decksurgeon
177
about CERACHROM - The Ceramic Bezel
the inventor of the technique is Eric Grippo [R&D Ceramic Manager at ROLEX SA] and the Patent assignee is Rolex SA itself.
The youtube marketing video can be viewed here:
The patent in summary is for the following:
According to this process for manufacturing a ceramic element intended to be fitted onto a watch case, the visible surface of which has features, a soluble layer is selectively deposited on said visible surface, the thickness of said soluble layer being at least equal to the height of said features, a first tie layer of the Ti, Ta, Cr or Th type is vacuum-deposited by magnetron sputtering with a thickness of at least 100 nm by physical vapor deposition (PVD) on said surface thus selectively coated, followed, without venting atmosphere, by PVD deposition of said second layer made of Au, Pt, Ag, Ni, Pd, TiN, CrN, ZrN or alloys thereof with a thickness of at least 100 nm, and then said soluble layer is dissolved.
Problems with the current processes and ceramic deposition patents:
Problems with the current processes and ceramic deposition patents:
A process has already been proposed, in DE 2 533 524 and in EP 0 230 853, for depositing a metalized layer on a ceramic substrate that consists in depositing a CuO or Ti first layer with a thickness of at least 100 nm followed by a copper, silver, gold or nickel second layer. The adhesion between the two layers is obtained by passage through a furnace. In the case of copper and CuO, the temperature of the furnace must be between the CuO eutectic and the melting point of copper, i.e. between 1068° and 1078° C., which temperature is completely incompatible with the use of a photosensitive resin or photoresist, so that such processes do not allow the mask to be retained for the purpose of a subsequent electroforming operation.
[1]Given that these processes do not allow the use of photosensitive materials, using techniques widely employed in the fabrication of electronic components in particular, it therefore cannot be used to actively grow features, such as digits, by electroforming since such masks would not withstand the temperature of the furnace treatment for bonding the layers.
[2]Also proposed, in CH 636 238, is a process for forming symbols on watch parts made of an electrically non-conducting material, on which a metal layer, such as a Cr layer, is vacuum-deposited, this metal layer is covered with a photoresist in which apertures corresponding to the shape of the symbols have been formed, and a layer of a second metal, such as Au, Ni Rh, Va, is deposited electrochemically on the first metal layer through the apertures made in the layer of photoresist. Next, the resist is dissolved and then the first metal layer is chemically etched until the substrate reappears.
[3]The main drawback of this approach stems from the fact that the chemical etching used to remove the first layer causes corrosion of the second layer. Furthermore, the deposition of the first layer by vacuum evaporation does not make it possible to achieve sufficient adhesion to form features on a watch case part, such as a watch bezel.
[1]Given that these processes do not allow the use of photosensitive materials, using techniques widely employed in the fabrication of electronic components in particular, it therefore cannot be used to actively grow features, such as digits, by electroforming since such masks would not withstand the temperature of the furnace treatment for bonding the layers.
[2]Also proposed, in CH 636 238, is a process for forming symbols on watch parts made of an electrically non-conducting material, on which a metal layer, such as a Cr layer, is vacuum-deposited, this metal layer is covered with a photoresist in which apertures corresponding to the shape of the symbols have been formed, and a layer of a second metal, such as Au, Ni Rh, Va, is deposited electrochemically on the first metal layer through the apertures made in the layer of photoresist. Next, the resist is dissolved and then the first metal layer is chemically etched until the substrate reappears.
[3]The main drawback of this approach stems from the fact that the chemical etching used to remove the first layer causes corrosion of the second layer. Furthermore, the deposition of the first layer by vacuum evaporation does not make it possible to achieve sufficient adhesion to form features on a watch case part, such as a watch bezel.
This is because the abovementioned document proposes the formation of symbols on a watch case is protected by a watch glass, which is not the case with the bezel, which constitutes the most exposed part of the watch case. Symbols fitted onto a watch case bezel are therefore not protected, so that the process according to CH 636 238 does not allow symbols to be fixed onto a bezel with sufficient adhesion.
How Rolex remedy the problems/drawbacks of the above patents:
[A] The invention is firstly a process for manufacturing a ceramic element intended to be fitted onto a watch case, the visible surface of which has features as above. Next, the subject of the invention is a ceramic element.
[B]The essential advantage of this invention is that it allows selective formation of features, without any shape limitation, giving rise to a novel product, offering novel esthetic possibilities and making it possible to renew and improve the appearance of watches, in particular the appearance of watches having fixed and rotary bezels.
[C]The process according to the present invention makes it possible to achieve excellent adhesion of the raised features to the surface of the ceramic element, this being of great importance, above all when the features are raised features since a wrist watch case in particular is very exposed to all kinds of external attack, especially to being knocked.
[D]Advantageously, the visible surface on which the features are formed is a frustoconical or frustopyramidal surface that consequently requires a particular masking technique.
[E] A sintered substrate 1 made of ZrO2, Al2O3 or a mixture of the two, on the surface of which a layer of a photosensitive polymer or photoresist is deposited for the purpose of forming a conformal layer for the selective deposition of the features. The thickness of this layer 2 depends on the method of implementation used to form the features, according to whether these will be substantially surface features or raised features.
[F] Then a mask is applied to this layer 2 of photoresist, of the RISTON® MM150 type, so as to selectively irradiate this layer 2 with UV light in order to cure those parts of the layer 2 of photoresist that, have to remain on the substrate 1.
[B]The essential advantage of this invention is that it allows selective formation of features, without any shape limitation, giving rise to a novel product, offering novel esthetic possibilities and making it possible to renew and improve the appearance of watches, in particular the appearance of watches having fixed and rotary bezels.
[C]The process according to the present invention makes it possible to achieve excellent adhesion of the raised features to the surface of the ceramic element, this being of great importance, above all when the features are raised features since a wrist watch case in particular is very exposed to all kinds of external attack, especially to being knocked.
[D]Advantageously, the visible surface on which the features are formed is a frustoconical or frustopyramidal surface that consequently requires a particular masking technique.
[E] A sintered substrate 1 made of ZrO2, Al2O3 or a mixture of the two, on the surface of which a layer of a photosensitive polymer or photoresist is deposited for the purpose of forming a conformal layer for the selective deposition of the features. The thickness of this layer 2 depends on the method of implementation used to form the features, according to whether these will be substantially surface features or raised features.
[F] Then a mask is applied to this layer 2 of photoresist, of the RISTON® MM150 type, so as to selectively irradiate this layer 2 with UV light in order to cure those parts of the layer 2 of photoresist that, have to remain on the substrate 1.
This layer 2 is then developed in a 0.85% Na2CO3 bath according to the indications provided by the photoresist supplier, in order to dissolve the unirradiated parts of the layer 2 in order to bare surface portions 1a of the substrate 1. These portions have the shapes chosen for forming the features. This operating method corresponds to a standard photolithographic process.
[G] It should be pointed out that in the illustrated examples, the substrate 1 shown in cross section by corresponds in fact to a portion of the ceramic element according to the present invention. This portion may especially correspond to a radial section of this ceramic element consisting of a circular ring of rectangular cross section. Preferably, this ring has a frustoconical shape so that the visible surface is inclined relative to the axis of revolution of this ring.
[H] For this reason, the mask used to form the features in the polymer layer 2 is not a conventional mask, but a polymer mask that has been thermoformed in order to give it a shape complementary to that of the ceramic substrate. This polymer mask, which has a certain degree of flexibility, is applied to the layer 2 with sufficient pressure for it to conform to this layer 2 over its entire area.
[I] Once this operation of forming the features has been carried out, the substrate 1 thus selectively coated by the layer 2 is placed in a vacuum coating chamber in which a first tie, layer 3 is deposited by the technique of PVD (physical vapor deposition) with magnetron sputtering, which makes it possible to ensure greater adhesion of the tie layer 3 than would be obtained using the PVD technique without a magnetron.
[G] It should be pointed out that in the illustrated examples, the substrate 1 shown in cross section by corresponds in fact to a portion of the ceramic element according to the present invention. This portion may especially correspond to a radial section of this ceramic element consisting of a circular ring of rectangular cross section. Preferably, this ring has a frustoconical shape so that the visible surface is inclined relative to the axis of revolution of this ring.
[H] For this reason, the mask used to form the features in the polymer layer 2 is not a conventional mask, but a polymer mask that has been thermoformed in order to give it a shape complementary to that of the ceramic substrate. This polymer mask, which has a certain degree of flexibility, is applied to the layer 2 with sufficient pressure for it to conform to this layer 2 over its entire area.
[I] Once this operation of forming the features has been carried out, the substrate 1 thus selectively coated by the layer 2 is placed in a vacuum coating chamber in which a first tie, layer 3 is deposited by the technique of PVD (physical vapor deposition) with magnetron sputtering, which makes it possible to ensure greater adhesion of the tie layer 3 than would be obtained using the PVD technique without a magnetron.
Furthermore, thanks to the magnetron sputtering, the temperature of the substrate 1 may be kept low, well below 100° C., during the deposition operation. It is thanks to the use of this deposition technique that it is possible to deposit the tie layer on the substrate 1 selectively coated with the polymer layer 2 and to ensure excellent adhesion of this tie layer 3 for the substrate 1, without having to carry out a heat treatment at a temperature liable to destroy the polymer.
[J]While still maintaining a vacuum in the deposition chamber, a second layer 4 is formed by magnetron sputtering using a target of the Au, Ag, Pt, Pd, TiN, CrN or Ni type. The thickness of this second layer is greater then 500 nm and preferably between 500 nm and 15 ?m.
[K]The equipment used to carry out the vacuum deposition by magnetron sputtering comprises:
[J]While still maintaining a vacuum in the deposition chamber, a second layer 4 is formed by magnetron sputtering using a target of the Au, Ag, Pt, Pd, TiN, CrN or Ni type. The thickness of this second layer is greater then 500 nm and preferably between 500 nm and 15 ?m.
[K]The equipment used to carry out the vacuum deposition by magnetron sputtering comprises:
a cylindrical stainless steel chamber with a turbomolecular pumping system and a rotary vane pump; a substrate holder of the carousel type having a vertical rotation axis and vertically positioned substrates, and the possibility of carrying out biased RF sputtering on the substrate holder;
[L]two vertical rectangular magnetron cathodes mounted so as to face the carousel at an angle of 120° relative to the axis of the carousel;
[M]two cathodes, namely a Ti99.99 target and an Au99.99 target;
[N] a supply for the cathodes, by means of an RF (13.56 MHz) 600 W generator with a manual impedance-matching box; a gas feed (purity: 5.7-6.0) via a mass flowmeter; and pressure monitoring by a Penning gauge, for monitoring the limiting vacuum and by a capacitive gauge (absolute measurement) for monitoring the working pressure.
[O]The parts are cleaned in an ultrasonic bath with a 20% isopropyl alcohol/80% deionized water mixture for five minutes and then dried with a nitrogen gun.
[P]The substrates are stripped by placing the chamber under vacuum, pumping down to a pressure of less than 5×10-2 Pa. An ion cleaning operation is carried out on the surface of the substrates by reverse sputtering: RF power on the substrate holder: >100 W; argon flow rate: >15 cm3/min; oxygen flow rate: >5 cm3/min; total pressure: <5 Pa; and duration: 20-30 minutes.
[Q] The titanium sublayer deposition conditions are the following:
[O]The parts are cleaned in an ultrasonic bath with a 20% isopropyl alcohol/80% deionized water mixture for five minutes and then dried with a nitrogen gun.
[P]The substrates are stripped by placing the chamber under vacuum, pumping down to a pressure of less than 5×10-2 Pa. An ion cleaning operation is carried out on the surface of the substrates by reverse sputtering: RF power on the substrate holder: >100 W; argon flow rate: >15 cm3/min; oxygen flow rate: >5 cm3/min; total pressure: <5 Pa; and duration: 20-30 minutes.
[Q] The titanium sublayer deposition conditions are the following:
RF power on the cathode: >150 W; argon flow rate: >5 cm3/min; argon pressure: <5 Pa; and thickness of the layer: >100 nm, preferably >100 nm and <1500 nm.
[R]While still maintaining vacuum in the chamber, the substrates are moved, by rotation of the carousel, toward a small cathode equipped with the Au99.99 target. The deposition conditions are the following: RF power on the cathode: >50 W; argon flow rate: >10 cm3/min; argon pressure: <5 Pa; and thickness of the layer: at least >100 nm, preferably >500 nm and <15 ?m.
[S]The substrates thus obtained are entirely coated with the titanium tie layer, which is itself coated with the gold layer,
[T] After this second layer 4 has been deposited, the substrate is removed from the vacuum deposition chamber and the choice of two solutions made.
[U]According to a first method of implementation, the substrate 1 selectively coated with the polymer layer 2 and with the layers 3 and 4 is subjected to an electroforming operation using the same noble metal as that used for the second layer 4, in this example, gold.
[R]While still maintaining vacuum in the chamber, the substrates are moved, by rotation of the carousel, toward a small cathode equipped with the Au99.99 target. The deposition conditions are the following: RF power on the cathode: >50 W; argon flow rate: >10 cm3/min; argon pressure: <5 Pa; and thickness of the layer: at least >100 nm, preferably >500 nm and <15 ?m.
[S]The substrates thus obtained are entirely coated with the titanium tie layer, which is itself coated with the gold layer,
[T] After this second layer 4 has been deposited, the substrate is removed from the vacuum deposition chamber and the choice of two solutions made.
[U]According to a first method of implementation, the substrate 1 selectively coated with the polymer layer 2 and with the layers 3 and 4 is subjected to an electroforming operation using the same noble metal as that used for the second layer 4, in this example, gold.
The entire advantage of the invention lies in the possibility of keeping the polymer mask intact for its use in the subsequent selective electroforming operation. An additional layer 5 is therefore deposited with the desired thickness by electroforming. The gold bath used in this case has a high Au content and allows electroforming with a layer of at least 0.10 mm, preferably a few tenths of a millimeter, in thickness. The operating conditions for the electroforming process are those indicated by the suppliers of the electroforming bath. The duration of the process depends on the thickness of the layer deposited. The rate of growth of the deposit is about 10 ?m/h.
[V]According to a second method of implementation illustrated by, after the substrate selectively coated with the layers 3 and 4 has been removed, the polymer layer 2 is dissolved, as was carried out previously in order to pass from the step shown, in such a way that only the layer 3 and 4 that were on the parts 1a where the ceramic substrate was not covered by the dissolved polymer layer 2 remain on the substrate 1. In this case, owing to the thickness of the layers 3, 4, the features are practically flush with the surface of the substrate 1.
(** this is the exact reason why the gold ceramic bezels on the GMT are smooth and flush and dont have the indentations like the 116010 submariner's bezel)
[W]As a variant, the ceramic element according to the present invention, instead of being in the form of a frustoconical ring could be in the form of a polygonal frame with a face inclined to the central axis of this element, thus constituting a truncated pyramid.
[V]According to a second method of implementation illustrated by, after the substrate selectively coated with the layers 3 and 4 has been removed, the polymer layer 2 is dissolved, as was carried out previously in order to pass from the step shown, in such a way that only the layer 3 and 4 that were on the parts 1a where the ceramic substrate was not covered by the dissolved polymer layer 2 remain on the substrate 1. In this case, owing to the thickness of the layers 3, 4, the features are practically flush with the surface of the substrate 1.
(** this is the exact reason why the gold ceramic bezels on the GMT are smooth and flush and dont have the indentations like the 116010 submariner's bezel)
[W]As a variant, the ceramic element according to the present invention, instead of being in the form of a frustoconical ring could be in the form of a polygonal frame with a face inclined to the central axis of this element, thus constituting a truncated pyramid.
Here is the CERECHROM Bezel close up. The numerical pits are "filled" using a special deposition process as explained above
More posts:
Essential Adventure Gear You Can Trust - The Rolex Submariner
There are numerous threads/posts/websites dedicated to the Rolex Submariner. May I present humbly the 116610LV equipped with the famed ceramic bezel. Suffice to say since 1954 The Rolex Oyster Perpetual Submariner is a superb family of dive watches well k...
Nice post. I never saw all green Rolex Sub in the real.
I have to say that I didn't pay any consideration to it, be honest. But your pictures are making me re considering my position. I don't know if it will be enough to make me want to get one, but at least I will see one in the flesh. Which is a good start! ...
I know a few guys who...
....bought this and put it straight into the safe for their kids when they are older. I have also never seen one in real life...just scans. I think one of the things that the Sub does well, generally, is make itself amenable to very different insert colou...
Next time you come to Paris, we'll go to a Rolex Boutique together.
And we'll try to see one in the flesh... Which one will we wear for the occasion? A Big Crown, a 5508, A DRSD? ;) Best, Nicolas
Or you both dear friends can come down here to visit me...
...and I ll show you mine and you can try on your wrists! I ll be delighted! Cordial regards from the Pampas! Abel.
the dial is actually a bit of a "chameleon" to be honest...
depending on the lighting conditions and angle of the watch. the green dial can actually look like a black dial. a bit of a "chameleon" to be honest. A few others thought it was a black dial from a distance till they came up close and had a look to realis...
The "LUME" (illumination) shot in total darkness....
this is what the watch looks like in total darkness. The lume has been charged by shining a diving torch over it for a few moments (Underwater Kinetics eLED light cannon, 825lumens, 10 seconds) Rolex Submariner illumination shot (blue!) You can see that t...
thanks amanico, the lume on the Sub is Rolex's own Chromalight
Chromalight is exclusive to Rolex and its relationship to SuperLuminova is unknown to me. However, i have noticed the “Swiss Made” designation on the dial is still the same so it is assumed that it is a form of LumiNova? No? but it is very bright indeed. ...
about CERACHROM - The Ceramic Bezel
the inventor of the technique is Eric Grippo [ R&D Ceramic Manager at ROLEX SA ] and the Patent assignee is Rolex SA itself. The youtube marketing video can be viewed here: The patent in summary is for the following: According to this process for man...
Informative Post!
Wow, thank you for the informative photo essay. I have seen the Green Sub in the flesh and it is quick stunning. Even better, it is great to hear that you are using this watch for its intended purpose and actually getting it wet! Keep it up! V/R Mike
Rolex and diving 100% fit
Thanks for the great post and I love the fact you Rolex gets to enjoy the life it was destined for. Just back from the Bahamas Best Bill ...
Next to your kit
more like amateurPro. I am just an old school diver getting re acquainted with the new school of diving. We did not know much back in the day but now with the new technologies less risk more fun. You have some great kit there I don't think it gets any bet...
This thread has given me renewed...
pride in wearing one of the best dive/tool watches on the universe! Thanks for sharing the experience. :) Fernando
Great post and photos! Thanks for sharing! As an owner myself of green Sub...
...I enjoyed this post so much! Cordial regards Abel.
Soo...
Mine says Hello!! to your beautiful Ceramic Green Sub!! Completely agree with you, that the green dial "plays" with light (daylight, idoors, etc.) showing different shades, and getting close to black sometimes. That makes for a very interesting dial, and ...
