Package device substrate including platform portion

Abstract

A package device substrate including a platform portion is disclosed. A method for reducing curvature and stress of a substrate of a packaged device is disclosed. In some embodiments, a device may include a substrate including a base portion connected with a platform portion, where the platform portion extends from a first major side of the base portion. The device may also include a direct-copper bonding (DCB) substrate coupled to the substrate, where the DCB substrate includes a first conductive layer coupled to the insulating substrate layer, and where the first conductive layer is coupled to the platform portion of the substrate.

Description

Technical Field

[0001] The present disclosure generally relates to the field of circuit protection devices. More specifically, embodiments of the present disclosure relate to a packaged device that includes a substrate having a platform portion to reduce stress and deformation of the packaged device. Background Art

[0002] Substrates are commonly used in power modules to assist in the thermal management of the modules. For example, the substrate helps to accelerate heat dissipation from the die / chip to the outside of the package and supports mounting the module onto an application board.

[0003] Existing substrates are typically single-layer, rectangular metal plates with a thickness of 1-5 mm, depending on the required thermal application. The length and width of the rectangle vary from product to product. During use, the substrate is affected by heat, which causes bending and then deformation of the substrate. This bending / deformation increases the overall package stress, which often leads to reliability failures.

[0004] Therefore, an improved substrate design with reduced deformation is needed. Summary of the Invention

[0005] The Summary of the Invention is provided to introduce a selection of concepts in a simplified form that are further described below. The Summary of the Invention is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0006] In one method, a device can include a substrate that includes a base portion coupled to a platform portion, where the platform portion extends from a first major side of the base portion. The device can further include a direct-copper-bonded (DCB) substrate coupled to the substrate, where the DCB substrate includes a first conductive layer coupled to an insulating substrate layer, and where the first conductive layer is coupled to the platform portion of the substrate.

[0007] In another method, a power transistor device can include a substrate having a base portion integrally formed with a platform portion, where the platform portion extends away from a first major side of the base portion, and a direct-copper-bonded (DCB) substrate is coupled to the substrate. The DCB substrate can include an insulating substrate layer sandwiched between a first conductive layer and a second conductive layer, where the first conductive layer is coupled to the platform portion of the substrate by solder.

[0008] In yet another method, a method of forming a power transistor device may include forming a substrate including a base portion and a platform portion extending from a first major side of the base portion, and coupling a direct-copper bonding (DCB) substrate to the substrate, wherein the DCB substrate may include a first conductive layer coupled to an insulating substrate layer, and wherein the first conductive layer is coupled to the platform portion of the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The drawings illustrate exemplary methods of the disclosed embodiments designed thus far for practical application of their principles, and in which:

[0010] Figure 1A A top perspective view of a component in accordance with an embodiment of the present disclosure is depicted;

[0011] Figure 1B A side view of a component in accordance with an embodiment of the present disclosure is depicted;

[0012] Figure 1C An exploded side view of a component in accordance with an embodiment of the present disclosure is depicted;

[0013] Figure 2A A top perspective view of a component in accordance with an embodiment of the present disclosure is depicted;

[0014] Figure 2B A side view of a component in accordance with an embodiment of the present disclosure is depicted;

[0015] Figure 2C An exploded side view of a component in accordance with an embodiment of the present disclosure is depicted;

[0016] Figure 3A A top perspective view of a component in accordance with an embodiment of the present disclosure is depicted;

[0017] Figure 3B A side view of a component in accordance with an embodiment of the present disclosure is depicted;

[0018] Figure 4A A top perspective view of a component in accordance with an embodiment of the present disclosure is depicted;

[0019] Figure 4B A side view of a component in accordance with an embodiment of the present disclosure is depicted; and

[0020] Figure 5 is a flow chart of a method for assembling a portion of a power transistor device in accordance with an embodiment of the present disclosure.

[0021] The drawings are not necessarily to scale. The drawings are merely representative and are not intended to depict specific parameters of the present disclosure. The drawings are intended to depict exemplary embodiments of the present disclosure and are thus not to be considered as limiting of the scope. In the drawings, like numbers represent like elements.

[0022] In addition, for clarity, some components in certain figures may be omitted or not drawn to scale. Cross-sectional views may be in the form of "slices" or "near-sighted" cross-sectional views, and for clarity, some background lines that would otherwise be visible in a "true" cross-sectional view are omitted. In addition, for clarity, some reference numerals may be omitted in certain figures. Detailed Description

[0023] Components, devices, systems, and methods in accordance with the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments are shown. The components, devices, systems, and methods may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0024] As will be described in more detail herein, embodiments of the present disclosure provide a substrate design with additional metal having one or more steps on top of a typical rectangular parallelepiped, where a direct-copper bonding (DCB) substrate (alternatively referred to as a DBC substrate) may be fixed on top of the additional metal. One or more steps of the metal substrate may be integrally formed as a uniform body and may be fabricated by stamping, etching, laser, CNC, and / or cutting methods. It will be understood that the number of steps and the size of one or more individual steps may vary.

[0025] Advantageously, this substrate design reduces the curvature of the substrate, e.g., after heat treatment, and ensures reduced deformation of the substrate during extreme temperature conditions (e.g., -40°C to 217°C). This reduction in curvature and deformation directly reduces the overall package stress that the substrate would otherwise emit under extreme conditions and typically results in failure of reliability tests, such as temperature cycle tests or power cycle tests. With the reduction in the substrate curvature of the final product, embodiments of the present disclosure also help reduce stress during the screw mounting process.

[0026] Turning Figures 1A - 1C to, device 100, such as a power semiconductor device module, will be described. As shown, device 100 may include a substrate 102 having a first major side 104 opposite a second major side 106, a first end 108 opposite a second end 110, and a first side 112 opposite a second side 114. In the illustrated embodiment, first side 112 and second side 114 are longer than first end 108 and second end 110. Although generally rectangular in shape, it will be understood that substrate 102 may have a different shape or configuration in alternative embodiments.

[0027] The substrate 102 may include a base portion 120 connected to a first platform portion 122, wherein the first platform portion 122 extends from a first major side 104 of the base portion 120. The substrate 102 may further include a second platform portion 124 that also extends from the first major side 104 of the base portion 120. In some embodiments, the first platform portion 122 and the second platform portion 124 are separated from each other by a gap 126. Each of the first platform portion 122 and the second platform portion 124 may have a cuboid or rectangular shape partially defined by sidewalls 130 that extend perpendicular to the first major side 104 of the base portion 120. The angle of the sidewalls 130 relative to the plane defined by the upper surface of the first major side 104 may vary between 45° and 90°. Although shown as being substantially the same as each other, the first platform portion 122 and the second platform portion 124 may have different sizes and / or shapes in alternative embodiments.

[0028] The substrate 102 (including the base portion 120, the first platform portion 122, and the second platform portion 124) may be made of the same metal or other materials with high mechanical strength (e.g., copper, copper alloy, aluminum, aluminum alloy, steel, stainless steel, or other metal and / or metal alloy components) to prevent or reduce deformation of the device 100. In various embodiments, the substrate 102 may be a single or homogeneous body of material, which may be fabricated into the base portion 120, the first platform portion 122, and the second platform portion 124 by means such as stamping, etching, laser, CNC, or cutting.

[0029] The device 100 may further include a first DCB substrate 134 and a second DCB substrate 136 coupled to the substrate 102, wherein the first DCB substrate 134 and the second DCB substrate 136 are separated from each other by the gap 126. In alternative embodiments, DAB (Direct Aluminum Bonde) substrates may be used. As shown, the first DCB substrate 134 may be coupled to the upper surface 138 of the first platform portion 122 by solder 140, while the second DCB substrate 136 may be similarly coupled to the upper surface 142 of the second platform portion 124 by solder 144. In some embodiments, the first DCB substrate 134 and the second DCB substrate 136 may include an insulating substrate layer 146 (e.g., alumina) sandwiched between a first conductive layer 150 (e.g., copper) and a second conductive layer 152 (e.g., copper). As shown, the second conductive layer 152 may be fixed to the upper surface 138 of the first platform portion 122 and the upper surface 142 of the second platform portion 124. Although non-limiting, the insulating substrate layer 146 may extend beyond the perimeters of the first conductive layer 150 and the second conductive layer 152. Due to the structure of the device 100, there may be a lower substrate curvature / warpage, which reduces the overall package stress, especially during screw mounting.

[0030] Steering Figures 2A - 2C Figures 2A - 2C , device 200 will be described, such as a power semiconductor device module. Device 200 may be the same or similar to device 100 described above in many respects. Therefore, for the sake of brevity, only certain aspects of device 200 will be described below. As shown, substrate 202 may include a base portion 220 connected to a first platform portion 222 and a second platform portion 224, both the first platform portion 222 and the second platform portion 224 extending from a first major side 204 of the base portion 220. As shown, the first platform portion 222 and the second platform portion 224 are separated from each other by a gap 226.

[0031] Device 200 may further include a first DCB substrate 234 coupled to the first platform portion 222 by solder 240, and a second DCB substrate 236 coupled to the second platform portion 224 by solder 244. In some embodiments, the first DCB substrate 234 and the second DCB substrate 236 may include an insulating substrate layer 246 (e.g., alumina) sandwiched between a first conductive layer 250 (e.g., copper) and a second conductive layer 252 (e.g., copper), wherein the second conductive layer 252 may be fixed to the upper surfaces of the first platform portion 222 and the second platform portion 224.

[0032] Each of the first platform portion 222 and the second platform portion 224 may include multiple layers or horizontal portions. For example, the first platform portion 222 and the second platform portion 224 each have a first horizontal portion 256 and a second horizontal portion 258, wherein the first horizontal portion 256 and the second horizontal portion 258 define a stepped sidewall 260. As shown, the first horizontal portion 256 may extend vertically (e.g., in the y direction) from the first major side 204 of the base portion 220 of the substrate 202, and the second horizontal portion 258 may extend vertically from the first horizontal portion 256. The first DCB substrate 234 and the second DCB substrate 236 may be directly fixed to the upper surface 262 of the second horizontal portion 258. In this embodiment, the first horizontal portion 256 has a larger footprint (e.g., dimensions in the x direction and / or z direction) than the second horizontal portion 258. Although shown as being substantially the same, the thicknesses (e.g., in the y direction) of the first horizontal portion 256 and the second horizontal portion 258 may be different in alternative embodiments.

[0033] The first horizontal portion 256 and the second horizontal portion 258 may each have a cuboid or rectangular shape, and the angle of the side wall of each horizontal portion with respect to the plane defined by the upper surface of the first main side 204 may vary between 45° and 90°. The first horizontal portion 256, the second horizontal portion 258, and the base portion 220 may be integrally formed of the same material and may be manufactured by stamping, etching, laser, CNC, or cutting, etc. As a result of the first platform portion 222 and the second platform portion 224 of the device 200, there may be a lower substrate curvature / warpage, which reduces the overall package stress, especially during screw mounting.

[0034] Turning Figures 3A - 3B , device 300, such as a power semiconductor device module, will be described. Device 300 may be the same as or similar to devices 100, 200 described above in many aspects. Therefore, for the sake of brevity, only certain aspects of device 300 will be described below. As shown, the substrate 302 may include a base portion 320 connected to the platform portion 322. Device 300 may further include a DCB substrate 334 coupled to the platform portion 322 by solder. In this embodiment, there is only a single platform portion 322 and a single DCB substrate 334. As shown, the dimensions of the platform portion 322 and the DCB substrate 334 may be approximately the same in the x-direction and the z-direction.

[0035] Turning Figures 4A - 4B , device 400 will be described. Device 400 may be the same as or similar to device 200 described above in many aspects. Therefore, for the sake of brevity, only certain aspects of device 400 will be described below. As shown, the substrate 402 may include a base portion 420 connected to the first platform portion 422 and the second platform portion 424, both of which extend from the first main side 404 of the base portion 420. As shown, the first platform portion 422 and the second platform portion 424 are separated from each other by a gap 426.

[0036] Device 400 may further include a first DCB substrate 434 coupled to the first platform portion 422 and a second DCB substrate 436 coupled to the second platform portion 424. Each of the first platform portion 422 and the second platform portion 424 may include multiple layers or horizontal portions. For example, the first platform portion 422 and the second platform portion 424 each have a first horizontal portion 456 and a second horizontal portion 458, wherein the first horizontal portion 456 and the second horizontal portion 458 define a stepped sidewall 460. As shown, the first horizontal portion 456 may extend perpendicularly (e.g., in the y direction) from a first major side 404 of a base portion 420 of the substrate 402, and the second horizontal portion 458 may extend perpendicularly from the first horizontal portion 456. The first DCB substrate 434 and the second DCB substrate 436 may be directly fixed to the upper surface of each second horizontal portion 458. In this embodiment, the second horizontal portion 458 has a larger footprint (e.g., dimensions in the x direction and / or z direction) than the first horizontal portion 456 such that the second horizontal portion 458 partially overhangs the first horizontal portion 456. Although shown as being substantially the same, the thickness (e.g., in the y direction) of the first horizontal portion 456 and the second horizontal portion 458 may be different in alternative embodiments.

[0037] The first horizontal portion 456 and the second horizontal portion 458 may each have a cuboid or rectangular shape, wherein the angle of the sidewall of each horizontal portion with respect to the plane defined by the upper surface of the first major side 404 may vary between 45° and 90°. The first horizontal portion 456, the second horizontal portion 458, and the base portion 420 may be integrally formed of the same material and may be manufactured by stamping, etching, laser, CNC, or cutting, etc. Due to the first platform portion 422 and the second platform portion 424 of the device 400, there may be a lower substrate curvature / warpage, which reduces the overall package stress, especially during screw mounting.

[0038] Now turning to Figure 5 , a flowchart of a demonstration method 500 is shown. At block 501, the method 500 may include forming a substrate including a base portion and a platform portion extending from a first major side of the base portion. In some embodiments, forming the substrate further includes forming a second platform portion extending from the first major side of the base portion, wherein the second platform portion is separated from the platform portion by a gap.

[0039] In some embodiments, the platform may have a first horizontal portion and a second horizontal portion, wherein the first horizontal portion and the second horizontal portion define a stepped sidewall of the platform portion.

[0040] In some embodiments, the substrate may be manufactured by stamping, etching, laser, CNC, or cutting, etc.

[0041] At block 502, method 500 may further include coupling a DCB substrate to the substrate, where the DCB substrate includes a first conductive layer coupled to an insulating substrate layer, and where the first conductive layer is coupled to a platform portion of the substrate.

[0042] In some embodiments, method 500 may further include coupling a second DCB substrate to a second platform portion, where the second DCB substrate also includes a first conductive layer coupled to an insulating substrate layer, and where the first conductive layer is coupled to the second platform portion.

[0043] In some embodiments, method 500 may further include connecting the first conductive layer to one or more platform portions of the substrate using solder.

[0044] Although not shown, one or more semiconductor devices may be formed on one or more DCB substrates. In some non - limiting embodiments, semiconductor die assemblies (e.g., insulated gate bipolar transistor (IGBT) dies and free - wheeling diode dies) may be formed over one or more DCB substrates.

[0045] As used herein, an element or step recited in the singular and preceded by the word "a" or "an" should be understood to not exclude a plurality of elements or steps, unless such exclusion is explicitly recited. Further, a reference to "one embodiment" of the present disclosure is not to be construed as excluding the existence of additional embodiments that also incorporate the recited features.

[0046] The use of the terms "comprises," "comprising," "includes," "including," or "has" and variations thereof herein is intended to cover the items listed thereafter and equivalents thereof as well as additional items. Thus, the terms "comprises," "comprising," "includes," "including," or "has" and variations thereof are open - ended expressions and may be used interchangeably herein.

[0047] As used herein, the phrases "at least one," "one or more," and "and / or" are open - ended expressions and are both conjunctive and disjunctive in operation. For example, the expressions "at least one of A, B, and C," "at least one of A, B, or C," "one or more of A, B, and C," "one or more of A, B, or C," and "A, B, and / or C" mean A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B, and C together.

[0048] All directional references (e.g., proximal, distal, above, below, upward, downward, left, right, lateral, longitudinal, front, rear, top, bottom, over, under, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are for identification purposes only to assist the reader in understanding the present disclosure. Directional references do not impose limitations, particularly with respect to the location, orientation, or use of the present disclosure. Unless otherwise stated, connection references (e.g., attach, couple, connect, and join) shall be construed broadly and may include intermediate members between assemblies of elements and relative movement between elements. Thus, a connection reference does not necessarily infer that two elements are directly connected and in a fixed relationship to each other.

[0049] Furthermore, identification references (e.g., primary, secondary, first, second, third, fourth, etc.) are not intended to imply importance or priority but rather are used to distinguish one feature from another. The drawings are for illustrative purposes, and the dimensions, positions, sequences, and relative dimensions reflected in the drawings may vary.

[0050] Additionally, the terms "substantially" or "approximately" and the terms "approximate" or "approximately" may be used interchangeably in some embodiments and may be described using any relative measure acceptable to a person of ordinary skill in the art. For example, these terms may be used as a comparison with a reference parameter to indicate a deviation that can provide the desired function. Although non-limiting, the deviation from the reference parameter may be, for example, an amount less than 1%, less than 3%, less than 5%, less than 10%, less than 15%, less than 20%, and so on.

[0051] Although certain embodiments of the present disclosure have been described herein, the present disclosure is not limited thereto, as the present disclosure is as broad as the art will permit and the specification may be read accordingly. Thus, the foregoing description should not be construed as limiting. Instead, the foregoing description is merely exemplary of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the appended claims herein.

Claims

1. A device, comprising: A substrate, the substrate including a base portion connected to a platform portion, wherein the platform portion extends from a first major side of the base portion; And A direct-copper bonding (DCB) substrate coupled to the substrate, wherein the DCB substrate includes a first conductive layer coupled to an insulating substrate layer, and wherein the first conductive layer is coupled to the platform portion of the substrate.

2. The device according to claim 1, further comprising solder connecting the first conductive layer to the platform portion of the substrate.

3. The device according to claim 1, wherein, The DCB further includes a second conductive layer coupled to the insulating substrate layer.

4. The device according to claim 1, further comprising: A second platform portion extending from the first major side of the base portion, wherein the second platform portion is separated from the platform portion by a gap; And A second DCB substrate coupled to the second platform portion, wherein the second DCB substrate includes a first conductive layer coupled to an insulating substrate layer, and wherein the first conductive layer is coupled to the second platform portion.

5. The device according to claim 1, wherein, The platform portion has a first horizontal portion and a second horizontal portion.

6. The device according to claim 5, wherein, The first horizontal portion and the second horizontal portion define a stepped sidewall of the platform portion.

7. The device according to claim 5, wherein, The platform includes a height, a width, and a depth, and wherein a first width of the first horizontal portion is greater than a second width of the second horizontal portion.

8. The device according to claim 5, wherein, The platform includes a height, a width, and a depth, and wherein a first width of the first horizontal portion is less than a second width of the second horizontal portion.

9. The device according to claim 8, wherein, The second horizontal portion partially overhangs the first horizontal portion.

10. The device according to claim 1, wherein, The base portion and the platform portion are integrally formed.

11. The device according to claim 1, wherein, The base portion and the platform portion are of the same material.

12. A power transistor device, comprising: A substrate including a base portion integrally formed with a platform portion, wherein the platform portion extends away from a first major side of the base portion; A direct-copper bonding (DCB) substrate coupled to the substrate, wherein the DCB substrate includes an insulating substrate layer sandwiched between a first conductive layer and a second conductive layer, and wherein the first conductive layer is coupled to the platform portion of the substrate by solder.

13. The power transistor device according to claim 12, further comprising: A second platform portion extending from the first major side of the base portion, wherein the second platform portion is separated from the platform portion by a gap; And A second DCB substrate coupled to the second platform portion, wherein the second DCB substrate includes a first conductive layer coupled to an insulating substrate layer, and wherein the first conductive layer is coupled to the second platform portion.

14. The power transistor device according to claim 12, wherein, The platform portion has a first horizontal portion and a second horizontal portion, and wherein the first horizontal portion and the second horizontal portion define a stepped sidewall of the platform portion.

15. The power transistor device according to claim 14, wherein, The platform includes a height, a width, and a depth, and wherein a first width of the first horizontal portion is greater than a second width of the second horizontal portion.

16. The power transistor device according to claim 14, wherein, The platform includes a height, a width, and a depth, and wherein a first width of the first horizontal portion is less than a second width of the second horizontal portion such that the second horizontal portion partially overhangs the first horizontal portion.

17. The power transistor device according to claim 12, wherein, The base portion and the platform portion are of the same material.

18. A method of forming a power transistor device, the method comprising: Form a substrate including a base portion and a platform portion extending from a first major side of the base portion; Couple a direct - copper - bonding (DCB) substrate to the substrate, wherein the DCB substrate includes a first conductive layer coupled to an insulating substrate layer, and wherein the first conductive layer is coupled to a platform portion of the substrate.

19. The method according to claim 18, wherein Coupling the DCB substrate to the substrate includes connecting the first conductive layer to the platform portion of the substrate using solder.

20. The method according to claim 18, wherein Forming the substrate further includes: Forming a second platform portion extending from the first major side of the base portion, wherein the second platform portion is separated from the platform portion by a gap; and Coupling a second DCB substrate to the second platform portion, wherein the second DCB substrate includes a first conductive layer coupled to an insulating substrate layer, wherein the first conductive layer is coupled to the second platform portion, wherein each of the platform portion and the second platform portion has a first horizontal portion and a second horizontal portion, and wherein the first horizontal portion and the second horizontal portion define a stepped sidewall of the platform portion.

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