KR20230151532A - Carrier substrates and methods for manufacturing carrier substrates for electrical, especially electronic components - Google Patents

Abstract

The carrier substrate 1, in particular a metal-ceramic substrate, comprises an insulating layer 11 and a metal layer 12, which has an etched sidewall profile 2, in particular at least in the area of the main extension plane (HSE). ending with a sidewall profile etched in the cardinal direction (P) parallel to
When viewed in the cardinal direction P, the side wall profile 2 extends from a first edge 15 on the upper side 31 of the metal layer 12 facing away from the insulating layer 11 . extending to a second edge (16) on the bottom side (32) of the metal layer (12),
The side wall profile 2 when viewed in the cardinal direction P has at least one first section A1 with a straight course and at least one second section A2 with a curved course.

Description

Carrier substrates and methods for manufacturing carrier substrates for electrical, especially electronic components

The present invention relates to carrier substrates and methods for manufacturing carrier substrates for electrical, particularly electronic components.

Carrier substrates are well known from the prior art, for example printed circuit boards or circuit boards, for example from DE 10 2013 104 739 A1, DE 19 927 046 B4 and DE 10 2009 033 029 A1. Typically, connection areas for electrical components and conductor paths are arranged on one component side of the carrier substrate, and the electrical components and conductor paths can be interconnected to form an electrical circuit. The essential components of the carrier substrate are an insulating layer, preferably made of ceramic, and a metal layer bonded to the insulating layer. Due to their relatively high dielectric strength, insulating layers made of ceramics have proven to be particularly advantageous. The metal layer can then be structured to provide conductor paths and/or connection areas for electrical components.

In addition to low thermal resistance, a resistance that contributes to the lifetime of the corresponding carrier substrate is also desirable. For example, it has proven advantageous to leave a depression in the edge area of the metal layer to reduce mechanical stress and improve the fracture behavior of the Mastercard. In particular, improvement of the fracture behavior of Master Card is disclosed in EP 1 061 783 A2. However, this generally reduces the effective working surface for connecting electrical or electronic components.

To improve thermal shock resistance, it is already known from DE 10 2018 123 681 A1 to provide a sidewall profile with local maxima and local minima. The side wall profile of EP 3 474 643 A1 provides at least two recesses in the side wall profile.

On the basis of this background, the present invention sets its object to further improve the carrier substrates known from the prior art, especially with regard to thermal shock resistance and/or effective size of the working surface.

This is solved by the carrier substrate according to claim 1 and the method according to claim 9. Additional advantages and features of the invention result from the detailed description and accompanying drawings as well as the dependent claims.

According to the invention, there is provided a carrier substrate, in particular a metal-ceramic substrate, comprising an insulating layer, preferably a ceramic layer, and a metal layer, wherein the metal layer has at least a sidewall profile, in particular an etched sidewall, in the cardinal direction parallel to the main stretch. Ending at the outermost circumference in the area having the profile, the sidewall profile when viewed in the cardinal direction extends from a first edge on the top side of the metal layer facing away from the insulating layer to a second edge on the bottom side of the metal layer facing the insulating layer, and When viewed from , the side wall profile has at least one first section with a straight course and at least one second section with a curved course.

Compared to carrier substrates known from the prior art, according to the invention it is provided that the side wall profile comprises a first section with a straight course and a second section with a curved course. This sidewall profile has been shown to not only provide the desired benefits in terms of thermal shock resistance, but also to be reliable in operation and easy to manufacture. In particular, it is possible to create a sidewall profile in a single etch step with a first section having a straight course and a second section having a curved course. A straight course is understood as a course of each first section, which can be described as a straight course or a curvature whose radius of curvature, taking production tolerances into account, is greater than 50 times the metal layer or the first thickness of the metal layer. For example, such a straight course can be seen in a cross-sectional view extending perpendicular to the main plane of extension.

Preferably, the insulating layer includes Al ₂ O ₃ , Si ₃ N ₄ , AlN, ZTA (zirconia reinforced alumina), MgO, BeO, SiC or high density MgO (greater than 90% of theoretical density), TSZ (tetragon stabilized zirconia). Alternatively, ZTA is used as a material for ceramics. In this context, it is conceivable that the insulating layer is designed as a compound or hybrid ceramic in which several insulating layers with different material compositions are overlapped and bonded together. Forms an insulating layer to combine various desired properties. For example, it is conceivable to form an IMB by forming an insulating layer of an organic material such as resin. Conceivable materials for the metal layer are copper, aluminum, molybdenum and/or their alloys, and laminates such as CuW, CuMo, CuAl, AlCu and/or CuCu, especially copper sandwiches with cuprous and cupric layers. Includes structure. Here, the particle size of the first copper layer is different from the second copper layer.

Preferably, the sidewall profile is created by an etching step. Alternatively or additionally, it may be contemplated that the sidewall profile is created by milling and/or laser ablation. Furthermore, the carrier substrate is preferably provided with at least one additional metal layer and/or one additional insulating layer in addition to the metal layer and the insulating layer. In this case, the carrier substrate is preferably assembled in a sandwich structure, and the insulating layer is arranged between the metal layer and the additional metal layer. More preferably, the additional metal layer is provided as unstructured. That is, the additional metal layer is continuous on the side of the ceramic layer opposite the metal layer. In this case, the additional metal layer forms a back metallization that allows the use of relatively thin insulating layers, for example less than 800 μm.

It is also conceivable that when viewed along the circumferential direction (i.e. along the direction along the general path of the first and second edges around the working surface) the second edge limits the mating surface in the main extension plane and thus has: You can. It has a circumferentially serpentine stamp edge shape and/or a serrated course, in particular the serpentine stamp edge shape and/or serrated course extending over the entire circumferential second edge. metal layer. The serpentine stamp edge shape and/or serrated course of the metal layer extends only over a partial region of the second edge of the metal layer or a plurality of partial regions are adjacent to each other at a certain distance when viewed in the circumferential direction. By forming a structured and/or modulated course of the second edge, its surface enlargement is arranged such that the latter can be advantageously distributed essentially independently of the location of occurrence of the mechanical stress. Preferably, the first edge is similarly modulated. However, the side wall profile in the direction of rotation may have irregular recesses, i.e. small and large recesses that are mixed or alternating with each other, or in a wavy, rectangular, parallelogram or jagged design.

In particular, the bonding surface is provided such that it does not extend over the entire length of the insulating layer along the cardinal direction. That is, the insulating layer protrudes in the direction of the main extension plane relative to the metal layer, in particular relative to the second edge. Preferably, the metal layer is structured and the first and second edges are formed as a result of structuring measures, for example etching of isolation trenches or surface milling. Furthermore, the metal layer can be considered to have weakening material in the peripheral area extending from the first edge towards the center of the metal layer or towards the working surface, i.e. inward. Accordingly, when viewed in the cardinal direction, the peripheral area is on the opposite side of the sidewall profile with respect to the first edge. Material weakening should be understood in particular as a change or modulation of the metal layer thickness. For example, material weakening should be understood as a dome-shaped depression on top of a metal layer. Preferably, the ratio of the extended length of the edge region and the total length of the metal layer bisected in the same direction is a value of 0.25 or less, more preferably 0.15 or less, and most preferably 0.1 or less. It is also conceivable that an additional peripheral area is formed on the metal layer opposite the peripheral area when viewed in the cardinal direction (the ratios described here take into account the extension of the peripheral area and the additional peripheral area). Preferably, the dimensions of the peripheral area, i.e. in particular the ratio of the extension of the peripheral area seen in the cardinal direction with respect to the entire length of the metal layer measured in the same direction, are determined depending on the first thickness of the metal layer. For example, for a metal layer with a first thickness greater than 150 μm (e.g., 0.4 to 2.5 mm), the ratio of the peripheral area extent when viewed in the cardinal direction to the entire length of the metal layer is 0.35 or less, when measured in the same direction; Preferably it is 0.25 or less, most preferably 0.18 or less. In this case, the extent or total length is measured in particular in a direction perpendicular to the path of the first edge. In particular, the extended measurement starts from the first edge and goes towards the central region of the metal layer.

It is also preferred that the second edge is circumferentially covered, in particular at least partially or completely, with filler material. In this case, the filler is suitable to suppress the formation of cracks at the edges, i.e. to suppress or even completely prevent their expansion. Preferably, the filler comprises a plastic material such as polyimide, polyamide, epoxy or polyetheretherketone. In this context, it is also conceivable that ceramic components are added to plastic materials. Examples of such additives are silicon nitride, aluminum nitride, aluminum oxide, boron nitride or glass.

It is also conceivable for carbon fibers, glass fibers and/or nanofibers to be added to the plastic material. Preferably, the filler material is provided to be heat-resistant, i.e., such that the filler material does not melt at the temperatures encountered during the manufacture of the carrier substrate after application of the filler material and/or during soldering. Furthermore, the filler material is further preferably provided so as to be suitable for forming a strong and sound bond with the insulating layer, preferably the selected ceramic material, and the metal layer, preferably the selected metal such as copper. It is also intended that the coefficient of thermal expansion of the filler material is equal to or greater than that of the insulating layer and/or metal layer. For example, the coefficient of thermal expansion of the filler is more than three times greater than that of the metal layer.

Preferably, the sidewall profile has a local maximum and at least one local minimum, namely a local maximum and a local minimum, arranged between the first edge and the second edge. For the purposes of the present invention, the terms “maximum” and “minimum” mean the height or thickness of the metal layer at that location relative to the surface of the insulating layer facing the metal layer. That is, protrusions or protrusions, for example in the form of pre-mounds or pre-ridges, are formed in the side wall profile. Advantageously, it has been found that a sidewall profile with at least one local maximum and one local minimum can significantly improve thermal shock resistance. In particular, the cardinal direction extends outward, ie from the area provided as a working surface by the metal layer to the metal-free area on the carrier substrate. The improvement of the thermal shock resistance due to the sidewall profile with local maxima and local minima advantageously allows material weakening, for example in the form of a dome-shaped cavity, to be omitted in the peripheral area. The working surface above the metal layer can be increased. In this case, the side wall profile is formed in a cross section perpendicular to the main extension plane and parallel to the cardinal direction or outside the metal layer in that cross section. Preferably, the number of local maxima and local minima is in each case 5 or less. More preferably, there is exactly one local maximum and one local minimum.

It is preferable that an inflection point or a reversal point is formed between the first edge and the second edge. Preferably, the local maximum is located between the inflection point or turning point and the second edge, and the local minimum is located between the first edge and the inversion point or inflection point. For example, the sidewall profile can be described at least in part by a third-order polynomial. It is conceivable to design the side wall profile to be at least 50%, preferably at least 75%, along the circumference of the metal layer, that is, along a closed curve within the main extension plane at the outermost circumference of the metal layer. It is desirable to have complete local maxima and local minima. By local maximum/minimum, the person skilled in the art understands in particular the region where the sidewall profile is no more/less than the local maximum/minimum. In this context, the sidewall profile in the form of a global maximum or minimum may assume values greater or less than the local maximum or minimum. For example, the sidewall profile at the first edge assumes an overall maximum and at the second edge it assumes an overall minimum. Additionally, it is preferred that the edge profile extends continuously, i.e. essentially continuously, along the cardinal direction.

Preferably, the straight course of the at least one first section is inclined with respect to the main extending plane by a second angle greater than 20°, preferably between 20° and 50°, more preferably between 25° and 40°. It is intended to be It was found that such a steep straight course is possible without negatively affecting thermal shock resistance or sidewall profile generation. At the same time, due to the relatively steep inclination, the arrangement of the individual metal sections of the carrier substrate is designed to be as economical and space-saving as possible in terms of installation space.

Preferably, the curved area of the at least one second section is intended to be concavely curved. Preferably, only one second section, in particular only one concavely curved second section, is intended or intended to be formed.

Additionally, it is preferred that at least one first section is arranged between the local maximum and the second edge. In particular, it is intended that only one first section is arranged between the local maximum and the second edge and preferably only one first section and only one second section are formed. In particular, the straight course extends from the second edge to a local maximum, in particular the local maximum closest to the second edge. That is, the first section does not include a curved section or has no curved section. If we think about it, the first section comprises, for example, a plurality of differently inclined straight courses. Moreover, it is alternatively and/or additionally conceivable for a plurality of curved areas with different radii of curvature to be formed in the second section.

According to a preferred embodiment of the invention, the metal layer is intended to have a first thickness outside the side wall profile, in particular in the central region intended as the working surface, and a second thickness at the local maximum, where the second thickness is Less than 1 thickness. This ensures that local maxima do not protrude from the top of the metal layer. In this case, the local maximum extends circumferentially in a bead-like manner and forms a protrusion in height with respect to the overall maximum of the side wall profile, ie the first edge.

In this case, the ratio of the second thickness to the first thickness is 0.55 or less, preferably 0.5 or less, more preferably 0.45 or less. Properly fixing the second thickness ensures that a straight course is established between the first section, particularly the local maximum, and the second edge.

The local maximum can be thought of as part of a plateau or dome-shaped protrusion. When viewed in the circumferential direction (i.e. along the direction of extension of the first edge or the second edge), the local maximum is at least 50% of the total circumference of the metal layer, preferably at least 75% of the metal layer, more preferably at least 75% of the metal layer. extends completely along the circumference of the metal layer. It is also preferred that the metal layer has a first thickness at the first edge, in particular representing the first thickness of the maximum thickness of the metal layer.

Advantageously, the sidewall profile measured in the cardinal direction extends over a first length between the first edge and the second edge, wherein the ratio between the first length and the first thickness takes a value between 0.5 and 2.5. It is intended. Preferably it is between 0.8 and 2.2, most preferably between 1.1 and 1.9. This allows a relatively wide sidewall profile to be realized. By comparison, the ratio of the first length to the first thickness is typically less than or equal to 0.5. This expansion of the sidewall profile has been shown to have a positive impact on thermal shock resistance as well as support heat dissipation. This is because, especially for components placed very close to the first edge, the area under the sidewall profile of the metal layer for heat transfer can also be used. The wide sidewall profile also allows the structure to be set into local maxima and local minima in a more controlled manner. Preferably, the second thickness is intended to be measured at a distance of 2/5 of the first length from the second edge, when viewed in the cardinal direction, especially if local maxima should not be clearly visible from the side wall profile.

Preferably, the sidewall profile is intended to extend from the second edge on the bottom side to a local maximum over a second length, wherein the ratio between the second and first lengths is between 0.2 and 0.7, more preferably 0.25. Assume a value between and 0.6, most preferably 0.3 to 0.5. In other words, it turns out to be particularly advantageous if the local maximum, i.e. the local height of the sidewall profile when viewed from the second edge, is arranged in the first half, or preferably in the area between the first edges. The sidewall profile is half and first 1/3. In this way, local maxima are located particularly at the outermost edges of the metal layer, supporting the thermal shock resistance of the entire carrier substrate.

Preferably, the first imaginary straight connecting line passing through the first edge and the second edge is inclined at a first angle with respect to the bonding surface where the metal layer is bonded to the insulating layer, and the first straight first connecting line passes through the first edge and the second edge. 2 The connection line is preferably formed by passing through the metal layer. The second edge and the local maximum are inclined at a second angle relative to the mating surface, wherein the ratio of the second angle to the first angle is less than or equal to 0.8, more preferably less than or equal to 0.7, and most preferably less than or equal to 0.6. This is further advantageous for carrier substrates with a relatively large first thickness, for example between 0.4 mm and 2.5 mm. In this embodiment, the local maximum is intended to be formed in a flat sidewall profile, especially within the first third. It has already been shown that a significant improvement in thermal shock resistance can already be achieved by using a very flat sidewall profile of the first third (viewed from the second edge) with local maxima that are not very pronounced. Additionally, these courses can be covered relatively easily with fillers or grouting materials. In the case of a carrier substrate having a relatively small first thickness, it is more preferred that the second angle is larger than the first angle. For example, the ratio of the second angle to the first angle assumes a value between 0.5 and 2, more preferably between 0.6 and 1.6, and most preferably between about 0.7 and 1.2. Instead of a local maximum, it is also conceivable to place a point outside the sidewall profile at a distance of 2/5 times the first length from the second edge when viewed in the cardinal direction.

Preferably, it is intended that the second angle is smaller than the first angle or the first angle is larger than the second angle. This ratio between the first and second angles has been shown to be particularly advantageous for carrier substrates with a relatively large first thickness. Preferably, in this case the first thickness is greater than 300 μm, more preferably greater than 400 μm, most preferably greater than 500 μm or even greater than 1 mm. For example, the first thickness assumes a value between 300 μm and 5 mm, more preferably between 400 μm and 3 mm, and most preferably between 500 μm and 1 mm. Most preferably, the first thickness is greater than 1.3 mm, and most preferably greater than 1.8 mm.

Preferably, the ratio between the first angle and the second angle varies along a circumferential direction running parallel to the main plane of extension; In particular, the ratio is periodically modulated, for example. In this context, it is conceivable that the ratio between the first and second angles is also at least partially reversed. That is, there are parts where the first angle is greater than the second angle and parts where the second angle is greater than the first angle.

In a preferred embodiment, the ratio between the second thickness and the first length is intended to assume a value of between 0.08 and 0.4, more preferably between 0.09 and 0.35, most preferably between 0.1 and 0.3 or even 0.2. The angle is smaller than the first angle. In particular, at values between 0.1 and 0.3, the thermal shock resistance is greatly improved, significantly extending the life of the carrier substrate.

In a further embodiment of the invention, the metal layer is intended to have a third thickness as a local minimum, wherein the ratio of the third thickness to the second thickness is between 0.1 and 1, more preferably between 0.3 and 0.95, more preferably assumes a value between 0.5 and 0.9. This is particularly advantageous if the local minimum has a thickness significantly smaller than the local maximum, for example when grouting material or filler material can penetrate into the depressions in the area of the local minimum, leading to It has been proven that Applies to additional shape alignment, for example when viewed from the cardinal directions. In this case, the ratio of the third thickness to the second thickness may vary when viewed in the circumferential direction. In particular, the ratio between the third thickness and the second thickness can be periodically modulated along the circumferential direction.

In a particularly preferred embodiment, the metal layer has a thickness of 0.2 to 1 mm, more preferably 0.25 to 0.8 mm, most preferably 0.3 to 0.6 mm or 0.4 to 2.5 mm, more preferably 0.5 to 2 mm, most preferably 0.6 mm. It is intended to have a first thickness of between 1.5 mm and 1.5 mm. Advantageously, sidewall profiles with local maxima and local minima have been shown to have a beneficial effect on thermal shock resistivity for carrier substrates with one typical first thickness and for relatively large first thicknesses. Preferably, the first thickness is greater than 1 mm, more preferably greater than 1.5 mm and most preferably greater than 2 mm. Particularly in the case of carrier substrates with a relatively large first thickness, it is desirable for the insulating layer, i.e. in particular the ceramic layer, to accommodate a thickness of less than 1.1 mm, preferably less than 0.8 mm and more preferably less than 0.6 mm. This additionally allows the heat diffusivity of the carrier substrate to be optimized.

Preferably, the sidewall profile when viewed in the cardinal direction is intended to extend over a first length that is no greater than 1000 μm, more preferably between 150 μm and 800 μm, and most preferably between 300 μm and 600 μm. This makes it possible to provide a relatively narrow sidewall profile, which allows the metal sections to be arranged on the carrier substrate in a space-saving manner.

Another aspect of the invention relates to a master card comprising a plurality of carrier substrates separated from each other by at least one predetermined cut line, wherein the predetermined cut line is adjacent to a local maximum and a sidewall profile having the local maximum. So it extends along this. It is especially minimal along the second edge. The individual carrier substrates are cut and separated during the manufacturing process along predetermined cut points. Preferably, the predetermined breaking point runs along the sidewall profile of the additional metal layer, ie the sidewall profile opposite the metal layer to the insulating layer in the stacking direction perpendicular to the main expansion plane. The sidewall profile according to the invention has been shown to have a beneficial effect on the fracture behavior of the Master Card during separation of the individual carrier substrates. In particular, the probability of damage to the carrier substrate during separation is reduced, thereby reducing the need to exclude unusable carrier substrates. In particular, the amount of metal per unit volume (specific amount of metal) in the side wall profile is 20-70%, more preferably 20-65%, most preferably 25-50% compared to the central area of the metal layer with the working surface. It is intended to decrease to

Preferably, the side wall profile, especially the second edge, for example of the additional metal layer or back metallization, has a distance from the predetermined breaking point measured in the cardinal direction of less than or equal to 1 mm, more preferably between 0.05 and 1 mm. Preferably, the ratio of the distance measured in the cardinal direction between the second edge and the predetermined breaking point and the first length is a value between 0.3 and 2.5, more preferably between 0.4 and 2.0, most preferably between 0.5 and 1.5. Take the value between This applies in particular to relatively large first thicknesses, ie between 0.4 mm and 2.5 mm. Preferably, it is intended that the distance between the second edge and the predetermined breaking point, measured in the main direction, is less than the first length. Furthermore, in order to separate the individual carrier substrates, it is intended to provide two predetermined groups of breaking points that intersect each other and preferably run perpendicularly.

Preferably, the carrier substrate is embedded within the encapsulation, especially together with the first electrical component. The carrier substrate, especially with its curved etched edge profile, can be embedded particularly effectively with encapsulation and forms an effective shape fit or fixation. This particularly applies to etch edge profiles where the second angle is greater than the first angle. In this case, the encapsulation is preferably solid, so that no cavities are formed between the encapsulation and the carrier substrate. This makes it advantageous to realize particularly compact electronic modules in which the carrier substrate is advantageously protected from impacts.

Furthermore, it is preferably intended that the second electrical component is external to the encapsulation, where the first electrical component is connected to the first electrical component via an interconnection, which preferably passes through the encapsulation. For example, the interconnection in the as-manufactured state is intended to contact the upper side of the first electrical component, i.e. with the terminal on the opposite side of the carrier substrate in the stacking direction in the assembled state. Moreover, it is preferred that the additional metallization, in particular the structured metallization, is intended to be external to the encapsulation to allow easy connection of the second electrical or electronic component.

Preferably, the manufactured carrier substrate has a bonding layer formed between the metal layer and the insulating layer, and the bonding agent layer of the bonding layer preferably has a sheet resistance greater than 5 ohm/sq, more preferably greater than 10 ohm/sq, More preferably, it is greater than 20 ohm/sq. Compared to the carrier substrate known in the prior art, the sheet resistance of the binder layer of the bonding layer is already greater than 5 ohm/sq, more preferably greater than 10 ohm/sq, and most preferably greater than 20 ohm/sq. It is intentional. The determined sheet resistance is directly related to the proportion of active metal in the binder layer, which is critical to the bonding of the at least one metal layer to the insulating layer. Sheet resistance increases as the active metal content of the adhesive layer decreases. A correspondingly high sheet resistance therefore corresponds to a low active metal content in the binder layer.

It has been shown that increasing the active metal content favors the formation of a brittle intermetallic phase, which in turn is detrimental to the pull-out strength of the metal layer relative to the insulating layer. In other words, challenging sheet resistance is used to describe improved pull-off strength, i.e. increased bonding layer, due to reduced formation of brittle intermetallic phases. A particularly strong bond between the at least one metal layer and the ceramic element can therefore be achieved by selective adjustment of the sheet resistance. This increased bond strength has a beneficial effect on the service life of the carrier substrate. To determine the sheet resistance, we first try to remove the metal layer and, if necessary, the solder base layer from the fabricated carrier substrate, for example by etching. Thereafter, the sheet resistance is measured through four-point measurements on the top side or bottom side of the carrier substrate from which at least one metal layer and solder base layer have been removed. In particular, the sheet resistance of a material sample should be understood as the resistance over a square surface area. Surface resistance is generally expressed in Ohm/sq (square) units. The physical unit of sheet resistance is Ohm.

Preferably, the thickness of the bonding layer measured in the stacking direction is intended to be averaged over a plurality of measurement points within a predetermined area or within a plurality of areas parallel or running parallel to the main extension plane to assume a value of . is 0.20 mm or less, more preferably 10 μm or less, and most preferably 6 μm or less. When referring to a plurality of regions, it is meant in particular that one or more metal layers are subdivided into regions of equal size as much as possible and that one or more values for the thickness, preferably a plurality of measurements, are recorded. In each of these areas, at least one metal layer is subdivided. The thicknesses determined at different points are arithmetically averaged.

Preferably, the bonding layer is a binder layer containing an active metal, and preferably the proportion of the active metal in the binder layer containing an active metal is 15% by weight or more, preferably more than the above weight%, and most preferably Preferably it is 25% by weight or more.

Preferably, the bonding layer and/or the additional bonding layer is intended to be a bonding layer comprising an active metal. In particular, the bonding layer is intended to be formed solely from a bonding layer containing an active metal. In this case, the binder layer within the binder layer has a bond with the components of the ceramic elements such as nitrogen, oxygen, and carbon and other components of the ceramic. In a corresponding manner, the binder layer comprises, for example, titanium nitride, titanium oxide, and/or titanium carbide. For example, the bonding layer includes only a bonding layer containing an active metal, i.e., the bonding layer does not have silver or other basic solder components. In this case, the thickness of the bonding layer measured in the stacking direction for a plurality of measurement points within the main extending plane or a surface parallel to the plurality of surfaces is less than 0.003 mm (3000 nm), more preferably 0.001 mm (1500 nm). It is intended to assume values that are smaller, most preferably smaller than 0.0005 mm (500 nm) or even smaller than 0.00035 mm (350 nm). In particular in the case of these bonding layers in which the solder base material and/or the silver component are omitted, much thinner bonding layers can be formed in a corresponding manner.

In particular, the binder layer comprising the active metal is intended to have a substantially constant thickness, in particular in contrast to the solder base layer, which is modulated due to the bending of the insulating layer. In particular, the measurements of thickness measured within the surface or surfaces have a distribution assigned a standard deviation of less than 0.2 μm, more preferably less than 0.1 μm, more preferably less than 0.05 μm. In particular, physical and/or chemical vapor deposition of the active metal layer and the resulting bonding layer makes it possible to achieve a homogeneous and uniformly distributed thickness of the bonding layer, in particular consisting solely of the binder layer. In this context, the binder layer may have a certain thickness if it is formed additionally on the solder base material.

In another aspect of the invention, the carrier substrate, in particular a metal-ceramic substrate, comprises an insulating layer and a metal layer, the metal layer having a sidewall profile etched in at least regions in the main direction extending parallel to the main plane of extension (HSE). , ending in particular with an etched sidewall profile, wherein, when viewed in the cardinal direction, the sidewall profile extends from a first edge on the upper side of the metal layer facing away from the insulating layer to a second edge on the lower side of the metal layer towards the insulating layer. do. A layer characterized in that, when viewed in the cardinal direction, the side wall profile has at least one first section with a convex curved course and at least one second section with a concave curved course. All the advantages and features described in relation to a carrier substrate with a straight first section can similarly be transferred to a carrier substrate with a convexly curved second section.

In particular, it has been demonstrated that this sidewall profile not only provides the desired advantages in terms of thermal shock resistance, but is also reliable in operation and easy to manufacture. In particular, it is possible to create a sidewall profile in a single etch step with a first section having a straight course and a second section having a curved course. In this regard, it is further preferred that the first section is formed immediately adjacent to the second edge and the second section is formed immediately adjacent to the first edge. A third straight section is believed to be formed between the first and second sections. For example the side wall profile consists of a first section, a second section and a third section.

It is also conceivable for the straight third section to be arranged immediately adjacent to the second edge and/or between the first and second sections.

Preferably, the convexly curved first section is intended to have a first radius of curvature greater than 200 μm, more preferably greater than 400 μm, more preferably greater than 1000 μm, more preferably greater than 5000 μm, wherein the concave The second section of the curved portion preferably has a second radius of curvature that is larger than the first radius of curvature. It is also conceivable that the first radius of curvature is larger than the second radius of curvature. The fourth length of the straight third section is preferably smaller than the first radius of curvature and/or the second radius of curvature, more preferably at least 3 times smaller, more preferably at least 5 times smaller or even 7.5 times smaller. It is more than twice smaller. In particular, it was shown that thermal shock resistance can be optimized by adjusting the ratio of the radius of curvature.

For example, the ratio of the first radius of curvature to the first radius of curvature takes a value between 0.8 and 33, more preferably between 2 and 33, and most preferably between 10 and 33. The curvature and/or the second radius of curvature is smaller than the first thickness.

Moreover, it is more desirable if the first edge protrudes at the beginning of the side wall profile, preferably in the second section, at the first edge in the cardinal direction. That is, the edge progression is initially towards the center of the metal layer and then curves towards a second edge on top of the ceramic element.

Another aspect of the invention relates to a method for producing a carrier substrate according to any one of the preceding claims, wherein the sidewall profile is preferably produced by an etching step, in particular a single etching step. All the features and advantages described for the carrier substrate can be similarly transferred to the process and vice versa.

Additionally, it is further preferred that masking using striped masking sections over subsequent sidewall profiles is used for etching. This ensures that the desired sidewall profile is reliably achieved during operation. A person skilled in the art will position and dimension the stripe masking sections in a manner that achieves the required sidewall profile. The path of the striped masking section therefore determines the subsequent edge path of the structured metal section.

To bond a metal and a ceramic, the metal layer is preferably bonded to the insulating layer by an AMB process and/or a DCB process.

Those skilled in the art understand that the “DCB process” (direct copper bonding technology) or “DAB process” (direct aluminum bonding technology) is a process that serves for example to join metal layers or sheets (e.g. copper sheets or foils). or aluminum sheets or foils) using metal or copper sheets or metal or copper foils having a layer or coating (fused layer) on the surface to bond them to each other and/or to the ceramic or ceramic layer. In the process described for example in US 3 744 120 A or DE 23 19 854 C2, this layer or coating (melting layer) forms a eutectic with a melting temperature lower than that of the metal (e.g. copper). Placing a foil over a ceramic and heating all the layers essentially melts the metal or copper only in the molten or oxide layer areas and allows them to bond together.

In particular, the DCB process has the following process steps, for example:

- oxidizing the copper foil to create a uniform copper oxide layer;

- placing copper foil on the ceramic layer;

- heating the compound to a processing temperature of about 1025 to 1083° C., for example about 1071° C.;

- Cooling to room temperature.

The active soldering process for joining, for example, a metal layer or a metal foil, in particular a copper layer or copper foil, with a ceramic material is understood as a process that is also used in particular for the production of metal-ceramic substrates. In addition to the main components such as copper, silver and/or brazing alloys are used to braze between a metal foil (e.g. copper foil) and a ceramic substrate (e.g. aluminum nitride ceramic) at temperatures between approximately 650 and 1000°C. Alternatively, gold also contains active metals. This active metal, for example at least one element of the group Hf, Ti, Zr, Nb, Ce, establishes the connection between the solder and the ceramic through a chemical reaction, while the connection between the solder and the metal is metallic. Brazing connection. Alternatively, thick film processes may also be considered for adhesion.

It is more preferable that the metal layer is bonded to the insulating layer by a DCB process or a DAB process. Surprisingly, it was found that thermal shock resistance can be significantly improved especially when the metal layer is bonded to the insulating layer by the DCB process.

According to a further aspect of the invention, the method for producing a carrier substrate, in particular a metal-ceramic substrate, according to the invention is intended to comprise:

- providing at least one metal layer and an insulating layer, in particular a ceramic element, a glass element, a glass-ceramic element and/or a heat-resistant plastic element, the at least one metal layer and the insulating layer extending along the main expansion plane,

- arranging the at least one metal layer and the insulating layer vertically in a stacking direction extending perpendicular to the main extension surface, disposing an active metal layer between the at least one metal layer and the insulating layer,

- Bonding the at least one metal layer to the insulating layer via the active metal layer, forming a bonding layer between the at least one metal layer and the insulating layer. All advantages and properties described for metal-ceramic substrates can be similarly transferred to the process and vice versa.

In particular, certain processes make it possible to realize sheet resistances of at least 5 ohm/sq, more preferably at least 10 ohm/sq and most preferably at least 20 ohm/sq. Finally, the described process makes it possible to realize a technically useful connection between the ceramic element and the metal layer and to realize a thin and homogeneously thick bonding layer with the above sheet resistance.

In particular, the use of a separately applied active metal layer allows it to be made relatively thin, thus realizing the required relatively thin thickness of the bonding layer, especially averaged over the various blade values within a particular region(s). Examples of active metals include titanium (Ti), zirconium (Zr), hafnium (Hf), chromium (Cr), niobium (Nb), cerium (Ce), tantalum (Ta), magnesium (Mg), lanthanum (La), and Vanadium (V), etc. It should be noted here that the metals La, Ce, Ca and Mg can be easily oxidized. Additionally, the elements Cr, Mo and W are not typical active metals, but they do not form intermetallic phases with at least one metal layer (e.g. copper) and have no solid solubility, so they are active metals with Si ₃ N ₄ and at least one metal layer or solder. It should be noted that it is suitable as a contact layer between system or solder materials.

Preferably, the active metal content in the active metal layer is intended to be at least 15% by weight, more preferably at least 25% by weight and most preferably at least 25% by weight.

Preferably it is intended that the proportion of non-metallic impurities in the aligned active metal layer is 0.1% by weight or less, more preferably 0.05% by weight or less and most preferably 0.01% by weight or less. Minimizing impurities is advantageous in making the layer thickness smaller because, if impurities are present, only a portion of the active metal can contribute to bonding at least one metal layer to the insulating layer, while the remaining active metal is bound by the impurities. By appropriately ensuring a relatively low impurity ratio, more effective bonding is realized, which reduces the proportion of active metals and can consequently make the bonding layer thinner.

Preferably, an active metal layer with a thickness of 10 nm to 1000 nm, more preferably 50 nm to 750 nm and most preferably 100 to 500 nm is intended to be used. Furthermore, the active metal is preferably applied by physical and/or chemical vapor deposition to the insulating layer and/or solder base material, which is preferably also in the form of a foil. For example, it is conceivable to roll the active metal together with the solder material to the desired thickness to form a relatively thin bonding layer between at least one metal layer and the insulating layer.

Preferably, a solder film of 20 μm or less, more preferably 12 μm or less, and most preferably 8 μm or less is used. For example, the thickness of the solder layer assumes a value between 2 and 20 μm, or between 2 and 5 μm, more preferably between 8 and 15 μm, and most preferably between 5 and 10 μm. It is also conceivable for the solder substrate to be provided as a foil, a paste, a layer formed by physical and/or chemical vapor deposition, and/or an electroplated layer.

It is also conceivable that bonding through the active metal layer is performed during a hot isotropic pressing process. Preferably, in the hot isotropic press the metal vessel is subjected to a heating and pressure device at a gas pressure of 100 to 2000 bar, more preferably 150 to 1200 bar, most preferably 300 to 1000 bar and a processing temperature of at least 300°C. It is preferred that the temperature is applied up to the melting temperature of one metal layer, especially below the melting temperature. Accordingly, the metal layers, i.e. the first metal layer and/or the second metal layer of the metal vessel, can be formed directly in a metal bonding process, for example without the required temperature of the DCB or DAB process and/or as a solder base material used in the active solder process. It is advantageously shown that it is possible to bond to the ceramic element without. Additionally, by utilizing or using appropriate gas pressure, metal ceramic substrates can be manufactured with as few voids as possible without gas inclusions between the metal layer and the ceramic element. In particular, the process parameters mentioned in DE 2013 113 734 A1 and explicitly referenced herein are used.

Furthermore, it is further preferred that at least one metal layer and/or at least one further metal layer are joined to the insulating layer by an active soldering process and/or a hot isostatic pressing process and/or DCB. process. For example, the method of manufacturing a metal-ceramic substrate is intended to include:

- providing a soldering layer, especially in the form of at least one soldering foil or brazing foil,

- coating the insulating layer and/or at least one metal layer and/or at least one solder layer with at least one active metal layer,

- arranging at least one solder layer between the insulating layer and the at least one metal layer along the stacking direction to form a solder system comprising the at least one solder layer and the at least one active metal layer, the solder material at least one solder layer is preferably free of melting point lowering substances or phosphorus-free substances,

- Joining at least one metal layer to at least one ceramic layer via a soldering system by an active soldering process.

In particular, a multilayer soldering system is intended, comprising at least one solder layer, preferably a solder layer free of melting point lowering elements, more preferably free of phosphorus, and at least one active metal layer. The separation of at least one active metal layer and at least one solder layer has proven to be particularly advantageous since relatively thin solder layers can be realized, especially if the solder layer is a foil. Otherwise, relatively large solder layer thicknesses must be achieved for solder materials containing active metals due to the brittle intermetallic phase and the high elastic modulus and high yield strength of typical active metals. Therefore, for active metal-containing solder layers, it is not the minimum thickness required for the joining process that determines the minimum solder layer thickness of the solder layer, but the minimum technically feasible layer thickness of the solder layer. Minimum solder layer thickness of the solder layer. As a result, thicker solder layers containing active metal are more expensive than thinner layers. By being free of phosphorus, those skilled in the art will understand that in particular the proportion of phosphorus in the solder layer is less than or equal to 150 ppm, less than or equal to 100 ppm and most preferably less than or equal to 50 ppm.

In the present invention, the term essentially means a deviation of +/- 15%, more preferably +/- 10%, most preferably +/- 5% from the respective exact value and/or a deviation that is not critical to the function. It means deviation in the form of change.

Additional advantages and features arise from the following description of preferred embodiments of the subject matter according to the invention with reference to the accompanying drawings. Accordingly, the individual features of the individual embodiments may be combined with each other within the scope of the invention.

1 is a schematic diagram of a carrier substrate according to a first preferred embodiment of the present invention;
Figure 2 is a schematic diagram of a carrier substrate according to a second preferred embodiment of the present invention.
3 is a schematic diagram of a carrier substrate according to a third preferred embodiment of the present invention;
Figure 4 is a schematic diagram of a carrier substrate according to a fourth preferred embodiment of the present invention.

Figure 1 shows a carrier substrate 1 according to a first preferred embodiment of the invention. This carrier substrate 1 preferably serves as a carrier for electronic or electrical components that can be connected to the carrier substrate 1. The essential components of this carrier substrate 1 are an insulating layer 11 extending along the main extension plane (HSE) and a metal layer 12 bonded to the insulating layer 11. The insulating layer 11 is made of at least one material containing ceramic. The metal layer 12 and the insulating layer 11 are arranged up and down along the stacking direction S extending perpendicular to the main extension surface HSE, and are materially bonded to each other through the bonding surface 25. In the completed state, metal layer 12 is configured to form a conductor path or connection point for electrical components. For example, this structure is etched into the metal layer 12. However, a permanent bond, especially a material bond, must be formed between the metal layer 12 and the insulating layer 11 in advance.

Systems for producing carrier substrates for permanently bonding the metal layer 12 to the insulating layer 11 , especially in the SFB (super flat-bonding) bonding process, are designed, for example, when a pre-composite of metal and ceramics is heated, the bonding occurs. It comes true. For example, the metal layer 12 is made of copper, and the metal layer 12 and the insulating layer 11 are bonded using a Direct-Copper-Bonding (DCB) bonding process. Alternatively, metal layer 12 may be bonded to ceramic layer 11 using an active soldering process.

In particular, the metal layer 12 has an upper side 31 facing away from the ceramic layer 11 and a bottom side 32 facing away from the ceramic layer 11 . The upper side 31 of the metal layer 12 thereby comprises a working surface 17 on which, in particular, electrical or electronic components can be mounted. The upper side 31 is limited in the direction parallel to the main plane of extension HSE by the first edge 15, while the bottom side 32 of the metal layer 12 is connected via the bonding surface 25 to the ceramic layer ( 11) is physically combined with it. The mating surface 25 is limited outwardly in the direction parallel to the main plane of extension HSE by a second edge 16 . In this case, the first edge 15 and the second edge 16 are not limited outwardly by the second edge 15 and 16 when viewed in the stacking direction S perpendicular to the main extension plane HSE. . They lie congruent with each other but are offset from each other along the cardinal direction (P). In particular, the cardinal direction P extends, for example, from the central region of the metal layer 12 , where the working surface 17 is intended, to the outside of the area of the carrier substrate 1 free of metal, i.e. the essentially ceramic layer It is executed towards the area forming the exterior of (1). The first edge 15 is connected by a second edge 16. The side wall profile 2 extends along the cardinal direction P. For example, the sidewall profile 2 is created by an etching process, in particular a single etching step. The side wall profile 2 forms the outer side of the metal layer 12 in the area between the first edge 15 and the second edge 16, especially when viewed in a cross section extending perpendicular to the main plane of extension HSE. .

In order to improve thermal shock resistance, the side wall profile 2 is intended to have at least one local maximum 21 and at least one local minimum 22 between the first edge 15 and the second edge 16. . In this case, the local minimum 22, when viewed in the cardinal direction P, is preferably located between the first edge 15 and the local maximum 21.

In particular, it has been shown to be advantageous for thermal shock resistance if the side wall profile 2 has at least one first section A1 with a straight course and at least one second section A2 with a curved course. In the embodiment shown in Figure 1 exactly one first section A1 and exactly one second section A2 are formed. Accordingly, the first section (A1) is directly adjacent to the second section (A2). Preferably, the first section A1 extends in a straight course between the second edge 16 and the local maximum 21 .

In particular, the metal layer 12 is intended to have a first thickness D1 in the central region, i.e. in particular in the region of the working surface 17 and a second thickness D2 at the local maximum 21, where the first thickness (D1) is greater than the second thickness (D2). Preferably, the ratio of the second thickness D2 to the first thickness D1 is assumed to be 0.55 or less, more preferably 0.45 or less, and most preferably 0.35 or less. That is, the side wall profile 2 has additional convexities or ridges, for example in the form of hillocks or protruding ridges.

Furthermore, the side wall profile 2 measured in the cardinal direction P extends over a first length L1, and the ratio between the first length L1 to the first thickness D1 is between 0.5 and 2.5, furthermore Preferably it is intended to take values between 0.8 and 2.5. 2.2, most preferably between 1.1 and 1.9.

It is particularly preferred that the metal layer 12 has a third thickness D3 of a local minimum 22, where the ratio of the third thickness D3 to the second thickness D2 is a value between 0.1 and 1, further Preferably a value between 0.3 and 0.95 is assumed, and is most preferred. Preferably it is 0.5 to 0.9. Figure 1 also shows a first virtual straight connection line (V1) and a second virtual straight connection line (V2). The second connection line (V2) runs along the straight course of the first section (A1). The first connecting line (V1) passes through the first edge (15) and the second edge (16) and is inclined by a first angle (W1) with respect to the joining surface (25), while the second connecting line (V2) passes through the first edge (15) and the second edge (16). 2 passes through edge (16) and local maximum point (21). That is, the second connection line V2 is inclined by a second angle W2 with respect to the coupling surface 25. Preferably, the second angle W2 is intended to be greater than the first angle W1. For example, the ratio of the second angle W2 to the first angle W1 assumes a value between 0.5 and 2, more preferably between 0.6 and 1.6, and most preferably between about 0.7 and 1.2. . In particular, the second angle W2 takes a value greater than 20°, more preferably between 20° and 50°, and most preferably between 25° and 40°.

The sidewall profile 2 is intended to extend from the second edge 16 on the bottom side 32 over a second length L2 to a local maximum 21, where the second length L2 to the first length The ratio between (L1) assumes a value between 0.2 and 0.7, more preferably between 0.25 and 0.6, and most preferably between 0.3 and 0.5. Preferably, the ratio between the second thickness (D2) to the first length (L1) assumes a value between 0.05 and 0.5, more preferably between 0.08 and 0.4, most preferably between 0.1 and 0.3 or even 0.23. It is intended to.

Additionally, the first section (A1) is intended to extend in the dimensioned cardinal direction (P) over a second length (L2), and the second section (A2) is intended to extend over a fourth length (L4), wherein The ratio of the fourth length (L4) to the second length (L2) is assumed to be between 0.25 and 0.75, more preferably between 0.4 and 0.6, and most preferably between 0.45 and 0.55.

Additionally, in the illustrated embodiment of Figure 1, the first thickness D1 is between 0.2 mm and 1 mm, more preferably between 0.25 mm and 0.8 mm, and most preferably between 0.3 mm and 0.6 mm.

Figure 2 schematically shows a carrier substrate 1 according to a second preferred embodiment of the invention. Here, the embodiment essentially corresponds to that of Figure 1 in that the first thickness D1 has a value between 0.4 and 2.5 mm, more preferably between 0.5 and 2 mm, most preferably between 0.6 and 1.5 mm. It is different only in That is, compared to the embodiment of Figure 1, this is a relatively thick metal layer 12 in the central region. Preferably, the ratio of the second thickness 2 to the first thickness 1 is assumed to be between 0.01 and 0.5, more preferably between 0.05 and 0.4, and most preferably between 0.07 and 0.3. Preferably, the ratio of the second angle W2 to the first angle W1 is 0.8 or less, more preferably 0.7 or less, and most preferably 0.6 or less.

Figure 3 schematically shows a carrier substrate 1 according to a fourth preferred embodiment of the invention, wherein the sidewall profile 2 has several local maxima 21 and several local minima 22. In this case, the metal layer 12 has the same thickness at the local maximum 21 and local minimum 22, respectively. However, it is also conceivable that the metal layer 12 has different thicknesses at different local maxima 21 and/or local minima 22 . In particular, the embodiment of FIG. 3 has several second sections A2 between the local maximum 21 and the first edge 15 .

Figure 4 schematically shows a carrier substrate 1 according to a third preferred embodiment of the invention. In particular, the embodiment of FIG. 4 is characterized in that the first section A1 has a convex curve instead of the straight course of the first section A1. Accordingly, when viewed in the cardinal direction P, the side wall profile comprises at least one first section A1 with a convex curved course and at least one second section A2 with a concave curved course. Preferably, the first section A1 is arranged immediately adjacent to the second edge 16 and in particular the second section A2 is arranged immediately adjacent to the first edge 15 . A straight third section may be formed between the first section (A1) and the second section (A2). In an exemplary embodiment, the edge course includes a first section (A1), a second section (A2), and a third section (A3).

Furthermore, the convex course of the first section (A1) has a first radius of curvature (R1) and/or the concave course of the second section (A2) has a second radius of curvature (R2). Preferably, the first radius of curvature R1 is greater than 200 μm, more preferably greater than 400 μm, most preferably greater than 1000 μm and/or even greater than 5000 μm. Additionally, the second radius of curvature R2 is intended to have a value between 100 μm and 1000 μm, more preferably between 150 μm and 700 μm and most preferably between 180 and 500 μm.

Most preferably, the ratio of the first radius of curvature (R1) to the second radius of curvature (R2) is greater than 0.8, more preferably greater than 2, most preferably greater than 0.6 or greater than 10. It is intended to be assumed.

That is, the first radius of curvature R1 is larger than the second radius of curvature R2, in particular at least 1.5 times larger. For example, the ratio of the first radius of curvature to the first radius of curvature is assumed to have a value between 0.8 and 33, more preferably between 2 and 33, and most preferably between 10 and 33. Moreover, it is particularly intended that a corresponding ratio of the first and/or second radii of curvature is formed when the first thickness D1 of the metal is formed. Layer 12 is greater than 300 μm, more preferably greater than 400 μm, and most preferably greater than 500 μm. However, it is also conceivable that the first thickness D1 is smaller than 300 μm.

Additionally, it is conceivable that a third section A3 representing a straight course is disposed between the first section A1 having a convex curved course and the second section A2 having a concave curved course. Thereby, the straight course extends over a fourth length L4, which preferably assumes a value of less than 250 μm, more preferably of less than 150 μm and most preferably of less than 100 μm. Additionally, the insulating layer 11 or the ceramic element preferably has a thickness (D) that is smaller than the first thickness (D1) of the metal layer (12).

Furthermore, the first edge 15 is preferably intended to project at least relative to an adjacent partial area of the second section A2 when viewed in the main direction P. This creates a kind of protrusion above the concave second section and the edge course of the second section A2 slightly hollows out or recesses the metal layer 12 .

Furthermore, the side wall profile preferably extends from the first edge 15 to the second edge 16 over a distance greater than 0.5 mm along the cardinal direction P parallel to the main plane of extension HSE. Preferably, the ratio of the first length L1 to the first thickness D1 is greater than 0.5, more preferably greater than 0.65, and most preferably greater than 0.8. Additionally, it is conceivable that the ratio of the first length L1 to the first thickness D1 is 2.5 or less, more preferably 2.2 or less, and most preferably 1.8 or less. Preferably, the sidewall profile along the cardinal direction P is shorter than 2.5 mm, more preferably shorter than 2.2 mm and most preferably shorter than 1.8 mm. This indication, in particular regarding the length of the side wall profile and the second radius of curvature R2, preferably also applies to the embodiments of FIGS. 1 and 2 or to any embodiment in which a concave second section A2 is formed, for example For example, a straight first section D1 formed immediately adjacent the second edge 16 is provided.

1: Carrier substrate 2: Sidewall profile
8: Predetermined breaking point 11: Insulating layer
12: metal layer 15: first edge
16: second edge 17: work surface
21: Local value 22: Local minimum value
25: mating surface 31 upper side
32: bottom side 100: master card
D: Thickness D1: First thickness
D2: Second thickness D3: Third thickness
V1: 1st connection line V2: 2nd connection line
L1: first length L2: second length
L3: 3rd length L4: 4th length
W1: first angle W2: second angle
S: Stacking direction HSE: Main expansion plane
P: Cardinal direction R1: First radius of curvature
R2: Second radius of curvature A: Distance
A1: Section 1 A2: Section 2
A3: Section 3

Claims (15)

In the carrier substrate 1, especially a metal-ceramic substrate,
It includes an insulating layer 11 and a metal layer 12,
The metal layer (12) ends with an etched side wall profile (2), in particular in the cardinal direction (P) parallel at least in area to the main plane of extension (HSE),
When viewed in the cardinal direction P, the side wall profile 2 extends from a first edge 15 on the upper side 31 of the metal layer 12 facing away from the insulating layer 11 . extending to a second edge (16) on the bottom side (32) of the metal layer (12),
Carrier substrate, characterized in that the side wall profile (2) when viewed in the cardinal direction (P) has at least one first section (A1) with a straight course and at least one second section (A2) with a curved course. . 2. Carrier substrate according to claim 1, characterized in that the sidewall profile (2) has at least one local maximum (21) and at least one local minimum (22). 2. The method according to claim 1, wherein the straight course of the first section (A1) is greater than 20°, preferably between 20° and 50°, more preferably between 25° and 40°, with respect to the main plane of extension (HSE). A carrier substrate characterized in that it is inclined at a second angle (W2). 2. Carrier substrate according to claim 1, characterized in that the curved area of at least one second section (A2) is concavely curved. Carrier substrate according to any one of the preceding claims, characterized in that at least one first section (A1) is arranged between a local maximum and the second edge (16). The metal layer ( 12 ) according to claim 1 , wherein the metal layer ( 12 ) has a first thickness ( D1 ) outside the side wall profile ( 2 ), especially in the central area serving as the working surface ( 17 ), and a second thickness ( D2), and the ratio of the second thickness (D2) to the first thickness (D1) is 0.55 or less, more preferably 0.5 or less, and most preferably 0.45 or less. According to any one of the preceding claims, wherein the first virtual straight connecting line (V1) passing through the first edge (16) and the second edge (15) is a first connection line (V1) where the metal layer (12) is connected to the insulating layer (11). inclined with respect to the mating surface 25, joined at an angle W1,
An imaginary straight second connecting line V2 passing through the second edge 16 and the local maximum 21 forms a bonding surface ( 25) and is inclined at a first angle W1,
Carrier substrate, characterized in that the imaginary straight second connecting line (V2) passing through the second edge (16) and the local maximum (21) is inclined with respect to the bonding surface (25) at a second angle (W2). 2. The side wall profile (2) according to any one of the preceding claims, wherein the side wall profile (2) extends over a first length (L1) which, when viewed in the cardinal direction, is less than or equal to 1000 μm, more preferably between 150 μm and 800 μm, and most preferably between 300 μm and 600 μm. A carrier substrate characterized in that. In the carrier substrate 1, especially a metal-ceramic substrate,
It includes an insulating layer 11 and a metal layer 12,
The metal layer (12) ends with an etched side wall profile (2), in particular in the cardinal direction (P) parallel at least in area to the main plane of extension (HSE),
When viewed in the cardinal direction P, the side wall profile 2 extends from a first edge 15 on the upper side 31 of the metal layer 12 facing away from the insulating layer 11 . extending to a second edge (16) on the bottom side (32) of the metal layer (12),
Carrier, characterized in that the side wall profile (2) when viewed in the cardinal direction (P) has at least one first section (A1) with a convex curved course and at least one second section (A2) with a concave curved course. Board. 10. The method of claim 9, wherein the convexly curved first section has a first radius of curvature (R1) of at least 200 μm, more preferably at least 400 μm, most preferably at least 1000 μm, most preferably at least 5000 μm,
Carrier substrate, characterized in that the concavely curved second section (A2) preferably has a second radius of curvature (R2) that is greater or less than the first radius of curvature (R1). The method of claim 1, wherein a bonding layer 12 is formed between the metal layer 10 and the insulating layer 30 of the manufactured carrier substrate 1, and the bonding layer 13 of the bonding layer 12 is 5 ohm/ A carrier substrate characterized by having a sheet resistance of sq or more, more preferably 10 ohm/sq or more, and most preferably 20 ohm/sq or more. The method of claim 11, wherein the bonding layer 12 is a bonding layer 13 containing an active metal, and the proportion of the active metal in the bonding layer 13 including the active metal is 15% by weight or more, more preferably. A carrier substrate, characterized in that the above weight% or more, most preferably 25% by weight or more. Method according to any one of the preceding claims, characterized in that the sidewall profile (2) is preferably produced by an etching step, in particular a single etching step. Method according to any one of the preceding claims, characterized in that masking is used with striped masking sections on the subsequent side wall profile (2). Method for producing a carrier substrate (1) according to any one of claims 1 to 13, in particular a metal-ceramic substrate,
- Providing at least one metal layer (10) and an insulating layer (30), in particular a ceramic element (30), a glass element, a glass-ceramic element and/or a heat-resistant plastic element, at least one metal layer (10) and an insulating layer. (30) extends along the main extension surface (HSE),
- arranging the at least one metal layer 10 and the insulating layer 30 vertically in a stacking direction (S) extending perpendicular to the main surface (HSE), the at least one metal layer 10 and the insulating layer An active metal layer (15) is disposed between (30), and
- Bonding at least one metal layer 10 to the insulating layer 30 through the active metal layer 15 and forming a bonding layer 12 between the at least one metal layer 10 and the insulating layer 30. A method characterized by comprising: