DEVICE PACKAGE WITH FLEXIBLY ALIGNED LEAD FRAME CLIP

Abstract

A package includes a semiconductor die mounted on a lead frame. A source contact is located on the semiconductor die. The package also includes a lead column shared by multiple leads, which form the package's external connections. The lead column features a clip-locking feature. A clip connects the source contact to the lead column. The clip has a key structure that engages with the clip-locking feature in the lead column.

Description

TECHNICAL AREA

[0001] This description refers to the packaging of semiconductor dies and integrated circuits. BACKGROUND

[0002] A semiconductor package is a housing made of metal, plastic, glass, or ceramic that contains one or more semiconductor devices or integrated circuits. Individual components are fabricated on semiconductor wafers (usually silicon or silicon carbide wafers) before being disassembled into dies, tested, and packaged. The package provides means for connecting semiconductor devices or integrated circuits to the external environment, such as a printed circuit board, via leads like solder pads, balls, or pins; and it protects them from threats such as mechanical impact, chemical contamination, and light exposure. Given the increasing demand for high-performance integrated circuits, improvements in packaging technologies are needed to address performance and reliability issues. SUMMARY

[0003] From one perspective, a package includes a semiconductor die mounted on a lead frame. A source contact is located on the semiconductor die. The package further includes a lead column shared by a multitude of leads, which form the external connections of the package. The lead column features a clip-locking feature. A clip connects the source contact to the lead column. The clip has a key structure that engages with the clip-locking feature in the lead column.

[0004] From one perspective, a package encloses a semiconductor die positioned at a variable location on a paddle within a lead frame. The semiconductor die includes a source contact point. The package further includes a clip that connects the source contact point to a lead column of the lead frame, forming an external connection for the package. The clip is aligned relative to the variable position of the semiconductor die on the paddle and the lead column.

[0005] In one respect, a method includes arranging a semiconductor die at a variable location on a paddle in a lead frame. The semiconductor die has a source contact point. The method further includes aligning a clip to connect a lead column of the lead frame to the source contact point on the semiconductor die, which is arranged at the variable location on the paddle.

[0006] The details of one or more implementation methods are set out in the accompanying drawings and the following description. Other features will become apparent from the description, the drawings, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 illustrates an exemplary lead frame according to at least one implementation. Fig. 2A and Fig. 2B illustrate views of an example clip, which, in conjunction with the lead frame of Fig. 1 can be used. Fig. Figures 3A to 3E illustrate views of the lead frame of Fig. 1 in various stages of a process to configure a clip to connect a source contact point of a semiconductor die to one or more external package leads of a semiconductor die package. Fig. Figure 4A illustrates a top view of a lead frame. Fig. 1 and represents the permissible ranges of the positions of a pair of spaced keys of a clip. Fig. Figure 4B illustrates a cross-sectional view of a flexibly oriented clip along the AA direction in Fig. 4A. Fig. 5A and Fig. 5B, Fig. 6A and Fig. 6B and Fig. 7A and Fig. Figure 7B illustrates examples of source contact points arranged at different locations on a paddle in a lead frame. Fig. Figure 8A illustrates an example lead frame. Fig. Figure 8B illustrates a cross-sectional view of the lead frame of Fig. 8A along the direction AA in Fig. 8A. Fig. Figure 8C illustrates a cross-sectional view of the lead frame of Fig. 8A along the BB direction in Fig. 8A. Fig. 9A, Fig. 10A, Fig. 11A and Fig. 12A illustrates examples of semiconductor die and source contacts located at various points on a paddle in the lead frame of Fig. are arranged in 8A. Fig. 9B, Fig. 10B, Fig. 11B and Fig. Figure 12B illustrates cross-sectional views of key structures that connect the semiconductor die to the source contact points along the AA direction. Fig. 9A, Fig. 10A, Fig. Connect 11A or 12A. Fig. 9C, Fig. 10C, Fig. 11C and Fig. Figure 12C illustrates cross-sectional views of key structures that define the semiconductor die and the source contact points along the BB direction. Fig. 9A, Fig. 10A, Fig. Connect 11A or 12A. Fig. Figure 13 illustrates in a top view a keyhole structure in a lead column of another exemplary lead frame. Fig. 14A, Fig. 14B, Fig. 14C and Fig. 14D illustrates views of the lead column of Fig. 13 and a key for a clip column for different configurations of the semiconductor die and a paddle. Fig. Figure 15 illustrates yet another example of a lead frame. Fig. Figure 16 is a flowchart illustrating an exemplary procedure for packaging a semiconductor die. DETAILED DESCRIPTION

[0007] Manufacturing a semiconductor device package can involve soldering or sintering to join or bond two components together. Soldering is a process in which two metal surfaces are joined using a molten filler metal called solder. Sintering is a process in which particles fuse into a solid mass using, for example, a combination of pressure and / or heat, without melting the materials.

[0008] A semiconductor device package includes at least one semiconductor die mounted on a lead-frame structure. In some implementations, the semiconductor device package may include multiple semiconductor dies of different types. For example, in a hybrid die package configuration, the semiconductor device package may include a silicon carbide device die (SiC device die) and a silicon device die.

[0009] In an example of a semiconductor device package, a semiconductor die is mounted on a first section of the lead frame, which includes a paddle or flag. The semiconductor die can be glued, sintered, and / or soldered to the paddle or flag. A second section of the lead frame includes leads that provide external electrical connections (outside the package) for a single device or integrated circuit within the semiconductor die. Device contact points (e.g., a gate contact, a signal sensing contact, a Kelvin probe contact, and a source contact, etc.) on the semiconductor die can be electrically connected to one or more of the leads. The leads extending to an outside of the package body form external terminals that can be used to mount the package onto a printed circuit board or lead strip.In example implementations, the connection pins can be installed in sockets or coupled to a printed circuit board (PCB) or terminal block (e.g. soldered, sintered).

[0010] Many package types can be used in various applications. Some are defined by international, national, or industry standards, while others are specific to a single manufacturer. The number and configuration of a package type's external connection pins can also be defined by international, national, or industry standards.

[0011] The lead frame for a package can be manufactured by removing material from a flat plate or sheet of copper, a copper alloy, or an iron-nickel alloy. Material removal techniques for producing the lead frame can include etching (suitable for high lead density) or stamping (suitable for low lead density). A mechanical bending process can be applied after either technique.

[0012] An exemplary semiconductor die package may include a discrete semiconductor device, such as a power transistor, a silicon carbide MOSFET (SiC MOSFET), or another device. In example implementations, the semiconductor die package may include a single semiconductor die or a hybrid plurality of dies of different types (e.g., a SiC die and a silicon die (Si die), etc.). The disclosure herein applies to both surface-mount device packages (SMD packages) and through-hole packages. In example implementations, the semiconductor die package may have xy dimensions of several millimeters (e.g., about 5 mm to about 50 mm).

[0013] In a power module package, a DAP (Die Attach Pad) is formed on the paddle or flag in the first section of a lead frame. The discrete semiconductor device (semiconductor die) can be glued, sintered, and / or soldered onto the DAP. The second section of the lead frame includes leads that form the external connections of the package. The leads can include lead columns that are connected to individual device contact points (e.g., a gate contact, a signal sensing contact, and a source contact) on the semiconductor die. In example implementations, wires are wire-bonded (e.g., soldered) to connect some of the contact points (e.g., gate contact and signal sensing contact) to individual lead columns on corresponding leads in the lead frame.In example implementations, the source contact point can be connected to a lead column by a clip shared by one or more leads of the lead frame. The source contact point in an example power module package can be connected to a lead column by a clip shared by, for example, two to ten leads (e.g., five leads) of the lead frame. A clip contact area with the device contact point is larger than the contact areas achieved by wire bonding. This increased contact area allows for better heat dissipation from the die top to the lead frame, thus reducing the maximum junction temperature during operation. Furthermore, a clip connection can exhibit better current carrying capacity and lower inductance than a wire bond.

[0014] This disclosure describes a flexibly oriented clip and a lead frame with a clip-locking feature in a lead column of the lead frame. The flexibly oriented clip can be, for example, a metal strip with a generally rectangular shape. One end of the metal strip can be attached (e.g., bonded, soldered) to contact the lead column. This end of the metal strip can form (or be attached to) a clip column that is secured to the lead column. An opposite second end of the metal strip (the flexibly oriented clip tip) can be attached (e.g., soldered) to a device contact point (e.g., the source contact point) on the semiconductor die.The clip locking feature in the lead column is configured to receive and hold the flexibly oriented clip in a suitable geometric position such that the flexibly oriented clip tip is connected, for example, to the source contact point of the semiconductor die arranged in the lead frame.

[0015] The flexibly aligned clip and clip locking feature in the lead frame's lead column prevent problems caused by misalignment of the semiconductor die and the interconnect clip during package assembly (e.g., during soldering or sintering processes). For example, if the semiconductor die or interconnect clip shifts or rotates in its position on the lead frame (e.g., over molten solder), the interconnect clip can touch the edge of the semiconductor die's source contact point. This can cause problems during assembly, potentially leading to a failed final test or even the package's reliability test. By using the flexibly aligned clip and clip locking feature in the lead frame's lead column, such problems can be avoided by flexibly aligning the interconnect clip's position to compensate for any misalignment of the semiconductor die.

[0016] According to the principles of this disclosure, one end of a flexibly oriented clip can include a pair of spaced-apart projections (e.g., keys, prongs, or pins). The pair of spaced-apart projections (keys) can be perpendicular (e.g., in the z-direction) to the plane (e.g., the xy-plane) of the flexibly oriented clip. The clip locking feature in the lead post can include a hole structure (a keyhole structure) cut into the lead post and configured to receive the pair of spaced-apart projections (e.g., keys, prongs, or pins) of the flexibly oriented clip. The clip locking feature is configured to hold the flexibly oriented clip in a position where it is correctly aligned with and in contact with the source contact point of the die.

[0017] In example implementations, the keyhole structure in the lead column can include at least one slot running along a section of a long side of the lead column (e.g., in an x-direction). In other example implementations, the keyhole structure in the lead column can include a first horizontal slot running from an edge (e.g., a left edge) of the lead column toward the center of the lead column, and a second horizontal slot running from an opposite edge (e.g., a right edge) of the lead column toward the center of the lead column (e.g., in a minus-x direction). The two horizontal slots can be separated by an uncut section of width d at the center of the lead column. The slot (or slots) can be configured to receive the pair of spaced protrusions (e.g., keys, prongs, or tenons) of the flexibly oriented clip.The flexibly oriented clip (the flexibly oriented clip tip) can run perpendicular (e.g. in a y-direction) to the slot or slots, with the pair of spaced-apart projections (e.g. key, prong or tenon) of the flexibly oriented clip being placed and locked in the slot or slots.

[0018] Fig. Figure 1 shows a top view of an exemplary lead-frame 100 that can be used in a semiconductor die package according to the implementations described herein. Lead-frame 100 can, for example, be made of conductive materials such as a metal sheet (e.g., copper, copper alloy, nickel-plated or silver-plated metal sheets, etc.). Lead-frame 100 can include a first section 101 and a second section 102, as shown at least in Fig. 1 shown.

[0019] The first section 101 of the lead frame 100 can include a paddle 110, which, for example, has a rectangular shape with a length L (e.g., in the x-direction) and a width W (e.g., in the y-direction). The paddle 110 can be configured to move the semiconductor die (e.g., die 410, Fig. 3B) to pick up and hold. In example implementations, paddle 110 can be coupled to a header section (e.g., header 112) that is positioned above (e.g., in the y-direction) the flag. Header 112 can be electrically connected to the semiconductor die and can, for example, form an external drain or ground connection for the semiconductor die in the package.

[0020] The second section 102 of the lead frame 100 can include a variety of leads (e.g., Lead 1, Lead 2, Lead 3, Lead 4, Lead 5, Lead 6, and Lead 7, etc.) that can, for example, form the external signal leads of the semiconductor die package. Although in Fig. 1. If a specified number of leads is shown, the number of leads can be adjusted from the one in Fig. The ends of the multitude of leads that are closest to, for example, the first section 101, may differ. They may be attached to or linked to the respective lead column. For example, Lead 1 is linked to Lead Column 10 and Lead 2 to Lead Column 20. Some of the leads may share a common lead column. In the Fig. In the example shown, leads 3 to 7 can be coupled together with a lead column 30. The various lead columns can be coupled to the device contact points (e.g., gate contact point, signal acquisition contact point, Kelvin contact point, and source contact point, etc.) in the semiconductor die mounted on paddle 110 by wire bonds or clip connections.

[0021] Fig. Figure 1 schematically shows, for example, a clip 190 that can form a clip connection between lead column 30 and semiconductor die 410, which is mounted on paddle 110. Clip 190 can, for example, be a rectangular metal sheet. Fig. In Figure 1, clip 190 is shown as a dashed rectangle. One end of clip 190 may have a pair of spaced-apart protrusions 91 that extend perpendicular to the xy-plane of the clip (e.g., in the z-direction). Clip 190 can be aligned in the x-direction, for example, so that it is positioned above the semiconductor die 410 mounted on paddle 110, by placing the spaced-apart protrusions 91 in the keyhole structure (i.e., in slots 31 and 33) of the lead column 30 and sliding clip 190 into the aligned position in the x-direction. Clip 190 can, for example, be soldered to a central section 32 of the lead column 30. This arrangement of the spaced-apart protrusions 91 in the keyhole structure restricts the movement of the clip and, for example, prevents rotation of the clip in the xy-plane when the clip is soldered to the lead column 30.

[0022] In example implementations, lead column 30 can be replaced by a clip (e.g., clip 200, Fig. 2A and Fig. 2B) with the source contact point on the semiconductor die (e.g. source contact point 44 of the semiconductor die 410, Fig. 3B) connected, which is mounted on paddle 110.

[0023] Although in Fig. While only one semiconductor die is shown in Figure 1, more than one semiconductor die 410 can be attached to the paddle 110. The semiconductor dies can be of different types (e.g., hybrid dies) and can be arranged in different ways within the diagram. Fig. The lead frames shown in section 1 are coupled to 100. Further examples of hybrid die scenarios are described in detail (e.g., before). Fig. 1 and after Fig. 16).

[0024] Fig. 2A and Fig. Figure 2B illustrates a top view and a side view of an example clip 200. Clip 200 can be flexibly aligned to connect the source contact point of a semiconductor die to a lead column of a lead frame.

[0025] Clip 200 can, for example, be a metal strip with a generally rectangular shape in an xy-plane. Clip 200 can have a length CL (e.g., in the y-direction) and a width CW (e.g., in the x-direction). A section of Clip 200 at one end of the metal strip can be configured to be attached (e.g., soldered) to a device contact point (e.g., the source contact point) on the semiconductor die. The section of Clip 200 configured to attach to the source contact point on the semiconductor die can be referred to as the "clip tip" (e.g., clip tip 212). An opposite second end of the metal strip can be attached to, or form, a clip pillar 214. Clip pillar 214 can be configured to be attached (e.g., soldered) to the lead pillar of the lead frame.In example implementations, clip column 214 can have a length CPL (in the y-direction) and a width CPW (in the x-direction).

[0026] In example implementations, clip column 214 can include a clip locking feature (e.g., a key structure 220) which, in conjunction with the keyhole structure of the lead column 30, restricts or limits the movement of the clip 200. The clip locking feature can, for example, prevent movement of the clip tip 212 from an initially set or aligned position on the source contact point of the semiconductor die.

[0027] In example implementations, the clip locking feature (e.g., key structure 220) can include, for instance, a specific geometric arrangement of protrusions (e.g., keys, prongs, or pins). In example implementations, the specific geometric arrangement of protrusions can include, for instance, a pair of protrusions spaced apart in the x-direction. Such a pair of spaced protrusions, when placed in the slots 31 and 33 of the lead column (which extends in the x-direction), can allow an initial movement of the clip 210 in the x-direction to bring the clip tip 212 into contact with a device contact point (e.g., source contact point 44) on the semiconductor die 410. The clip locking feature (e.g., key structure 220), in conjunction with the keyhole structure, can then hinder or limit further movement of the clip tip 212 from its initially aligned position.The clip locking feature (e.g., key structure 220) can, for example, restrict and / or limit the translation of the clip tip in the y-direction (based on the width of the slots in the y-direction) and restrict the rotation of the clip tip in the xy-plane. This rotation restriction can be compared to the rotation of the clip tip that might be possible if the key structure consisted of only a single projection or no projection at all.

[0028] In an example implementation, the clip locking features (e.g., keys, prongs, or pins) can, for instance, have a cylindrical or rectangular cross-section (in the xy-plane). The cylindrical or rectangular cross-sections can have dimensions corresponding to the widths of the slots in the keyhole structure in the post 30.

[0029] Key structure 220 can be a rectangular metal rod 222 ( Fig. 2B) include, which is attached to clip column 214 (or is part of the metal strip that forms clip column 214). Key structure 220 may, for example, have a length KL (in the y-direction) and a width KW (in the x-direction). The width KW of key structure 220 may be equal to, less than, or greater than the width CPW of clip column 214. In the Fig. In the example implementation shown in Figure 2A, the width KW of the key structure 220 is, for example, larger than the width CPW of the clip column 214.

[0030] As in Fig. As shown in Figure 2B, key structure 220 can include a pair of spaced-apart keys, prongs, or pins (e.g., key 218) attached to the ends (e.g., ends 216) of the rectangular metal rod 222 forming key structure 220. The pair of spaced-apart keys (e.g., key 218) can be perpendicular (e.g., in the z-direction) to the plane (e.g., xy-plane) of the clip 200.

[0031] Clip column 214 can be configured to be picked up and held by a pick-and-place manufacturing line tool in order to be placed in a suitable geometric position (e.g., a flexibly oriented position) to, for example, connect the source contact point of the semiconductor die arranged in the lead frame with the lead column (e.g., lead column 30). Fig. 1) to connect in the lead frame (e.g., lead frame 100).

[0032] In example implementations, such as in Fig. As shown in Figure 1, lead column 30 in lead frame 100 can have a rectangular shape with a length Pl (in the x-direction) and a width Pw (in the y-direction). In example implementations, lead column 30 can enclose a keyhole structure configured to engage the pair of spaced keys, prongs, or pins of the flexibly oriented clip (e.g., clip 200). Fig. 2A and Fig. 2B). The keyhole structure can, for example, include a pair of slots 31, 33 extending inward along a section of a longitudinal side of the lead column from opposite edges of the lead column 30 (e.g., in the x-direction and the minus-x-direction) to a central section 32 of the lead column. In example implementations, the slots 31, 33 can have a rectangular shape. The pair of slots 31, 33 can allow the pair of spaced keys, prongs, or pins held therein to be displaced in the x-direction, thus enabling movement of the clip 200 in the x-direction for flexible alignment, for example, with the source contact point.

[0033] In example implementations, the slots in the keyhole structure can help to limit the rotational movement of the clip during assembly by restricting the movement of the pair of spaced keys, prongs, or pins to the x-direction of the slots.

[0034] Slot 31 can, for example, extend from a left edge L of the lead column towards the middle section 32 (e.g., horizontally). Slot 33 can, for example, extend from a right edge R of the lead column towards the uncut middle section 32 (e.g., horizontally). Fig. 1 and Fig. 5A, Fig. 6A and Fig. 7A (and Fig. In Figures 8A to 14, the left direction L and the right direction R in the x-direction refer to the left and right sides of a viewer of the figures. Slot 31 and slot 33 can have lengths S1 and S2, respectively (in the z-direction). Slot 31 and slot 33 can each have the same or a similar width Sw. Furthermore, the uncut central section 32, which separates slot 31 and slot 33, can have a width d (in the x-direction). In example implementations, the width Sw of each slot 31 and slot 33 can be approximately one-third or less than one-third of the width PW of the lead column 30.

[0035] Fig. 3A to 3E illustrate views of the Lead Frame 100 ( Fig. 1) in various stages of a process for configuring the flexibly oriented clip 200 ( Fig. 2A), to connect a source contact point of a semiconductor die (e.g. semiconductor die 410) to package leads of a semiconductor chip die package 300. Fig. Figure 3A shows a bare Lead Frame 100 at the beginning of the process. Fig. Figure 3B shows a semiconductor die 410 mounted on paddle 110 of the lead frame 100. The semiconductor die 410 can be mounted on a die mounting pad (DAP) on a surface S of a paddle 110 of the lead frame 100. The semiconductor die 410 can be attached to the DAP by solder, adhesive, or sintered bonding. The semiconductor die 410 can be, for example, a silicon carbide-oxide-semiconductor field-effect transistor (MOSFET), an insulated-gate bipolar transistor (IGBT), or another power device die. An upper surface of the semiconductor die 410 can include various device contact points (e.g., gate contact 41, source sensing contact 42, Kelvin contact 43, and source contact 44, etc.).

[0036] Fig. Figure 3C shows, for example, a solder layer 35 that can be applied to the source contact point 44. Furthermore, a layer of solder 36 can be applied to the central section 32 of the lead column 30. Solder 35 can be used to connect one end of the clip 200 ( Fig. 2A) to attach to source contact point 44 of the semiconductor die 130. Solder 36 can be used to attach a second end of the clip 200 ( Fig. 2A) to attach to a lead column (e.g., lead column 30, which is connected to the package leads).

[0037] Fig. Figure 3D shows, for example, a flexibly oriented clip 200 that is positioned to connect the source contact point 44 of the semiconductor die 130 to the lead column 30. In example implementations, clip column 214 can be placed over solder 36 onto the central section 32 of the lead column 30, while the first section (e.g., clip tip 212) of the metal strip of clip 210 is placed over solder 35, which is located on the source contact point 44 of the semiconductor die. Furthermore, the key structure 220 of clip column 214 can be aligned with the keyhole structure (e.g., slots 31 and 33) in the lead column 30 such that the pair of keys 218 (in Fig. (3D not visible) sits in slots 31 and 33.

[0038] Fig. Figure 3E shows the flexibly oriented clip 200, which connects the source contact point 44 of the semiconductor die 130 to the lead column 30 after a solder reflow and cleaning step. Furthermore, the various other device contact points (e.g., gate contact point 41, source sensing contact point 42, Kelvin contact point 43, and source contact point 44, etc.) can be connected to the corresponding lead columns by wire bonding 17. The semiconductor die 410 and sections of the lead frame can then be encapsulated in a molding compound to form a molded body 310 of the semiconductor die package 300.

[0039] In example implementations, the pair of spaced keys (e.g., key 218) of the clip column 214 can slide from one end of the respective slots (e.g., slots 31 and 33) in the lead column 30 to the opposite end of the respective slots in the x-direction. Accordingly, the flexibly oriented clip tip (the metal strip of clip 210) attached to the clip column 214 can have a permissible position range (in the x-direction) over paddle 110 of the lead frame 100. During assembly of the semiconductor die package, keys 218 and clip column 214, respectively, can be moved within the permissible range to compensate for any misalignments in the positioning of the source contact point 44 on paddle 110 (so that the flexibly oriented clip tip is aligned with the source contact point 44 on paddle 110).

[0040] Fig. Figure 4A shows a top view of the lead frame of Fig. 1, in which permissible position ranges of the pair of spaced keys (e.g. key 218) in slots 31 and 33 are represented by arrows Ra. Fig. Figure 4B shows a cross-sectional view of the flexibly oriented clip 200 ( Fig. 2A) along the direction AA in Fig. 4A.

[0041] Fig. 5A, Fig. 6A and Fig. Figure 7A illustrates in a top view examples of clips 210 arranged at different locations on paddle 110, which are connected to lead column 30 by a flexibly oriented clip 200. Fig. 5B, Fig. 6B and Fig. Figure 7B shows cross-sectional views of the flexibly oriented clip 200 and the lead column 30 of Fig. 5A, Fig. 6A and Fig. 7A.

[0042] Fig. 5A, Fig. 6A and Fig. Figure 7A, for example, shows in a top view the source contact point 44, which is located at distances d1, d2, and d3 from a right edge R of the paddle 110. Distance d1 can be greater than distance d2, which can be greater than distance d3. In each of these three cases, the flexibly oriented clip 200 is aligned with the source contact points by sliding the key structure 220 (which is attached to the clip column 214 and encloses the keys 218) into the keyhole structure (e.g., slots 31 and 33) in the lead column 30 to position the flexibly oriented clip 200 over the source contact point. For example, as shown in Fig. As shown in Figure 5B, the key structure 220 is pushed into a far left position so that the flexibly oriented clip 200 is located directly above the source contact point 44, which is arranged at a distance d1 from the right edge R of the paddle 110 ( Fig. 5A). Furthermore, as in Fig. As shown in Figure 6B, the key structure 220, for example, can be moved into an intermediate position so that the flexibly oriented clip 200 is located directly above the source contact point 44, which is arranged at a distance d2 from the right edge R of the paddle 110 ( Fig. 6A). Furthermore, as in Fig. As shown in Figure 7B, the key structure 220, for example, can be moved to a fully right position, so that the flexibly oriented clip 200 is located directly above the source contact point 44, which is arranged at a distance d3 from the right edge R of the paddle 110 ( Fig. 7A).

[0043] In example implementations, an optical inspection tool (not shown) can be used to determine the position of the source contact point 44 arranged on paddle 110, and a pick-and-place tool can be used to position the flexibly aligned clip 200 accordingly to connect source contact point 44 to lead column 30.

[0044] In the embodiments described above, for example with reference to Fig. 1, Lead column 30 is configured with a keyhole structure enclosing a pair of rectangular slots (e.g. slots 31 and 33) each having straight edges running horizontally in the x-direction, both at the top and bottom edges of the rectangular openings of the slots.

[0045] In an example implementation, a keyhole structure of the lead column 30 can additionally be configured with vertical notches or slots (which run, for example, in the y-direction) that perpendicularly intersect the pair of rectangular slots (e.g., slots 31 and 33) that run horizontally in the x-direction.

[0046] Fig. Figure 8A shows an example of a Lead Frame 800, where a Lead Column 80 (like Lead Column 30 in the Lead Frame 100, Fig. 1) has a keyhole structure that 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 the left edge L of the lead column to a central section 32 of the lead column. The keyhole structure further includes a plurality of vertical rectangular slots (e.g., slots 81) extending from approximately a top edge PT of the lead column toward a bottom edge PB of the lead column. Fig. Figure 8A shows, for example, two vertical slots 81 extending perpendicularly in the y-direction above the horizontal slot 31, and two vertical slots 81 extending perpendicularly in the y-direction above the horizontal slot 33. Slots 81 can have a height or length H (in the y-direction) and a width w (in the x-direction). The two adjacent vertical slots 81 intersecting the horizontal slot 33 can have a slot spacing w1, and similarly, the two adjacent vertical slots 81 intersecting the horizontal slot 31 can have a slot spacing w1. The perpendicularly intersecting vertical slots 81 form the edges of the horizontal slots 31 and 33, which extend in the y-direction with steps in the vertical x-direction.The vertical slots (for example, vertical slots 81) run perpendicularly across both the upper edges (UE) and the lower edges (LE) of the horizontal slot 31 and the horizontal slot 33.

[0047] The vertical notches or slots 81 in the lead frame 800 have a height or length H in the y-direction that is greater than the width Sw (along the y-axis) of slots 33 and 31 in frame 100. Thus, the keyhole structure in lead frame 800 can provide a larger clip position range on the y-axis than the keyhole structure in frame 100. In example implementations, the height or length H of the vertical slots 81 in the y-direction can be twice or more than twice the width Sw of slots 33 and 31 in the y-direction.

[0048] Fig. 8B is a cross-sectional view of the Lead-Frame 800 along the AA direction in Fig. 8A, and Fig. 8C is a cross-sectional view of the Lead-Frame 800 along the BB direction in Fig. 8A.

[0049] Fig. 9A, Fig. 10A, Fig. 11A and Fig. Figure 12A illustrates examples of semiconductor dies 410 and source contact points 44 arranged at various locations on paddles 110 of the lead frame 800. The source contact points 44 shown in these figures are connected to the lead column 80 of the lead frame 800 by a flexibly oriented clip 200. Fig. 9A, Fig. 10A and Fig. Figure 11A shows, for example, a semiconductor die 410 arranged at a distance D1 from a right edge R of the paddle 110, and Fig. Figure 12A, for example, shows a semiconductor die 410 arranged at a distance D4 from a right edge R of the paddle 110. As in Fig. 9A, Fig. 10A, Fig. 11A and Fig. As shown in Figure 12A, semiconductor die 410 is further arranged at a height h1, h2, h3 or h4 from a lower edge BE of the paddle 110.

[0050] In each of these four cases ( Fig. 9A, Fig. 10A, Fig. 11A and Fig. 12A) The flexibly aligned clip 200 is aligned with the source contact points by moving the key structure 220 (which is attached to clip column 214) in the keyhole structure in the lead column 80. Key 218 in key structure 220 ( Fig. 2B) are placed in the keyhole structure in lead column 80 of the lead frame 800 in suitable slot positions (e.g., slots 31, 33, 81) to position the flexibly oriented clip 200 over the source contact point. For example, in the cases of Fig. 9A, Fig. 10A and Fig. 11A, as shown in the cross-sectional views of the Fig. 9B, Fig. 10B and Fig. 11B shows key structure 220 in the far right position in horizontal slot 31 and, as in Fig. As shown in 12B, it can be moved to an intermediate position in the horizontal slot 31. Furthermore, for example, for the Fig. The position shown in Figure 9A indicates that the key structure 220 is positioned on an upper right edge in the horizontal slot 31, as shown in Figure 9A. Fig. 9C shown; and for the in Fig. 10A, Fig. 11A and Fig. In the positions shown in 12A, key structure 220 can be positioned on an upper left edge in the horizontal slot 31, as shown in Fig. 10C, Fig. 11C or 12C shown.

[0051] In example implementations, an optical inspection tool (not shown) can be used to determine the position of the source contact point 44 arranged on paddle 110, and a pick-and-place tool can be used to position the flexibly aligned clip 200 accordingly to connect source contact point 44 to lead column 80.

[0052] The exemplary Lead-Frame 800 (above with reference to Fig. (8A discussed) features a keyhole structure in the lead column 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 the left edge L of the lead column toward a central section 32 of the lead column. The keyhole structure further includes a plurality of vertical rectangular slots (e.g., slots 81) extending from approximately a top edge PT of the lead column toward a bottom edge PB of the lead column. The vertical slots (e.g., vertical slots 81) extend perpendicularly across both a top edge and a bottom edge of horizontal slot 31 and horizontal slot 33.

[0053] The vertical notches or slots 81 in the frame 800 have a height or length H in the y-direction that is greater than the width Sw (along the y-axis) of the slots 33 and 31 in the frame 800.

[0054] In other implementations, such as in Fig. As shown in Figure 13, the vertical slots (for example, vertical slots 82 and 83) can open into the horizontal slots, but do not run perpendicularly over both an upper and a lower edge of horizontal slot 31 and horizontal slot 33. Vertical slots 82 and 83 can alternately run only on one side of the horizontal slots and then on the other side of the horizontal slots. Fig. Figure 13 shows section 102 of a lead frame 1300 with a keyhole structure in the lead column 85, which (like lead column 80 of Fig. 8A) includes a pair of horizontal slots (e.g., horizontal slots 31 and 33). The horizontal slots extend horizontally inward in the x-direction from the right edge R and the left edge L of the lead column toward a central section 32 of the lead column. In the lead column 85, as in Fig. As shown in Figure 13, the vertical slots 82, which open towards the horizontal slots 31 and 33, extend upwards (in the y-direction) from the upper edges UE of the horizontal slots. Furthermore, the vertical slots 83, which also open towards the horizontal slots 31 and 33, extend downwards (in the minus-y-direction) from the lower edges LE of the horizontal slots. The vertical slots 82 alternate in position with the vertical slots 83 along the x-direction as they cross (or open towards) the horizontal slots.

[0055] The vertical slots 82 can have a height h7 above the upper edges UE of the horizontal slots, and the vertical slots 83 can have a height h8 below the lower edges LE of the horizontal slots. Including the width (Sw) of the horizontal slot (e.g., slot 31 or slot 33), the vertical slots 82 can have a height = Sw + h7, and the vertical slots 83 can have a height = Sw + h8. A height range covered by the arrangement of the vertical slots in the lead column 85 can enable more precise positioning of the flexibly oriented clip in a semiconductor package along the Y-axis.

[0056] The foregoing illustrates Fig. 9A, Fig. 10A, Fig. 11A and Fig. 12A Examples of semiconductor dies 410 and source contact points 44 located at various positions on paddles 110 of lead frame 800 ( Fig. 8) are arranged. The ones in these Fig. 9A, Fig. 10A, Fig. 11A and Fig. The source contact points 44 shown in 12A are connected by the flexibly aligned clip 200 to the lead column 80 of the lead frame 800. Fig. 9A, Fig. 10A, Fig. 11A and Fig. Figure 12A shows, for example, semiconductor die 410, which is arranged at a distance D1, D2, D3 or D4 from a right edge R of the paddle 110. Furthermore, as shown in Fig. 9A, Fig. 10A, Fig. 11A and Fig. Figure 12A shows that semiconductor dies 410 are arranged at a height h1, h2, h3 or h4 from a lower edge BE of the paddle 110.

[0057] In example implementations, Lead-Frame 800 can be replaced by Lead-Frame 1300, which features the keyhole structure in the Lead column 85, as described in Fig. 13 is shown. Key 218 in key structure 220 of clip 200 ( Fig. 2B) can be placed either in the vertical slots 82 or the vertical slots 83 in the lead column 85 to control the positioning of the flexibly oriented clip on the y-axis in a semiconductor package.

[0058] Fig. 14 A, Fig. 14B, Fig. 14C and Fig. Figure 14D shows a cross-sectional view of the lead column 85 and the key 218 of the key structure 220 (in the xy-plane of the lead column 85) for different configurations of the semiconductor die 410 and paddle 110, each in Fig. 9A, Fig. 10A, Fig. 11A and Fig. 12A are shown.

[0059] Fig. 14 A corresponds to the example of a semiconductor die 410, which is located at a distance D1 from the right edge R of the paddle 110 ( Fig. 9A). Fig. Figure 14A shows that the keys 218 of the clip 200 can be placed in vertical slots 83 along the lower edges LE of the horizontal slots 31 and 33 to control the positioning of the flexibly oriented clip on the y-axis in a semiconductor package.

[0060] Fig. 14B corresponds to the example of the semiconductor die 410, which is located at a distance D2 from the right edge R of the paddle 110 ( Fig. 10A). Fig. Figure 14B shows that the keys 218 of the clip 200 can be placed in vertical slots 82 along the top edges UE of the horizontal slots 31 and 33 to control the positioning of the flexibly oriented clip on the y-axis in a semiconductor package.

[0061] Fig. 14C corresponds to the example of a semiconductor die 410 located at a distance D3 from the right edge R of the paddle 110 ( Fig. 11A). Fig. Figure 14C shows that the keys 218 of the clip 200 can be placed in vertical slots 83 along the lower edges LE of the horizontal slots 31 and 33 to control the positioning of the flexibly oriented clip on the y-axis in a semiconductor package.

[0062] Fig. 14D corresponds to the example of a semiconductor die 410 located at a distance D4 from the right edge R of the paddle 110 ( Fig. 12A). Fig. Figure 14D shows that the keys 218 of the clip 200 can be placed in vertical slots 82 along the top edges UE of the horizontal slots 31 and 33 to control the positioning of the flexibly oriented clip on the y-axis in a semiconductor package.

[0063] Fig. Figure 15 shows a top view, which is another example of a Lead-Frame 1400 that can be used in a semiconductor die package. Lead-Frame 1500 can be used like Lead-Frame 100 ( Fig. 1) include a first section 101 and a second section 102.

[0064] The second section 102 of the Lead Frame 1500 can be used like Lead Frame 100 ( Fig. 1) Include a multitude of leads (e.g., Lead 1, Lead 2, Lead 3, Lead 4, Lead 5, Lead 6, and Lead 7, etc.) that can, for example, form the external signal leads of the semiconductor die package. The lead columns of the various leads can be coupled to the device contact points (e.g., gate contact, signal sensing contact, Kelvin contact, and source contact, etc.) in the semiconductor die mounted on paddle 110 by wire bonds or clip connections. Leads 3 to 7 can utilize a common lead column 90.

[0065] In exemplary implementations, Lead Column 90 can have a keyhole structure that allows the Lead Column to be connected via a flexibly oriented clip (e.g., Clip 200, Fig. 2A and Fig. 2B) with the source contact point on the semiconductor die (e.g. source contact point 44 of the semiconductor die 410, Fig. 3B) to be connected, which is mounted on paddle 110.

[0066] In example implementations, Lead Column 90 in Lead Frame 1500 can have a rectangular shape with a length Pl (in the x-direction) and a width Pw (in the y-direction). In example implementations, Lead Column 90 can enclose a keyhole structure configured to engage the pair of spaced keys, prongs, or pins of the flexibly oriented clip (e.g., Clip 200). Fig. 2A and Fig. 2B). The keyhole structure may, for example, include a single slot 91 extending horizontally (in the x-direction) from approximately a right edge R of the lead column to approximately a left edge L of the lead column. Slot 91 may have a rectangular shape with a width Sw in the y-direction and a length sl in the x-direction. In example implementations, the width Sw of slot 91 may be approximately one-third or less than one-third of the width PW of the lead column 90.

[0067] Fig. Figure 16 is a flowchart illustrating an exemplary procedure 1600 for packaging a semiconductor die.

[0068] Method 1600 involves placing a semiconductor die at a variable location on a paddle in a lead frame (1610). The semiconductor die may include a source contact point. Placing a semiconductor die on the paddle may include placing the semiconductor die on a solder layer (e.g., a solder pad). For example, the semiconductor die may end up at a variable location on the paddle after the solder has been reflowed.

[0069] Method 1600 further includes aligning a clip to connect a lead column of the lead frame to the source contact point on a semiconductor die located at the variable site on the paddle (1620). In example implementations of Method 1500, aligning the clip 1620 may include coupling one end of the clip to a clip locking feature in the lead column.

[0070] The clip can, for example, enclose a key structure. The key structure can, for example, include at least one pair of keys that are perpendicular to a plane of the clip. Furthermore, aligning the clip includes placing the pair of keys in at least one slot of the clip's locking feature in the lead column.

[0071] In example implementations, aligning the clip to connect the lead column of the lead frame 1620 involves soldering a first section of the clip to the source contact point and soldering a second section of the clip to a section of the lead column.

[0072] Method 1600 further comprises: encapsulating the semiconductor die, the clip and a section of the lead frame in a molding compound (1630).

[0073] In example implementations, a package can contain (e.g., enclose) multiple semiconductor dies arranged on a lead-frame structure. The multiple dies can be 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 can be made of different semiconductor materials (e.g., silicon and silicon carbide).

[0074] In some implementations, one or more of the multiple semiconductor dies can be connected to corresponding lead columns that lead to the external terminals of the package. In example implementations, one or more of the multiple semiconductor dies can be connected to one or more of the corresponding lead columns using one or more clips (e.g., the flexibly oriented clip 200) in conjunction with clip locking features (keyhole structures) in the lead columns (e.g., lead columns 30, 80, 85, and 90), as described above with reference to Fig. 1 to Fig. 16 described.

[0075] In some example implementations, one or more of the multiple semiconductor dies (which are not connected by the flexibly oriented clips (e.g., the flexibly oriented clip 200) with keyhole structures in the lead columns) can be connected to respective lead columns (e.g., lead column 30, 80, 85, and 90) using clips (non-flexibly oriented clips), wire bonds, and / or solder ball grid arrays.

[0076] For example, a first semiconductor die can be connected to the flexible-aligned clip (as described herein (e.g., flexible-aligned clip 200)), and a second semiconductor die can be connected to a lead column (e.g., lead columns 30, 80, 85, and 90) using a clip. Alternatively, a first semiconductor die can be connected to the flexible-aligned clip (as described herein), and a second semiconductor die can be connected to a lead column using wire bonding. Finally, a first semiconductor die can be connected to the flexible-aligned clip (as described herein), and a second semiconductor die can be connected to a lead column using a solder ball grid array.

[0077] It is understood that in the foregoing description, when an element, such as a layer, region, substrate, or component, is described as being on, connected to, electrically connected, coupled, or electrically coupled to another element, it may be directly on, connected to, or coupled to the other element, or it may involve one or more intervening elements. Conversely, when an element is described as being "directly on," "directly connected to," or "directly coupled to" another element or layer, no intervening elements or layers are present. Although the terms "directly on," "directly connected to," or "directly coupled to" may not be used in the detailed description, elements shown as being "directly on," "directly connected to," or "directly coupled" may be identified as such.The claims of the application may be amended, if necessary, to specify exemplary relationships that are described in the patent specification or shown in the figures.

[0078] As used in the patent specification and claims, a singular form may include a plural form unless a specific case is clearly indicated in relation to the context. Spatial terms (e.g., above, over, upper, under, below, beneath, lower, and the like) are intended to include various orientations of the device in use or operation in addition to the orientation shown in the figures. In some implementations, the relative terms "above" and "below" may each include "vertically above" and "vertically below," respectively. In some implementations, the term "adjacent" may include "laterally adjacent to" or "horizontally adjacent to."

[0079] Some implementations can be implemented using various semiconductor processing and / or packaging techniques. Some embodiments can be implemented using different types of semiconductor processing techniques in conjunction with semiconductor substrates, including, but not limited to, silicon (Si), gallium arsenide (GaAs), gallium nitride (GaN), silicon carbide (SiC), and / or the like.

[0080] While certain features of the described implementations have been illustrated as described herein, many modifications, substitutions, changes, and equivalents are now apparent to the person skilled in the art. It is therefore understood that the accompanying claims are intended to cover all such modifications and changes that fall within the scope of protection of the implementations. It is understood that they have been presented only as examples, without being limiting, and that various changes to form and details may be made. Each section of the apparatus and / or method described herein may be combined in any combination, except for mutually exclusive combinations. The implementations described herein may include various combinations and / or subcombinations of the functions, components, and / or features of the various described implementations.

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