Additively printed metal layer on a diamond substrate

Abstract

A metallized substrate adapted to receive a laser diode thereon that includes a diamond substrate, one or more, optional bonded metal layers deposited on the diamond substrate, wherein the one or more bonded metal layers have a bonded metal layer thickness, and one or more metal layers formed, by laser consolidation, on the one or more bonded metal layers, wherein the one or more metal layers have a metal layer thickness.

Description

ADDITIVELY PRINTED METAL LAYERON A DIAMOND SUBSTRATECross-Reference to Related Application^)

[0001] This International PCT Patent Application relies on and claims priority to United States Provisional Patent Application Serial No. 63 / 658,265, filed on June 10, 2024, the entire contents of which are incorporated herein by reference.Field of the Invention

[0002] The present invention encompasses, inter alia, an additively printed metal layer (e.g., a copper cladding) on a diamond film or chemical vapor deposited (“CVD”) diamond substrate resulting in the creation of a compliant, high thermal conductivity sub-mount for a laser diode, also referred to herein as a metallized substrate.Description of the Related Art

[0003] It is known that low power laser diodes may be mounted on diamond substrates, because diamond material provides high thermal conductivity.

[0004] High thermal conductivity is preferred to dissipate the heat generated by the laser diode and / or diodes positioned thereon.

[0005] Conventionally, mounting laser diodes on a diamond substrate presents a number of difficulties, e.g., the coefficient of thermal expansion (“CTE”) of the diamond substrate is typically not matched to most semiconductor laser materials. Typically, a judiciously thick layer of metal is deposited on top of the diamond substrate to compensate for the CTE mismatch. The metal provides an electrical path to the laser diode for an electrical connection. However, metal layers of appropriate thickness are not easily formed on or attached to a diamond substrate.

[0006] The formation of a suitable metal layer on a diamond substrate remains a challenge to those seeking to take advantage of the thermally conductive properties of diamond substrates.Summary of the Invention

[0007] The present invention seeks to address one or more deficiencies in the prior art.

[0008] Specifically, the present invention provides one or more methods for depositing metal layers on diamond substrates in a manner where the metal layers are suitably adhered to the diamond substrate to permit the construction of a laser diode on the diamond substrate.

[0009] The present invention also provides a construction for a substrate for a laser diode.

[0010] In one embodiment, the present invention provides for a metallized substrate adapted to receive a laser diode thereon. The metalized substrate includes a diamond substrate, one or more bonded metal layers deposited on the diamond substrate, wherein the one or more bonded metal layers have a bonded metal layer thickness, and one or more metal layers formed, by laser consolidation, on the one or more bonded metal layers, wherein the one or more metal layers have a metal layer thickness.

[0011] In this embodiment, it is contemplated that the one or more bonded metal layers include titanium. Moreover, the bonded metal layer may have a thickness that is 0.1 - 400 nm.

[0012] Still further, it is contemplated that the one or more metal layers include copper. Here, the metal layer thickness is contemplated to be 1 - 400 pm. More specifically, the metal layer thickness may be 25 - 85 pm.

[0013] Another contemplated embodiment provides a metallized substrate adapted to receive a laser diode thereon, where the metallized substrate includes a diamond substrate and one or more metal layers formed, by laser consolidation, on the diamond substrate, wherein the one or more metal layers have a metal layer thickness.

[0014] In this embodiment, the one or more metal layers include copper.

[0015] The metal layer thickness is contemplated to be 1 - 400 pm. More specifically, the metal layer thickness may be 25 - 85 pm.

[0016] The present invention also provides a method of manufacturing a metallized substrate adapted to receive a laser diode thereon. As discussed above, the metallized substrate is contemplated to include a diamond substrate, one or more bonded metal layers deposited on the diamond substrate, wherein the one or more bonded metal layers have a bonded metal layer thickness, and one or more metal layers formed, by laser consolidation, on the one or more bonded metal layers, wherein the one or more metal layers have a metal layer thickness. Here, the method includes depositing the one or more bonded metal layers onto the diamond substrate, depositing the one or more metal powder layers onto the one or more bonded metal layers, applying a laser beam to the one or more metal powder layers, and, via application of the laser beam to the one ormore metal powder layers, consolidating the one or more metal powder layers to form the one or more metal layers.

[0017] For this method, the one or more bonded metal layers are contemplated to be titanium.

[0018] For this method, the bonded metal layer thickness is 0.1 - 400 nm.

[0019] Here, the one or more metal layers are contemplated to include copper.

[0020] The metal layer thickness is contemplated to be 1 - 400 pm, with one specific metal layer thickness contemplated as 25 - 85 pm.

[0021] In another embodiment, the present invention provides a method of manufacturing a metallized substrate adapted to receive a laser diode thereon. Here, the metallized substrate includes a diamond substrate, and one or more metal layers formed, by laser consolidation, on the diamond substrate, wherein the one or more metal layers have a metal layer thickness. The method includes depositing the one or more metal powder layers onto the diamond substrate, applying a laser beam to the one or more metal powder layers, and, via application of the laser beam to the one or more metal powder layers, consolidating the one or more metal powder layers to form the one or more metal layers.

[0022] As before, the one or more metal layers is contemplated to include copper. Moreover, the metal layer thickness may be 1 - 400 pm, with 25 - 85 pm being a more specifically contemplated range.

[0023] Still further advantages and features of the present invention will be made apparent by the discussion presented herein.Brief Description of the Drawings

[0024] The present invention will now be described in connection with the drawings appended hereto, in which:

[0025] Fig. 1 is a perspective, graphical illustration of a diamond substrate of the type for formation of a laser diode thereon;

[0026] Fig. 2 is a perspective, graphical illustration of a functionalized diamond substrate, which comprises the diamond substrate illustrated in Fig. 1 together with a thin reactive metal layer deposited thereon so that the adhesion of the thin metal to diamond is robust;

[0027] Fig. 3 is a graphical, side view of the functionalized diamond substrate illustrated in Fig. 2, highlighting the thin seed metal layer deposited thereon;

[0028] Fig. 4 is a graphical, side view of functionalized diamond substrate illustrated in Fig.3, having a layer of metal powder deposited on the thin seed metal layer, thereby transforming the functionalized diamond substrate into an intermediate diamond substrate according to a first embodiment of the present invention;

[0029] Fig. 5 is a graphical, side view of the intermediate diamond substrate illustrated in Fig.4, showing the application of a laser beam thereto;

[0030] Fig. 6 is a graphical, side view of the intermediate diamond substrate illustrated in Fig.5, after application of the laser beam thereto, resulting in the formation of a metallized substrate, possibly requiring several, repeated steps, as illustrated in Fig. 4 and Fig. 5, to achieve the required thickness;

[0031] Fig. 7 is a perspective, graphical illustration of the metallized substrate illustrated in Fig. 6;

[0032] Fig 8 is a perspective, graphical illustration of the metallized substrate illustrated in Fig. 7 after the addition of a solder strip thereto, forming a laser diode heatsink submount substrate;

[0033] Fig. 9 is a graphical, side view of a diamond substrate upon which is layered a metal using laser powder fusion technique, establishing an intermediate substrate according to a second embodiment of the present invention;

[0034] Fig. 10 is a graphical, side view of the diamond substrate illustrated in Fig. 9, showing the application of a laser beam thereto, forming a metallized substrate;

[0035] Fig. 11 is a graphical, side view of the metallized substrate shown in Fig. 10;

[0036] Fig. 12 is a graphical representation of a first pattern for scanning the laser beam onto the metal powder layer;

[0037] Fig. 13 is a graphical representation of a second pattern for scanning the laser beam onto the metal powder layer;

[0038] Fig. 14 is a graphical representation of a third pattern for scanning the laser beam onto the metal powder layer;

[0039] Fig. 15 is a flow chart illustrating a first method for manufacturing a metallized substrate adapted to support a laser diode according to the present invention; and

[0040] Fig. 16 is a flow chart illustrating a second method for manufacturing a metallized substrate adapted to support a laser diode according to the present invention.Detailed Description of Embodiment(s) of the Invention

[0041] The present invention will now be described in connection with several examples and embodiments. The present invention should not be understood to be limited solely to the examples and embodiments discussed. To the contrary, the discussion of selected examples and embodiments is intended to underscore the breadth and scope of the present invention, without limitation. As should be apparent to those skilled in the art, variations and equivalents of the described examples and embodiments may be employed without departing from the scope of the present invention.

[0042] In addition, aspects of the present invention will be discussed in connection with specific materials and / or components. Those materials and / or components are not intended to limit the scope of the present invention. As should be apparent to those skilled in the art, alternative materials and / or components may be employed without departing from the scope of the present invention.

[0043] In the illustrations appended hereto, for convenience and brevity, the same reference numbers are used to refer to like features in the various examples and embodiments of the present invention. The use of the same reference numbers for the same or similar structures and features is not intended to convey that each element with the same reference number is identical to all other elements with the same reference number. To the contrary, the elements may vary from one embodiment to another without departing from the scope of the present invention.

[0044] Still further, in the discussion that follows, the terms “first,” “second,” “third,” etc., may be used to refer to like elements. These terms are employed to distinguish like elements from similar examples of the same elements. For example, one fastener may be designated as a “first” fastener to differentiate that fastener from another fastener, which may be designated as a “second fastener.” The terms “first,” “second,” “third,” are not intended to convey any particular hierarchy between the elements so designated.

[0045] It is noted that the use of “first,” “second,” and “third,” etc., is intended to follow common grammatical convention. As such, while a component may be designated as “first” in one instance, that same component may be referred to as “second, “third,” etc., in a separate instance. The use of “first,” “second,” and “third,” etc., therefore, is not intended to limit the present invention.

[0046] Fig. 1 is a perspective, graphical illustration of a diamond substrate 10 of the type for formation of a laser diode thereon.

[0047] In this simplified illustration, the diamond substrate 10 is shown as a rectangular plate with a first side 12, a second side 14, a third side 16, a fourth side 18, a top side 20, and a bottom side 22.

[0048] While shown as a rectangular structure, the diamond substrate 10 may have any suitable shape, as required and / or as desired, for a particular configuration of one or more laser diodes thereon. For example, the diamond substrate may be square, circular, elliptical, triangular, polygonal, and / or irregularly shaped without departing from the scope of the present invention.

[0049] In this illustrated example, the diamond substrate 10 is constructed as a diamond, manufactured via chemical vapor deposition (“CVD”). It is noted that CVD is merely an example of one way in which the diamond substrate 10 may be created. The present invention is not intended to be limited only to diamond substrates 10 manufactured via a CVD process. Other processes are contemplated to fall within the scope of the present invention.

[0050] It is noted that the thickness of the diamond substrate 10 may be selected as required and / or as desired for a particular implementation. In one contemplated embodiment, the diamond substrate 10 may be constructed as a thin film, as should be apparent to those skilled in the art.

[0051] As noted above, and as should be apparent to those skilled in the art, the diamond substrate 10 is preferred as a substrate for the manufacture of a laser diode, because diamond has a high thermal conductivity and, therefore, is well-suited to dissipate heat generated during operation of the laser diode.

[0052] As discussed in detail in the paragraphs that follow, the metallized substrate 48, 68 of the present invention is contemplated to have at least one or two constructions. The metallized substrate 48 according a first embodiment is illustrated in connection with Figs. 2 - 8. The metallized substrate 68 according to a second embodiment is illustrated in connection with Figs. 9 - 11.

[0053] Fig. 2 is a perspective, graphical illustration of a functionalized diamond substrate 24. The functionalized diamond substrate 24 differs from the diamond substrate 10 in that the functionalized diamond substate 24 includes one or more metal layers bonded thereto.

[0054] In the embodiment illustrated in Fig. 2, the functionalized diamond substrate 24 includes a first bonded metal layer 26 and a second bonded metal layer 28 deposited thereon.These layers also are referred to as “seed layers” herein. In this example, the first and second bonded metal layers 26, 28 are made of titanium (Ti) metal that has been sputtered onto the top side 20 of the diamond substrate 10. It is noted that sputtering is merely exemplary of one nonlimiting technique for depositing the bonded metal layers 26, 28 onto the substrate. Other techniques may be employed, such as evaporation and / or other thin film deposition processes.

[0055] The first bonded metal layer 26 and the second bonded metal layer 28 are provided so that one or more metal layers 44 (discussed hereinbelow) may be deposited thereon.

[0056] As discussed hereinbelow, the metal layers 44 are contemplated to be made from copper (Cu) or an alloy made with Cu. However, copper and copper alloys do not adhere readily to the diamond substrate 10. Simply, copper and its alloys do not share a bonding affinity with diamond. As such, when copper is sputtered onto a diamond material, the copper metal does not form a suitable bond with the diamond material. Under some operating conditions, the copper metal has a tendency to delaminate from the diamond material.

[0057] As should be apparent to those skilled in the art, there are a few reasons why copper and copper alloys do not adhere well to diamond. First, copper does not have an atomic affinity for diamond and vice-versa. As such, copper does not form a strong bond to the diamond material. Second, the coefficient of thermal expansion (“CTE”) for copper differs considerably from the CTE for diamond. As a result, copper and diamond do not expand at the same rates. Specifically, when heated, copper expands more than diamond, which can result in separation of the copper metal from the diamond material. These variables, among others, are believed to contribute to delamination of the copper from the diamond material, especially at the high temperatures generated by laser diodes.

[0058] To avoid delamination of the copper or copper alloy from the diamond substrate 10, the bonded metal layers (or seed metal layers) 26, 28 are first sputtered onto the diamond substrate 10. The bonded metal layers 26, 28 acts as an adherent to secure the copper and / or copper alloy metal layers 44 to the diamond substrate 10.

[0059] In one contemplated embodiment of the present invention, titanium (Ti) is employed for the bonded metal layers 26, 28. Titanium and its alloys have a greater affinity for the diamond substrate 10 and, therefore, are suitable materials for the bonded metal layers 26, 28.

[0060] In other embodiments, alloys of titanium are contemplated for the bonded metal layers 26, 28. For example, a titanium-copper (Ti-Cu) alloy may be employed. Other than titanium, thebonded metal layers 26, 28 may be made from nickel (Ni) and / or platinum (Pt). Still further, the bonded metal layers 26, 28 may be made from combinations of Ti, Ni, and / or Pt. In addition, a chromium -zirconium-copper (Cr-Zr-Cu) may be employed for the bonded metal layers 26, 28.

[0061] It is noted that the metals and alloys discussed for use as the bonded metal layers 26, 28 are merely exemplary of the large variety of materials that may be employed. Other metals and metal alloys may be employed without departing from the scope of the present invention.

[0062] The bonded metal layers 26, 28 are contemplated to have a thickness 30 of a few monolayers to several hundred nanometers of the selected material. Specifically, the thickness 30 of the bonded metal layers 26, 28 is contemplated to be less than 1 pm or 1,000 nm.

[0063] Without limiting the present invention, in selected specific examples, the thickness 30 of the bonded metal layers 26, 28 is contemplated to fall within a range of 0.1 - 400 nm. Other ranges for the thickness 30 include, but are not limited to 100 - 300 nm, 150 - 250 nm, and 175 — 225 nm.

[0064] Without limiting the present invention, the thickness 30 of the bonded metal layers 26, 28 is contemplated to be uniform across the top surface 20 of the diamond substrate 10.

[0065] It is noted, however, that variations in the thickness 30 (herein referred to as the “bonded metal layer thickness” 30) are permitted, as should be apparent to those skilled in the art. In other words, the bonded metal layer thickness 30 need not be uniform across the entire top surface 20 of the diamond substrate 10.

[0066] In the embodiment of the functionalized diamond substrate 24 shown in Fig. 2, there are two bonded metal layers 26, 28. Each bonded metal layer 26, 28 is contemplated to be associated with one electrical contact for the laser diode. As such, one of the bonded metal layers 26, 28 is contemplated to act as positive electrical contact while the other is contemplated to act as a negative electrical contact.

[0067] It is noted that the configuration of the bonded metal layers 26, 28 illustrated in Fig. 2 is merely exemplary of one configuration contemplated by the present invention.

[0068] In the contemplated embodiment, the functionalized diamond substrate 24 is contemplated to be configured to support a single laser diode thereon.

[0069] As should be apparent to those skilled in the art, numerous other configurations for bonded metal layers 26, 28 may be employed without departing from the scope of the present invention. For example, if the diamond substrate is contemplated to support two or more laserdiodes, additional pairs of bonded metal layers 26, 28 are contemplated to be added to the diamond substrate 10.

[0070] Additionally, it is noted that the illustrated shapes of the bonded metal layers 26, 28 are merely exemplary of the embodiment discussed herein. The bonded metal layers 26, 28 may have any shape and configuration as required and / or desired for a particular installation.

[0071] It is also contemplated that the bonded metal layers 26, 28 may comprise two or more layers stacked atop one another. In other words, while the bonded metal layers 26, 28 are illustrated as single (or mono) layers, several layers of metal may be layered to form the bonded metal layers 26, 28 without departing from the scope of the present invention.

[0072] Fig. 3 is a graphical, side view of the functionalized diamond substrate 24 illustrated inFig. 2.

[0073] The bonded metal layer thickness 30 is visible in this side view.

[0074] Fig. 4 is a graphical, side view of the functionalized diamond substrate 24 illustrated in Fig. 3. In this view, a metal powder layer 32 has been deposited atop the bonded metal layers 26, 28. This configuration, therefore, is referred to as an intermediate diamond substrate 34.

[0075] In the illustrated embodiment, the metal powder layer 32 is deposited onto the bonded metal layers 26, 28 such that the metal powder layer 32 is commensurate in area with the bonded metal layers 26, 28. In other words, the location and shape of the metal powder layer 32 is contemplated to be identical to the location and shape of the bonded metal layers 26, 28. For this reason, the metal powder layer 32 also is referred to as plural metal powder layers 32 herein.

[0076] It is noted that the shape, size, and configuration of the metal powder layer 32 is not intended to be limiting of the present invention. The shape and size of the metal powder layer 32 may differ from that of the bonded metal layers 26, 28 without departing from the scope of the present invention. It is noted, however, that, where the metal powder layer 32 differs in shape and configuration from the bonded metal layers 26, 28, the metal powder layer 32 is contemplated to have a footprint equal to or smaller than that of the bonded metal layers 26, 28. As discussed in greater detail herein, the metal powder layer 32 is adhered to the bonded metal layers 26, 28.

[0077] While not apparent from the side view provided by Fig. 4, the metal powder layer 32 is contemplated to have at least two segments, one atop the first bonded metal layer 26 and another atop the second bonded metal layer 28. Specifically, the number of segments forming the metal powder layer 32 is contemplated to be commensurate with the number of bonded metal layers 26,28. As noted, therefore, the metal powder layer 32 should not be understood to be a single element of the present invention.

[0078] The metal powder layer 32 is contemplated to have a metal powder layer thickness 36 of approximately 300 pm. A broad range for the metal powder thickness 36 is contemplated to fall with a range of 1 - 400 pm. Specific ranges for the metal powder layer thickness 36 include, but are not limited to, 10 - 50 pm, 25 - 75 pm, 50 - 95 pm, 100 - 500 pm, 150 - 450 pm, 200 - 400 pm, and 250 - 350 pm. Other thicknesses may be employed, as required and / or as desired for a particular application without departing from the scope of the present invention. For example, in one, alternative contemplated embodiment, the metal powder layer may have a thickness 36 within a range of 20 - 100 pm (microns). Concerning this embodiment, other contemplated thicknesses 36 for the metal powder layer include, but are not limited to, 25 - 85 pm, 30 - 80 pm, 40 - 80 pm, 50 - 80 pm, and 60 - 80 pm.

[0079] Fig. 5 is a graphical, side view of the intermediate diamond substrate 34 illustrated in Fig. 4.

[0080] In this illustration, a laser 38 is shown. The laser 38 generates a laser beam 40 that is directed onto the metal powder layer 32. Specifically, the laser 38 generates a laser beam 40 that is scanned across the metal powder layer 32 in the direction of the arrows 42. This is also referred to as the scan direction 42.

[0081] The laser beam 40 is contemplated to be a continuous wave (“CW”) laser to melt and consolidate the metal powder in the metal powder layer 32. However, the present invention is not limited solely to the use of a CW laser 38. A combination of a CW and a pulsed laser that are targeted to the same location may be employed without departing from the scope of the present invention.

[0082] Regardless of the type of laser 38 employed (e.g., a CW laser, a pulsed laser, and / or a combined CW and pulsed laser), when the laser 38 is focused on the metal powder layer 32, the laser beam 40 causes the metal powder to melt and consolidate into a metal layer 44, which is illustrated in Fig. 6. The application of the laser beam 40 to the metal powder layer 32 to form the metal layer 44 is referred to both as “consolidation” and as “laser consolidation” or “laser powder fusion” herein.

[0083] It is noted that the metal layer 44 need not be formed via a single pass of the laser 38. To the contrary, multiple metal powder layers 32 may be deposited successively on top of oneanother and subsequently consolidated via application of the laser 38 thereto. In other words, the metal layer 44 may be built up from multiple, thinner layers of the metal material.

[0084] The metal powder is contemplated to be copper (Cu). Alternatively, the metal powder may be an alloy of copper, such as a titanium-copper alloy or a copper-chromium-zirconium alloy. Still other alloys of copper are contemplated to fall within the scope of the present invention.

[0085] With further reference to Fig. 6, the metal layer 44 has a metal layer thickness 46. In the illustrated embodiment, the metal layer thickness 46 is the same, or nearly the same, as the metal powder layer thickness 36. However, the metal layer thickness 46 may differ from the metal powder layer thickness 36 without departing from the scope of the present invention.

[0086] Fig. 6 is a graphical, side view of the intermediate diamond substrate 34 illustrated in Fig. 5, after application of the laser beam 38 thereto. Since the metal layer 44 has been formed by the melting and consolidation of the metal powder layer 32, this construction is referred to as a metallized substrate 48.

[0087] Fig. 7 is a perspective, graphical illustration of the metallized substrate 48 illustrated in Fig- 6.

[0088] Like the metal powder layer 32, the metal layer 44 is divided into a first metal layer 50 and a second metal layer 52. For this reason, the metal layer 44 also is referred to as “metal layers.”

[0089] Since the first metal layer 50 and the second metal layer 52 are formed from the metal powder deposited as the metal powder layer 32, it is contemplated that the metal layers 50, 52 are commensurate in area with the bonded metal layers 26, 28. Specifically, the location and shape of the metal layers 50, 52 is contemplated to be identical to the location and shape of the bonded metal layers 26, 28.

[0090] It is noted that the shape, size, and configuration of the metal layers 50, 52 are not intended to be limiting of the present invention. The shape and sizes of the metal layers 50, 52 may differ from that of the bonded metal layers 26, 28 without departing from the scope of the present invention. It is noted, however, that, where the metal layers 50, 52 differ in shape and configuration from the bonded metal layers 26, 28, the metal layers 50, 52 are contemplated to have a footprint equal to or smaller than that of the bonded metal layers 26, 28.

[0091] As should be apparent from a comparison between Fig. 2 and Fig. 7, the metal layers 50, 52 are contemplated to be positioned atop the first bonded metal layer 26 and the second bonded metal layer 28, respectively.

[0092] Consistent with the metal powder layer 32, the metal layers 50, 52 are contemplated to have a metal layer thickness 46 of approximately 300 pm. Consistent with the discussion of the metal powder layer thickness 36, the metal layer thickness 46 is contemplated to fall within a range of 1 - 400 pm. Specific ranges for the metal layer thickness 46 include, but are not limited to , 10- 50 pm, 25 - 75 pm, 50 - 95 pm, 100 - 500 pm, 150 - 450 pm, 200 - 400 pm, and 250 - 350 pm. Other thicknesses may be employed, as required and / or as desired for a particular application without departing from the scope of the present invention. For example, other specific contemplated thicknesses include, but are not limited to, 25 - 85 pm, 30 - 80 pm, 40 - 80 pm, 50- 80 pm, and 60 - 80 pm.

[0093] Fig 8 is a perspective, graphical illustration of the metallized substrate 48 illustrated in Fig. 7. In this view, a solder strip 54 has been added. This configuration is referred to as a laser diode heatsink submount substrate 56.

[0094] The solder strip 54 is contemplated to be made from gold (Au) and tin(Sn) and / or a combination of gold and tin. Other materials may be used for the solder strip 54 without departing from the scope of the present invention.

[0095] This configuration is referred to as the laser diode heatsink submount substrate 56, because a laser diode 58 may be mounted thereon, as also indicated by Fig. 8. Here, the laser diode 58 is depicted in graphical form for ease of reference.

[0096] Fig. 9 is a graphical, side view of a diamond substrate 10 upon which is layered a metal powder layer 60 according to a second embodiment of the present invention.

[0097] For simplicity, the metal powder layer 60 is applied to the diamond substrate 10 in the same pattern as illustrated in Fig. 7.

[0098] In this embodiment, the bonded metal layers 26, 28 are omitted.

[0099] The metal powder layer 60 shares the same properties as the metal powder layer 32 discussed above. Accordingly, the discussion of the metal powder layer 32 is applicable to the metal powder layer 60.

[0100] The combination of the diamond substrate 10 and the metal powder layer 60 is referred to as an intermediate diamond substrate 62, consistent with the terminology employed herein.

[0101] As discussed hereinabove, the metal powder layer 60 is not contemplated to bond suitably to the diamond substrate 10 using conventional techniques. To overcome this difficulty, a laser 64 applies a laser beam 66 to the metal powder layer 60 as illustrated in Fig. 10.

[0102] Fig. 10 is a graphical, side view of the intermediate diamond substrate 62 illustrated in Fig. 9. In this view, the laser 64 applies the laser beam 66 thereto, forming a metallized substrate 68, which is shown in Fig. 11. After application of the laser beam 66 thereto, the metal powder layer 60 melts and consolidates to form a metal layer 70.

[0103] The laser beam 66 is contemplated to be a high power laser beam 66 that is pulsed when the laser beam 66 is applied to the metal powder layer 60. The pulsing of the laser beam 66 is indicated by the dotted arrow 72 provided in Fig. 10.

[0104] It is also envisioned that two co-axially overlapping beams, i.e., one pulsed with a high peak power over a short period of time and a second beam that is continuous wave (“CW”) will be applied simultaneously during the scanning process. The laser beams also could be non-co- axial, but the spots from those two sources are contemplated to overlap at the same spot where the melt pool is formed, thereby establishing an attachment of the metal to the underlying diamond surface. The pulsed laser functionalizes the diamond surface to robustly bond to the metal which is liquified by the CW laser beam. It is also possible that only a pulsed laser beam may be used to functionalize the diamond surface to form a good bond to the metal powder that melts with sufficient energy in the laser pulse.

[0105] Fig. 11 is a graphical, side view of the metallized substrate 68 formed after application of the laser beam 66 illustrated in Fig. 10.

[0106] With respect to the pulsed laser beam 66, the precise mechanism that permits the formation of the metallized substrate 68 is not entirely understood. Without limiting the present invention, it is believed that the application of intense, laser pulses 66 excites the carbon atoms in the diamond substrate 10, thereby placing the carbon atoms into an excited state where they are more receptive to the metals making up the metal powder layer 60. As a result, after the metal powder layer 60 coalesces into the metal layer 70, the metal layer 70 remains suitably affixed to the diamond substrate 10 so that the metal layer 70 does not delaminate from the diamond substrate 10.

[0107] With respect to the application of the laser beams 40, 66 described hereinabove, Figs. 12-14 provide graphical illustrations of three exemplary scanning patterns that may be employed.

[0108] Fig. 12 is a graphical representation of a first pattern for scanning the laser beam 40, 66 onto the metal powder layer 32, 60 deposited onto the diamond substrate 10.

[0109] The arrows 74 indicate a back and forth scan of the laser beam 40, 66.

[0110] Fig. 13 is a graphical representation of a second pattern for scanning the laser beam 40, 66 onto the metal powder layer 32, 60 deposited onto the diamond substrate 10.

[0111] Here, the arrows 76 form a spiral pattern.

[0112] Fig. 14 is a graphical representation of a third pattern for scanning the laser beam 40, 66 onto the metal powder layer 32, 60 deposited onto the diamond substrate 10.

[0113] Here, the arrows 78 form a diagonal pattern.

[0114] It is noted that the patterns illustrated in Figs. 12-14 are merely exemplary and are not limiting of the present invention.

[0115] Fig. 15 is a flow chart illustrating a first method 80 of manufacturing the metallized substrate 48 that is illustrated in connection with Figs. 2 - 8.

[0116] The method starts at step 82.

[0117] At step 84, one or more bonded metal layers 26, 28 are deposited onto the diamond substrate 10.

[0118] At step 86, one or more metal powder layers 32 are deposited onto the bonded metal layers 26, 28.

[0119] At step 88, a laser beam 40 is applied to the one or more metal powder layers 32.

[0120] At step 90, as a result of laser consolidation, one or more metal layers 44 are formed from the one or more metal powder layers 32.

[0121] The method 80 ends at step 92.

[0122] Fig. 16 is a flow chart illustrating a second method of manufacturing the metallized substrate 68 that is illustrated in connection with Figs. 9 - 11.

[0123] The method 94 starts at step 96.

[0124] At step 98, one or more metal powder layers 60 are deposited onto the diamond substrate 10.

[0125] At step 100, a laser beam 66 is applied to the one or more metal powder layers 60.

[0126] At step 102, as a result of laser consolidation, one or more metal layers 70 are formed from the one or more metal powder layers 60.

[0127] The method 94 ends at step 104.

[0128] As discussed hereinabove, the embodiments of the present invention are exemplary only and are not intended to limit the present invention. Features from one embodiment are interchangeable with other embodiments, as should be apparent to those skilled in the art. As such,variations and equivalents of the embodiments described herein are intended to fall within the scope of the claims appended hereto.

Claims

What is claimed is:

1. A metallized substrate adapted to receive a laser diode thereon, the metallized substrate comprising: a diamond substrate; one or more bonded metal layers deposited on the diamond substrate, wherein the one or more bonded metal layers have a bonded metal layer thickness; and one or more metal layers formed, by laser consolidation, on the one or more bonded metal layers, wherein the one or more metal layers have a metal layer thickness.

2. The metallized substrate according to claim 1, wherein the one or more bonded metal layers comprise titanium.

3. The metalized substrate according to claim 1 , wherein the bonded metal layer thickness is 0.1 - 400 nm.

4. The metalized substrate according to claim 1, wherein the one or more metal layers comprise copper.

5. The metalized substrate according to claim 1, wherein the metal layer thickness is 1 — 400 pm.

6. The metalized substrate according to claim 1, wherein the metal layer thickness is 25 - 85 pm.

7. A metallized substrate adapted to receive a laser diode thereon, the metallized substrate comprising: a diamond substrate; and one or more metal layers formed, by laser consolidation, on the diamond substrate, wherein the one or more metal layers have a metal layer thickness.

8. The metalized substrate according to claim 7, wherein the one or more metal layers comprise copper.

9. The metalized substrate according to claim 7, wherein the metal layer thickness is 1 — 400 pm.

10. The metalized substrate according to claim 7, wherein the metal layer thickness is 25 - 85 pm.

11. A method of manufacturing a metallized substrate adapted to receive a laser diode thereon, the metallized substrate comprising a diamond substrate, one or more bonded metal layers deposited on the diamond substrate, wherein the one or more bonded metal layers have a bonded metal layer thickness, and one or more metal layers formed, by laser consolidation, on the one or more bonded metal layers, wherein the one or more metal layers have a metal layer thickness, the method comprising: depositing the one or more bonded metal layers onto the diamond substrate; depositing the one or more metal powder layers onto the one or more bonded metal layers; applying a laser beam to the one or more metal powder layers; and via application of the laser beam to the one or more metal powder layers, consolidating the one or more metal powder layers to form the one or more metal layers.

12. The method according to claim 11, wherein the one or more bonded metal layers comprise titanium.

13. The method according to claim 11, wherein the bonded metal layer thickness is 0.1 - 400 nm.

14. The method according to claim 11, wherein the one or more metal layers comprise copper.

15. The method according to claim 11 , wherein the metal layer thickness is 1 - 400 gm.

16. The method according to claim 11, wherein the metal layer thickness is 25 - 85 gm.

17. A method of manufacturing a metallized substrate adapted to receive a laser diode thereon, the metallized substrate comprising a diamond substrate, and one or more metal layers formed, by laser consolidation, on the diamond substrate, wherein the one or more metal layers have a metal layer thickness, the method comprising: depositing the one or more metal powder layers onto the diamond substrate; applying a laser beam to the one or more metal powder layers; and via application of the laser beam to the one or more metal powder layers, consolidating the one or more metal powder layers to form the one or more metal layers.

18. The method according to claim 17, wherein the one or more metal layers comprise copper.

19. The method according to claim 17, wherein the metal layer thickness is 1 - 400 pm.

20. The method according to claim 17, wherein the metal layer thickness is 25 - 85 gm.

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