Semiconductor package and method

Abstract

The invention relates to a semiconductor package and a method. A package includes a semiconductor die disposed on a lead frame. A source contact pad is disposed on the semiconductor die. The package also includes a lead post shared by a plurality of leads forming external terminals of the package. The lead post has a clip locking feature. A wire clamp connects the source contact pad to the lead post. The wire clamp has a key structure coupled to a wire clamp locking feature in the lead post.

Description

Technical Field

[0001] This specification relates to the packaging of semiconductor dies and integrated circuits. Background Technology

[0002] Semiconductor packaging includes a metal, plastic, glass, or ceramic housing containing one or more semiconductor devices or integrated circuits. Individual components are fabricated on a semiconductor wafer (typically a silicon or silicon carbide wafer) before being diced into dies, tested, and packaged. This packaging provides a method for connecting semiconductor devices or integrated circuits to external environments such as printed circuit boards via leads such as pads, balls, or pins; and provides protection against threats such as mechanical shock, chemical contamination, and light exposure. With the increasing demand for high-performance integrated circuits, improved packaging technologies are needed to address performance and reliability issues. Summary of the Invention

[0003] This application relates to semiconductor packaging and methods.

[0004] In one aspect, a package includes a semiconductor die disposed on a lead frame. Source contact pads are disposed on the semiconductor die. The package also includes lead posts shared by multiple leads forming external terminals of the package. The lead posts have clamp locking features. The clamps connect the source contact pads to the lead posts. The clamps have a key structure coupled to the clamp locking features in the lead posts.

[0005] In one aspect, a package includes a semiconductor die disposed at a variable position on a paddle within a lead frame. The semiconductor die includes source contact pads. The package also includes wire clips that connect the source contact pads to lead posts of the lead frame forming external terminals of the package. The wire clips are aligned relative to the lead posts and the variable position of the semiconductor die on the paddle.

[0006] In one aspect, a method includes positioning a semiconductor die at a variable position on a paddle within a leadframe. The semiconductor die has source contact pads. The method also includes aligning wire clips to connect lead posts of the leadframe to the source contact pads on the semiconductor die positioned at the variable position on the paddle.

[0007] Details of one or more specific embodiments are set forth in the accompanying drawings and the following description. Other features will be apparent from the specification and drawings, as well as from the claims. Attached Figure Description

[0008] Figure 1 An exemplary lead frame according to at least one specific embodiment is illustrated.

[0009] Figure 2A and Figure 2B Examples of what can be combined with Figure 1 A view of an exemplary wire clamp used in conjunction with a lead frame.

[0010] Figures 3A to 3E Examples Figure 1 The view shows a lead frame at various stages of the process of configuring wire clamps to connect the source contact pads of a semiconductor die to one or more external package leads of a semiconductor die package.

[0011] Figure 4A Examples Figure 1 The plan view of the lead frame depicts the permissible range of positions for a pair of spaced-apart keys of the wire clamp.

[0012] Figure 4B Examples along Figure 4A A cross-sectional view of the flexible aligned wire clamp, taken from direction AA in the middle.

[0013] Figure 5A and Figure 5B , Figure 6A and Figure 6B as well as Figure 7A and Figure 7B Examples of source contact pads located at various positions on the paddle-shaped component within the lead frame are shown.

[0014] Figure 8A An exemplary lead frame is shown.

[0015] Figure 8B Examples Figure 8A along Figure 8A A cross-sectional view of the lead frame taken in direction AA.

[0016] Figure 8C Examples Figure 8A along Figure 8A A cross-sectional view of the lead frame taken from the direction BB in the middle.

[0017] Figure 9A , Figure 10A , Figure 11A and Figure 12A Examples are shown in the settings. Figure 8A Examples of source contact pads and semiconductor dies at various locations on the paddle-shaped component in the lead frame.

[0018] Figure 9B , Figure 10B , Figure 11B and Figure 12B Examples of connecting edges are given respectively. Figure 9A , Figure 10A , Figure 11A and Figure 12AA cross-sectional view of the bonding structure between the source contact pad and the semiconductor die, taken from direction AA.

[0019] Figure 9C , Figure 10C , Figure 11C and Figure 12C Examples of connecting edges are given respectively. Figure 9A , Figure 10A , Figure 11A and Figure 12A A cross-sectional view of the source contact pad and the bonding structure of the semiconductor die, taken from direction BB.

[0020] Figure 13 A keyhole structure in the lead post of another exemplary lead frame is illustrated in a plan view.

[0021] Figure 14A , Figure 14B , Figure 14C and Figure 14D Examples Figure 13 A view of the lead posts, and the bonds of the wire clamp posts for various configurations of paddles and semiconductor dies.

[0022] Figure 15 Another exemplary lead frame is shown.

[0023] Figure 16 This is a flowchart illustrating an exemplary method for packaging a semiconductor die. Detailed Implementation

[0024] The fabrication of semiconductor device packages may involve soldering or sintering to join or bond two components together. Soldering is a process that uses a molten filler metal called solder to bond two metal surfaces together. Sintering is a process that fuses particles together into a solid block using, for example, a combination of pressure and / or heat without melting the material.

[0025] A semiconductor device package includes at least one semiconductor die mounted on a lead frame structure. In some specific embodiments, a semiconductor device package may include multiple semiconductor dies of various types. For example, in a hybrid die package configuration, the semiconductor device package may include silicon carbide (SiC) device dies and silicon device dies.

[0026] In an exemplary semiconductor device package, a semiconductor die is mounted on a first section of a leadframe, including paddle or flag-shaped elements. The semiconductor die may be bonded, sintered, and / or soldered to the paddle or flag-shaped elements, for example. A second section of the leadframe includes leads that provide external electrical connections (outside the package) to individual devices or integrated circuits within the semiconductor die. Furthermore, device contact pads on the semiconductor die (e.g., gate contact pads, signal sensing contact pads, Kelvin probe contact pads, and source contact pads, etc.) may be electrically connected to one or more leads. Leads extending outside the package form external terminal pins that can be used to mount the package onto a printed circuit board (PCB) or terminal block. In an exemplary embodiment, the terminal pins may be mounted in a socket or coupled (e.g., soldered, sintered) to a PCB or terminal block.

[0027] Various package types are available for a wide range of applications. Some are defined by international, national, or industry standards, while others are specific to individual manufacturers. The number and configuration of external terminal pins for a package type can be defined by international, national, or industry standards.

[0028] Lead frames for packaging can be manufactured by removing material from a flat plate or sheet made of copper, copper alloys, or iron-nickel alloys. Techniques for removing material to manufacture lead frames may include etching (for high-density leads) or stamping (for low-density leads). A mechanical bending process may be applied after either of these techniques.

[0029] Exemplary semiconductor die packages may include discrete semiconductor devices, such as power transistors, silicon carbide (SiC) MOSFETs, or other devices. In exemplary embodiments, a semiconductor die package may include a single semiconductor die or a mixture of multiple different types of dies (e.g., SiC dies and silicon (Si) dies, etc.). The disclosure herein applies to surface mount device (SMD) packages and also to through-hole packages. In exemplary embodiments, the xy dimensions of a semiconductor die package may be several millimeters (e.g., about 5 mm to about 50 mm). The xy dimensions of a semiconductor die package may also be several millimeters (e.g., about 5 mm to about 50 mm).

[0030] In a power module package, a DAP (die attachment pad) is formed on a paddle or flag-shaped element in a first section of the leadframe. Discrete semiconductor devices (semiconductor dies) can be bonded, sintered, and / or soldered to the DAP. A second section of the leadframe includes leads forming external terminals of the package. The leads may include lead posts that connect to individual device contact pads (e.g., gate contact pads, signal sensing contact pads, and source contact pads) on the semiconductor die. In an exemplary embodiment, wire bonding (e.g., soldering) is performed on the wires to connect several contact pads (e.g., gate contact pads and signal sensing contact pads) to individual lead posts on corresponding leads in the leadframe. In an exemplary embodiment, source contact pads can be connected via wire clips to lead posts shared by one or more leads of the leadframe. In an exemplary power module package, source contact pads can be connected via wire clips to lead posts shared, for example, by two to ten leads (e.g., five leads) of the leadframe. The contact area between the wire clamp and the device contact pad is larger than that obtained through wire bonding. This increased contact area allows for better heat dissipation from the top of the die to the lead frame, thereby reducing the maximum junction temperature during operation. Furthermore, wire clamp connections offer better current carrying capacity and lower inductance than wire bonding.

[0031] This disclosure describes a flexible alignment clamp and a lead frame with clamp locking features in the lead post of the lead frame. For example, the flexible alignment clamp may be a metal bar that is generally rectangular in shape. One end of the metal bar may be attached (e.g., joined, soldered) to contact the lead post. This end of the metal bar may be formed (or attached) to the clamp post, which is attached to the lead post. A second, opposing end of the metal bar (the flexible alignment clamp tip) may be attached (e.g., soldered) to a device contact pad (e.g., a source contact pad) on a semiconductor die. The clamp locking features in the lead post are configured to receive and hold the flexible alignment clamp in a suitable geometric position such that the flexible alignment clamp tip connects to, for example, a source contact pad of the semiconductor die disposed in the lead frame.

[0032] The clamp locking features and flexible alignment of the clamps in the leadframe's lead posts prevent misalignment between the semiconductor die and the connector clamps during package assembly (e.g., during soldering or sintering operations). For example, if the semiconductor die or connector clamp shifts or rotates in position within the leadframe (e.g., above molten solder), the connector clamp may come into contact with the edge of the semiconductor die's source contact pad. This can be a problem during assembly, potentially leading to final package test failure or even reliability test failure. Such problems are avoided by allowing the connector clamps to flexibly align to compensate for semiconductor die misalignment, using the clamp locking features and flexible alignment of the clamps in the leadframe's lead posts.

[0033] According to the principles of this disclosure, one end of the flexible alignment clamp may include a pair of spaced-apart protrusions (e.g., keys, pins, or short pins). The pair of spaced-apart protrusions (keys) may extend (e.g., in the z-direction) perpendicular to the plane (e.g., the xy-plane) of the flexible alignment clamp. The clamp locking feature in the lead post may include a hole structure (keyhole structure) cut into the lead post and configured to receive the pair of spaced-apart protrusions (e.g., keys, pins, or short pins) of the flexible alignment clamp. The clamp locking feature is configured to hold the flexible alignment clamp in a position where it is properly aligned with and in contact with the source contact pads of the die.

[0034] In an exemplary embodiment, the keyhole structure in the lead post may include at least a slot that extends (e.g., in the x-direction) along a portion of the length of the lead post. In an exemplary embodiment, the keyhole structure in the lead post may include a first horizontal slot and a second horizontal slot, the first horizontal slot extending from an edge (e.g., the left edge) of the lead post toward the center of the lead post, and the second horizontal slot (e.g., in the negative x-direction) extending from an opposite edge (e.g., the right edge) of the lead post toward the center of the lead post. The two horizontal slots may be separated by an uncut portion of width d at the center of the lead post. The slots (or slots) may be configured to receive a pair of spaced protrusions (e.g., keys, pins, or short pins) of a flexibly aligned wire clip. The flexibly aligned wire clip (flexibly aligned wire clip tips) may extend (e.g., in the y-direction) perpendicular to one or more slots, wherein a pair of spaced protrusions (e.g., keys, pins, or short pins) of the flexibly aligned wire clip are placed and locked in one or more slots.

[0035] Figure 1 A plan view of an exemplary leadframe 100 for use in a semiconductor die package according to a specific embodiment described herein is shown. The leadframe 100 may be made of a conductive material such as a metal sheet (e.g., copper, copper alloy, nickel-plated or silver-plated metal sheet, etc.). The leadframe 100 may include a first segment 101 and a second segment 102, such as at least... Figure 1 As shown.

[0036] The first segment 101 of the lead frame 100 may include a paddle-shaped member 110, which is rectangular in shape, for example, having a length L (e.g., in the x-direction) and a width W (e.g., in the y-direction). The paddle-shaped member 110 may be configured to receive and hold a semiconductor die (e.g., Figure 3BThe die 410. In an exemplary embodiment, the paddle 110 may be coupled to a head portion (e.g., head 112) disposed above the flag (e.g., in the y direction). The head 112 may be electrically connected to the semiconductor die and may, for example, form an external drain terminal or ground terminal for the semiconductor die in a package.

[0037] The second segment 102 of the lead frame 100 may include multiple leads (e.g., lead 1, lead 2, lead 3, lead 4, lead 5, lead 6, and lead 7, etc.), which may, for example, form external signal leads of a semiconductor die package. Although Figure 1 A specific number of leads is shown, but the number of leads can be different. Figure 1 The quantities shown. The ends of multiple leads closest to, for example, the first segment 101, can be attached or coupled to corresponding lead posts. For example, lead 1 is coupled to lead post 10, while lead 2 is coupled to lead post 20. Some of these leads may share a common lead post. Figure 1 In the example shown, leads 3 to 7 can be coupled together to lead post 30. Each lead post can be coupled to device contact pads (e.g., gate contact pads, signal sensing contact pads, Kelvin contact pads, and source contact pads, etc.) in a semiconductor die mounted on the paddle 110 via wire bonding or wire clamp connection.

[0038] Figure 1 A wire clip 190 is schematically shown, which forms a wire clip connection between the lead post 30 and the semiconductor die 410 mounted on the paddle 110. For example, the wire clip 190 may be a rectangular metal sheet. Figure 1 In the diagram, the wire clamp 190 is shown as a dashed rectangle. One end of the wire clamp 190 may have a pair of spaced protrusions 91 extending perpendicular to the xy-plane of the wire clamp (e.g., in the -z direction). The wire clamp 190 can be aligned, for example, in the x-direction, such that the wire clamp 190 is positioned above the semiconductor die 410 mounted on the paddle 110 by placing the spaced protrusions 91 in the keyhole structure of the lead post 30 (i.e., in slots 31 and 33) and sliding the wire clamp 190 in the x-direction to the aligned position. The wire clamp 190 can be soldered, for example, to the middle portion 32 of the lead post 30. This arrangement of the spaced protrusions 91 in the keyhole structure constrains the movement of the wire clamp and prevents, for example, rotation of the wire clamp in the xy-plane when the wire clamp is soldered, for example, to the lead post 30.

[0039] In an exemplary specific implementation, a wire clamp (e.g., Figure 2A and Figure 2B The wire clamp 200 connects the lead post 30 to the source contact pad on the semiconductor die mounted on the paddle 110 (e.g., Figure 3BThe source contact pad 44 of the semiconductor die 410.

[0040] Although Figure 1 Only one semiconductor die is shown, but more than one semiconductor die 410 may be attached to the paddle 110. The semiconductor dies may be of different types (e.g., hybrid dies) and may be coupled in different ways. Figure 1 The lead frame 100 is shown. Further examples of hybrid die scenarios are described in detail (e.g., in...). Figure 1 Before and Figure 16 after).

[0041] Figure 2A and Figure 2B Plan view and side view of an exemplary wire clip 200 are shown respectively. The wire clip 200 allows for flexible alignment to connect the source contact pads of a semiconductor die to the lead posts of a lead frame.

[0042] The wire clamp 200 may be, for example, a metal strip that is generally rectangular in shape in the xy plane. The length of the wire clamp 200 may be CL (e.g., in the y-direction) and the width may be CW (e.g., in the x-direction). A portion of the wire clamp 200 at one end of the metal strip may be configured to be attached (e.g., soldered) to a device contact pad (e.g., a source contact pad) on a semiconductor die. This portion of the wire clamp 200 configured to be attached to the source contact pad on the semiconductor die may be referred to as a "wire clamp tip" (e.g., wire clamp tip 212). Opposite second ends of the metal strip may be attached to or form wire clamp posts 214. The wire clamp posts 214 may be configured to be attached (e.g., soldered) to lead posts of a lead frame. In an exemplary embodiment, the length of the wire clamp post 214 may be CPL (in the y-direction) and the width may be CPW (in the x-direction).

[0043] In an exemplary embodiment, the wire clamp post 214 may include a wire clamp locking feature (e.g., a key structure 220) that engages with the keyhole structure of the lead post 30 to constrain or limit movement of the wire clamp 200. The wire clamp locking feature may, for example, prevent the wire clamp tip 212 from moving away from an initially set or aligned position on the source pad of the semiconductor die.

[0044] In an exemplary embodiment, the clamp locking feature (e.g., key structure 220) may include, for example, a specific geometric arrangement of protrusions (e.g., keys, pins, or short ferrules). In an exemplary embodiment, the specific geometric arrangement of the protrusions may include, for example, a pair of protrusions spaced apart in the x-direction. When placed in slots 31 and 33 of the lead post (extending in the x-direction), such a pair of spaced protrusions allows the clamp 210 to initially move in the x-direction to position the clamp tip 212 in contact with a device contact pad (e.g., source contact pad 44) ​​on the semiconductor die 410. The clamp locking feature (e.g., key structure 220) combined with the keyhole structure can constrain or limit further movement of the clamp tip 212 away from its initial aligned position. The clamp locking feature (e.g., key structure 220) may (based on the y-direction width of the slot) define and / or limit translation of the clamp tip in the y-direction and limit rotation of the clamp tip in the xy-plane. This restriction on rotation can be compared to the rotation of the clamp tip that may occur when the key structure is a single protrusion or has no protrusion at all.

[0045] In an exemplary embodiment, the cross-section of the clamp locking feature (e.g., key, pin, or short ferrule) may be, for example, cylindrical or rectangular (in the xy plane). The dimensions of the cylindrical or rectangular cross-section may match the width of the slot in the keyhole structure in post 30.

[0046] The key structure 220 may include a rectangular metal strip 222. Figure 2B The rectangular metal strip is attached to the wire clamp post 214 (or as part of a metal busbar forming the wire clamp post 214). The length of the bond structure 220 can be, for example, KL (in the y-direction) and the width is KW (in the x-direction). The width KW of the bond structure 220 can be equal to, less than, or greater than the width CPW of the wire clamp post 214. Figure 2A In the exemplary embodiment shown, the width KW of the key structure 220 is, for example, greater than the width CPW of the wire clamp post 214.

[0047] like Figure 2B As shown, the key structure 220 may include a pair of spaced keys, pins, or short inserts (e.g., key 218) attached to an end (e.g., end 216) of the rectangular metal strip 222 forming the key structure 220. The pair of spaced keys (e.g., key 218) may extend (e.g., in the z-direction) perpendicular to the plane (e.g., the xy-plane) of the wire clamp 200.

[0048] The wire clamp post 214 can be configured to be received and held by a pick-and-place assembly wire tool to be placed in an appropriate geometry (e.g., a flexible alignment position) to connect, for example, the source contact pad of a semiconductor die disposed in a lead frame to a lead post in the lead frame (e.g., lead frame 100). Figure 1 (Lead post 30).

[0049] In an exemplary specific implementation, such as Figure 1 As shown, the lead post 30 in the lead frame 100 may be rectangular in shape, with a length of P1 (in the x-direction) and a width of Pw (in the y-direction). In an exemplary embodiment, the lead post 30 may include a keyhole structure configured to receive a flexibly aligned wire clip (e.g., Figure 2A and Figure 2B The wire clamp 200 comprises a pair of spaced-apart keys, pins, or short pins. The keyhole structure may, for example, include a pair of slots 31, 33 (e.g., in the x-direction and the negative x-direction) extending inward from opposite edges of the lead post 30 along a portion of the lead post's length toward the central portion 32 of the lead post. In an exemplary embodiment, the slots 31, 33 may be rectangular in shape. The slots 31, 33 allow the pair of spaced-apart keys, pins, or short pins received therein to slide in the x-direction, thereby allowing the wire clamp 200 to move in the x-direction for flexible alignment with, for example, source contact pads.

[0050] In an exemplary embodiment, the slot in the keyhole structure can help limit the rotational movement of the wire clamp during assembly by constraining the movement of a pair of spaced-apart keys, pins, or short ferrules in the x-direction of the slot.

[0051] Slot 31 may extend, for example, from the left edge L of the lead post toward the central portion 32 (e.g., horizontally). Slot 33 may extend, for example, from the right edge R of the lead post toward the uncut central portion 32 (e.g., horizontally). Figure 1 and Figure 5A , Figure 6A and Figure 7A (as well as Figures 8A to 1 In 4), the left direction L and right direction R in the x-direction refer to the left and right sides of the observer in the figure. The lengths of slots 31 and 33 can be S1 and S2 (in the x-direction), respectively. The widths Sw of slots 31 and 33 can be the same or similar. Furthermore, the width of the uncut intermediate portion 32 separating slots 31 and 33 can be d (in the x-direction). In an exemplary embodiment, the width Sw of slots 31 and 33 can be approximately one-third or less than the width PW of the lead post 30.

[0052] Figures 3A to 3E An example is shown in the wire clamp 200 which is in a flexible alignment position. Figure 2A The lead frame 100 is configured to be used in various stages of the process of connecting the source contact pads of a semiconductor die (e.g., semiconductor die 410) to the package leads of the semiconductor die package 300. Figure 1 (view of ). Figure 3AThe bare lead frame 100 at the start of the process is shown. Figure 3B A semiconductor die 410 is shown disposed on a paddle 110 of a lead frame 100. The semiconductor die 410 can be disposed on die attachment pads (DAPs) on the surface S of the paddle 110 of the lead frame 100. The semiconductor die 410 can be attached to the DAP by solder, adhesive, or sintering. The semiconductor die 410 can be, for example, a SiC metal-oxide-semiconductor field-effect transistor (MOSFET), an insulated-gate bipolar transistor (IGBT), or other power device die. The top surface of the semiconductor die 410 may include various device contact pads (e.g., gate contact pad 41, source sensing contact pad 42, Kelvin contact pad 43, and source contact pad 44, etc.).

[0053] Figure 3C A solder layer 35, for example, can be applied to the source contact pad 44. Additionally, a solder layer 36 can be applied to the middle portion 32 of the lead post 30. The solder 35 can be used to attach the wire clamp 200 ( Figure 2A One end of the wire clamp 200 is attached to the source contact pad 44 of the semiconductor die 130. Solder 36 can be used to attach the wire clamp 200 ( Figure 2A The second end of the lead is attached to a lead post (e.g., lead post 30 connected to the package lead).

[0054] Figure 3D A flexible alignment wire clip 200 is shown, for example, positioned at a location for connecting the source contact pad 44 of a semiconductor die 130 to a lead post 30. In an exemplary embodiment, the wire clip post 214 can be positioned over the solder 36 on the middle portion 32 of the lead post 30, while the first portion of the metal wire clip row 210 (e.g., the wire clip tip 212) is positioned over the solder 35 disposed on the source contact pad 44 of the semiconductor die. Furthermore, the bond structure 220 of the wire clip post 214 can be aligned with the keyhole structure (e.g., slots 31 and 33) in the lead post 30, such that a pair of bonds 218 (in...) Figure 3D (Not visible in the middle) is located in slots 31 and 33.

[0055] Figure 3E A flexible alignment wire clip 200 is shown for connecting the source contact pad 44 of the semiconductor die 130 to the lead post 30 after solder reflow and cleaning steps. Furthermore, various other device contact pads (e.g., gate contact pad 41, source sensing contact pad 42, Kelvin contact pad 43, and source contact pad 44, etc.) can be connected to their respective lead posts via wire bonding 17. The semiconductor die 410 and portions of the lead frame can then be encapsulated in molding compound to form a molded body 310 of the semiconductor die package 300.

[0056] In an exemplary embodiment, a pair of spaced-apart keys (e.g., keys 218) of the wire clip posts 214 can slide in the x-direction from one end of a corresponding slot (e.g., slots 31 and 33) in the lead post 30 to the opposite end of the corresponding slot. Thus, the flexibly aligned wire clip tips (rows of metal wire clips 210) attached to the wire clip posts 214 can have a permissible range of positions (in the x-direction) above the paddle 110 of the lead frame 100. During assembly of the semiconductor die package, the keys 218 / wire clip posts 214 can slide within this permissible range to match any misalignment that occurs in the positioning of the source contact pads 44 on the paddle 110 (such that the flexibly aligned wire clip tips are aligned with the source contact pads 44 on the paddle 110).

[0057] Figure 4A It shows Figure 1 A plan view of the lead frame, wherein the permissible range of the positions of a pair of spaced-apart keys (e.g., key 218) in slots 31 and 33 is depicted by arrow Ra. Figure 4B Show along Figure 4A The flexible alignment of the wire clamp 200 ( ) is cut in the direction AA. Figure 2A ) sectional view.

[0058] Figure 5A , Figure 6A and Figure 7A An example of a wire clamp 210 located at various positions on the paddle 110 is shown in plan view, which is connected to the lead post 30 by a flexibly aligned wire clamp 200. Figure 5B , Figure 6B and Figure 7B It shows Figure 5A , Figure 6A and Figure 7A A cross-sectional view of the flexible alignment of the wire clamp 200 and the lead post 30.

[0059] Figure 5A , Figure 6A and Figure 7A For example, a plan view shows source contact pads 44 respectively disposed at distances d1, d2, and d3 from the right edge R of the paddle 110. Distance d1 may be greater than distance d2, and distance d2 may be greater than distance d3. In each of these three examples, the flexible alignment clamp 200 is aligned with the source contact pad by sliding the key structure 220 (which has attached clamp posts 214 and includes a key 218) in the keyhole structure (e.g., slots 31 and 33) in the lead post 30 to place the flexible alignment clamp 200 above the source contact pad. For example, as Figure 5B As shown, the key structure 220 can slide to the leftmost position, so that the flexibly aligned wire clip 200 is directly above the source contact pad 44, which is set at a distance d1 from the right edge R of the paddle-shaped member 110. Figure 5A In addition, for example, such as Figure 6B As shown, the key structure 220 can slide to the middle position, so that the flexibly aligned wire clip 200 is directly above the source contact pad 44, which is set at a distance d2 from the right edge R of the paddle 110. Figure 6A In addition, for example, such as Figure 7B As shown, the key structure 220 can slide to the rightmost position, so that the flexibly aligned wire clip 200 is directly above the source contact pad 44, which is set at a distance d3 from the right edge R of the paddle-shaped member 110. Figure 7A ).

[0060] In an exemplary embodiment, an optical inspection tool (not shown) can be used to determine the position of the source contact pad 44 disposed on the paddle 110, and a pick-and-place tool can be used to position the flexibly aligned wire clamp 200 accordingly to connect the source contact pad 44 to the lead post 30.

[0061] In the implementation schemes described above, for example, refer to Figure 1 The lead post 30 is configured to have a keyhole structure comprising a pair of rectangular slots (e.g., slot 31 and slot 33), each rectangular slot having a straight edge extending horizontally in the x-direction on the top and bottom edges of the rectangular opening of the slot.

[0062] In an exemplary embodiment, the keyhole structure of the lead post 30 may also be configured to have a vertical notch or slot (e.g., extending in the y direction) that intersects perpendicularly with a pair of rectangular slots (e.g., slots 31 and 33) extending horizontally in the x direction.

[0063] Figure 8A An exemplary lead frame 800 is shown, in which lead posts 80 (similar to...) Figure 1 The lead post 30 in the lead frame 100 has a keyhole structure comprising a pair of horizontal slots (e.g., horizontal slots 31 and 33) extending horizontally inward in the x-direction from the right edge R and left edge L of the lead post toward the middle portion 32 of the lead post. The keyhole structure also includes a plurality of vertical rectangular slots (e.g., slot 81) extending from near the top edge PT of the lead post toward the bottom edge PB of the lead post. Figure 8ATwo vertical slots 81 extending vertically across a horizontal slot 31 in the y-direction and two vertical slots 81 extending vertically across a horizontal slot 33 in the y-direction are shown, for example. The height or length of the slots 81 can be H (in the y-direction) and the width is w (in the x-direction). The spacing between two adjacent vertical slots 81 crossing the horizontal slot 33 can be w1, and similarly, the spacing between two adjacent vertical slots 81 crossing the horizontal slot 31 can be w1. The vertically intersecting vertical slots 81 shape the edges of the horizontal slots 31 and 33, which extend in the y-direction, with a step in the vertical x-direction. The vertical slots (e.g., vertical slots 81) extend vertically across both the upper edge (UE) and the lower edge (LE) of the horizontal slots 31 and 33.

[0064] The vertical notch or slot 81 in the lead frame 800 has a height or length H in the y-direction, which is greater than the width Sw (along the y-axis) of slots 33 and 31 in the frame 100. Therefore, the range of y-axis clamping positions provided by the keyhole structure in the lead frame 800 can be larger than the range provided by the keyhole structure in the frame 100. In an exemplary embodiment, the height or length H of the vertical slot 81 in the y-direction can be twice or more than twice the width Sw of slots 33 and 31 in the y-direction.

[0065] Figure 8B It is along Figure 8A The sectional view of the lead frame 800 cut in direction AA, and Figure 8C It is along Figure 8A A cross-sectional view of the lead frame 800 cut from the direction BB.

[0066] Figure 9A , Figure 10A , Figure 11A and Figure 12A Examples of semiconductor dies 410 and source contact pads 44 located at various positions on the paddle 110 of the leadframe 800 are shown. The source contact pads 44 shown in these figures are connected to the lead posts 80 of the leadframe 800 via flexible alignment wire clips 200. Figure 9A , Figure 10A and Figure 11A This illustrates, for example, a semiconductor die 410 positioned at a distance D1 from the right edge R of the paddle 110, while Figure 12A This illustrates, for example, a semiconductor die 410 positioned at a distance D4 from the right edge R of the paddle-shaped member 110. Furthermore, as... Figure 9A , Figure 10A , Figure 11A and Figure 12AAs shown, semiconductor dies 410 are respectively disposed at heights h1, h2, h3 and h4 from the bottom edge BE of the paddle 110.

[0067] In these four examples ( Figure 9A , Figure 10A , Figure 11A and Figure 12A In each instance, the flexibly aligned wire clamp 200 is aligned with the source contact pad by sliding the bond structure 220 (attached to the wire clamp post 214) within the keyhole structure in the lead post 80. The bond structure 220 ( Figure 2B The key 218 in the lead frame 800 is placed in an appropriate slot position (e.g., slot 31, slot 33, slot 81) in the keyhole structure of the lead post 80 to place the flexibly aligned wire clip 200 above the source contact pad. For example, for Figure 9A , Figure 10A and Figure 11A Examples, such as Figure 9B , Figure 10B and Figure 11B As shown in the cross-sectional view, the key structure 220 can slide to the rightmost position in the horizontal slot 31, and as... Figure 12B As shown, it slides to the middle position in the horizontal slot 31. Furthermore, for example, for... Figure 9A As shown, the bond structure 220 can be positioned as follows: Figure 9C At the upper right edge of the horizontal slot 31 shown. And for Figure 10A , Figure 11A and Figure 12A As shown in the figure, the bond structure 220 can be positioned at, respectively, such as Figure 10C , Figure 11C and Figure 12C The upper left edge of the horizontal slot 31 shown.

[0068] In an exemplary embodiment, an optical inspection tool (not shown) can be used to determine the position of the source contact pad 44 disposed on the paddle 110, and a pick-and-place tool can be used to position the flexibly aligned wire clamp 200 accordingly to connect the source contact pad 44 to the lead post 80.

[0069] (The above text is for reference) Figure 8AThe exemplary lead frame 800 discussed has a keyhole structure in the lead post 80, which includes a pair of horizontal slots (e.g., horizontal slots 31 and 33) extending horizontally inward in the x-direction from the right edge R and left edge L of the lead post toward the middle portion 32 of the lead post. The keyhole structure also includes a plurality of vertical rectangular slots (e.g., slots 81) extending from near the top edge PT of the lead post toward the bottom edge PB of the lead post. The vertical slots (e.g., vertical slots 81) extend vertically across both the upper and lower edges of the horizontal slots 31 and 33.

[0070] The vertical notch or slot 81 in the frame 800 has a height or length H in the y direction, which is greater than the width Sw (along the y-axis) of the slots 33 and 31 in the frame 800.

[0071] In other specific implementations, such as Figure 13 As shown, vertical slots (e.g., vertical slots 82 and 83) may open into horizontal slots, but do not extend vertically across both the upper and lower edges of horizontal slots 31 and 33. Vertical slots 82 and 83 may alternately extend only on one side of the horizontal slot and then on the other side of the horizontal slot. Figure 13 A section 102 of a lead frame 1300 with a keyhole structure in a lead post 85 is shown. This lead post (similar to...) Figure 8A The lead post 80 includes a pair of horizontal slots (e.g., horizontal slot 31 and horizontal slot 33). The horizontal slots extend horizontally inward in the x-direction from the right edge R and left edge L of the lead post toward the middle portion 32 of the lead post. In the lead post 85, as... Figure 13 As shown, the vertical slot 82 leading to the horizontal slots 31 and 33 extends upward (in the y-direction) from the upper edge UE of the horizontal slot. Furthermore, the vertical slot 83 leading to the horizontal slots 31 and 33 extends downward (in the negative y-direction) from the lower edge LE of the horizontal slot. When the vertical slots 82 and 83 intersect (or lead to) the horizontal slots, they are alternately arranged along the x-direction.

[0072] The height h7 of the vertical slot 82 may be higher than the upper edge UE of the horizontal slot, and the height h8 of the vertical slot 83 may be lower than the lower edge LE of the horizontal slot. Including the width (Sw) of the horizontal slot (e.g., slot 31 or slot 33), the vertical slot 82 may have a height = Sw + h7, and the vertical slot 83 may have a height = Sw + h8. The height range covered by the arrangement of the vertical slots in the lead post 85 allows for more accurate y-axis positioning of the flexibly aligned wire clips within the semiconductor package.

[0073] In the above text, Figure 9A , Figure 10A , Figure 11A and Figure 12A Examples of semiconductor dies 410 and source contact pads 44 disposed at various locations on the paddle 110 of the lead frame 800 (FIG. 8) are shown. Figure 9A , Figure 10A , Figure 11A and Figure 12A The source contact pad 44 is connected to the lead post 80 of the lead frame 800 via a flexibly aligned wire clamp 200. Figure 9A , Figure 10A , Figure 11A and Figure 12A This illustrates, for example, a semiconductor die 410 positioned at distances D1, D2, D3, and D4 from the right edge R of the paddle-shaped member 110, respectively. Additionally, as... Figure 9A , Figure 10A , Figure 11A and Figure 12A As shown, the semiconductor die 410 can be configured to be at a distance of height h1, height h2, height h3 and height h4 from the bottom edge BE of the paddle 110, respectively.

[0074] In an exemplary specific implementation, the lead frame 800 may be composed of having Figure 13 The lead frame 1300 with the keyhole structure in the lead post 85 shown can be replaced. The wire clamp 200 ( Figure 2B The bond 218 in the bond structure 220 is placed in the vertical slot 82 or vertical slot 83 in the lead post 85 to control the positioning of the flexibly aligned wire clamp y-axis in the semiconductor package.

[0075] Figure 14A , Figure 14B , Figure 14C and Figure 14D They are shown respectively Figure 9A , Figure 10A , Figure 11A and Figure 12A Cross-sectional views of lead posts 85 and bond 218 (in the xy plane of lead posts 85) of various configurations of semiconductor die 410 and paddle 110.

[0076] Figure 14A Corresponding to being set with paddle-shaped member 110 ( Figure 9A Example of a semiconductor die 410 whose right edge R is a distance D1 from the edge R. Figure 14A The key 218 of the wire clamp 200 is shown to be placed in the vertical slot 83 along the lower edge LE of the horizontal slots 31 and 33 to control the y-axis positioning of the flexibly aligned wire clamp in the semiconductor package.

[0077] Figure 14B Corresponding to being set with paddle-shaped member 110 ( Figure 10A Example of a semiconductor die 410 with its right edge R separated by a distance D2. Figure 14B The key 218 of the wire clamp 200 is shown to be placed in the vertical slot 82 along the upper edge UE of the horizontal slot 31 and the horizontal slot 33 to control the y-axis positioning of the flexibly aligned wire clamp in the semiconductor package.

[0078] Figure 14C Corresponding to being set with paddle-shaped member 110 ( Figure 11A Example of a semiconductor die 410 with its right edge R separated by a distance D3. Figure 14C The key 218 of the wire clamp 200 is shown to be placed in the vertical slot 83 along the lower edge LE of the horizontal slots 31 and 33 to control the y-axis positioning of the flexibly aligned wire clamp in the semiconductor package.

[0079] Figure 14D Corresponding to being set with paddle-shaped member 110 ( Figure 12A Example of a semiconductor die 410 with its right edge R separated by a distance D4. Figure 14D The key 218 of the wire clamp 200 is shown to be placed in the vertical slot 82 along the upper edge UE of the horizontal slot 31 and the horizontal slot 33 to control the y-axis positioning of the flexibly aligned wire clamp in the semiconductor package.

[0080] Figure 15 A plan view of yet another exemplary lead frame 1400 that can be used in a semiconductor die package is shown. Similar to lead frame 100 ( Figure 1 The lead frame 1500 may include a first segment 101 and a second segment 102.

[0081] Similar to lead frame 100 ( Figure 1 The second segment 102 of the leadframe 1500 may include multiple leads (e.g., leads 1, 2, 3, 4, 5, 6, and 7, etc.), which may, for example, form external signal leads for a semiconductor die package. The lead posts of each lead may be coupled to device contact pads (e.g., gate contact pads, signal sensing contact pads, Kelvin contact pads, and source contact pads, etc.) mounted on the paddle 110 via wire bonding or wire clamp connections. Leads 3 through 7 may share a common lead post 90.

[0082] In an exemplary embodiment, the lead post 90 may include a keyhole structure that allows the lead post to pass through a flexibly aligned wire clip (e.g., Figure 2A and Figure 2BThe wire clamp 200 is connected to the source contact pad on the semiconductor die mounted on the paddle 110 (e.g., Figure 3B The source contact pad 44 of the semiconductor die 410.

[0083] In an exemplary embodiment, the lead post 90 in the lead frame 1500 may be rectangular in shape, with a length of P1 (in the x-direction) and a width of Pw (in the y-direction). In an exemplary embodiment, the lead post 90 may include a keyhole structure configured to receive a flexibly aligned wire clip (e.g., Figure 2A and Figure 2B The wire clamp 200 comprises a pair of spaced-apart keys, pins, or short inserts. The keyhole structure may, for example, include a single slot 91 extending horizontally from near the right edge R (in the x-direction) of the lead post to near the left edge L. The slot 91 may be rectangular in shape, with a width Sw in the y-direction and a length sl in the x-direction. In an exemplary embodiment, the width Sw of the slot 91 may be approximately one-third or less than the width PW of the lead post 90.

[0084] Figure 16 This is a flowchart illustrating an exemplary method 1600 for packaging a semiconductor die.

[0085] Method 1600 includes positioning a semiconductor die at a variable position on a paddle within a leadframe (1610). The semiconductor die may include source contact pads. Positioning the semiconductor die on the paddle may include positioning the semiconductor die on a solder layer (e.g., pads). For example, after solder reflow, the semiconductor die may be rolled up at a variable position on the paddle.

[0086] Method 1600 further includes aligning wire clips to connect the lead posts of the lead frame to source contact pads (1620) on a semiconductor die disposed at a variable position on the paddle. In an exemplary embodiment of method 1500, aligning wire clip 1620 may include coupling one end of the wire clip to a wire clip locking feature in the lead post.

[0087] The wire clamp may, for example, include a key structure. The key structure may, for example, include at least one pair of keys extending perpendicular to the plane of the wire clamp. Furthermore, aligning the wire clamp includes placing the pair of keys into at least one slot in a wire clamp locking feature within the lead post.

[0088] In an exemplary embodiment, aligning the wire clamp to connect the lead post of the lead frame 1620 includes soldering a first portion of the wire clamp to the source contact pad and soldering a second portion of the wire clamp to a portion of the lead post.

[0089] Method 1600 further includes: encapsulating a portion of the semiconductor die, wire clip, and lead frame in a molding compound (1630).

[0090] In an exemplary embodiment, the package may include (e.g., encapsulate) multiple semiconductor dies disposed on a lead frame structure. The multiple dies may include dies made of the same semiconductor material (e.g., silicon or silicon carbide), or in the case of a hybrid multi-die package, the multiple dies may include dies made of different semiconductor materials (e.g., silicon and silicon carbide).

[0091] In some implementations, one or more semiconductor dies from a plurality of semiconductor dies can be connected to corresponding lead posts that lead to external terminals of a package. In an exemplary implementation, one or more wire clips (e.g., flexible alignment wire clip 200) can be used in conjunction with wire clip locking features (keyhole structures) in the lead posts (e.g., lead posts 30, 80, 85, and 90) to connect one or more semiconductor dies from a plurality of semiconductor dies to corresponding one or more lead posts, as referenced above. Figures 1 to 16 As described.

[0092] In some exemplary embodiments, wire clips (non-flexibly aligned wire clips), wire bonding, and / or solder ball grid arrays can be used to connect one or more semiconductor dies (which are not connected to the keyhole structure in the lead post via flexiblely aligned wire clips (e.g., flexible aligned wire clip 200)) to the corresponding lead posts (e.g., lead posts 30, 80, 85, and 90).

[0093] For example, a first semiconductor die can be connected to a flexible alignment clamp (as described herein (e.g., flexible alignment clamp 200)), and the clamp can be used to connect a second semiconductor die to, for example, lead posts (e.g., lead posts 30, 80, 85, and 90). Alternatively, a first semiconductor die can be connected to a flexible alignment clamp (as described herein), and a wire bond can be used to connect a second semiconductor die to, for example, a lead post. Yet another example is that a first semiconductor die can be connected to a flexible alignment clamp (as described herein), and a solder ball grid array can be used to connect a second semiconductor die to, for example, a lead post.

[0094] It should be understood that in the foregoing description, when an element such as a layer, region, substrate, or component is referred to as being on, connected to, electrically connected to, coupled to, or electrically coupled to another element, the element may be directly on, connected to, or coupled to the other element, or one or more intermediate elements may be present. Conversely, when an element is referred to as being directly on, directly connected to, or directly coupled to another element or layer, no intermediate element or layer is present. Although the terms "directly on," "directly connected to," or "directly coupled to" may not be used throughout the specific embodiments, elements shown as being directly on, directly connected to, or directly coupled to an element can be referred to in this manner. The claims of this application (if any) may be amended to state the exemplary relationships described in the specification or shown in the drawings.

[0095] As used in this specification and claims, the singular form may include the plural form unless the context specifically indicates otherwise. In addition to the orientations shown in the figures, spatially relative terms (e.g., above, on, above, below, under, beneath, etc.) are intended to cover different orientations of the device in use or operation. In some embodiments, the relative terms above and below may respectively include vertically above and vertically below. In some embodiments, the term proximity may include lateral proximity or horizontal proximity.

[0096] Some specific implementations can be achieved using various semiconductor processing and / or packaging technologies. Some specific implementations can be achieved using various types of semiconductor processing technologies associated with a semiconductor substrate, including but not limited to, silicon (Si), gallium arsenide (GaAs), gallium nitride (GaN), silicon carbide (SiC), etc.

[0097] While certain features of the described embodiments have been illustrated herein, many modifications, alternatives, variations, and equivalents will now occur to those skilled in the art. Therefore, it should be understood that the appended claims are intended to cover all such modifications and variations falling within the scope of the embodiments. It should be understood that these modifications and variations are presented by way of example only and not limitation, and various changes in form and detail are possible. Any parts of the apparatus and / or method described herein can be combined in any way, except for mutually exclusive combinations. The embodiments described herein may include various combinations and / or sub-combinations of the functions, components, and / or features of the different embodiments described.

Claims

1. A package, the package comprising: A semiconductor die, wherein the semiconductor die is disposed on a lead frame; Source contact pads are disposed on the semiconductor die; A lead post, shared by multiple leads forming external terminals of the package, the lead post having a wire clamp locking feature; and A wire clamp that connects the source contact pad to the lead post, the wire clamp having a key structure coupled to a wire clamp locking feature in the lead post.

2. The package of claim 1, further comprising a molding body encapsulating at least a portion of the lead frame and the semiconductor die.

3. The package of claim 1, wherein a first end of the wire clamp is engaged to the source contact pad, and a second end of the wire clamp is engaged to the lead post.

4. The package of claim 3, wherein the coupling of the bond structure in the wire clamp and the wire clamp locking feature in the lead post aligns the position of the wire clamp with the position of the source contact pad on the semiconductor die.

5. The package of claim 1, wherein the wire clip is a metal busbar, and wherein the key structure includes a pair of spaced protrusions, the pair of protrusions including a key, pin, or short pin extending perpendicular to the plane of the wire clip.

6. The package of claim 5, wherein the clamp locking feature in the lead post is a hole structure cut into the lead post and configured to receive the pair of spaced protrusions of the clamp.

7. The package of claim 6, wherein the hole structure includes a first slot and a second slot, the first slot extending horizontally from one edge of the lead post toward the center of the lead post, the second slot extending horizontally from an edge of the lead post opposite to the edge toward the center of the lead post, the first slot and the second slot being separated by an uncut portion in the middle of the lead post.

8. The package of claim 7, wherein the hole structure further comprises at least one vertical slot and at least one other vertical slot, the at least one vertical slot extending perpendicularly across the first slot and the at least one other vertical slot extending perpendicularly across the second slot.

9. The package according to claim 7, wherein the hole structure further comprises: At least one vertical slot, the vertical slot extending vertically away from the first slot along the upper edge of the first slot to the first slot; and At least one second vertical slot, the at least one second vertical slot extending along the lower edge of the first slot toward the first slot and extending vertically away from the first slot.

10. The package of claim 9, wherein the at least one vertical slot leading to the first slot along the upper edge of the first slot and the at least one second vertical slot leading to the first slot along the lower edge of the first slot are alternately arranged along the length of the first slot.

11. The package of claim 6, wherein the aperture structure includes a single slot extending horizontally along the length of the lead post from one side of the lead post to a second side of the lead post.

12. The package of claim 1, wherein the lead frame comprises a flat plate or sheet made of copper, a copper alloy, or an iron-nickel alloy.

13. The package according to claim 1, wherein the wire clamp is made of copper, a copper alloy, or an iron-nickel alloy.

14. The package of claim 1, wherein the semiconductor die comprises a silicon carbide (SiC) power transistor.

15. A package, the package comprising: A semiconductor die, the semiconductor die being disposed at a variable position on a paddle in a lead frame, the semiconductor die including a source contact pad; and A wire clamp connects the source contact pad to the lead post of the lead frame, the lead post forming the external terminal of the package, and the wire clamp is aligned with the lead post and the semiconductor die in the variable position on the paddle.

16. The package of claim 15, wherein the lead post includes a keyhole structure configured to receive the key structure of the wire clip and to hold the wire clip in an aligned position.

17. A method, the method comprising: The semiconductor die is positioned at a variable location on a paddle in a lead frame, the semiconductor die including a source contact pad; as well as Align the wire clamps to connect the lead posts of the lead frame to the source contact pads on the semiconductor die at the variable positions provided on the paddle.

18. The method of claim 17, wherein aligning the wire clamp includes coupling one end of the wire clamp to a wire clamp locking feature in the lead post.

19. The method of claim 18, wherein the key structure includes at least a pair of protrusions extending perpendicular to the plane of the clamp, and wherein flexibly aligning the clamp includes placing the pair of protrusions in at least one slot of the clamp locking feature in the lead post.

20. The method of claim 19, wherein flexibly aligning the wire clamp to connect the lead post of the lead frame comprises: The first portion of the wire clamp is bonded to the source contact pad, and the second portion of the wire clamp is bonded to a portion of the lead post.

21. The method according to claim 17, further comprising: The semiconductor die, the wire clip, and a portion of the lead frame are encapsulated in molding compound.

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