Circuit carrier and method

Abstract

The invention relates to a circuit carrier and a method. The invention relates to a circuit carrier (10) for at least one electrical component (22), comprising a metal substrate layer (12), a first electrically insulating layer (14) arranged on the metal substrate layer (12), a second electrically insulating layer (16) arranged on the first electrically insulating layer (14), and an electrically conductive layer (18) arranged on the second electrically insulating layer (16), the electrically conductive layer has at least one conductor path (20) for electrically connecting at least one electrical component (22), at least one of the two electrically insulating layers (14, 16) being colored such that the two electrically insulating layers (14, 16) have different colours.

Description

Technical Field

[0001] The invention relates to a circuit carrier, in particular a circuit carrier designed as an insulated metal-based printed circuit board. The invention further relates to a method for producing a circuit carrier. The invention further relates to a method for determining the number of insulating layers in a circuit carrier. Background Art

[0002] Circuit carriers and in particular circuit carriers with metal substrate layers, as are present, for example, in insulated metal substrate printed circuit boards, must meet a wide range of requirements. An example of an important requirement, in particular in the automotive sector, is sufficient insulation of the aforementioned metal substrate layer with respect to electrical components electrically connected to the circuit carrier. In particular in the area of ​​quality management and / or component testing, strict regulations in the area of ​​insulation apply which need to be complied with. Summary of the invention

[0003] The object of the present invention is therefore to provide a circuit carrier which meets the high demands on the insulation capacity of the electrical components mounted on it. It is also an object of the present invention to provide a method for producing such a circuit carrier. It is also an object of the present invention to provide a method for determining the number of insulating layers in a circuit carrier.

[0004] These objects are achieved by the subject matter of the independent patent claims. Advantageous embodiments are the subject matter of the dependent claims.

[0005] According to a first aspect of the present invention, a circuit carrier is provided, in particular a circuit carrier configured as an insulated metal substrate printed circuit board for at least one electrical component. The circuit carrier comprises: a metal substrate layer, a first electrically insulating layer arranged on the metal substrate layer, a second electrically insulating layer arranged on the first electrically insulating layer, and a conductive layer arranged on the second electrically insulating layer, wherein the conductive layer comprises at least one printed conductor for electrically connecting at least one electrical component. In the circuit carrier according to the present invention, at least one of the two electrically insulating layers is colored, so that the two electrically insulating layers have different colors.

[0006] The circuit carrier according to the invention is based at least in part on the recognition that the latest requirements in the field of electrical insulation of circuit carriers with metal substrate layers require at least two clearly identifiable electrically insulating layers, which are applied on the metal substrate layer. The circuit carrier according to the first aspect is based at least in part on the recognition that these requirements can be met if two insulating layers applied directly one above the other have different colors. Due to the different colors, the electrically insulating layers can be clearly identified and the number of electrically insulating layers can be determined. Therefore, the circuit carrier according to the invention has at least one electrically insulating insulating layer, which is colored so that after coloring, the two electrically insulating layers have different colors. This idea is based on the recognition that in the case of insulating layers applied directly one above the other, it is impossible to identify two insulating layers arranged adjacent to each other themselves in some cases. However, due to the different colors, it is possible to clearly and unambiguously confirm the number of electrically insulating layers. This identification and / or determination of the number of insulating layers can be carried out, for example, in a test that can be performed to release the circuit carrier.

[0007] In an advantageous embodiment, at least one of the two insulating layers is colored so that the two insulating layers can be identified as two distinct or delimited insulating layers at least in a cross section of the circuit carrier, in particular in a cross-sectional grinding slice, on the basis of their different colors. This preferred embodiment is based at least in part on the recognition that in order to determine and / or evaluate the layer structure of such a circuit carrier, a cross-sectional grinding slice of the circuit carrier is usually produced. Producing the cross-sectional grinding slice may, for example, require exposing a cross-sectional surface, in particular a full cross section, of the circuit carrier. The exposed cross-sectional surface can then be prepared (for example, ground and / or polished) in order to be able to evaluate the number of layers and, if necessary, the layer thickness of the layers in the circuit carrier thus prepared. By coloring at least one of the two insulating layers according to the preferred embodiment so that the two insulating layers can be identified as two distinct insulating layers at least in a cross section of the circuit carrier on the basis of their different colors, it is possible, for example, to determine the number of insulating layers in the circuit carrier by counting the differently colored insulating layers when, during or after the creation of the cross-sectional grinding slice. In this case, at least one of the two insulating layers can be colored such that at least in a cross section of the circuit carrier, in particular in a cross-sectional view, the edge of the respective insulating layer and / or the entire cross section of the respective insulating layer can be clearly identified.

[0008] It is particularly advantageous if at least one of the two insulating layers is colored so that the two distinct insulating layers can be identified with the naked eye. In other words, at least one of the two insulating layers is colored so that the color of the insulating layer is in the visible color spectrum. This particularly preferred design makes it possible to identify a plurality of distinct or delimited insulating layers with the naked human eye, i.e. without the aid of other test materials and / or test equipment, such as an IR camera or the like. In other words, this preferred design provides that at least one of the two electrically insulating layers is colored so that the color of the colored insulating layer is in a range visible to the human eye, such as in the visible light spectrum or color spectrum or in the visible component of the electromagnetic spectrum.

[0009] Another preferred embodiment provides that the electrically insulating layer is colored with particles of different colors. By using particles of different colors, insulating layers of different colors can be easily provided, especially in the production process.

[0010] In another advantageous embodiment, the circuit carrier according to the invention further comprises: a further electrically insulating layer, in particular a third electrically insulating layer, arranged on the conductive layer; a further electrically insulating layer, in particular a fourth electrically insulating layer, arranged on the third insulating layer; and a further conductive layer, in particular a second conductive layer, arranged on the further electrically insulating layer, in particular the fourth electrically insulating layer and having at least one further electrical conductor track for electrically connecting at least one electrical component. By arranging further electrically insulating layers, in particular the third and fourth electrically insulating layers, on the conductive layer and arranging further conductive layers, in particular the second conductive layer on the fourth insulating layer, it is possible to connect at least one electrical component to one and / or two conductive layers. This increases the wiring possibilities. This can be advantageous in particular in the case of a plurality of components on the circuit carrier.

[0011] Preferably, the third and / or fourth insulating layer is colored so that the two electrical insulating layers, ie the third and fourth insulating layer or more generally directly superposed insulating layers, have different colors. The color of the third and / or fourth insulating layer can be the same or different from the color of the first or second insulating layer.

[0012] According to a second aspect of the present invention, a method for manufacturing a circuit carrier for at least one electrical device is provided, wherein the method comprises the following steps: providing a metal substrate layer; applying a first electrically insulating layer to the metal substrate layer; applying a second electrically insulating layer to the first electrically insulating layer; and applying a conductive layer to the second electrically insulating layer, wherein the conductive layer has at least one printed conductor for electrically connecting at least one electrical device, and wherein at least one of the two electrically insulating layers is colored so that the two electrically insulating layers have different colors.

[0013] In a preferred embodiment of the method according to the invention, the coloring is performed before, during or after the application of the corresponding insulating layer. For example, the corresponding electrically insulating layer can be immersed in a pigment before application. For example, the electrically insulating layer can be colored during application by adding colored particles to the material composition of the insulating layer, such as a plastic suspension. However, the corresponding insulating layer can also be colored after application, for example by immersing the preassembly and / or the entire circuit carrier in a colored solution, which results in at least the corresponding electrically insulating layer being colored and thus having a different color than the other electrically insulating layer.

[0014] In another preferred embodiment, the coloring is performed such that the two insulation layers are recognizable as two distinct or delimiting insulation layers at least in a cross section, in particular a cross-sectional view, of the circuit carrier on the basis of their different colors.

[0015] Another preferred embodiment of the method according to the invention further comprises the following steps: applying a further electrically insulating layer, in particular a third electrically insulating layer, to the electrically conductive layer; applying a further electrically insulating layer, in particular a fourth electrically insulating layer, to the third insulating layer; and applying a further electrically conductive layer, in particular a second electrically conductive layer, to the further electrically insulating layer, in particular the fourth electrically insulating layer, wherein the further electrically conductive layer, in particular the second electrically conductive layer also has at least one conductor track for electrically connecting at least one electrical component. With this preferred embodiment of the method according to the invention, in particular a plurality of electrical components can be electrically connected to the first and / or second electrical layer, thereby increasing the wiring possibilities.

[0016] The third and / or fourth electrically insulating layer is preferably colored, so that the two electrically insulating layers, ie the third and fourth insulating layer or generally directly superimposed insulating layers, have different colors.

[0017] According to a third aspect of the present invention, a method for determining the number of insulating layers in a circuit carrier, in particular in a circuit carrier according to the first aspect and / or its design scheme, is provided, wherein the method comprises the following steps: creating a cross-section of the circuit carrier, in particular a cross-sectional grind, and determining the number of insulating layers in the circuit carrier based on the different colors of the insulating layers.

[0018] In a preferred design of the method according to the third aspect, the step of creating a cross-sectional grind of the circuit carrier comprises the following steps: exposing a cross-sectional surface, in particular a full cross-section, of the circuit carrier, for example by means of a grinder, and preparing the cross-sectional surface (cross section) for determining the number of insulating layers, for example by grinding and / or polishing the cross-sectional surface.

[0019] In another preferred design of the method according to the third aspect, in order to determine the number of insulating layers in the circuit carrier, the circuit carrier or at least one insulating layer of the circuit carrier is colored, in particular so that the colored insulating layer has a different color relative to other insulating layers, in particular insulating layers directly above or below it.

[0020] In a further preferred embodiment of the method according to the third aspect, coloring is performed before or after the creation of the cross section, in particular before or after the creation of the cross-sectional view of the circuit carrier. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features and tasks of the present invention will become apparent to those skilled in the art by carrying out this teaching and considering the accompanying drawings. Among them:

[0022] Figure 1 The schematic diagram shows the layer structure of a circuit carrier according to the invention, which has two electrically insulating layers arranged one above the other and directly adjacent to each other and which have different colors.

[0023] Figure 2 A schematic diagram shows the layer structure of one specific embodiment of a circuit carrier according to the invention, which has two electrically insulating layers of different colors and further third and fourth insulating layers and a further second electrical layer for connecting electrical components.

[0024] Figure 3 The schematic diagram shows a flow chart for carrying out the method for producing a circuit carrier according to the invention.

[0025] Figure 4 A schematic diagram shows a flow chart for carrying out the method for determining the number of electrically insulating layers in a circuit carrier according to the invention.

[0026] Throughout the figures, elements of the same design or function are provided with the same reference symbols. DETAILED DESCRIPTION

[0027] First, you should refer to Figure 1 ,Should Figure 1 Schematic diagram showing the layer structure of the circuit carrier 10. The circuit carrier 10 can be, for example, an insulated metal substrate layer printed circuit board (in English: insulated metal substrate IMS printed circuit board).

[0028] The circuit carrier 10 has a metal substrate layer 12, which consists of aluminum, copper, another metal or another metal alloy. Due to the metal content in the metal substrate layer 12, the metal substrate layer 12 is electrically conductive. However, the metal substrate layer 12 is characterized by a particularly high thermal conductivity and can be connected, for example, in a thermally conductive manner to a cooler (not shown), which is particularly advantageous when dissipating heat from high-power components.

[0029] The circuit carrier 10 has a first electrically insulating layer 14 arranged or applied on a metal substrate layer 12. The circuit carrier 10 has a second electrically insulating layer 16 applied or arranged on the first electrically insulating layer 14. The two electrically insulating layers 14, 16 can be constructed from an electrically insulating material such as plastic, ceramic, resin, etc. The electrically insulating layers 14, 16 serve to electrically insulate with respect to the metal substrate layer 12. The electrically insulating layers 14, 16 are applied directly on top of each other. In other words, there are no other layers between the first electrically insulating layer 14 and the second electrically insulating layer 16. In yet another way of speaking, the upper side of the first electrically insulating layer 14 contacts the lower side of the second electrically insulating layer 16.

[0030] The circuit carrier 10 further comprises an electrically conductive layer 18 which is applied or arranged on the second electrically insulating layer 16. The electrically conductive layer 18 comprises at least one conductor track. An electrical component 22 is arranged on the electrically conductive layer 18 and is electrically connected to the conductor track 20 of the electrically conductive layer 18. Figure 1 In the specific example of FIG. 1 , the electrical connection is made by means of bonding wires 24. In other embodiments not shown, the electrical connection can of course be made by other means.

[0031] As in Figure 1 As schematically shown in FIG. 1 , the two electrically insulating layers 14, 16 differ due to their colors. This is schematically shown by a first electrically insulating layer marked as light grey and a second electrically insulating layer marked as dark grey. Of course, the colors of the electrically insulating layers can be arbitrary and are not limited to Figure 1 Colors shown in .

[0032] In the circuit carrier 10 according to the invention, at least one of the two electrically insulating layers 14, 16 is colored so that two electrically insulating layers 14, 16 arranged directly one above the other can be identified as two distinct insulating layers 14, 16 based on their different coloring or colors. Thus, the two insulating layers 14, 16 can be distinguished based on their color or coloring.

[0033] The circuit carrier 10 can be cut, for example, by means of a cross section through the circuit carrier 10, in particular by means of a cross-sectional cut of the circuit carrier 10. Figure 1The schematic layer structure shown in is visible. The cross-sectional grinding disc is produced, for example, by cutting the circuit carrier 10, for example with the aid of a grinding machine, and exposing a cross-sectional surface, in particular a full cross-section, of the circuit carrier 10. The exposed cross-sectional surface can subsequently be prepared, for example, by means of grinding and / or polishing. In the cross section or cross-sectional grinding disc, the two electrically insulating layers 14, 16 can be identified as two distinct insulating layers 14, 16. In particular, at least one of the electrically insulating layers 14, 16 can be colored so that the different insulating layers can be identified with the naked eye, that is, without the aid of technical devices (cameras, etc.), based on their different colors. If the circuit carrier 10 is checked, for example within the scope of quality control or within the scope of an inspection method, the number of insulating layers 14, 16 (in Figure 1 ” in the specific example).

[0034] Coloring of at least one of the two electrically insulating layers 14, 16 may be performed before, during or after applying the corresponding electrically insulating layer 14, 16. Coloring of at least one of the two electrically insulating layers 14, 16 may be performed before or after creating a cross section or transverse section.

[0035] Figure 1 The specific example of is shown that the entire cross section of the respective insulating layer 14, 16 is colored. However, within the scope of the present disclosure, it is sufficient if only the contour edges of the respective electrically insulating layer have a different color. For example, it is conceivable that before, during or after applying the corresponding electrically insulating layer 14, 16, the respective insulating layer 14, 16 is colored so that only the contour of the respective insulating layer 14, 16 appears a different color, so that the number of discrete insulating layers can be determined thereby.

[0036] The coloring of at least one of the two directly superposed electrically insulating layers 14, 16 can be carried out, for example, by introducing colored particles into the corresponding insulating layer 14, 16. The introduction of the colored particles can be carried out before, during or after the application of the corresponding insulating layer 14, 16. For example, it is conceivable that the corresponding insulating layer 14, 16 is first produced, then colored, for example by immersion in a colored solution, and then the colored insulating layer is applied. Alternatively or additionally, when applying the insulating layer, the colored particles can be introduced into a material suspension, for example a plastic suspension, so that a colored plastic suspension can be applied and the insulating layers 14, 16 are thus colored during the application of the suspension. Alternatively or additionally, it is also possible to color the insulating layer after the application of the corresponding insulating layer. For example, this can be carried out by immersing a pre-assembly (Vorbaugruppe) of the circuit carrier 10 or the entire circuit carrier 10 in a colored solution, especially after exposing the cross section or the cross-section grinding.

[0037] Any other possible options for indicating the coloration of a corresponding number of insulation layers in the circuit carrier 10 are conceivable.

[0038] Advantageously, the respective insulating layers 14, 16 are colored so that the insulating layers 14, 16 are identifiable with the naked eye due to their different colors. Advantageously, a color is selected that is in the visible spectrum or color spectrum or in a component of the electromagnetic spectrum that is identifiable with the human eye.

[0039] Now you should refer to Figure 2 ,Should Figure 2 Show Figure 1 Schematic diagram of the layer structure of one specific embodiment of a circuit carrier 10 .

[0040] exist Figure 2 In this embodiment, the circuit carrier has a metal substrate layer 12, a first electrically insulating layer 14 and a second electrically insulating layer 16, which is applied directly on the first electrically insulating layer 14 and differs from the first electrically insulating layer 14 in color (due to its coloring). Figure 2 The circuit carrier 10 has a first electrically conductive layer 18 with conductor tracks 20 for applying an electrical component 22. Figure 1 The circuit carrier 10 is implemented differently. Figure 2 In an embodiment of the present invention, a further electrically insulating layer, in particular a third electrically insulating layer 26 and a further electrically insulating layer, in particular a fourth electrically insulating layer 27, are applied to the first electrically conductive layer. The third electrically insulating layer 26 and / or the fourth electrically insulating layer 27 can have the same or a different color than the two first electrically insulating layers 14, 16. The third insulating layer 26 and / or the fourth insulating layer 27 can likewise be colored or possibly uncolored. Preferably, the third and / or the fourth insulating layer 26, 27 is colored so that the two insulating layers 26, 27 - similarly to the insulating layers 14, 16 - in particular at least in a cross section and / or a cross-sectional view of the circuit carrier 10 can be recognized as two distinct insulating layers.

[0041] exist Figure 2In an embodiment of the present invention, further conductive layers, in particular a second conductive layer 28, are arranged on the fourth electrically insulating layer 27. The second conductive layer 28 has at least one further conductor track 30, which can be used to electrically connect the electrical component 22. By means of the second conductive layer 28, the electrical component 22 can be connected not only to the conductor tracks 20 of the first electrical layer 18, but also to the conductor tracks 30 of the second electrical layer 28. Here, depending on the application, the electrical component 22 can be connected to the first conductive layer 18 and / or the second conductive layer 28. The third and fourth electrically insulating layers 26, 27 are used for electrical insulation. In particular, when a plurality of components 22 are electrically connected to the circuit carrier 10, the third and fourth electrically insulating layers 26, 27 and the second conductive layer 28 are useful, because the wiring possibilities are thereby increased with sufficiently high insulation.

[0042] Now you should refer to Figure 3 ,Should Figure 3 A method for manufacturing a circuit carrier, such as bonding Figure 1 and 2 Schematic representation of a flow chart of a method for a circuit carrier 10 is described.

[0043] The method comprises step 300, wherein a metal substrate layer is provided, such as a bonding Figure 1 and 2 The metal substrate layer 12 mentioned above. In step 302, a first electrical insulating layer, such as a bonding Figure 1 and 2 The first electrically insulating layer 14 mentioned is applied to the metal substrate layer. In step 304, a second electrically insulating layer, such as a bonding Figure 1 and 2 The second electrically insulating layer 16 mentioned is applied to the first electrically insulating layer. In step 306, a conductive layer, such as a bonding Figure 1 and 2 The mentioned electrically conductive layer 18 is applied to the second electrically insulating layer. Figure 3 In the method shown in , at least one of the two electrically insulating layers is now colored so that the two electrically insulating layers have different colors and can thus be distinguished from one another, in particular in cross-sections or cross-sectional views of the circuit carrier. Figure 3 The dotted line step 308 should be shown in FIG. Figure 3 In the specific example of , the second electrically insulating layer applied in step 304 is colored. It is not important whether this coloring is now performed before, during or after the application of this layer.

[0044] Of course, it is also conceivable that in other embodiments not shown, the first electrically insulating layer and / or the second electrically insulating layer is colored. In such a case, the method will have an additional step, in which the corresponding first or second insulating layer is also colored. The coloring of the first insulating layer can be carried out simultaneously with the coloring of the second insulating layer, before or after the coloring of the second insulating layer. It is important that after coloring, the two insulating layers arranged directly one above the other have different colors.

[0045] exist Figure 3 In the specific example of , two further optional method steps are also indicated by means of a dot-dash box. It is therefore conceivable that after applying the first conductive layer (step 306), a further step 310 is performed, in which further electrically insulating layers, in particular the third and fourth electrically insulating layers, such as a combination of Figure 2 The third and fourth insulating layers 26, 27 mentioned are applied to the first conductive layer. In step 312 after step 310, other conductive layers, in particular the second conductive layer, such as a combination of Figure 2 The mentioned second electrical layer 28 is applied to the fourth electrically insulating layer 27. This increases the wiring possibilities when electrically connecting electrical components on the circuit carrier. The third and / or fourth insulating layer can be colored, at least so that the two insulating layers can be identified as two distinct insulating layers at least in a cross section or cross-sectional view of the circuit carrier based on their different colors.

[0046] Now you should Figure 4 ,Should Figure 4 A method for performing a method for determining a circuit carrier, such as combining Figure 1 and 2 A schematic illustration of a flow chart of the method for determining the number of electrically insulating layers in a circuit carrier 10 which has already been described.

[0047] In accordance with Figure 4 In the method, a cross section, in particular a cross-sectional surface, of a circuit carrier is generated in step 400. Subsequently, in step 402, the number of insulating layers in the circuit carrier is determined in the cross section or the cross-sectional surface based on the different colors of the insulating layers.

[0048] Here, producing the cross-sectional grinding disc may include further steps, such as step 404, in which a cross-sectional surface, in particular a full cross-section, of the circuit carrier is exposed, and step 406, in which the exposed cross-sectional surface is prepared for determining the number of insulating layers. Preparation may include grinding, polishing, etc.

[0049] Here, determining the number of insulating layers in the circuit carrier based on different colors (step 402) can include a step 408, in which at least one of the directly superimposed insulating layers of the circuit carrier is colored so that the number of directly superimposed insulating layers can be determined based on different colors. The coloring is preferably performed before or after the cross section or cross-sectional grinding is created. The coloring is preferably performed so that the different colors of the insulating layers can be recognized by the naked eye.

[0050] Can be based on Figure 3 and / or Figure 4 The bonding of the circuit carrier 10 is achieved in the corresponding steps of the method Figure 1 and 2 Describe the characteristics.

Claims

1. A circuit carrier (10) for at least one electrical component (22), comprising: - a metal substrate layer (12), - a first electrically insulating layer (14) arranged on the metal substrate layer (12), - a second electrically insulating layer (16) arranged on said first insulating layer (14), and an electrically conductive layer (18) arranged on the second electrically insulating layer (16), the electrically conductive layer having at least one conductor track (20) for electrically connecting the at least one electrical component (22), wherein At least one of the two electrically insulating layers (14, 16) is colored, so that the two electrically insulating layers (14, 16) have different colors.

2. A circuit carrier (10) according to claim 1, wherein at least one of the two electrically insulating layers (14, 16) is colored so that the two electrically insulating layers (14, 16) can be identified as two distinct insulating layers (14, 16) based on their different colors at least in a cross section, in particular a cross-sectional grind, of the circuit carrier (10).

3. The circuit carrier (10) according to claim 2, wherein at least one of the two insulating layers (14, 16) is colored such that the two distinct insulating layers (14, 16) are identifiable with the naked eye.

4. The circuit carrier (10) according to claim 1, wherein the electrically insulating layers (14, 16) are colored with particles of different colors.

5. The circuit carrier (10) according to claim 1, wherein at least one of the two electrically insulating layers (14, 16) is colored such that the color of the colored insulating layer (14, 16) is in a range visible to the human eye.

6. The circuit carrier (10) according to claim 1, further comprising: - a further electrically insulating layer, in particular a third electrically insulating layer (26), arranged on the electrically conductive layer (18), - a further electrically insulating layer, in particular a fourth electrically insulating layer (27), arranged on the third insulating layer (26), and A further electrically conductive layer, in particular a second electrically conductive layer (28), which is arranged on the fourth electrically insulating layer (27) and has at least one further electrical conductor track (30) for electrically connecting the at least one electrical component (22).

7. The circuit carrier (10) according to claim 6, wherein the third insulating layer (26) and / or the fourth insulating layer (27) is colored such that the two electrically insulating layers (26, 27) have different colors.

8. A method for producing a circuit carrier (10) for at least one electrical component (22), comprising the following steps: - providing a metal substrate layer (12), - applying a first electrically insulating layer (14) onto the metal substrate layer (12), - applying a second electrically insulating layer (16) onto said first electrically insulating layer (14), and - applying an electrically conductive layer (18) onto the second electrically insulating layer (16), wherein the electrically conductive layer (18) has at least one conductor track (20) for electrically connecting the at least one electrical component (22), and wherein At least one of the two electrically insulating layers (14, 16) is colored, so that the two electrically insulating layers (14, 16) have different colors.

9. The method according to claim 8, wherein the coloring is performed before, during or after the application of the respective electrically insulating layer (14, 16).

10. The method according to claim 8, wherein the coloring is performed such that the two insulation layers are recognizable as two distinct insulation layers at least in a cross section, in particular a cross-sectional view, of the circuit carrier on the basis of their different colors.

11. The method according to any one of claims 8 to 10, further comprising: - applying a further electrically insulating layer, in particular a third electrically insulating layer (26), onto the electrically conductive layer (18), - applying a further electrically insulating layer, in particular a fourth electrically insulating layer (27), onto the third insulating layer (26), - applying a further electrically conductive layer, in particular a second electrically conductive layer (28), onto the fourth electrically insulating layer (27), the further electrically conductive layer having conductor tracks (30) for electrically connecting at least one electrical component (22), and - coloring the third and / or fourth insulating layer (26, 27) so that the two electrically insulating layers (26, 27) have different colors.

12. A method for determining the number of insulating layers (14, 16) in a circuit carrier (10), in particular in a circuit carrier (10) according to any one of claims 1 to 6, comprising the following steps: - creating a cross-section, in particular a cross-sectional view, of the circuit carrier (10), and - determining the number of insulating layers (14, 16) in the circuit carrier (10) based on the different colors of the insulating layers (14, 16).

13. The method according to claim 12, wherein the step of creating a cross-sectional view of the circuit carrier comprises the following steps: - exposing a cross-sectional surface, in particular a full cross-sectional surface, of the circuit carrier, and - preparing a cross-sectional surface for determining the number of said insulating layers (14, 16).

14. The method according to claim 12, wherein the circuit carrier (10) or at least one insulating layer (14, 16) of the circuit carrier (10) is colored in order to determine the number of insulating layers (14, 16) in the circuit carrier (10).

15. The method of claim 14, wherein coloring is performed before or after creating the cross-section or transverse section.

Images