GB2536689A

GB2536689A - Carrier and insert

Info

Publication number: GB2536689A
Application number: GB1505144.4A
Authority: GB
Inventors: Francis Dunne Barry; Edward Weatherburn Paul; Stuart Noel Stokes Andrew
Original assignee: INEX MICROTECHNOLOGY Ltd
Current assignee: INEX MICROTECHNOLOGY Ltd
Priority date: 2015-03-26
Filing date: 2015-03-26
Publication date: 2016-09-28
Also published as: WO2016151329A1; GB201505144D0

Abstract

A carrier 102 bears at least one insert 104, the insert being retained by compression exerted by the carrier. The carrier may be a ceramic substrate bearing a diamond, sapphire or carbide insert, the insert being compressively retained by the ceramic substrate shrinking around the insert. The ceramic may comprise an oxide, a nitride, a silicate or feldspars. The carrier may be arranged to receive the insert when in a first state and to compressively retain the insert when in a second state. The substrate may shrink irreversibly on heating, firing or curing. For example, a ceramic substrate is fired to form a shrink fit around a diamond insert, thereby applying a compression force to retain the insert. The carrier may be used to connect a heat generating component such as a transistor, an integrated circuit, a switch, an optical element or an RF element to a heat sink. The optical element may be an optical modulator and the inserts may provide an optical and/or thermal path from the modulator.

Description

CARRIER AND INSERT

Background

[0001] Ceramics are being increasingly used to realise high density circuits within electronics, optics and other fields. Progressively increasing performance demands and circuit density gives rise to thermal management challenges. High density circuits such as, for example, integrated circuits, also give rise to thermal issues notwithstanding the powers involved being relatively low and the increasing challenge of heat extraction from modern multi-chip modules with increasingly small form factor. Similarly, the performance of optical components such as lasers, optical modulators and associated driver elements can be adversely affected by thermal issues.

[0002] It is an objective of embodiments to at least mitigate the effects of one or more of the above problems or other problems.

Brief description of the drawings

[0003] Embodiments will now be described by way of example only with reference to the accompanying drawings in which: [0004] figure 1 shows a first embodiment of a ceramic substrate and diamond insert before mounting according to an embodiment; [0005] figures 2A and 2B illustrate the ceramic substrate with the diamond insert mounted within it according to an embodiment; [0006] figure 3 shows a carrier bearing an insert according to an embodiment prior to assembly; [0007] figure 4 illustrates carrier and an insert according to an embodiment; [0008] figure 5 shows a further carrier for a respective insert prior to assembly; [0009] figure 6 illustrates the further carrier and respective insert in an assembled state; [0010] figure 7 shows an assembly schematic according to an embodiment; [0011] figure 8 illustrates a second assembly schematic according to an embodiment; [0012] figure 9 illustrates an optical circuit according to an embodiment; [0013] figure 10 depicts a substrate bearing a plurality of inserts according to an embodiment; [0014] figure 11 shows a pre-fired carrier and insert; [0015] figure 12 shows a fired carrier and insert; [0016] figure 13 depicts a carrier having a profiled insert receiving feature in a first, insert receiving, state; [0017] figure 14 depicts the carrier of figure 13 having a profiled insert receiving feature in a second, insert retaining, state; [0018] figure 15 shows profiled carrier receiving features and profiled inserts; and [0019] figure 16 illustrates keyed insert profiles and carrier features.

Detailed description of embodiments

[0020] Referring to figure 1, there is shown a view 100 of substrate 102 retaining an insert 104 using compression forces induced by shrinkage of the substrate. The substrate can be a ceramic substrate. The insert can be a diamond insert. The substrate 102 and the insert 104 have dimensions that allow the insert 104 to be mounted within the substrate 102. It can be appreciated that the substrate 102 has a hole 106 for receiving the insert 104. The hole 106 has a predetermined length, dl and a predetermined width, d2. The insert 104 also has a predetermined length, d3, and a predetermined width, d4. The dimensions of the hole 106 and the insert 104 are necessarily arranged such that d1>d3 and d2>d4.

[0021] Although the insert 104 is to be mounted within the hole 106, possible known mounting techniques such as, for example, brazing or using epoxy, would have a number of disadvantages. Such techniques would undesirably leave unwanted residues on both the ceramic substrate 102 and the diamond insert 104. Suitably, embodiments are provided in which the substrate is dimensioned to ensure that when fired, it contracts sufficiently to exert forces on the insert to retain the insert in position. In embodiments in which the substrate is a ceramic insert, firing sinters or vitrifies the ceramic, which, in turn, leads to the above contraction. Advantageously, embodiments support electrical connections that span the interface between the substrate and the insert, in particular, a ceramic substrate and a diamond insert by avoiding using prior art bonding technique such as brazing or epoxy.

[0022] Referring to figure 2A, there is illustrated a view 200 of the ceramic substrate 102 with the diamond insert 104 mounted in the hole 106 according to an embodiment. It can be appreciated that there is clearly a gap 202 between the insert 104 and the hole 106. It will be appreciated that the hole 106 is an embodiment of an insert receiving feature of the substrate. In contrast, referring to figure 2B, it can be appreciated that the hole 106 has, as a consequence of heating, has reduced in size such that the substrate bears down on or otherwise compresses the insert. It will be appreciated that the compression forces exerted by the insert are lateral, that is, the compression forces are in the direction of the shrinkage of the substrate.

[0023] An advantage follows from the embodiments, which is that the resulting bond between the ceramic substrate 102 and the diamond insert 104 is very strong.

[0024] During the operation of devices that are associated with the ceramic substrate 102 and the diamond insert 104, the bond between the substrate and the insert is subjected to varying stresses.

[0025] Even though thermal cycling and other operational use the bond between the ceramic substrate 102 and the diamond insert 104 results in the degree of physical coupling between the substrate, which has been irreversibly shrunk, and the insert, not being adversely affected.

[0026] Referring to figure 3, there is illustrated another view 300 of a carrier 302 and an insert 304 according to an embodiment prior to assembly. It can be appreciated that the substrate 302 has a hole 306 for receiving the insert 304. Again, the dimensions of the insert 304 and the respective hole 306 are predetermined such that mounting the insert 304 within the carrier 302 and then firing the ceramic substrate 302 causes the substrate to irreversibly shrink or contract, which, in turn, exerts a compression or compressive force on the insert 304. It will be appreciated that embodiments can be realised in which the compression or compressive force exerted on the insert 304 is a lateral compression force or lateral compressive force.

[0027] Once the insert 304 has been mounted on or within the ceramic substrate 302, the assembly is heated to a predetermined temperature for a predetermined period of time. The predetermined temperature and the predetermined period of time are selected, in one embodiment, to ensure that the ceramic substrate 302 contracts sufficiently to retain the insert 304 in situ. Embodiments are provided in which the insert 304 is subjected to a compression force exerted by the carrier.

[0028] Embodiments can be realised in which the contraction of the ceramic substrate 302 is due to, or follows as a natural consequence of, vitrification of vitreous components of the ceramic substrate, which melt and fuse together. Embodiments are provided in which the melting and fusing together of the vitreous components result in an increase in shrinkage and an increase in thestrength of the ceramic substrate.

[0029] The initial contraction of the material of the substrate 302 surrounding the insert 304 due to firing is irreversible. Furthermore, the shrinkage or contraction is far greater than any thermal expansion and contraction experienced under conventional operating conditions.

[0030] One skilled in the art will appreciate that the extent of the contraction or shrinkage of the substrate such as, for example, a ceramic substrate 302 can be varied according to one or more than one parameter. For example, the degree of dimensional variation of the substrate can be influenced by one or more than one of the chemical composition of the ceramic or its precursors, the vitrification temperature and the length of time for which the ceramic is held at a predetermined, preferably maximum, vitrification temperate.

[0031] One skilled in the art will appreciate that the degree of vitrification can affect the degree of shrinkage or contraction.

[0032] Embodiments can be realised using several manufacturing methods, which are described below.

[0033] A first method of manufacturing a carrier such as, for example, a ceramic substrate, bearing an insert, such as, for example, a diamond insert, comprises machining in an unfired or partially fired substrate a receiving feature. The receiving feature can be one or more of an aperture, a hole, a recess, a through-hole or via taken jointly and severally in any and all combinations. The receiving feature has dimensions relative to the insert such that on heating the substrate, the latter contracts or otherwise shrinks sufficiently to exert a compression force on the insert.

[0034] Therefore, one skilled in the art will appreciate that the receiving feature is machined in an oversized manner in a way that firing, such as, for example, sintering or vitrifying, the ceramic will cause the resulting ceramic substrate to grip the insert.

[0035] Once the insert is in situ relative to the substrate or carrier, the combination is fired to shrink the carrier so that it applies compression forces to the insert.

[0036] A second method of manufacturing a carrier such as, for example, a ceramic substrate, bearing an insert such as, for example, a diamond insert comprises preforming the substrate with predetermined dimensions relative to the insert by casting, moulding or the like. Again, the receiving feature can be one or more of an aperture, a hole, a recess, a through-hole or via taken jointly and severally in any and all combinations. The receiving feature has dimensions relative to the insert such that on heating the substrate, the latter contracts or otherwise shrinks sufficiently to exert a compression force on the insert.

[0037] An embodiment was realised by forming a substrate using a ceramic comprising alumina, aluminium silicates and feldspars (KAISi308, NaAlSi308, CaAl2Si208). The ceramic was fired using a predetermined temperature profile resulting in suitable vitrification of the ceramic producing a ceramic substrate that retained a diamond insert 304 using compression, that is, the ceramic substrate gripped the insert 304.

[0038] An embodiment of such a predetermined temperature profile comprises a temperature ramp from a first temperature, such as, for example, 300C, to a second temperature such as, for example, 1250C.

[0039] The ceramic was held at the second predetermined temperature for a respective period of time. Embodiments can be realised in which the predetermined period of time was 30 minutes.

[0040] Following such firing, the resulting ceramic substrate exhibited a 10.6% isotropic shrinkage when compared to the pre-fired ceramic. One skilled in the art will appreciate that the shrinkage can be controlled to a high degree of accuracy and that it is highly predictable when consistent ceramic compositions are fired under the same controlled conditions.

[0041] An embodiment of a ceramic substrate holding a 4.9mm insert was realised using the above method. The insert resisted a force, normal to the plane of the ceramic and the insert, of 28N. It will be appreciated that this is a considerable increase in the load bearing capability of embodiments compared to the prior art described above.

[0042] One skilled in the art appreciates that firing is an embodiment of heating. The firing can be realised using a conventional convection or conduction oven such as, for example, a kiln or using electromagnetic waves as a source of energy to heat the carrier. Firing results in vitrification that, in turn, results in the carrier shrinking and hardening.

[0043] Figure 4 illustrates a carrier 302 and an insert 304 according to an embodiment. In embodiments that use a ceramic substrate as the substrate 302, the process of firing or otherwise vitrifying the ceramic substrate results in the substrate shrinking. The shrinking process results in the substrate 302 exerting a compression force on the insert 304. The insert 304 can be subjected to a compressive stress as a result of the shrinkage. The resulting bond between the ceramic substrate 302 and the insert 304 is significantly greater than the bond resulting from brazing or using epoxy as can be appreciated from the above 28N normal force test.

[0044] Figure 5 shows a view 500 of a further carrier 502 for receiving a respective insert 504 prior to assembly. The further insert 504 and carrier 502 can be fabricated using any of the compositions and materials described herein. Accordingly the carrier 502 can be, for example, a substrate such as the above substrate 302. Additionally, or alternatively, the insert 504 can be substantially the same as the above insert 304, but for the dimensions of the insert. The insert according to the present embodiment is planar. The insert 502 has a predetermined height, d5. The substrate has a predetermined height, d6. Embodiments can be realised in which d5<d6.

[0045] However, one skilled in the art will appreciate that the carrier 502 has a different insert receiving feature 506. In the embodiment shown in figure 5, the receiving feature 506 is a recess. The recess can have any prescribed shape according to the insert to be accommodated. In the illustrated embodiment, the recess 506 is substantially planar and has dimensions corresponding to a substantially planar insert 504.

[0046] Figure 6 illustrates the further carrier 502 and respective insert 504 in an assembled state in which the substrate 502 is arranged to grip or otherwise exert a compression force on the insert 504 as indicated above. The compression force will comprise one or more than one compression force such as, for example, a lateral compression force. Embodiments can be realised in which the one or more than one compression force is exerted on one or more than one respective surface or facet of the insert, preferably, according to one or more than one direction of shrinkage of the substrate.

[0047] Figure 7 depicts a view 700 of an assembly according to an embodiment. The assembly comprises a carrier 702 bearing an insert 704 according to embodiments such as those described herein. A preferred embodiment of the carrier 702 is a carrier according to an embodiment such as, for example, a ceramic carrier. A preferred embodiment of an insert 704 is an insert according to an embodiment such as, for example, a diamond insert.

[0048] The assembly 700 comprises a component 706. The normal operation of the component 706 can result in heat being generated, that is, the component 706 is an embodiment of a heat source. For example, the component could be one or more than one of a transistor, an integrated circuit such as, for example, a microprocessor or other integrated circuit, a switch, an optical element, an RE element, a microwave element or some other electromagnetic radiation element or any other device that generates heat.

[0049] Optionally, the substrate 702 can have one or more than one conductive layer associated with the component 706. Embodiments can be realised in which the one or more than one conductive layer comprises one or more than one electrically conductive track. In the embodiment illustrated in figure 7, two electrically conductive tracks 708 and 710 are shown. The tracks provide at least one of power and signals to the component 706.

[0050] It can be appreciated that the insert 704 is positioned relative to the component 706 so that they are in thermal contact with one another. Therefore, the insert 704 can provide a thermal path via which heat associated with the component 706 can be conducted.

[0051] The insert 704 is also arranged to be in thermal contact with a heat dissipation structure 712. The heat dissipation structure 712 is arranged to dissipate or otherwise conduct 7 heat away from the insert 704, which, in turn, assists in cooling the component 706. The heat dissipation 712 structure can be active or passive. For example, embodiments can be realised in which the heat dissipation structure 712 is a passive structure composed of a good heat conducting material such as, for example, copper, aluminium, gold or an alloy. Alternatively, or additionally, the heat dissipation structure 712 can be an active heat dissipation structure such as, for example, a thermoelectric cooler, a fan or a liquid cooled structure.

[0052] It will be appreciated that the height profile of the assembly shown in figure 7 is relatively low, which advantageously follows from the insert forming a conductive path through the substrate to a heat sink or other heat dissipation structure disposed on the other side of the substrate 702 to the component 706. Furthermore, the remaining one or more than one of the exposed surfaces of the component 706 is available for other uses such as, for example, one or more than one further connection or stacking additional components or the like.

[0053] Figure 8 depicts a view 800 of an assembly according to an embodiment. The assembly comprises a carrier 802 bearing an insert 804 according to embodiments such as those described herein. A preferred embodiment of the carrier 802 is a carrier according to an embodiment such as, for example, a ceramic carrier. A preferred embodiment of an insert 804 is an insert according to an embodiment such as, for example, a diamond insert.

[0054] The assembly 800 comprises a component 806. The normal operation of the component 806 can result in heat being generated, that is, the component 806 is an embodiment of a heat source. For example, the component could be one or more than one of a transistor, an integrated circuit such as, for example, a microprocessor or other integrated circuit, a switch, an optical element, an RF element, a microwave element or some other electromagnetic radiation element or any other device that generates heat.

[0055] Optionally, the substrate 802 can have one or more than conductive layer associated with the component 806. Embodiments can be realised in which the one or more than one conductive layer comprises one or more than one electrically conductive track. In the embodiment illustrated in figure 8, a single electrically conductive track 808 is shown. The track 808 may provide at least one of power and signals to the component 806.

[0056] It can be appreciated that the insert 804 is positioned relative to the component 806 so that they are in thermal contact with one another. Therefore, the insert 804 can provide a thermal path via which heat associated with the component 806 can be conducted.

[0057] The insert 804 is also arranged to be in thermal contact with a heat dissipation structure 812. The heat dissipation structure 812 is arranged to dissipate or otherwise conduct heat away from the insert 804, which, in turn, assists in cooling the component 806. The heat dissipation 812 structure can be active or passive. For example, embodiments can be realised in which the heat dissipation structure 812 is a passive structure composed of a good heat conducting material such as, for example, copper, aluminium, gold or an alloy. Alternatively, or additionally, the heat dissipation structure 812 can be an active heat dissipation structure such as, for example, a thermoelectric cooler, a fan or a liquid cooled structure.

[0058] It will be appreciated that the height profile of the assembly shown in figure 8 is relatively low, which advantageously follows from the insert forming a conductive path along the substrate to a heat sink or other heat dissipation structure disposed adjacent to component 806 on the same of the substrate 802 as the component 806.

[0059] Figure 9 illustrates an electro-optical modulator 900 according to an embodiment. The modulator 900 comprises an electro-optical material 902 for receiving light such as for example laser light 904. The light is modulated in response to one or more than one signal (not shown) applied to one or more than one electrical contact of the optical material 902. In the embodiment illustrated, two electrical contacts 906 and 98 are shown.

[0060] The optical material 902 is mounted in thermal contact, preferably also direct or indirect physical contact, with an insert 910 according to any of the embodiments described herein. The insert 910 is carried or otherwise retained by compression forces exerted by a respective carrier 912. The respective carrier 912 can be a substrate according to any of the embodiments described herein.

[0061] Optionally, a heat dissipation structure 914 is provided that is in thermal contact with the insert 910 so that heat associated with the modulator is dissipated.

[0062] Figure 10 depicts a view 1000 of a substrate 1002 bearing a plurality of inserts according to an embodiment. In the embodiment shown, two inserts 1004 and 1006 are shown. 9 However, embodiments are not limited to two inserts. Embodiments can be realised in which two or more than two inserts are mounted in the substrate.

[0063] The substrate 1002 comprises respective features 1008 and 1010 for receiving the inserts 1004 and 1006. In the embodiment shown, the receiving features 1008 and 1010 are through-holes or via. However, embodiments are not limited to such receiving features. Embodiments can equally well be realised in which the one or more than one receiving feature is a recess within the substrate 1002 for receiving one or more than one respective insert 10 10. It will be appreciated that embodiments can be realised in which the one or more than one insert of the inserts are substantially planar as per figures band 6, or some other shape and that respective insert receiving features are correspondingly adapted to receive those inserts.

[0064] Figure 11 shows a view 1100 of an unfired or partially fired ceramic substrate 1102. The ceramic substrate 1102 has an insert receiving feature 1104. In the embodiment illustrated, the insert receiving feature is a recess. It can be appreciated that the recess optionally has a number of additional formations 1106 to 1112. The formations 1106 to 1112 can be, for example, stress relieving formations. The formations 1106 to 1112 in the illustrated embodiment are substantially circular formations. It can be appreciated that there is a gap 1114 between the left edge of the recess and the left edge of the insert 1104. It can also be appreciated that there is a gap 1116 between the bottom edge of the recess and the insert. The insert 1104 in the illustrated embodiment is a diamond insert, but can equally well be an insert formed of another material subject to it having an appropriate heat response relative to the substrate to allow is to be retained by a compression force exerted by the substrate following contraction of the substrate.

[0065] Figure 12 depicts a view 1200 of the ceramic substrate 1202 with the insert 1204 being firmly retained by the ceramic substrate due to lateral compression forces exerted by the substrate 1202 onto the insert 1204. It can be seen that the gaps 1214 and 1216 mentioned above have gone due to contraction of the substrate 1202. As indicated herein the contraction stems from the firing process, which vitrifies the ceramic that, in turn, leads to the shrinkage.

[0066] Figure 13 shows a plan view 1300 of a carrier 1302. The carrier 1302 is adapted to retain an insert 1304 through compression forces exerted on the insert 1304 by the carrier. The carrier 1302 and insert 1304 can be any carrier and insert as described herein and, in particular, can be a ceramic carrier as described herein and a diamond insert as described herein.

[0067] It can be appreciated that the carrier 1302 comprises a profiled insert receiving feature 1306. The profiled insert receiving feature 1306 is arranged to influence the contact between the carrier 1302 and the insert 1304. In the embodiment illustrated, the profiled insert receiving feature 1306 is arranged to reduce the contact between the carrier 1302 and the insert 1304.

[0068] It can also be appreciated that the carrier 1302 is in an insert receiving state, that is, in an unfired or partially fired state in which the insert 1304 can be placed within the carrier 1302.

[0069] A further embodiment of such a profiled insert receiving feature 1306 was shown in and described with reference to figures 11 and 12. It can be appreciated that the profiled insert receiving feature of figures 11 and 12 effectively reduces the amount of contact between the substrate and the insert. In the embodiment of figures 12 and 13 the profiled receiving feature reduces the edge or lateral contact between the carrier 1102 and the insert 1104.

[0070] Referring to figure 14, there is shown a view 1400 of the carrier 1302 and insert 1304 of figure 13 but in an insert retaining state, that is, in a fired state, in which the substrate has contracted in size to clamp or otherwise grip the insert 1304 using the profiled features or sides of the profiled insert receiving feature 1306. It can be appreciated that the profiled insert receiving feature 1306 provides a plurality of points of contact with the insert 1304.

[0071] Although the embodiments described with reference to figures 13 and 14 have shown a laterally profiled insert receiving feature, embodiments can equally well, additionally or alternatively, provide a transverse or normal profile insert receiving feature. Suitably, figure 15 shows a view 1500 of a pair 1502 and 1504 of normally profiled insert receiving features.

[0072] Referring to the upper 1502 normally profiled insert receiving feature, it can be appreciated that the vertical or normal profile of the side walls of the receiving feature are shaped as frusto-triangles 1506 and 1508. Embodiments are not limited to such a normal 11 side wall profile. Embodiments can be realised in which some other profile is used. It can be appreciated that the insert 1510 does not bear profiled side walls or edges. However, embodiments can be realised in which one or more than one edge of the insert is profiled and one or more than one edge or side wall of the insert receiving feature is profiled, normally, laterally or both. Such an embodiment is shown in the lower 1504 normally profiled insert receiving feature. Again, it can be appreciated that the normal profiles are frusto-triangles 1506 and 1508, that is, each edge bears a frustum for engaging and retaining the insert 1510 using compression forces.

[0073] It can be appreciated that the profiled insert receiving features have been illustrated as having balanced profile features. In the illustrated embodiment, the left and right sides of the profiled insert receiving feature 1306 present an equal number of protrusions for retaining the insert 1304. Similarly, the upper and lower sides of the profiled insert receiving feature present an equal number of protrusions for engaging and retaining the insert 1304. It will also be appreciated that the upper and lower profiles are not the same as the left and right profiles. However, embodiment can be realised in which the upper and lower and left and right profiles are the same, or that selectable sides have the same profiles or that different profiles are used.

[0074] An advantage of the profiled insert receiving features is that embodiments can be realised that influence one or more than one of the mechanical, thermal and electrical coupling between a carrier and a respective insert. For example, reducing the area of contact between a carrier's insert engaging surfaces and an insert's carrier engaging surfaces can reduce at least one or more than one of the thermal conductivity, electrical conductivity and mechanical rigidity taken jointly and severally in any and all combinations of the coupling between the carrier and the insert. Such embodiments can advantageously influence one or more than one of a thermal, electrical or mechanical coupling taken jointly and severally in any and all combinations. For example. Such embodiments can influence one or more of the flow of heat, electricity or load taken jointly and severally in any and all combinations.

[0075] Referring to figure 16, there is shown an edge or lateral view 1600 of a profiled insert 1602 together with the walls of the insert receiving feature 1604 of the carrier. One or more than one edge or other surface of the insert 1602 can be profiled. In the embodiment illustrated, both the left 1606 and right 1608 edge surfaces are profiled. Alternatively, or 12 additionally, a single edge surface can be profiled or more than two edge surfaces can be profiled.

[0076] The profiled edge surfaces 1606 and 1608 are shown as having one or more than one recess or key feature 1610. In the embodiment illustrated the insert 1602 is shown as having two recesses or key feature.

[0077] During the firing or vitrification process, the substrate, particularly, if the substrate is a ceramic substrate, can form one or more than one complementary keying surface for engaging the insert 1602. In the embodiment illustrated, two 1612 and 1614 such complementary keying surfaces or features are provided. Therefore, in additional to the substrate retaining the insert using compression forces, the insert and the substrate are mechanically keyed together. It will be appreciated that such complementary surfaces are embodiments of cooperatively profiled surfaces [0078] Although the embodiments illustrated with reference to figure 16 show keys that influence and preferably prevent or at least restrict normal movement, embodiments can be realised with keys that influence and preferably prevent or at least restrict lateral movement. For example, an embodiment having an undercut into which the ceramic substrate or other substrate material flows during vitrification would present such a key.

[0079] Where the profiles of the insert receiving features permit, embodiments can be realised in which a conductive path or other connection between opposite surfaces of the carriers according to embodiment can be provided. For example, the profiled insert receiving feature 1306 of the embodiments described with reference to figures 13 and 14 can be realised as a profiled through-hole or via. Once the insert has been retained, one or more than one through-hole or via is presented, which can be used to form a connection between the opposite sides of the substrate. The connection can be an electrical connection via with one or more than one conductive path through the via or a physical connection [0080] The inserts described herein have been used as thermally conductive paths via which heat can be conducted. However, embodiments are not limited thereto. Any and all of the embodiments described herein can be modified so that the insert is an optical material. Such an optical material can provide, for example, a medium via which light can be conducted. The optical material can be transmissive at predetermined wavelengths.

[0081] It can be appreciated that the profiles can influence at least one or more than one of electrical coupling, thermal coupling and mechanical coupling, taken jointly and severally in any and all combinations, between the carrier and the insert. The carrier and insert can be any carrier and insert as described herein [0082] It can be appreciated that one or more than one embodiment of the embodiments described herein present a carrier with one or more than one insert engaging surface by which one or more than one compression force is applied, preferably laterally, to an insert. Furthermore, it can be appreciated that one or more than one embodiment of the embodiments described herein present an insert with one or more than one carrier engaging surface by which one or more than one compression force is received, preferably laterally, from the carrier. Additionally, or alternatively, the one or more than one insert according to embodiments also bears one or more than one accessible surface, that is, one or more than one non-carrier engaging surface. Conversely, embodiments can additionally or alternatively be realised in which a carrier has one or more than one non-insert engaging surface.

[0083] Although the above embodiments have been described with reference to the carrier being either a generic substrate or a ceramic substrate, embodiments are not limited thereto. Embodiments can be realised in which the substrate is fabricated from some other material that shrinks irreversibly on heating, firing or curing.

[0084] The above embodiments have been described with reference to the insert being a diamond insert, embodiments can alternatively be realised in which the insert can be, but not limited to, one or more of sapphire, such as, for example, optical sapphire, diamond such as, for example, CVD diamond, and a carbide such as, for example, silicon carbide taken jointly and severally in any and all combinations. Additionally, or alternatively, the insert can be formed from any other material that can withstand the firing process.

[0085] Although the above embodiments have been described with reference to the inserts being substantially planar, embodiments are not limited to such planar inserts. Any of the embodiments can be realised using inserts having some other prescribed shape such as, for example, a curved shaped such as, for example, a substantially planar circular shape, or other cylindrical shape. Furthermore, although the embodiments herein have been described with reference to insert receiving features and/or inserts having a substantially uniform cross-sectional, alternative embodiment can be realised in which the receiving features and/or inserts are not prisms. For example, embodiments can be realised in which the receiving feature and/or inserts are a frusto-shape such as, for example, a frusto-conical shape or any other non-uniform or non-prismatic shape.

[0086] One skilled in the art will appreciate that the vertical dimensions of the substrate may also benefit from careful control. This might be particularly the case when the resulting assembly of the substrate bearing the insert is intended to have substantially flush or otherwise coplanar surfaces. Alternatively, or additionally, if the substrate surface and the insert surfaces are intended, in the resulting, fired, assembly, to have offset surfaces, then again, the dimensions of the insert receiving feature will have to be accurately machined, mould, cast or otherwise formed.

[0087] Although the above embodiments have been described with reference to the inserts being larger, or at least presenting a larger contact area, than the components or heat sources, embodiments are not limited thereto. Embodiments can be realised in which the inserts are the same size, or at least present the same sized contact area, as the components and/or that are smaller, or at least present a smaller contact area, than that of the component or heat source.

Claims

CLAIMS1. A carrier, bearing at least one insert, the insert being retained by compression exerted by the carrier.
2. The carrier of claim 1, wherein the carrier exerts a lateral compression force on the insert through respective engaging surfaces of the insert and carrier.
3. The carrier of either of claims 1 and 2, wherein the carrier exerts the compression force on the insert by irreversible shrinkage of the carrier.
4 The carrier of either of claims 2 and 3, wherein the carrier exerts the lateral compression force on insert by irreversible shrinkage of the carrier by heating carrier and insert.
5. The carrier of any of claims 1 to 4, wherein the carrier is formed from a carrier material.
6. The carrier of claim 5, wherein the carrier material comprises a ceramic.
7. The carrier of claim 6, wherein the ceramic comprises one or more than one of: an oxide, a nitride, a silicate, feldspars or a combination thereof
8. The carrier of claim 7, wherein the ceramic comprises one or more than one of: aluminium oxide, aluminium nitride, aluminium silicate, silicon nitride, feldspars or a combination thereof.
9. The carrier of claim 5, wherein the carrier material comprises a composite.
10. The carrier of any of claims 1 to 9, wherein the carrier has a feature for retaining the insert.
11. The carrier of claim 10, wherein the feature for retaining the insert comprises at least one or more than one of: a. an aperture, b. a recess, c. a through-hole or a via having a uniform or non-uniform cross-section.
12. The carrier of claim 11, wherein the feature has a shape or profile that differs from the shape or profile of the insert.
13. The carrier of any of claims 1 to 12, wherein one or more than one carrier surface is arranged to be substantially coplanar with one or more than one insert surface.
14. The carrier of any of claims 1 to 13 wherein the insert provides a thermally conductive path.
15. The carrier of any of claims 1 to 14 wherein the insert is an optically transparent or translucent material at one of more than one respective wavelength.
16. The carrier of any of claims 1 to 15 wherein at least one of a carrier engaging surface of the insert and an insert engaging surface of the carrier are cooperatively profiled.
17. The carrier of claim 15, wherein at least one of a carrier engaging surface of the insert and an insert engaging surface of the carrier are profiled for influencing grip.
18. The carrier of any of claims 1 to 17 wherein the carrier engaging surfaces and/or insert engaging surfaces have profiles adapted to influence at least one or more than one of electrical coupling, thermal coupling and mechanical coupling between the carrier and the insert.
19. The carrier of any of claims 1 to 18, wherein a further carrier surface includes one or more than one electrically conductive layer.
20. The carrier of claim 19, wherein the one or more than one electrically conductive layer comprise a copper layer, an aluminium layer, a gold layer, conductive ink, a semiconducting layer, a transparent conductive layer, a conductive plastic, or combination thereof.
21. The carrier of any of either of claims 19 and 20, wherein the one or more than one electrically conductive layer is an electrically continuous track, the one or more than one electrically conductive track spanning an insert surface and a carrier surface.
22. The carrier of any of claims 1 to 21, bearing at least one further such insert the at least one further insert being compressively retained by the carrier.
23. An assembly comprising the carrier of any preceding claim, further comprising a heat dissipation structure at least thermally coupled to the insert. 17
24. The assembly of claim 23, wherein the heat dissipation structure is a passive structure.
25. The assembly of claim 24, wherein the passive structure is composed of copper, aluminium, gold or an alloy.
26. The assembly of claims 23, wherein the heat dissipation structure is an active structure.
27. The assembly of claim 26, wherein the active structure is a thermoelectric cooler, a fan or a liquid cooled structure.
28. An assembly comprising a carrier as in any of claims 1 to 22 having coupled thereto at least one or more than one heat source
29. The assembly of claim 28, wherein the at least one or more than one heat source comprises a component.
30. The assembly of claim 29, wherein the component comprises at least one or more than one of a transistor, an integrated circuit, a switch, an optical element or an RE element.
31. An assembly comprising an optical modulator and a carrier bearing an insert of any of claims 1 to 22.
32. The assembly of claim 31, wherein the insert is coupled to the optical modulator to provide a thermal path for conducting heat away from the optical modulator.
33. The assembly of either of claims 31 and 32, wherein the insert provides an optical path for the optical modulator.
34. An electronic system having an element that produces heat and the carrier bearing an insert as of any of claims 1 to 23, the insert being coupled to the element that produces heat to provide a thermal path.
35. A carrier for compressively retaining an insert; the carrier being arranged to receive the insert while the carrier is in a first carrier state.
36. The carrier of claim 35, wherein the first carrier state is one of a pre-fired state or a partially fired state.
37. The carrier of either of claims 35 to 36, wherein the carrier is adapted to compressively retain the insert in a second carrier state.
38. The carrier of claim 37, wherein the second carrier state is fired state.
39. The carrier of claim 38, in which the second carrier state is at least one of a partially fired or fired state.
40. A carrier bearing an insert substantially as described herein with reference to and/or as illustrated in the accompanying drawings.
41. A carrier for bearing an insert substantially as described herein with reference to and/or as illustrated in the accompanying drawings.