Packaging structure

Abstract

The utility model relates to a packaging structure. The packaging structure comprises a first lead frame, a first wafer, a conductive clamp and a packaging material. The first wafer is on the first lead frame. The conductive clamp is on the first wafer and electrically connected to the first wafer. The packaging material covers the first lead frame, the first wafer and a part of the conductive clamp. The conductive clamp has a first pin extension part extending out of the packaging material, and the first pin extension part has a first part bent towards a direction away from the first wafer. The configuration of the packaging structure is conducive to setting a heat dissipation device to further improve the heat dissipation efficiency.

Description

Technical Field

[0001] Some embodiments of this utility model relate to the packaging structure. Background Technology

[0002] In the semiconductor industry, multiple components can be housed within a single package structure, allowing for easy integration into various devices. A package structure can contain multiple components (such as a chip). Components are mounted on a substrate, and traces connect electrodes on the chip to specific terminals. Because a package structure contains multiple components, and these components generate heat during operation, a robust heat dissipation system must be designed to prevent overheating and ensure optimal performance. Utility Model Content

[0003] Some embodiments of this utility model provide a packaging structure comprising a first lead frame, a first wafer, a conductive clip, and a packaging material. The wafer is on the first lead frame. The conductive clip is on the first wafer and electrically connected to the first wafer. The packaging material covers a portion of the first lead frame, the first wafer, and the conductive clip, wherein the conductive clip has a first lead extension extending beyond the packaging material, and the first lead extension has a first portion bent in a direction away from the first wafer.

[0004] In some embodiments, a first portion of the first pin extension extends along a first sidewall of the packaging material toward a direction opposite to the first wafer.

[0005] In some embodiments, the first pin extension further includes a second portion extending along the top surface of the encapsulation material, the second portion of the first pin extension being connected to the first portion of the first pin extension.

[0006] In some implementations, the package structure further includes a carrier board, wherein a second portion of the first pin extension is connected to the carrier board.

[0007] In some embodiments, the package structure further includes a second leadframe and a second wafer, the second leadframe being adjacent to the first leadframe. The second wafer is on the second leadframe, wherein conductive clips are on the second wafer and electrically connect the first wafer and the second wafer simultaneously.

[0008] In some embodiments, the conductive clip also has a second pin extension extending beyond the encapsulation material, the second pin extension having a third portion bent toward the direction opposite to the second wafer, and the third portion and the first portion being located on opposite sides of the encapsulation material.

[0009] In some embodiments, the first pin extension further has a second portion extending along the top surface of the encapsulation material, the second portion of the first pin extension being connected to the first portion of the first pin extension, and the second pin extension further has a fourth portion extending along the top surface of the encapsulation material, the fourth portion of the second pin extension being connected to the third portion of the pin extension.

[0010] In some embodiments, the encapsulation structure further includes a conductive layer on the top surface of the encapsulation material, and the conductive layer contacts the first portion and the third portion.

[0011] In some embodiments, the package structure further includes a heat dissipation device on the side of the first lead frame away from the first wafer.

[0012] In some embodiments, the package structure also includes a heat dissipation device on the side of the conductive layer away from the first wafer. Attached Figure Description

[0013] Figure 1 A cross-sectional view of the packaging structure of some embodiments of this utility model is shown.

[0014] Figure 2A This is a cross-sectional view of the packaging structure of some embodiments of the present invention.

[0015] Figure 2B This is a cross-sectional view of the packaging structure of some embodiments of the present invention.

[0016] Figure 3 This is a cross-sectional view of a power module with a packaging structure according to some embodiments of the present invention.

[0017] Figure 4 A cross-sectional view of the process for manufacturing the packaging structure according to some embodiments of this utility model.

[0018] Figure 5 Some embodiments of this utility model Figure 4 Top view.

[0019] Figure 6 A cross-sectional view of the process for manufacturing the packaging structure according to some embodiments of this utility model.

[0020] Figure 7 Some embodiments of this utility model Figure 4 Top view.

[0021] Figures 8 to 9 A cross-sectional view of the process for manufacturing the packaging structure according to some embodiments of this utility model.

[0022] Figure 10A cross-sectional view of the process for manufacturing the packaging structure according to some embodiments of this utility model. Detailed Implementation

[0023] Figure 1 The diagram illustrates a cross-sectional view of a packaging structure 100 according to some embodiments of the present invention. The packaging structure 100 may include lead frames 110 and 112, wafers 120 and 122, conductive clips 130, and packaging material 140.

[0024] The lead frame 110 and 112 are adjacent to each other and are isolated from each other. In some embodiments, the lead frame 110 may be made of metal, such as copper.

[0025] Wafer 120 is on lead frame 110, and wafer 122 is on lead frame 112. Wafers 120 and 122 may be of the same type, such as metal-oxide-semiconductor field-effect transistor (MOSFET) wafers. In some embodiments, wafers 120 and 122 may be bonded to lead frames 110 and 112 respectively via adhesive layer 124. In some embodiments, adhesive layer 124 may be made of tin. Further details regarding wafers 120 and 122 will be described later.

[0026] Conductive clips 130 are mounted on and electrically connected to wafers 120 and 122. In a specific cross-sectional view, such as... Figure 1 As shown, the conductive clip 130 can extend to completely cover wafers 120 and 122. The conductive clip 130 may have a main conductive segment 131 that simultaneously electrically connects to and covers wafers 120 and 122, and pins 132 and 133 extending from both sides of the main conductive segment 131. Pin 132 is located on one side of wafer 120, and pin 133 is located on one side of wafer 122. In some embodiments, the conductive clip 130 can be bonded to wafers 120 and 122 via an adhesive layer 134. In some embodiments, the adhesive layer 134 may be made of tin. In some embodiments, the conductive clip 130 may be made of a metal, such as copper.

[0027] Encapsulation material 140 covers a portion of leadframes 110 and 112, wafers 120 and 122, and conductive clips 130, and exposes the bottom surfaces of leadframes 110 and 112. Leads 132 and 133 of conductive clips 130 have lead extensions 132A and 133A extending beyond the encapsulation material 140, respectively. Lead extension 132A has a portion P1 bent along the sidewall S1 of the encapsulation material 140 in a direction opposite to the wafer 120, and a portion P2 extending along the top surface S3 of the encapsulation material 140. The portion P2 of lead extension 132A connects to the portion P1 of lead extension 132A. Lead extension 133A has a portion P3 bent along the sidewall S2 of the encapsulation material 140 in a direction opposite to the wafer 122, and a portion P4 extending along the top surface S3 of the encapsulation material 140. Sidewall S2 is opposite to sidewall S1. A portion P4 of the pin extension 133A connects to a portion P3 of the pin extension 133A. The shape of the portions of the conductive clips 130 covered by the encapsulation material 140 is not limited. In some embodiments, such as... Figure 1 As shown, the portion of the conductive clip 130 whose pins 132 are covered by the encapsulation material 140 may have a vertical segment 132B extending from one end of the main conductive segment 131 and a horizontal segment 132C connecting the vertical segment 132B. The horizontal segment 132C of the pin 132 connects to the pin extension 132A. The portion of the conductive clip 130 whose pins 133 are covered by the encapsulation material 140 may have a vertical segment 133B extending from one end of the main conductive segment 131 and a horizontal segment 133C connecting the vertical segment 133B. The horizontal segment 133C of the pin 133 connects to the pin extension 133A. In some embodiments, the encapsulation material 140 may be made of silicone or epoxy resin.

[0028] Figure 2A This is a cross-sectional view of the packaging structure 200A according to some embodiments of the present invention. (Reference) Figure 2A The 200A package structure includes, in addition to Figure 1In addition to the components / elements of the package structure 100 (including lead frames 110, 112, wafers 120, 122, conductive clips 130, and package material 140), it also includes a carrier plate 210 and a heat sink 220. The components / elements of the package structure 100 are flip-up and placed on the carrier plate 210, so that portions P2 of lead extensions 132A and P4 of lead extensions 133A are electrically connected to the carrier plate 210. The heat sink 220 is located on the side of lead frame 110 away from wafer 120 and on the side of lead frame 112 away from wafer 122. In other words, wafer 120 and heat sink 220 are located on opposite sides of lead frame 110. Wafer 122 and heat sink 220 are located on opposite sides of lead frame 112. The heat sink 220 can be adhered to the exposed surfaces of lead frames 110 and 112 exposed to package material 140 using thermal paste 230. The heat dissipation device 220 may include a horizontal portion 222 and a plurality of protrusions 224 extending from the horizontal portion 222 in a direction away from the lead frames 110 and 112. In some embodiments, the carrier board 210 may be a printed circuit board. In some embodiments, the heat dissipation device 220 may be made of a material with good thermal conductivity, such as a metal like copper. The thermal paste 230 may have a base of silicone, epoxy resin, etc., and be filled with a thermally conductive filler, such as diamond, alumina, etc.

[0029] In this invention, the design of the lead extensions 132A and 133A of the conductive clip 130 can be used to increase the heat dissipation efficiency of the package structure 200A. Specifically, the lead extension 132A of the conductive clip 130 includes a portion P1 bent along the sidewall S1 of the package material 140 in a direction opposite to the wafer 120 and a portion P2 extending along the top surface S3 of the package material 140. The lead extension 133A of the conductive clip 130 includes a portion P3 bent along the sidewall S2 of the package material 140 in a direction opposite to the wafer 120 and a portion P4 extending along the top surface S3 of the package material 140. The portions P2 and P4 of the lead extensions 132A and 133A and 133A allow the components / elements of the package structure 100 to be electrically connected to the carrier plate 210 via flip-chip bonding. In this way, the exposed surfaces of lead frames 110 and 112 can face upwards and be used to mount the heat dissipation device 220 to increase the heat dissipation efficiency of the package structure 200A. Specifically, if the components / elements of the package structure 100 are joined to the carrier board 210 in a positive mounting manner (i.e., with... Figure 1The heat dissipation path of the package structure 200A is through the chips 120 and 122 to the carrier 210, and then through the carrier 210 to the surrounding environment, such as the surrounding air. This heat dissipation path is easily restricted by other devices or lines mounted on the carrier 210, resulting in poor heat dissipation efficiency. Therefore, if the components / elements of the package structure 100 can be electrically connected to the carrier 210 by flip-chip, the heat dissipation device 220 can be directly set on the exposed surfaces of the lead frames 110 and 112. Its heat dissipation path is not easily restricted by other devices or lines mounted on the carrier 210, thus increasing the heat dissipation efficiency of the package structure 200A. In addition, since the portion P2 of the lead extension 132A and the portion P4 of the lead extension 133A are bent inward towards the interior of the package structure 200A, the area occupied by the package structure 200A can be reduced, which is beneficial to increasing the component density per unit area.

[0030] Figure 2B This is a cross-sectional view of the packaging structure 200B according to some embodiments of the present invention. The packaging structure 200B and... Figure 2A The difference between package structures 200A and 200B is that package structure 200B also includes a carrier board 240. The carrier board 240 is located between the heat sink 220 and the leadframes 110, 112. The leadframes 110, 112 are bonded to a first side of the carrier board 240 via an adhesive layer 250, and the heat sink 220 is bonded to a second side (relative to the first side) of the carrier board 240 via thermal paste 230. In some embodiments, the carrier board 240 may be a carrier board with electrical circuits, such as a printed circuit board. The adhesive layer 250 may be made of tin. The configuration of package structure 200B can be used to increase the electrical connection paths of the chips 120, 122.

[0031] Figure 3 This is a cross-sectional view of the packaging structure 400 according to another embodiment of the present invention. (See reference) Figure 3 In addition to the components / elements of the packaging structure 100 (including lead frames 110, 112, wafers 120, 122, conductive clips 130, and packaging material 140), the packaging structure 400 also includes a carrier plate 210 and a heat dissipation device 220. The difference between the packaging structure 400 and the packaging structure 200A is the orientation of the components / elements of the packaging structure 100. Specifically, the components / elements of the packaging structure 100 are mounted to the carrier plate 210 in a positive-mount manner, therefore the lead frames 110 and 112 of the packaging structure 400 are electrically connected to the carrier plate 210. (See reference...) Figure 3In this embodiment, lead extension 132A does not have a portion P2, and lead extension 133A does not have a portion P4. Furthermore, the package structure 400 also includes a conductive layer 135 on the top surface S3 of the package material 140, and the conductive layer 135 contacts a portion P1 of lead extension 132A and a portion P3 of lead extension 133A. The conductive layer 135 is used to provide a heat dissipation device 220 to increase the heat dissipation efficiency of the package structure 400. The heat dissipation device 220 can be directly disposed on the side of the conductive layer 135 away from the wafers 120 and 122, and its heat dissipation path is less likely to be limited by other devices or lines mounted on the carrier 210, thus increasing the heat dissipation efficiency of the package structure 400.

[0032] Figure 4 , Figure 6 , Figures 8 to 9 A cross-sectional view of the process of manufacturing the packaging structure 100 for some embodiments of the present invention. Figure 5 Some embodiments of this utility model Figure 4 The top view, and Figure 4 for Figure 5 A cross-sectional view of line A-A'. Figure 7 Some embodiments of this utility model Figure 6 The top view, and Figure 6 for Figure 7 A cross-sectional view of line A-A'. (Reference) Figure 4 and Figure 5A wafer 120 is placed on a lead frame 110, a wafer 122 is placed on a lead frame 112, and a wafer 126 is placed on a lead frame 114. Wafer 120 is bonded to lead frame 110 via an adhesive layer 124, and wafer 122 is bonded to lead frame 112 via an adhesive layer 124. Lead frame 110 includes lead frames 110G and 110D, lead frame 112 includes lead frames 112G and 112S, and lead frames 110G, 110D, 112G, 112S, and 114 are spaced apart from each other. Wafers 120 and 122 may be power wafers, such as metal-oxide-semiconductor field-effect transistor (MOSFET) wafers. Wafer 126 may be a driver wafer. In some embodiments, wafers 120 and 122 may each have a source electrode, a gate electrode, and a drain electrode. The source and gate electrodes are located on one side of the wafer, and the drain electrode is located on the other side of the wafer. The orientation of wafer 120 on lead frame 110 is opposite to that of wafer 122 on lead frame 112. For example, the side of wafer 120 with source electrode 120S and gate electrode 120G faces upward, while the side with drain electrode (not shown) faces lead frame 110D. The drain electrode (not shown) of wafer 120 is bonded to lead frame 110D via adhesive layer 124, and the gate electrode 120G of wafer 120 is bonded to lead frame 110G via wire bonding 128. The side of wafer 122 with drain electrode 122D faces upward, while the side with source electrode and gate electrode (not shown) faces lead frame 112. The source electrode (not shown) of wafer 122 is bonded to lead frame 112S via adhesive layer 124, and the gate electrode (not shown) of wafer 122 is bonded to lead frame 112G via adhesive layer (not shown). Wafer 126 is mounted on lead frame 114 and bonded to lead frame 114 via wire bonding 128. Wafer 126 can also be bonded to at least one of wafers 120 and 122 via wire bonding 128. For example, see reference... Figure 5 The wafer 126 is bonded to the gate electrode 120G of the wafer 120 via wire bonding 128.

[0033] refer to Figure 6 and Figure 7Conductive clips 130 are placed on wafers 120 and 122, and the conductive clips 130 are electrically connected to wafers 120 and 122 via an adhesive layer 134. Specifically, the main conductive segment 131 of the conductive clip 130 is electrically connected to the source electrode 120S of wafer 120 and the drain electrode 122D of wafer 122, and the leads 132 and 133 of the conductive clip 130 extend outward from both sides of the main conductive segment 131 beyond the lead frame 110 and 112 in a top view. In some embodiments, the conductive clips 130 are pre-bent into a specific shape before being placed on wafers 120 and 122. Therefore, the shapes of the vertical segments 132B and horizontal segments 132C of the leads 132 extending from the main conductive segment 131, and the vertical segments 133B and horizontal segments 133C of the leads 133 are pre-formed.

[0034] refer to Figure 8 A packaging material 140 is formed covering lead frames 110, 112, 114, wafers 120, 122, 126, and conductive clips 130, wherein the leads 132 and 133 of the conductive clips 130 have lead extensions 132A and 133A extending beyond the packaging material 140, respectively. Specifically, after forming the packaging material 140, a portion of the horizontal segment 132C is exposed outside the packaging material 140, and this portion serves as the lead extension 132A; a portion of the horizontal segment 133C is exposed outside the packaging material 140, and this portion also serves as the lead extension 133A.

[0035] refer to Figure 9 The lead extensions 132A and 133A are bent such that lead extension 132A has a bent portion P1 along the sidewall S1 of the packaging material 140 facing away from the wafer 120, and lead extension 133A has a bent portion P3 along the sidewall S2 of the packaging material 140 facing away from the wafer 122. Next, lead extensions 132A and 133A are bent again such that lead extension 132A has a portion P2 extending along the top surface of the packaging material 140, and lead extension 133A has a portion P4 extending along the top surface S3 of the packaging material 140. In some embodiments, lead extensions 132A and 133A can be bent by a trim / form process. In some embodiments, the bending angle a1 between portion P1 of the pin extension 132A and the horizontal segment 132C, the bending angle a2 between portion P1 and portion P2 of the pin extension 132A, the bending angle a3 between portion P3 of the pin extension 133A and the horizontal segment 133C, and the bending angle a4 between portion P3 and portion P4 of the pin extension 133A are all between 60 degrees and 90 degrees. The sum of bending angles a1 and a2, and the sum of bending angles a3 and a4 are all between 160 degrees and 180 degrees.

[0036] After the encapsulation structure 100 is formed, it can be flipped to attach to the package. Figure 2A or Figure 2B The carrier board 210 is shown, and then a heat dissipation device 220 (or additional carrier board 240) is placed on the package structure 100 to form a package structure 200A or 200B.

[0037] Figure 10 This is a cross-sectional view showing the manufacturing process of the packaging structure 300 according to some embodiments of the present invention. The manufacturing process of the packaging structure 300 may be similar to that of the packaging structure 100. Specifically, the manufacturing process of the packaging structure 300 may be the same as... Figures 4 to 8 The process shown. After completion Figure 8 Following the initial process, the lead extensions 132A and 133A are bent such that lead extension 132A has a bent portion P1 along the sidewall S1 of the packaging material 140 facing away from the wafer 120, and lead extension 133A has a bent portion P3 along the sidewall S2 of the packaging material 140 facing away from the wafer 122. Next, a sputtering process is directly performed to form a conductive layer 135 on the top surface S3 of the packaging material 140. During the sputtering process, portions P1 of lead extension 132A and P3 of lead extension 133A may be higher than the top surface S3 of the packaging material 140 to serve as electrodes for the sputtering process. The conductive layer 135 may connect portions P1 of lead extension 132A and P3 of lead extension 133A. In some embodiments, the upper surfaces of portions P1 and P2 may also be coplanar with the top surface S3.

[0038] After the encapsulation structure 300 is formed, the encapsulation structure 100 can be bonded to... Figure 3 The carrier plate 210 is shown, and then a heat dissipation device 220 is placed on the packaging structure 100 to form the packaging structure 400.

[0039] In summary, in some embodiments, the lead extension of the packaging structure of this invention can extend to the sidewall of the packaging material and further to the top surface of the packaging material, meaning the lead extension extends beyond the packaging material, allowing the packaging structure to be flip-mounted onto an additional carrier board. The exposed surface of the lead frame of the packaging structure can be used to set up a heat dissipation structure. In other embodiments, the lead extension of the packaging structure of this invention can extend to the sidewall of the packaging material, and an additional conductive layer can be formed on the top surface of the packaging material. The conductive layer on the top surface of the packaging material can be used to set up a heat dissipation structure. The heat dissipation path of the packaging structure of this invention is not limited by other components on the carrier board, thus improving heat dissipation efficiency.

[0040] The above description is only a partial embodiment of the present utility model, not all of the embodiments. Any equivalent changes to the technical solution of the present utility model made by those skilled in the art through reading the specification of the present utility model shall be covered by the claims of the present utility model.

[0041] [Symbol Explanation]

[0042] 100, 200A, 200B, 300, 400: Package structure

[0043] 110, 110D, 110G, 112, 112G, 112S, 114: Conductor frame

[0044] 120, 122, 126: Chips

[0045] 120G: Gate electrode

[0046] 120S: Source electrode

[0047] 122D: Drain electrode

[0048] 124, 134, 250: Adhesive layer

[0049] 128: Stringing

[0050] 130: Conductive clip

[0051] 131: Main conductive segment

[0052] 132, 133: Pins

[0053] 132A, 133A: Pin extension

[0054] 132B, 133B: Vertical segments

[0055] 132C, 133C: Horizontal segment

[0056] 135: Conductive layer

[0057] 140: Packaging material

[0058] 210, 240: Carrier board

[0059] 220: Heat dissipation device

[0060] 222: Horizontal section

[0061] 224: Protrusion

[0062] 230: Thermal paste

[0063] A-A': line

[0064] a1, a2, a3, a4: Angles

[0065] P1, P2, P3, P4: Partial

[0066] S1, S2: Sidewalls

[0067] S3: Top surface.

Claims

1. A packaging structure, characterized in that, Include: First conductor frame; The first wafer is on the first lead frame; A conductive clip is attached to the first wafer and electrically connected to the first wafer; as well as A packaging material covers a portion of the first lead frame, the first wafer, and the conductive clip, wherein the conductive clip has a first pin extension extending beyond the packaging material, the first pin extension having a first portion bent in a direction away from the first wafer.

2. The packaging structure according to claim 1, characterized in that, The first portion of the first pin extension extends along the first sidewall of the packaging material and toward the direction opposite to the first wafer.

3. The packaging structure according to claim 1, characterized in that, The first pin extension further includes a second portion extending along the top surface of the packaging material, and the second portion of the first pin extension is connected to the first portion of the first pin extension.

4. The packaging structure according to claim 3, characterized in that, Also includes: A carrier board, wherein the second portion of the first pin extension is connected to the carrier board.

5. The packaging structure according to claim 1, characterized in that, Also includes: A second conductor frame, adjacent to the first conductor frame; and The second wafer is on the second lead frame, wherein the conductive clip is on the second wafer and simultaneously electrically connects the first wafer and the second wafer.

6. The packaging structure according to claim 5, characterized in that, The conductive clip also has a second pin extension that extends beyond the packaging material. The second pin extension has a third portion that is bent toward the opposite side of the second wafer, and the third portion and the first portion are located on opposite sides of the packaging material.

7. The packaging structure according to claim 6, characterized in that, The first pin extension also has a second portion extending along the top surface of the packaging material, the second portion of the first pin extension being connected to the first portion of the first pin extension, and the second pin extension also has a fourth portion extending along the top surface of the packaging material, the fourth portion of the second pin extension being connected to the third portion of the second pin extension.

8. The packaging structure according to claim 6, characterized in that, Also includes: A conductive layer is located on the top surface of the encapsulation material, and the conductive layer contacts the first portion and the third portion.

9. The packaging structure according to claim 8, characterized in that, Also includes: A heat dissipation device is located on the side of the conductive layer away from the first wafer.

10. The packaging structure according to claim 1, characterized in that, Also includes: A heat dissipation device is located on the side of the first lead frame away from the first wafer.

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