T and described fillet surface meets the relation of 0.07≤W/T≤0.30.

The manufacture method of 12. 1 kinds of glass substrates, the glass substrate described in manufacturing claims 6, is characterized in that,

As the milling tool ground described fillet surface, use and there is the rotating polishing tool with the abradant surface of rotating shaft direct cross, and the roughness of the peripheral part of described abradant surface is formed less than the roughness of inner peripheral portion, and relative to the boundary portion between the end face behind the face of at least one party in the surface of glass substrate and the back side and milled processed, make described rotating polishing tool relatively carry out rectilinear movement along this boundary portion length direction and rotate around described rotating shaft simultaneously, thus form described fillet surface by the peripheral part of described abradant surface and these both sides of inner peripheral portion.

The manufacture method of 13. 1 kinds of glass substrates, the glass substrate described in manufacturing claims 7, is characterized in that,

Smooth grinding process is implemented again after rough lapping process is implemented to the end face of glass substrate, then the milling tool had than described smooth grinding process fine size is utilized, particular abrasive process is implemented to the boundary portion between the face of at least one party in the surface of glass substrate and the back side and described end face, thus forms described fillet surface.