Multilayer substrate, power module, and electrical system

Abstract

The utility model relates to a multilayer substrate, a power module and an electrical system. The multilayer substrate may include: an insulating material layer; a first metal layer on one surface of the insulating material layer and attached to the insulating material layer; and a second metal layer on the other opposite surface of the insulating material layer and attached to the insulating material layer, in which the second metal layer includes: a first portion overlapping the insulating material layer and for attaching a chip thereon; and a second portion extending outwardly from the first portion and extending beyond the insulating material layer at least at opposite first and second sides of the second metal layer, the second portion having at least one pair of first notches extending inwardly from an edge, and each pair of first notches are respectively positioned at corresponding positions of the first side and the second side of the second metal layer.

Description

Technical Field

[0001] The present disclosure relates to the field of packaging, and more particularly, to a multi-layer substrate and a manufacturing method thereof, a power module and a manufacturing method thereof, and an electrical system. Background Art

[0002] Power module packages such as Intelligent Power Module (IPM) are gaining more and more attention. In IPM packages, power-side devices are mounted on a multi-layer substrate (such as a Direct Bond Copper (DBC) substrate) to improve heat dissipation and provide electrical connections.

[0003] The power module requires an encapsulation process for molding. One way is to use transfer molding. The current transfer molded module (TMM) uses retract pins to fix the multi-layer substrate to be encapsulated to prevent the turbulence and overflow of the liquid resin used in the molding process from causing the multi-layer substrate to be encapsulated to shift. However, the use of retract pins will inevitably lead to several blind holes in the transfer molded module after the resin is cured. The thickness of the blind holes and the encapsulation layer around the blind holes is insufficient, which may cause leakage or abnormal discharge, which in turn makes the transfer molded module prone to failure or damage.

[0004] Therefore, there is a need in the art for improved packages and methods of making the same (packaging methods). Summary of the invention

[0005] One of the objects of the present disclosure is to provide an improved multi-layer substrate and a method for manufacturing the same, an improved power module and a method for manufacturing the same, and an improved electrical system.

[0006] According to one aspect of the present disclosure, a multilayer substrate is provided, comprising: an insulating material layer; a first metal layer, on one surface of the insulating material layer and attached to the insulating material layer; and a second metal layer, on the other opposite surface of the insulating material layer and attached to the insulating material layer, wherein the second metal layer comprises: a first portion, overlapping with the insulating material layer and used for attaching a chip thereon; and a second portion, extending outward from the first portion and extending beyond the insulating material layer at least on opposite first and second sides of the second metal layer, the second portion having at least a pair of first notches extending inward from an edge, each pair of first notches being located at corresponding positions on the first and second sides of the second metal layer, respectively.

[0007] According to some embodiments of the present disclosure, the first metal layer includes: a first part, overlapping with the insulating material layer; and a second part, extending outward from the first part and extending beyond the insulating material layer at least on the opposite first and second sides of the first metal layer, the second part having at least one pair of second notches extending from the edge to the inside, wherein each pair of second notches are respectively located at corresponding positions on the first and second sides of the first metal layer, and wherein at least one of each first notch and the corresponding second notch matches the shape of the corresponding part of the clamping tool so that the at least one notch firmly clamps the clamping tool.

[0008] According to some embodiments of the present disclosure, a vertical projection of each pair of second recesses on the second metal layer at least overlaps with a portion of a corresponding pair of first recesses of the second metal layer that is used to clamp a clamping tool.

[0009] According to some embodiments of the present disclosure, the width of the open edge of the first recess is greater than the width of the inner portion of the first recess in a direction parallel to the open edge, and the width of the open edge of the second recess is greater than the width of the inner portion of the second recess in a direction parallel to the open edge.

[0010] According to some embodiments of the present disclosure, the width of the open edge of the first recess is smaller than the width of at least a portion of the inner portion of the first recess in a direction parallel to the open edge, and the width of the open edge of the second recess is smaller than the width of at least a portion of the inner portion of the second recess in a direction parallel to the open edge.

[0011] According to some embodiments of the present disclosure, the first recess includes two inner edges extending inwardly facing each other; the second recess includes two inner edges extending inwardly facing each other; each inner edge of the first recess and the second recess is configured such that, relative to an axis parallel to the direction in which the recess extends inwardly and passes through the innermost point of the inner edge, the slope of the inner edge gradually decreases as it extends toward the innermost point.

[0012] According to some embodiments of the present disclosure, each inner edge is one of the following shapes: a discontinuous differentiable arc; and a plurality of line segments with discontinuous slopes that are connected in sequence.

[0013] According to some embodiments of the present disclosure, wherein: an inner edge of the first recess is arc-shaped; and an inner edge of the second recess is arc-shaped.

[0014] According to some embodiments of the present disclosure, the first recess is a part of a circle or a part of an ellipse, and the second recess is a part of a circle or a part of an ellipse; or the first recess is a trapezoid, a square, a rectangle, or a combination of the above shapes, and the second recess is a trapezoid, a square, a rectangle, or a combination of the above shapes.

[0015] According to some embodiments of the present disclosure, the projection of the at least one pair of first recesses on the plane where the insulating material layer is located does not overlap with the insulating material layer.

[0016] According to some embodiments of the present disclosure, wherein: the insulating material layer includes a plurality of segments separated from each other; the first metal layer is integral; the second metal layer includes a plurality of segments separated from each other, each segment including at least a portion of the first part and at least a portion of the second part; and the respective segments of the second metal layer are respectively attached to the corresponding segments of the insulating material layer.

[0017] According to some embodiments of the present disclosure, wherein: the insulating material layer is a ceramic substrate; the first metal layer and the second metal layer are copper layers attached to the top surface and the bottom surface of the ceramic substrate, respectively; and the chip is a power chip.

[0018] According to some embodiments of the present disclosure, the first metal layer and the second metal layer are attached to the insulating material layer by sintering, brazing, soldering or curing.

[0019] According to another aspect of the present disclosure, a method for manufacturing a multi-layer substrate is provided, comprising: providing an insulating material layer, a first metal layer, and a second metal layer, and placing the insulating material layer between the first metal layer and the second metal layer, wherein: the first metal layer comprises: a first portion overlapping the insulating material layer, and a second portion extending outward from the first portion and extending beyond the insulating material layer at least on the first and second sides opposite to the first metal layer, and the second metal layer comprises: a first portion overlapping the insulating material layer and used for attaching a chip thereon, and a second portion extending outward from the first portion and extending beyond the insulating material layer at least on the first and second sides opposite to the second metal layer; attaching the first metal layer and the second metal layer to opposite surfaces of the insulating material layer; patterning the second metal layer to form at least a pair of first notches extending from an edge to an inner side in the second portion of the second metal layer, each pair of first notches being located at corresponding positions on the first and second sides of the second metal layer, respectively; and sawing the first metal layer to separate a plurality of multi-layer substrates.

[0020] According to some embodiments of the present disclosure, the manufacturing method also includes: patterning the first metal layer to form at least one pair of second recesses extending from the edge to the inside in the second part of the first metal layer, wherein each pair of second recesses are respectively located at corresponding positions on the first side and the second side of the first metal layer, and wherein at least one of each first recess and the corresponding second recess matches the shape of the corresponding part of the clamping tool, so that the at least one recess is firmly clamped to the clamping tool.

[0021] According to some embodiments of the present disclosure, a vertical projection of each pair of second recesses on the second metal layer at least overlaps with a portion of a corresponding pair of first recesses of the second metal layer that is used to clamp a clamping tool.

[0022] According to some embodiments of the present disclosure, wherein: the width of the open edge of the first recess is greater than the width of the inner portion of the first recess in a direction parallel to the open edge; and the width of the open edge of the second recess is greater than the width of the inner portion of the second recess in a direction parallel to the open edge.

[0023] According to some embodiments of the present disclosure, wherein: the width of the open edge of the first recess is smaller than the width of at least a portion of the inner portion of the first recess in a direction parallel to the open edge; and the width of the open edge of the second recess is smaller than the width of at least a portion of the inner portion of the second recess in a direction parallel to the open edge.

[0024] According to some embodiments of the present disclosure, the first recess includes two inner edges extending inwardly facing each other; the second recess includes two inner edges extending inwardly facing each other; each inner edge of the first recess and the second recess is configured such that, relative to an axis parallel to the direction in which the recess extends inwardly and passes through the innermost point of the inner edge, the slope of the inner edge gradually decreases as it extends toward the innermost point.

[0025] According to some embodiments of the present disclosure, each inner edge is one of the following shapes: a discontinuous differentiable arc; and a plurality of line segments with discontinuous slopes that are connected in sequence.

[0026] According to some embodiments of the present disclosure, wherein: an inner edge of the first recess is arc-shaped; and an inner edge of the second recess is arc-shaped.

[0027] According to some embodiments of the present disclosure, the first recess is a part of a circle or a part of an ellipse, and the second recess is a part of a circle or a part of an ellipse; or the first recess is a trapezoid, a square, a rectangle, or a combination of the above shapes, and the second recess is a trapezoid, a square, a rectangle, or a combination of the above shapes.

[0028] According to some embodiments of the present disclosure, the projection of the at least one pair of first recesses on the plane where the insulating material layer is located does not overlap with the insulating material layer.

[0029] According to some embodiments of the present disclosure, the manufacturing method also includes: before attaching the first metal layer and the second metal layer to two opposite surfaces of the insulating material layer, segmenting the insulating material layer to segment the insulating material layer into a plurality of segments separated from each other, wherein the first metal layer is integral, wherein patterning the second metal layer also includes: patterning the second metal layer to include a plurality of segments separated from each other, and wherein each segment of the second metal layer includes at least a portion of the first part and at least a portion of the second part, and are respectively attached to corresponding segments of the insulating material layer.

[0030] According to some embodiments of the present disclosure, the insulating material layer is a ceramic substrate, the first metal layer and the second metal layer are copper layers, and the chip is a power chip.

[0031] According to some embodiments of the present disclosure, the first metal layer and the second metal layer are attached to two opposite surfaces of the insulating material layer by sintering, brazing, soldering or curing.

[0032] According to another aspect of the present disclosure, a power module is provided, comprising: the multi-layer substrate as described above; and the chip, comprising a power semiconductor device, wherein the chip is attached to a first portion of a second metal layer of the multi-layer substrate.

[0033] According to some embodiments of the present disclosure, the power module also includes: a lead frame, the lead frame including leads attached to the second metal layer; and a molding compound, encapsulating at least a portion of the multi-layer substrate, the chip and at least a portion of the lead frame, wherein the molding compound exposes a surface of the first metal layer of the multi-layer substrate away from the chip, and wherein at least one pair of circular holes is provided in the molding compound, at least a portion of the vertical projection of the at least one pair of circular holes on the second metal layer substantially overlaps with a corresponding pair of first recesses of the second metal layer, and the at least one pair of circular holes can be used for mounting screws.

[0034] According to another aspect of the present disclosure, a method for manufacturing a power module is provided, comprising: providing a multilayer substrate as described above; and attaching a chip containing a power semiconductor device to a first portion of a second metal layer of the multilayer substrate; arranging the multilayer substrate and the chip attached together in a lead frame; attaching the leads of the lead frame to the second metal layer of the multilayer substrate; encapsulating at least a portion of the multilayer substrate, the chip and at least a portion of the lead frame with a molding compound based on a transfer molding process; and cutting an excess portion of the lead frame to obtain a packaged power module, wherein the molding compound exposes a surface of the first metal layer of the multilayer substrate away from the chip.

[0035] According to some embodiments of the present disclosure, encapsulating at least a portion of the multi-layer substrate, the power chip and at least a portion of the lead frame with a molding compound based on a transfer molding process includes: using at least one pair of clamping tools to clamp at least one pair of first notches of the second portion of the first metal layer of the multi-layer substrate and at least one pair of second notches of the second portion of the second metal layer to fix the multi-layer substrate, wherein each clamping tool in each pair of clamping tools clamps one notch of a corresponding pair of first notches and one notch of a corresponding pair of second notches; injecting molding compound; and after the molding compound is cured, removing the at least one pair of clamping tools.

[0036] According to some embodiments of the present disclosure, the at least one pair of clamping tools is removed so that at least one pair of circular holes is left in the molding compound, at least a portion of the vertical projection of each pair of circular holes on the second metal layer roughly overlaps with a corresponding pair of first recesses of the second metal layer, and the at least one pair of circular holes can be used to install screws.

[0037] According to another aspect of the present disclosure, an electrical system is provided, comprising the power module as described above.

[0038] Other features and advantages of the present disclosure will become more apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0040] The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0041] Figure 1 A schematic top view from one side of a multi-layer substrate according to some embodiments of the present disclosure is shown;

[0042] Figure 2 A schematic top view of a multi-layer substrate according to some embodiments of the present disclosure as viewed from another side is shown;

[0043] Figure 3A-3E Schematic diagrams of the shapes of the recesses according to some embodiments of the present disclosure are shown in FIG.

[0044] Figure 3F Schematically shows a schematic diagram of using positioning rods as clamping components to clamp a multi-layer substrate;

[0045] Figure 4 An exemplary flow chart showing a method for manufacturing a multi-layer substrate according to an embodiment of the present disclosure;

[0046] FIG. 5A to FIG. 5D Schematically shows the Figure 4 A schematic diagram of a device corresponding to some steps of the manufacturing method shown;

[0047] Figure 6 A schematic diagram of a power module according to some embodiments of the present disclosure is shown;

[0048] Figure 7 An exemplary flow chart of a method for manufacturing a power module according to an embodiment of the present disclosure is shown;

[0049] FIG. 8A to FIG. 8C Schematically shows the Figure 7 A schematic diagram of a device corresponding to some steps of the manufacturing method is shown.

[0050] Note that in the embodiments described below, sometimes the same reference numerals are used in common between different drawings to represent the same parts or parts with the same functions, and their repeated descriptions are omitted. In some cases, similar numbers and letters are used to represent similar items, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0051] For ease of understanding, the position, size, range, etc. of each structure shown in the drawings and the like may not represent the actual position, size, range, etc. Therefore, the present disclosure is not limited to the position, size, range, etc. disclosed in the drawings and the like. DETAILED DESCRIPTION

[0052] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present disclosure. In addition, techniques, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and devices should be considered part of the authorized specification.

[0053] It should be understood that the following description of at least one exemplary embodiment is in fact merely illustrative and is in no way intended to limit the present disclosure and its application or use. That is, the structures and methods herein are shown in an exemplary manner to illustrate different embodiments of the structures and methods in the present disclosure. However, those skilled in the art will appreciate that they merely illustrate exemplary ways of the present disclosure that can be implemented, rather than an exhaustive way. In addition, the drawings need not be drawn to scale, and some features may be enlarged to illustrate the details of specific components.

[0054] Figure 1 A schematic top view of a multi-layer substrate 100 viewed from one side according to some embodiments of the present disclosure is shown; and Figure 2 FIG. 1 is a schematic top view of a multilayer substrate 100 from another side according to some embodiments of the present disclosure. Figure 1 and 2 The multi-layer substrate 100 will be described.

[0055] like Figure 1 As shown, the multilayer substrate 100 may include a first metal layer 101, an insulating material layer 103, and a second metal layer 105. The first metal layer 101 is disposed on one surface (e.g., the bottom surface or the lower surface) of the insulating material layer 103 and is attached to the insulating material layer 103. The second metal layer 105 is disposed on another opposite surface (e.g., the top surface or the upper surface) of the insulating material layer 103 and is attached to the insulating material layer 103. In some embodiments, the first metal layer 101 and the second metal layer 105 may be attached to the insulating material layer 103 by, for example, but not limited to, sintering, brazing, soldering, or curing.

[0056] The second metal layer 105 may include a first portion 125, see Figure 2 , that is, the portion surrounded by the dotted frame 121. Here, the dotted frame schematically shows the outer contour of the insulating material layer 103. In addition, for the convenience of comparison, Figure 1 The dotted box 121 is also shown in FIG. The first portion 125 of the second metal layer 105 overlaps the insulating material layer 103 and is used to attach a chip thereon. Preferably, the chip may be (but not limited to) a die in which a power semiconductor device or other semiconductor devices are formed.

[0057] The second metal layer 105 may further include a second portion 127, such as Figure 2 It can be better seen that the portion outside the dotted box 121. Figure 2 As shown, the second portion 127 of the second metal layer 105 extends outward from the first portion 125 and is at least on the opposite first and second sides (eg, Figure 2The left and right sides of the second metal layer 105 shown in FIG. 1 extend beyond the insulating material layer 103. The second portion 127 of the second metal layer 105 may have at least one pair of first notches 107 extending from the edge to the inside, and each pair of first notches 107 is located at corresponding positions of the first side and the second side of the second metal layer 105, respectively. Figure 1 and Figure 2 In the embodiment, only one pair of first notches 107 is schematically shown, but those skilled in the art will appreciate that the second portion 127 of the second metal layer 105 may include more pairs of first notches. In some embodiments, the first side and the second side of the second metal layer 105 may be arranged to be substantially parallel to the width direction of the insulating material layer 103.

[0058] In some embodiments, the projection of the at least one pair of first notches of the second metal layer 105 on the plane where the insulating material layer 103 is located does not overlap with the insulating material layer 103. In other words, the inner edge of the notch 107 is outside the insulating material layer 103, so that in a top view, the insulating material layer 103 is not exposed from the notch 107, such as from a top view. Figure 1 Can be seen better.

[0059] Continue to refer Figure 1 and Figure 2 , the first metal layer 101 may include: a first portion 115 overlapping the insulating material layer 103, such as Figure 1 and extending outwardly from the first portion 115 and at least on the first and second sides of the first metal layer 101 (eg, Figure 1 The second portion 117 of the first metal layer 101 (shown in FIG. 1 ) extends beyond the insulating material layer 103. Preferably, the second portion 117 of the first metal layer 101 may have at least one pair of second notches 109 extending from the edge to the inside. Preferably, each pair of second notches 109 is located at the first side and the second side of the first metal layer 101 (for example, Figure 1 At corresponding positions on the left and right sides of the first metal layer 101 shown in .

[0060] At least one pair of first notches 107 of the second metal layer 105 can be used to set a clamping component therein. In a preferred embodiment, at least one pair of second notches 109 in the first metal layer 101 can also be used to set a clamping component therein to cooperate with at least one pair of first notches 107 so that the clamping component can more firmly fix the multilayer substrate 100. At least one of each first notch 107 and the corresponding second notch 109 matches the shape of the corresponding part of the clamping tool, so that the at least one notch can firmly clamp the clamping tool. In other words, the clamping tool can clamp one or both of the corresponding first notch and the second notch, which allows the multilayer substrate of the present disclosure to be clamped using a variety of clamping tools of different shapes, thereby improving the flexibility of use.

[0061] Preferably, a vertical projection of each pair of second recesses 109 on the second metal layer 105 may at least overlap with a portion of a corresponding pair of first recesses 107 of the second metal layer 105 for clamping a clamping tool.

[0062] Although Figure 1 and Figure 2 The notch is schematically shown as an arc shape (e.g., a part of a circle or an ellipse), but this is not intended to constitute any limitation. The notch according to the embodiment of the present disclosure can have any suitable shape suitable for fitting and fixing the clamping member. Preferably, the shape of the notch should be suitable for clamping the clamping member and allow a certain error range.

[0063] In some embodiments, the width of the open edge of the first notch may be greater than the width of the inner portion of the first notch in a direction parallel to the open edge, and the width of the open edge of the second notch may be greater than the width of the inner portion of the second notch in a direction parallel to the open edge. In this case, the clamping tool can be inserted into the notch in a direction parallel to the multilayer substrate. Preferably, the first notch may include two inner edges extending inwardly facing each other, and the second notch may include two inner edges extending inwardly facing each other. Each inner edge of the first notch and the second notch may be configured such that the slope of the inner edge gradually decreases as it extends toward the innermost point relative to an axis parallel to the direction in which the notch extends inwardly through the innermost point of the inner edge. For example, each inner edge may be one of the following shapes: a non-continuously derivable arc; and a plurality of line segments with discontinuous slopes and connected in sequence.

[0064] In some embodiments, the width of the open edge of the first recess is smaller than the width of at least a portion of the inner portion of the first recess in a direction parallel to the open edge, and the width of the open edge of the second recess is smaller than the width of at least a portion of the inner portion of the second recess in a direction parallel to the open edge. In this case, the clamping tool can be inserted into the recess in a direction perpendicular to the multilayer substrate.

[0065] In a preferred embodiment, the inner edge of the first recess may be arc-shaped, and the inner edge of the second recess may also be arc-shaped.

[0066] In a preferred embodiment, the first notch can be a part of a circle or a part of an ellipse, and the second notch can also be a part of a circle or a part of an ellipse. For example, the notch can be half of a circle or an ellipse, can be less than half of a circle or an ellipse, or can be more than half of a circle or an ellipse.

[0067] In a preferred embodiment, the first recess may be in the shape of a trapezoid, a square, a rectangle, or a combination of the above shapes, and the second recess may also be in the shape of a trapezoid, a square, a rectangle, or a combination of the above shapes.

[0068] Figure 3A-3E Schematic diagrams of the shapes of the notches according to some embodiments of the present disclosure are shown. Figure 3A and Figure 3B As shown in FIG. 1 , the two inner edges 1071 and 1072 of the notch 107 / 109 face each other and extend inwardly (ie, toward the interior of the corresponding metal layer). Figure 3A and Figure 3B As shown, the width a of the open edge of the notch 107 / 109 can be set to be greater than the width b of the inner portion of the notch in a direction parallel to the open edge, such as Figure 3B As shown. In some embodiments, the two inner edges of the notch 107 / 109 extend inwardly facing each other, and the distance between the two inner edges gradually decreases as they extend inwardly. In other words, the distance between the two inner edges gradually decreases in a first direction toward the inside of the corresponding metal layer (for example, as indicated by arrow 501 in the figure). As an example, the first direction can be the horizontal direction (X direction) in the figure; however, the present disclosure is not limited thereto.

[0069] In some embodiments, each inner edge (e.g., 1071 and 1072) of the notch 107 / 109 can be configured such that, relative to an axis parallel to the direction in which the notch extends inward (e.g., the X direction shown in the figure) passing through the innermost point (e.g., point P) of the inner edge, the slope of the inner edge (as shown by the tangent shown by the dotted line in the figure) gradually decreases as it extends toward the innermost point. Preferably, the shape of each inner edge can be a non-continuously derivable arc. For example, the arc can include a plurality of segments connected to each other, and the segments are non-continuously derivable.

[0070] Figure 3C Schematic diagrams showing the shapes of the recesses according to other embodiments of the present disclosure are shown in FIG. Figure 3C As shown in , the width of the open edge of the notch 107 / 109 can be set to be greater than the width of the inner portion of the notch in a direction parallel to the open edge. In a preferred embodiment, relative to an axis parallel to the direction in which the notch extends inward (e.g., the X direction shown in the figure) passing through the innermost point of the inner edge (e.g., point P), the slope of the inner edge gradually decreases as it extends toward the innermost point. In a preferred embodiment, each inner edge can be a plurality of line segments with discontinuous slopes that are sequentially connected.

[0071] In some embodiments, the first notch of the first metal layer may be trapezoidal, square, or rectangular, and the second notch of the second metal layer may be trapezoidal, square, or rectangular accordingly. Figure 3D and Figure 3E shown.

[0072] Setting the notch of the present disclosure to the shape as described above can bring many improvements to the use of the notch. When the width of the open edge of the notch is set to be greater than the width of the inner part of the notch in a direction parallel to the open edge, on the one hand, the distance between the outermost parts of the two inner edges of the notch is greater than the corresponding width of the clamping component, which makes it easy for the clamping component to find the notch and snap into it; on the other hand, the distance between the innermost parts of the two inner edges of the notch is less than or equal to the width of the clamping component, which makes the clamping component naturally snap into the position where the distance between the two inner edges is most matched with the width of the clamping component during the process of snapping into the notch, so that the clamping component can clamp the multi-layer substrate more firmly, reducing or eliminating the shaking or displacement of the clamped multi-layer substrate when applying the molding compound. When the width of the open edge of the notch is set to be less than the width of the inner part of the notch in a direction parallel to the open edge, the clamping component is inserted into the notch and can also firmly clamp the multi-layer substrate.

[0073] Figure 3FSchematic diagram of using positioning rods 330 as clamping components to clamp the multilayer substrate 100 is schematically shown in FIG. In the encapsulation process, the multilayer substrate 100 can be fixed or clamped by the positioning rods 330 so that the multilayer substrate 100 can remain stable when the molding compound (e.g., resin) is poured, and thus will not be displaced due to the turbulence and turbulence of the resin. The use of the clamping component and the notch in the metal layer of the multilayer substrate can, on the one hand, avoid the use of retraction pins, thereby avoiding the formation of blind holes above the substrate; on the other hand, the multilayer substrate can be clamped more firmly and the extrusion of the insulating material layer, such as a ceramic material, can be avoided.

[0074] In some embodiments, the size of the first metal layer 101 in a direction different from the first side and the second side opposite to the aforementioned first side (for example, the vertical direction in the figure) can be set to be smaller than the size of the insulating material layer 103, and correspondingly, smaller than the size of the second metal layer 105 in this direction, such as Figure 1 and 2 as shown in .

[0075] In some embodiments, the insulating material layer 103 may be integral, for example, the insulating material layer 103 may be a whole substrate. In other embodiments, the insulating material layer 103 may include a plurality of segments separated from each other. Figure 1 and Figure 2 1031 , 1032 , 1033 and 1034 are exemplarily shown in FIG. 1034 , but the present disclosure is not limited thereto, and the insulating material layer 103 may also have other numbers of segments. The segments are isolated from each other by gaps (eg, 1021 ).

[0076] In some embodiments, the first metal layer 101 may be integral, and the second metal layer 105 may include a plurality of segments separated from each other, each of which may include at least a portion of the first portion 125 and at least a portion of the second portion 127. Figure 1 and 2 1023, each segment of the second metal layer 105 is attached to a corresponding segment of the insulating material layer 103 to provide a secure and reliable fixation. In addition, the size of each segment of the second metal layer 105 can be configured based on the size of the corresponding segment of the insulating material layer 103 to which it is attached.

[0077] Each of the segments 1051, 1052, 1053, and 1054 may include at least a portion of the first portion 125 of the second metal layer 105 and a portion extending therefrom. The main body portion (also referred to as a chip attach portion) of each of the segments 1051, 1052, 1053, and 1054 may be used to attach a chip (e.g., a power chip) thereto. Figure 2 As shown, it can be at least a portion of the first portion 125 of the second metal layer 105. The portions of the segments 1051, 1052, 1053, 1054 extending from the main portion can be used to attach leads, as shown in FIG. Figure 2 As shown, it can therefore be referred to as a lead attachment portion.

[0078] Preferably, for the segments of the second metal layer 105 with smaller sizes, such as segments 1052, 1053 and 1054 (whose size can only accommodate one power chip attached thereto), the main body of the segment on which the chip is attached is attached to a corresponding segment of the insulating material layer 103, and the lead portion on which the lead is attached is attached to at least another different corresponding segment, thereby enhancing stability and further reducing the influence of stress and strain. Figure 1 and Figure 2 In the illustrated embodiment, the main portions (or chip attachment portions) of segments 1052, 1053 and 1054 are respectively attached to segments 1032, 1033 and 1034 of the insulating material 103, while their respective lead attachment portions are respectively attached to segments 1032 and adjacent 1031, 1032 and adjacent 1033, and 1033 and adjacent 1034 of the insulating material 103.

[0079] Preferably, for the segments of the second metal layer 105 with a larger size, such as segment 1051 (whose size can accommodate multiple power chips attached thereto), the size of the segment of the insulating material layer 103 attached thereto is set to be equivalent to segment 1051. For example, the main body portion (on which the power chip is attached) and the lead portion (on which the lead is attached) of the segment 1051 are overlapped with the segment 1031, thereby providing stable support for the process steps of attaching the chip and attaching the lead. However, the present disclosure is not limited to this. In other embodiments, segment 1051 can be attached to two or more segments of the insulating material layer according to actual needs.

[0080] In addition, segments 1055 and 1057 are also shown in the figure, on which no chips are arranged but which are only used to provide electrical connections (for example, electrical connections with leads).

[0081] It should be understood that the segments shown here are merely exemplary and are not intended to constitute any limitation. In some embodiments, the second metal layer 105 may have only a portion of the segments shown in the figure, such as only segment 1051, or segment 1051 and one or more of segments 1052-1057; or, may have more other additional segments.

[0082] In some embodiments, the insulating material layer 103 may include a ceramic material, and the first metal layer 101 and the second metal layer 105 may be formed of, for example, copper (Cu) or aluminum (Al) or other suitable metal materials. For example, the insulating material layer 103 may be a ceramic substrate, and the first metal layer 101 and the second metal layer 105 may be copper layers attached to the top and bottom surfaces of the ceramic substrate 103. Preferably, the chip to be attached to the first portion 125 of the second metal layer 105 is a power chip. Preferably, the multilayer substrate may be one of the following: a DBC substrate, an Active Metal Braze (AMB) substrate, a Direct Bonding Aluminum (DBA) substrate, or an Insulated Metal Substrate.

[0083] Combine the following Figure 4 as well as FIG. 5A to FIG. 5D A method for manufacturing a multi-layer substrate according to an embodiment of the present disclosure is described. Figure 4 An exemplary flow chart of a method for manufacturing a multi-layer substrate according to an embodiment of the present disclosure is shown, and FIG. 5A to FIG. 5D Schematically shows the Figure 4 The schematic diagram of the device corresponding to some steps of the manufacturing method shown. Those skilled in the art will understand that Figure 4 as well as FIG. 5A to FIG. 5D The described method for manufacturing a multi-layer substrate may be used to manufacture a multi-layer substrate (eg, the multi-layer substrate 100 ) according to an embodiment of the present disclosure, and thus the aforementioned corresponding description of the multi-layer substrate is also applicable hereto.

[0084] like Figure 4 As shown, the method 200 for manufacturing a multi-layer substrate according to an embodiment of the present disclosure may include step S210 , step S220 , and step S230 .

[0085] At step S210, Figure 5A As shown, an insulating material layer 103 , a first metal layer 101 and a second metal layer 105 are provided, and the insulating material layer 103 is placed between the first metal layer 101 and the second metal layer 105 .

[0086] In some embodiments, the first metal layer may include: a first portion overlapping the insulating material layer 103, and a second portion extending outwardly from the first portion and extending beyond the insulating material layer 103 at least on the first and second opposite sides of the first metal layer. The second metal layer 105 may include: a first portion overlapping the insulating material layer 103 and for attaching a chip thereon, and a second portion extending outwardly from the first portion and extending beyond the insulating material layer 103 at least on the first and second opposite sides of the second metal layer.

[0087] At step S220, Figure 5B As shown, the first metal layer 101 and the second metal layer 105 are attached to the opposite surfaces (e.g., the top and bottom surfaces) of the insulating material layer 103. In a preferred embodiment, the first metal layer 101 and the second metal layer 105 can be attached to the opposite surfaces (e.g., the top and bottom surfaces) of the insulating material layer 103 by sintering, brazing, soldering or curing.

[0088] At step S230, Figure 5C As shown, the second metal layer 105 is patterned to form at least one pair of first notches 107 extending from the edge to the inside in the second portion of the second metal layer 105, and each pair of first notches 107 is respectively located at corresponding positions on the first side and the second side of the second metal layer 105. Preferably, the projection of the at least one pair of first notches 107 on the plane where the insulating material layer 103 is located does not overlap with the insulating material layer 103.

[0089] At step S240, if Figure 5D As shown, the first metal layer 101 is sawed to separate the plurality of multi-layer substrates.

[0090] In some embodiments, the manufacturing method 200 of the multi-layer substrate may further include: patterning the first metal layer 101 to form at least one pair of second notches 109 extending from the edge to the inside in the second part of the first metal layer 101. Each pair of second notches 109 is located at corresponding positions on the first side and the second side of the first metal layer 101, respectively. At least one of each first notch 107 and the corresponding second notch 109 matches the shape of the corresponding part of the clamping tool, so that the at least one notch can be firmly clamped to the clamping tool. In other words, the clamping tool can clamp one or both of the corresponding first notch and the second notch, which enables the multi-layer substrate of the present disclosure to be clamped using a variety of clamping tools of different shapes, thereby improving the flexibility of use.

[0091] Preferably, a vertical projection of each pair of second recesses 109 on the second metal layer 105 may at least overlap with a portion of a corresponding pair of first recesses 107 of the second metal layer 105 for clamping a clamping tool.

[0092] In some embodiments, the width of the open edge of the first notch may be greater than the width of the inner portion of the first notch in a direction parallel to the open edge, and the width of the open edge of the second notch may be greater than the width of the inner portion of the second notch in a direction parallel to the open edge. In this case, the clamping tool can be inserted into the notch in a direction parallel to the multilayer substrate. Preferably, the first notch may include two inner edges extending inwardly facing each other, and the second notch may include two inner edges extending inwardly facing each other. Each inner edge of the first notch and the second notch may be configured such that the slope of the inner edge gradually decreases as it extends toward the innermost point relative to an axis parallel to the direction in which the notch extends inwardly through the innermost point of the inner edge. For example, each inner edge may be one of the following shapes: a non-continuously derivable arc; and a plurality of line segments with discontinuous slopes and connected in sequence.

[0093] In some embodiments, the width of the open edge of the first recess is smaller than the width of at least a portion of the inner portion of the first recess in a direction parallel to the open edge, and the width of the open edge of the second recess is smaller than the width of at least a portion of the inner portion of the second recess in a direction parallel to the open edge. In this case, the clamping tool can be inserted into the recess in a direction perpendicular to the multilayer substrate.

[0094] In a preferred embodiment, the inner edge of the first recess may be arc-shaped, and the inner edge of the second recess may also be arc-shaped.

[0095] In a preferred embodiment, the first notch can be a part of a circle or a part of an ellipse, and the second notch can also be a part of a circle or a part of an ellipse. For example, the notch can be half of a circle or an ellipse, can be less than half of a circle or an ellipse, or can be more than half of a circle or an ellipse.

[0096] In a preferred embodiment, the first recess may be in the shape of a trapezoid, a square, a rectangle, or a combination of the above shapes, and the second recess may also be in the shape of a trapezoid, a square, a rectangle, or a combination of the above shapes.

[0097] In some embodiments, the method 200 for manufacturing a multi-layer substrate may further include: before attaching the first metal layer 101 and the second metal layer 105 to the insulating material layer 103 , segmenting the insulating material layer 103 to segment the insulating material layer 103 into a plurality of segments separated from each other.

[0098] In some embodiments, the first metal layer 101 is integral.

[0099] In some embodiments, patterning the second metal layer 105 may further include: patterning the second metal layer 105 to include a plurality of segments separated from each other. Preferably, each segment of the second metal layer 105 may include at least a portion of the first portion and at least a portion of the second portion, and are respectively attached to corresponding segments of the insulating material layer 103.

[0100] In some embodiments, the insulating material layer 103 may be a ceramic substrate, the first metal layer 101 and the second metal layer 105 may be copper layers, and the chip to be attached to the second metal layer may be a power chip.

[0101] Figure 6 FIG. 2 shows a schematic diagram of a power module 300 according to some embodiments of the present disclosure. Figure 6 As shown, the power module 300 may include a multilayer substrate according to any embodiment of the present disclosure, and the aforementioned descriptions of the multilayer substrate 100 may be applicable hereto. The power module 300 may also include a chip 301 and / or 303, and the chip 301 may be, for example but not limited to, a power chip including a power semiconductor device. Optionally, the chip 303 may also be a cooperative chip including a device (e.g., a diode) that cooperates with the power device. The chip may be attached to a first portion of the second metal layer 105 of the multilayer substrate.

[0102] The power module 300 may further include a lead frame. Figure 6 As shown, the lead frame may include one or more leads, such as lead 311 attached (and thus electrically connected) to the second metal layer 105. Preferably, the lead frame may also include leads 313 and a chip attach area 315 for attaching, for example, a control die 317. Two chip attach areas 315 and two control dies 317 are shown in the figure.

[0103] The power chip 301 and the cooperation chip 303 may be electrically connected by wires 321 and electrically connected to corresponding leads 311. The control die 317 may be attached to the power chip 301 by wires 320 and to leads 313 by wires (not shown). The leads 311 and 313 may be electrically connected to the outside or to other components of the module.

[0104] The power module 300 may further include a molding compound 401, which encapsulates at least a portion of the multilayer substrate, the chip, and at least a portion of the lead frame, and exposes the surface of the first metal layer of the multilayer substrate away from the chip, for example, to dissipate heat. The molding compound is provided with at least one pair of circular holes 402, at least a portion of the vertical projection of the at least one pair of circular holes 402 on the second metal layer overlaps with a corresponding pair of first notches of the second metal layer, and can be used for mounting screws.

[0105] By using the multi-layer substrate or power module according to the embodiment of the present disclosure, a round hole for installing a screw can be formed on the outside of the multi-layer substrate in the power module (especially in the housing of the molding compound) while avoiding the blind hole caused by the retraction pin. When the packaged power module is further installed, the round hole can be directly used for screw fixing, thereby effectively improving the fixing effect and installation efficiency of the power module.

[0106] Combine the following Figure 7 as well as FIG. 8A to FIG. 8C A method for manufacturing a power module according to an embodiment of the present disclosure is described. Figure 7 An exemplary flow chart of a method for manufacturing a power module according to an embodiment of the present disclosure is shown, and FIG. 8A to FIG. 8C Schematically shows the Figure 7 The schematic diagram of the device corresponding to some steps of the method shown. Those skilled in the art will understand that Figure 7 as well as FIG. 8A to FIG. 8C The described method for manufacturing a power module may be used to manufacture a power module (eg, the power module 300 ) according to an embodiment of the present disclosure, and thus the aforementioned corresponding description of the power module is also applicable hereto.

[0107] like Figure 7 As shown, the method 400 for manufacturing a power module according to an embodiment of the present disclosure may include step S410 , step S420 , step S430 , step S440 , step S450 , and step S460 .

[0108] At step S410, Fig. 8A As shown, a multi-layer substrate 100 according to an embodiment of the present disclosure is provided.

[0109] At step S420 , a chip 301 including a power semiconductor device is attached to a first portion of the second metal layer 105 of the multi-layer substrate.

[0110] At step S430, Figure 8B As shown, the multi-layer substrate and the chip attached together are arranged in a lead frame 310 .

[0111] At step S440, continue to refer to Figure 8B , the leads 311 of the lead frame 310 are attached to the second metal layer 105 of the multi-layer substrate 100 .

[0112] Preferably, the method may further include interconnecting the components accordingly, including, for example: attaching, for example, a control die 317 through the leads 313 and the chip attach area 315 of the lead frame 310; electrically connecting the power chip 301 and the cooperation chip 303 through the wires 321, and electrically connecting to the corresponding leads 311; attaching the control die 317 to the power chip 301 through the wires 320, and / or attaching the control die 317 to the leads 313 through the wires (not shown). The leads 311 and 313 may be electrically connected to the outside or to other components of the module.

[0113] At step S450, if Figure 8C As shown, based on the transfer molding process, the molding compound 401 encapsulates at least a portion of the multi-layer substrate, the chip, and at least a portion of the lead frame 310. Preferably, the molding compound exposes the surface of the first metal layer of the multi-layer substrate away from the chip.

[0114] At step S460, a redundant portion of the lead frame is cut to obtain a packaged power module. Figure 6 as shown in .

[0115] In some embodiments according to the present disclosure, step S450 of encapsulating at least a portion of the multilayer substrate, the chip, and at least a portion of the lead frame with a molding compound based on a transfer molding process can be implemented by steps S4351 , S452 , and S453 described below.

[0116] At step S451, Figure 8B As shown, at least one pair of clamping tools 330 is used to clamp at least one pair of first notches of the second portion of the first metal layer of the multilayer substrate and at least one pair of second notches of the second portion of the second metal layer to fix the multilayer substrate, wherein each clamping tool in each pair of clamping tools clamps one notch of the corresponding pair of first notches and one notch of the corresponding pair of second notches.

[0117] At step S452 , the molding compound 401 is injected.

[0118] At step S453, after the molding compound 410 is cured, the at least one pair of clamping tools is removed. Removing the at least one pair of clamping tools can leave at least one pair of circular holes 402 in the molding compound 401, and at least a portion of the vertical projection of each pair of circular holes 402 on the second metal layer overlaps with a corresponding pair of first notches in the second metal layer, and can be used to install screws.

[0119] The present application also contemplates an electrical system, which may include a power module according to any embodiment of the present disclosure. As an example, the electrical system may include, for example, an inverter, a new energy vehicle, a wind power system, a solar power generation system, an energy storage system, or any other device or system that requires the application of the power module of the present disclosure.

[0120] As used herein, the word "chip" includes, but is not limited to, a die or a bare die. The term "overlapping" means at least partially overlapping, unless the context clearly indicates a different meaning.

[0121] The words "front", "rear", "top", "bottom", "above", "below", etc., if present, in the specification and claims are used for descriptive purposes and are not necessarily used to describe invariant relative positions. It should be understood that the words so used are interchangeable under appropriate circumstances, such that the embodiments of the disclosure described herein, for example, are capable of operation in other orientations than those illustrated or otherwise described herein.

[0122] As used herein, the word "exemplary" means "serving as an example, instance, or illustration," rather than as a "model" to be exactly copied. Any implementation described as an example herein is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, the present disclosure is not limited by any expressed or implied theory given in the above technical field, background technology, summary of the invention, or detailed description.

[0123] As used herein, the term "substantially" is intended to include any minor variations due to design or manufacturing imperfections, device or component tolerances, environmental influences, and / or other factors. The term "substantially" also allows for deviations from a perfect or ideal condition due to parasitic effects, noise, and other practical considerations that may exist in actual implementations.

[0124] In addition, the foregoing description may have referred to elements or nodes or features that are "connected" or "coupled" together. As used herein, unless otherwise expressly stated, "connection" means that one element / node / feature is directly connected (or directly communicates) with another element / node / feature electrically, mechanically, logically or otherwise. Similarly, unless otherwise expressly stated, "coupling" means that one element / node / feature can be mechanically, electrically, logically or otherwise connected to another element / node / feature in a direct or indirect manner to allow interaction, even if the two features may not be directly connected. In other words, "coupling" is intended to include direct and indirect connections of elements or other features, including connections using one or more intermediate elements.

[0125] In addition, the terms "first", "second" and the like may also be used herein for reference purposes only, and thus are not intended to be limiting. For example, the terms "first", "second" and other such numerical terms referring to structures or elements do not imply a sequence or order unless the context clearly indicates otherwise.

[0126] It should also be understood that when the term “include / comprises” is used in this document, it indicates the presence of the specified features, integers, steps, operations, units and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, units and / or components and / or their combinations.

[0127] In this disclosure, the term "provide" is used in a broad sense to cover all ways of obtaining an object, and thus "providing an object" includes but is not limited to "purchasing", "preparing / manufacturing", "arranging / setting up", "installing / assembling", and / or "ordering" an object, etc.

[0128] Those skilled in the art will appreciate that the boundaries between the above operations are merely illustrative. Multiple operations can be combined into a single operation, a single operation can be distributed in additional operations, and operations can be performed at least partially overlapping in time. Moreover, alternative embodiments may include multiple instances of specific operations, and the order of operations may be changed in other various embodiments. However, other modifications, variations, and replacements are equally possible. Therefore, this specification and accompanying drawings should be considered illustrative, not restrictive.

[0129] Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. The various embodiments disclosed herein may be combined in any manner without departing from the spirit and scope of the present disclosure. It should also be understood by those skilled in the art that various modifications may be made to the embodiments without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A multi-layer substrate, characterized in that: include: Insulating material layer; a first metal layer on one surface of the insulating material layer and attached to the insulating material layer; as well as A second metal layer is on another surface opposite to the insulating material layer and attached to the insulating material layer, wherein the second metal layer comprises: a first portion overlapping the insulating material layer and used to attach a chip thereto; and A second portion extends outward from the first portion and extends beyond the insulating material layer at least on the opposite first and second sides of the second metal layer, the second portion having at least one pair of first notches extending inward from the edge, each pair of first notches being located at corresponding positions on the first and second sides of the second metal layer, respectively.

2. The multi-layer substrate according to claim 1, characterized in that in, The first metal layer comprises: a first portion overlapping the insulating material layer; and a second portion extending outwardly from the first portion and extending beyond the insulating material layer at least on opposite first and second sides of the first metal layer, the second portion having at least a pair of second notches extending inwardly from an edge, Each pair of second notches is located at corresponding positions on the first side and the second side of the first metal layer, respectively; and At least one of each first notch and the corresponding second notch matches the shape of a corresponding portion of the clamping tool, so that the at least one notch securely engages the clamping tool.

3. The multi-layer substrate according to claim 2, characterized in that: in: A vertical projection of each pair of second recesses on the second metal layer at least overlaps with a portion of a corresponding pair of first recesses of the second metal layer that is used for clamping a clamping tool.

4. The multi-layer substrate according to claim 2, characterized in that: in: The width of the open edge of the first notch is greater than the width of the inner portion of the first notch in a direction parallel to the open edge, and The width of the open edge of the second recess is greater than the width of the inner portion of the second recess in a direction parallel to the open edge.

5. The multi-layer substrate according to claim 2, characterized in that: in: The width of the open edge of the first recess is smaller than the width of at least a portion of the inner portion of the first recess in a direction parallel to the open edge, and The width of the open edge of the second recess is smaller than the width of at least a portion of the inner portion of the second recess in a direction parallel to the open edge.

6. The multi-layer substrate according to claim 4, wherein: in: The first recess includes two inner edges extending inwardly facing each other; The second recess includes two inner edges extending inwardly facing each other; Each inner edge of the first notch and the second notch is configured as: With respect to an axis passing through an innermost point of the inner edge and parallel to a direction in which the notch extends inwardly, a slope of the inner edge gradually decreases as extending toward the innermost point.

7. The multi-layer substrate according to claim 6, wherein: in, Each inside edge is one of the following shapes: Non-continuously differentiable arcs; and Multiple line segments with discontinuous slopes that are connected in sequence.

8. The multi-layer substrate according to claim 2, wherein: in: The inner edge of the first notch is arcuate; and The inner edge of the second notch is arc-shaped.

9. The multi-layer substrate according to claim 2, wherein: in: The first notch is a portion of a circle or a portion of an ellipse and the second notch is a portion of a circle or a portion of an ellipse; or The first recess is trapezoidal, square, rectangular, or a combination of the above shapes, and the second recess is trapezoidal, square, rectangular, or a combination of the above shapes.

10. The multi-layer substrate according to claim 1, wherein: in: Projections of the at least one pair of first recesses on the plane where the insulating material layer is located do not overlap with the insulating material layer.

11. The multi-layer substrate according to any one of claims 1 to 10, characterized in that: in: The insulating material layer includes a plurality of segments separated from each other; The first metal layer is integral; The second metal layer includes a plurality of segments separated from each other, each segment including at least a portion of the first portion and at least a portion of the second portion; as well as The segments of the second metal layer are respectively attached to corresponding segments of the insulating material layer.

12. The multi-layer substrate according to any one of claims 1 to 10, characterized in that: in: The insulating material layer is a ceramic substrate; The first metal layer and the second metal layer are copper layers attached to the top surface and the bottom surface of the ceramic substrate, respectively; as well as The chip is a power chip.

13. The multi-layer substrate according to any one of claims 1 to 10, characterized in that: in, The first and second metal layers are attached to the insulating material layer by sintering, brazing, soldering or curing.

14. A power module, characterized in that: include: The multilayer substrate according to any one of claims 1 to 13; as well as The chip includes a power semiconductor device. Wherein, the chip is attached to a first portion of a second metal layer of the multi-layer substrate.

15. The power module according to claim 14, characterized in that: Also includes: a lead frame including leads attached to the second metal layer; as well as a molding compound encapsulating at least a portion of the multi-layer substrate, the chip, and at least a portion of the lead frame, wherein the molding compound exposes a surface of the first metal layer of the multi-layer substrate away from the chip, and The molding compound is provided with at least one pair of circular holes, at least a portion of the vertical projections of the at least one pair of circular holes on the second metal layer substantially overlaps with a corresponding pair of first notches of the second metal layer, and the at least one pair of circular holes can be used for mounting screws.

16. An electrical system, characterized in that: Comprising a power module as claimed in any one of claims 14 and 15.

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