Note: Descriptions are shown in the official language in which they were submitted.
o~
2010~-8060
The invention relates to a method of manufacturing a
stamper for the moulding oE an optical storage plate, which
optical storage plate comprises at least one substrate base plate
and one cover plate provided at a distance therefrom, which plates
are both manufactured from a synthetic resin by means of the
stamper according to an injection moulding or compression moulding
process and are welded together at least at their outer edge areas
via integrally formed meltable distance means, the substrate base
plate comprising an information layer and a microstructure at that
area which is copied from the stamper, the stamper being provided
with recesses at the outer edge area to form the meltable distance
means.
Optically readable, plate-shaped information carriers,
as they have been used for a long period o~ time as laser video
discs, digital audio discs or storage plates, enable an extremely
high storage density o~ the information to be stored and hence
become more and more important for the data technique in which,
however, it is required that the digital information to be stored
can be recorded by the operator himself of such a device.
~0 As is shown, for example, in EP-PA 0,094,273 it is known
in such optical storage plates to use a sandwich construction. By
the sandwich construction it is achieved that on the one hand
information can be recorded in the sensitive recording layer
through the substrate base plate using minimal laser power and on
- the other hand the storage layer is sufficiently protected from
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2~10~-8060
damage during the handling. On the basis of the mode of operation
of the information layer of such known plates an empty space is
required between the substrate base plate and the cover plate. In
the sandwich construction known from the above-mentioned
: la
Yj~
PHD 8 5 4 8 1 ;~ 2 ~ ,1 g B 6
EP . PA tha di9tAnc~3 b~ tweerl the ~u~tr~t~ ~a8~ pl~te
aIld ~he cover plQte 1~ ~3n~ured ~y di~tanos m~n~
comprl~ln~ inte~;ra~y ~orm~d wid~ lUg8 ~ In ~ddl~ion9
smaller1 thln 1 u~ are pro~ ,ded ~n top o;E ~he w~d0 lu~
5 which ~3r~re :for weldlng pU~'pO~3eB, In bhi~ Xnown ~ndwich
~on~tructiO~ th~ 3 th~ lu~zs ar~ nece~ary sinca ~or
welding it i5 lmportant t4 he~e~ a~ ~5mall o~ntRct ~urfe.cs~
pos~ible a~d ~ n thl~ mE~mcr to u~e Q minim~m ef
energy since ~upply of teo much ener~y will. load to warpln~
lO of ~he plsta~ .
For th~ manu~ture o:E ~t l~aet the thi~ lug0 of
the pl~teo~ r~e~e~ ar~ requir~3d in tho At~mper. Nvrm~lly~
~leotroplatec~ ~temper~ are u~ed wh~ch u~u~lly oon~ist o~
rl~clçO n thee~ ~tE~mpo;r~ a~ooesae~ must 4c pro~rlded
lS for ~uboequent produotion o~ the lu~a in tho ple~to~ ~t ha~
bson fou~d that the known method~ o~ manu~acturi~ tho
rec~e~ m~y re~ult in cont~min~t~on~ o~ th~ HteLmpo~ he3e
ar~ formed ln that durl~ 1;h~ ma~uf~ctur~ of the roo~s~e~
mQterl~l mu~t b~ r~movod whioh oQn ea~lly l~nd ln the
microstruoture, Moreover, e~oh timo bhe s~mpo~ i~ h~ndled,
the po~iblllty o~ dama~o or oontam~n~tion of ~id mloro-
struotur~ ~xi~t~, For th~ manll~actur~ o~ the roo~s~ ln
the ~tump~r it i~ mor~o~o~ im~ortant b~at ther ~r~ ~o~mod
Rocur~tely ~l~oo the ~ub~qua~Lt lug~ mu~t hAv~ ~ mo~t
26 accuret~lr de~ln~d a~d ~n ~L~ sm~ll a~ po~ible ¢ont~ot
~ur~oo w~th the oppo~itely located plato. Moroo~r ~t
~hc~ul~ be énsur~d that in t:~e manu~c,bure Or the ~tor~
plate no lnte~nal ~t~ aa Are fcrmed w~io~ may ra~ult
in w~rpl~ o~ the plabe~
3~ It iB ~ho ob~ct o~ t~ ~nv~tio~ to p~ovld~
an improved method o~ m~nuf`aoturl~ rooo~d~blo optioal
~torage platR~ in whiah thel r~ces~c~ ¢an be ~orme~ in the
stamper in a rapid a~d r~tl,on~l manner wlb~out ~nma~s or
o ontQmirl~ ti on
Aooo~dln~ to the ~n~ntio~ thi~ ob~oob i~
aohiov~d in thu~ the reoeo~le~ i~ the ~tampor or in R
negR~lve mould u~ed for bhe, mnnu~acture o~ tho ~b~mper ~ro
20lO~ 60
produced by means oE high energy radiation focused at a yiven
depth below the surface oE the stamper or o tAe mould by melting
and evaporating the material oE the stamper or mould in a
substantially circular track at the edge of the stamper or mould~
An essential advantage of this method is that the
recesses are produced without contact so that internal stresses in
the stamper are avoided. The form of the recesses depends on the
three parameters of the high energy radiation which can be
influenced. These three parameters are: intensity of the
radiation, duration of the effect of the radiation, and depth of
focusing of the radiation. By suitably matching said three
parameters a desired shape of the recesses can be produced
empirically while taking into account further influences, for
example, of the material. A negative focusing depth should in
principle not be excluded.
In plates having a central hole, distance means are
generally provided both in the outer edge area and also in the
area of the central hole, whereas in plates without a central hole
then are required only in the outer edge area.
According to a further embodiment of the invention it is
ensured that the dimensions of the recesses and the distance
means, respectively, are such that they ensure the desired
distance between the substrate base plate and the cover plate and,
for weIding, ensure a point or line contact with the respective
other plate.
An essential advantage of this embodiment is that the
above-described parameters in the manufacture of the recess are
~ 010~-8060
adjusted so that the subsequent distance means serve both for the
spacing of the two plates and for the welding. By using high
energy radiation and modulation thereof a discontinuous shape oE
the recesses and distance means, respectively, is possible. The
discontinuous distance means or lugs may be shaped and arranged so
that after welding a hermetically sealed cavity is Eormed between
the two plates.
3a
'.~
~;2~
P~ ) 85l~81 4 ~5 ~ 5 7 1 ~g6
AGcordin~ to ~ ~ur~her modi~i0d embod-lment o~
tho irlver~tion t1n~ hi~h on~r~y radiatio~ nl~r ~d~ u~y
be produoed by ~ er~
Accorclin~ to ~ ~urther modi~ d em~odim~3rlt o' tha
~i inveIltlon it i9 en~5ured thQ1; dur!ng th0 mQnu'~¢tu~e o' the
rece~e~ the ot~mpo~ ~ the mould, raopectivhly7 ~r~3
ar~ang~d ~o as to be ~t~tio~lary ~nd the l~aer b~3am i9
guided over the ~tamp*r oY~ r~oul~, re~pectlvelr~ in a
c~roulE~r traok~ by meeLIl~ o~ a oontrolle~blo optl¢al syE3t*m.
Ih~ ~tamper or the mould~ re~;peoti~olr~ mu~t ba
suppor~e~ in ~ de~ioe~, ~ prl30i~e mo~oment ~nd rot~tion~
re~pec~l~ely~ o~ thi~ device i~ not neoe~ary ~ooo~di~g to
the m~thod, Th~ npli~ie~ the con~tructio~ o~ the dev~ce
and ~coeler~tes the m~nu~o1;u~e o~ th~ rece~0~ ln the
lS ~t~mper or the mould~respeci;l~elr~ si~ce the controllable
optio~l ~y~tem aa~ ~uide the la~er ~eam in ~ su~tantlally
inertlAle~o man~ar to bhe re~pec~ive des~rad pooitlon~
The lnven~lon wLll be de~oribed in ~reat~r
detail with refere~ce to the drawing, ln which
~i~ure 1 i~ a ~ee~al ~lew of a re¢ord~le
optlcal stor~ge plute,
~igure ~ i~ ~ pl~n Ylew of ~hc ~tor~e pl~t~
shown in Fi~ure 1~
Fl~ure 3 i~ a rlr~3t ar~:an~Samcnt ~or th~3
2~ ma~u~acture o~ gr40ve~ ped reoe~es in at~mpers and mould~
r~p3ctl~ely~
F~gure 4 19 ~ pa~-LQl ~eÇtionBl view 0~ ~ ~roove-
ahape~ reca~ in a ~tamper ~nd a mould~ re~peotively~
Fl~ur~ ~, 6 ~nd 7 ohow di~r~mmatic~lly the
30 ~nu~c~ure o~ th~ di~tanoe m~an~ 3ynthetio re~in
pl~te~ .
~ ~ur~ 8 ~OWb th~ di~tanoe mean~ o~ ure r
welded to ~ plate~
~ i~ure 9 ~how~3 a l3eoon~ arra~ement ~or the
35 manu~Qcture o~ ~roo~e-sh~ped reoe~se~ in a ~tamper o~ mouldA
The ~o~ion~l ~iew o~ Fi~ure 1 o~ the reoordable
opbloal otorage pl~to 1 ~ho1~e ~ oub~trate b~0e pl~to 2
, .
~ 3
PHD B5~81 5 ~5.g.1g~6
havlng ~ oentra~ hole 3 w~lch on ito upper ~ide ha~ n
circular recordin~ l~y~r 4 l~rrQngod oen~r~lly ar~und the
centre hole 3. Out~lde th~ :r~oordi~ lar~r ~ th~ ~u~tr~te
base pl~te 2 in the out~r e/~ re~ ~d in th0 inncr oentre
hole ~re~ i~ pro~lded wlth oiroulQr di~t~no0 me~n~ or
lugj 5 ~nd 6 t~e h~i~ht o~ r~ ich ~ ~ e~sentlally l~r~er t~n
the thicknes~ o~ the recordlng layer 4. ~n the ar~
o~ the lug~ 5 ~nd 6 the ~u~trate bQ~e pl~te 2 i~ welded
to ~ cover plate 7 oovering it~ uppe~ ~lde ~nd aloo
0 compri~in~ a oe~tre hole 3 ;i~ a~reame~t wl th tho sub~trato
ba~e pla~ ~. Th~ ~ub~trate ba8e pl~te Z and t~o co~er plate
7 oon~i~t o~ a synthetlc re3~ or example~ polyoQrbonQtog
at lea~t the ~ynt~etlc re~ o~ the ~ub~tr~te ba~e plata
2 bein6 tran~parent~
A~ urt~er illu~trate~ in t~e plan ~iew o~
the record~ble optlcAl ~borage plQte 1 ~hown in Figure 2 7
the annular di~t~noe mean~ 5 and 5 mu~t ~y no mea~
rep~sent a closed ring but may a1YO be oompo~d o~ a
~aller or lar~er numb~r o* lu~ ~ectlon~ kept a~ ~ mutuQl
di~t~nce. Optlonally ~t ~hould be ~n~ured th~t a~t~
welding a hermetioall~ ~ealed oavity i~ ~ormed between ~he
pl~te~.
In p~i~olple the poB311:~ility al~lo exi~t~ to
ri~idly arr~n~e the lu~ 5 and 6 to th0 cover pl~te 7
25 in~tead o~ to bh~ substr~t0 base plate 2c ~t iB al~o
po~sible to oonetruct bot~ the eub~tr~te ba~e plabe 2 ~d
the co~er pl~te 7 wlth a~Mular lu~ 5 ~nd 6 whioh are
contrio with re~pect to eAc:h o~her. In ~ plate whloh oan
be uoed on two ~ide~ the two plab~s welded together m~y b~
construotod to b~ idenbio~l ~nd oon89qu~ntl~ oan ~e manu-
~acture~ wit~ tha u~e o~ only o~e stRmper. The lu~s may
optionQlly be ~rr~nged ~o ~:hat the lug~ of the two plats~
~i~ one within bhe obherO
The wel~ g operati~n wh~ch by w~y o~ example i~
36 per~o~med ulbra~onicRlly i8 the ~Qm~ ln ~11 the~e embedl-
ment~, In ordor ~o oon~ume the ~m~llest ~mount o~ ener~y
so a~ to prevent bha pos~ibili~y e~ w~rp:ln~ o~ the ~torage
PHD 85481 ~ 25, ~ 86
plate ~ tha lug~ ~ and 6 ~d~nt~geeu31y on~Ly have ~
width ln the erd~3r o~ m~eni. tude e~ 1 mm. Tho ~el~ht m~y ~e
r~strlcted to ~ :~r~ct.l~ of~ 1 mm~ It ~heulcl howe~er be
en~u~ed that tha hel~ht o~ the ciroul~r cavity ~ at the
~rea o~ the reoor~in~ l~ye~ ~ is uu~i¢iently lar~er than
the thioXne~ o~ the reoording l~yer 4 in order th~t ln
~perntin~ condition~ it i~ ~ub~t~ntl~lly pre~cn~ed
that the plateu ~ n thc reco~ding l~yer ~rea oontacb e~oh
o~her 9
A~ Ql~eady nebod ~ miorootructur0 i~ to b~
produced ~n the ~re~ o~ the r~¢~rding laye;r 1~ which may
h~ve th~ ~orm o~ ~ writing beam ~uide tr~ok. For the
m~nu~aotu~e o~ ~id writ ~g beam guide track it i~
advantageou~ to m~n~acture the 8ubs~r~te ba~o plato 2 by
mo~n~ o~ an in~ectlon mouldin~ prooeao w~ile u~ing ~tamyer~
derlved from a ma~tor by el~otroplating. A8 i~ sh~wn
dl~rammatio~lly in Figure 3, the lug~ 5 and 6 ~t th~
pl~te ar0 obt~ined oimultQneou~ly by me~n~ o~ such
sta~per,
2~ Fisure 3 ~how~ a t~rnt~ble 9 h~ving ~ mo~lded
portion 11 ~pporting a st~mper 10 in who~ pin 12 the
otQmpe~ 10 1~ oentred with i t~ centre hole. The turntable
g ~ rotatfld by mean~ o~ otor 13 and durin~ ~he
rotatlon the groo~e-~h~p~d :reoe~e~ oorreopondin~ to the
26 lu~ 5 ~n~ ~ shown in Figurls 1 are produood in bho ~tam~er
10 by meltin~ and ev~porQti~ o~ the stQmper m~te~ial by
mean~ o~ a l~ser 14 who~ ht be~m 1 ~ ocu~ed on t~e
~ur~Qce o~ the ~tamper 10. T~o bop o~ the ~tamper m~y bo
oovered b~ m~n~ o~ a templttte in a m~nner nob ~how~ in bhe
30 Fi~ure to protoob the mlcro)~b~uotur~I
In the e~l~r~ed s~ot~on AS ~w~ in Figu~ 4
the ~oore-~hapod rees~s 16 pr~duc~d by the laser 14 ~an be
3ee~, ~uring ~o~lding ~he ~ubs~r~te ba~e plate 29 the
do~i~ed lug~ ~ and 6~ ~esp~o~ively, are ~`orm~d in
35 accord~oe with b~o ~eetion~ ew o~ ure 5 a~ a ~ult
o~ the ~roo~e~haped reoe30 16 ~nd ar~ ~ubseque~tly
rel~a~ed from the mould ~ hown ln the ~e~tional vi~w
o~ ure 6~
2~3~9
PHD 85481 7 ~505~19~6
F~ura 7 :L~ ~ ~eot;:lon~l view o~ the lu~ 8}~0wn
in Fi~ur~ 6 taken on the line VII~VII ~ I~ mQy be ~oen bh~t
the lug~ v~ewod in ~he direotien o~ travel o;~ the pl~te,
i~ ~ubsbantially aemi-oylinclrio~l, A~ a :r7e~ult o~ el,
5 line contact between the lug Qnd t~e oover plate :i3
eno ured,
~ i~ure 8 a~;~in ~how~ 'che l ug o~ Fl~ure ~ but
bh~ ~ time ln a, condlbion 12~ w:hioh lb i~ weldç~d to a oove~
plat ~ ~
1~ P'l~u~a ~ ~ow~ a ~eoo~d arrangen~ent ~or t~e
mQ~Uf~aCtUre of~ groove--~h~ect ~ece~e~ ~n ote.mpera ~nd
mould~9 rospeot~vely. For the m~r~uf~cture o~ th~ r~3e~e~
16 ln the ~tamper 10 t~e l~,tter l~3 pro~ided ~o eL8 to b~
st~t~onELryr A l~e~ b~m 18 o~ er 17 l~ ~}~3wn
15 on the 9tampe~ 10 ~ ~ a mov~le l~n~ ZU o~ ~ oo~trollable
optical ~y~tem 19 where reoes~e~ 16 0.re prod~ced ~y meltln~
~;ld evaporatln~ a~ a re~ulb of the uo tion o~ the la~er 4eam,
In ~ convention~l manner ~ ~tQrnper 10 ~l~ow~ ~n
FiOEura~ ~ Rnd ~, re~peot~e~.y~ i~ obt~ined ~om a ma~ter
20 plate. ln th~t fir~t a father mould l~ m~;~u~0,0ture~1 ~rom the
m~ster pl.~te. From ~ thar mould whioh i8 a negatlve o~
the original pre~ent in t~e ma~ter a mother mould repre~en-
ting a positive i~ o4bainod~ From the mother mould fin~lly
se~reral e.~aln ne~e.tive st~mpera may be m0.~u~aotUr4d. I~l~
2~ pro~rldes the poY~ ty o;f produoing the g~oove-~hape~
reoe~ee~ to be made by th~ l~Yer beam al~eady ln tl~o
fe.th~3r mould beoau~e thcn the de~ired ~oove ~h~ped
r~oe~se~ ~re~ 80 0.utomatioally p~e89nt i~ all the ~tamper~
deri~d ~rom bhe ~athbr mou~.d y,~;~, the mot~er mould~
~ f`or reasono o~ preoi~lon ~nd the amoothne~s
o~ ~h~ ~u~ace~ a oompre~ioTl mouldln~ or in~ootio~
mouldi~g prooe~ io u~ed i~ t~e manU~Qoture o~ the oove~
plate 7, Ytamper~ whioh are u~ed for thi~ purpo~e may 40
u~ed ha~l~ lug~ 5 ~,~d 6 to be pro~rldod ln a oo~re~po~din~
35 mE~nnar with groo~ 3hapod receE~8e~, In aocordanee with a
~tampar ~ the h~l~ o~ ths mo~lld or ln~eoblon mould ~ormia~
~he lowor olde o~ bhe oov~ ~late 7 m~y be provi~d with
PHD 85l~81 8 ~ 5~1g86
the de~irod ~roove~~h~ped rece89~8 b~r me~ns o~ a h~ ~ h
energy la~er be~m.
The re~e~o~ are not neoe~s~rllr ~ormod ln ~ne
~ixL~lo opere.tioll by the 1~ 3~ bea.m, Xn~ea~ e l~er
b be~m m~ make ~everal pa.~el~ o~rer ~ho ~eLmper,
progr~s~i~el~ fos~min~ the rl30e~e~ 0 By ~r~rrin~ on8 or
more o~ the eQrl I er mention,3d vari~ble~, dl~erent pas~e~
m~y be u~3ed to ~orm pro~ile,~ rece~33e~ 1U8, lu~8 1~8 kno~m
~em ~he earlier montlon~d EP-PA 070~49273 m~y ~o :forme~
consistin~ of a wider p~rt and ~maller p~rts.
~ lle reoe~e~ ~orme~ by the l~Lser be~m may
be conti~uou~ ence o;E~ a ce~tr~ hole, a in~e
continuou~3 rec:e~ on the out0r edge could be ~u:~;Eicient.
The expre~ion reoe~ea i~ m~3ant to inolude on~ gle
15 rece~8 .
~0
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