Semiconductor package structure and packaging method

Abstract

The application provides a semiconductor packaging structure and a packaging method, and relates to the technical field of semiconductor packaging. The semiconductor packaging structure comprises a base island, a pin, a chip, a plastic package body and a metal layer. The pin is arranged along the outer periphery of the base island. The chip is attached to the base island. The chip and the pin are electrically connected by a wire bonding structure. The plastic package body covers the chip and the wire bonding structure. The metal layer is arranged on the outer periphery of the base island, the outer periphery of the pin, the side surface of the base island away from the plastic package body and the side surface of the pin away from the plastic package body. In this way, the heat dissipation performance is improved, the surface energy is reduced, the wetting angle is reduced, the plastic package body is more easily spread and seep into the narrow gap on the inner side of the base island, the dead angle and the lack of glue are reduced, and the cavity phenomenon is avoided.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging technology, and in particular to a semiconductor packaging structure and packaging method. Background Technology

[0002] With the rapid development of the semiconductor industry, DFN (Dual Flat No-lead) and QFN (Quad Flat No-lead) structures are widely used. To improve the wettable flank climb performance of solder paste during lead and base island soldering, a solderable plating layer is applied to the leads to form three-dimensional solder joints, enhancing the connection strength between the component and the circuit board. In existing DFN and QFN structures, the base island and the inner side of the leads are bare copper. Bare copper has high surface energy and is easily oxidized, resulting in a large wetting angle and poor spreadability of the molding compound material. When the molding compound comes into contact with the bare copper on the base island or the inner side of the leads, it can easily cause poor flowability of the molding compound, incomplete filling, dead corners, voids, or delamination. Summary of the Invention

[0003] The purpose of this invention is to provide a semiconductor packaging structure and packaging method that can improve the filling performance of the molding compound, reduce the risk of filling voids or structural delamination, and improve packaging reliability.

[0004] In a first aspect, the present invention provides a semiconductor packaging structure, comprising: Base Island; Pins, which are distributed along the outer periphery of the base island; The chip is mounted on the base island; the chip and the pins are electrically connected by a wire bonding structure. A molding compound that encapsulates the chip and the wire bonding structure; Metal layers are respectively disposed on the outer peripheral surface of the base island, the outer peripheral surface of the pin, the side surface of the base island away from the molding compound, and the side surface of the pin away from the molding compound.

[0005] In an optional embodiment, a first isolation groove is formed between the base island and the pin, and the groove wall of the first isolation groove is provided with a first step portion to form a first step groove on the base island and a second step groove on the pin; the first step groove and the second step groove are arranged opposite to each other.

[0006] In an optional embodiment, the walls of the first isolation groove, the first stepped groove, and the second stepped groove are respectively covered with the metal layer.

[0007] In an optional embodiment, the wall of the first isolation groove is provided with a second step portion to form a third step groove on the base island and a fourth step groove on the pin.

[0008] In an optional embodiment, the walls of the third step groove and the fourth step groove are respectively covered with the metal layer.

[0009] In an optional implementation, a first fence is provided at the edge of the base island.

[0010] In an optional implementation, the first fence comprises multiple segments spaced apart along the edge of the base island.

[0011] In an alternative implementation, the surface of the first fence on the side away from the base island is higher than the pin surface.

[0012] In an alternative implementation, the metal layer covers the outside of the first fence.

[0013] In an alternative implementation, the edge of the pin is provided with a second fence.

[0014] In an alternative implementation, the metal layer on the side of the pin away from the base island protrudes from the edge of the molding compound.

[0015] In an optional embodiment, the encapsulated body at least partially or completely fills the first isolation groove.

[0016] In an optional embodiment, the encapsulation body at least partially or completely fills the first step groove and the second step groove along the thickness direction of the base island.

[0017] Alternatively, the first isolation groove includes a first channel and a second channel along the thickness direction of the base island, the first stepped groove and the second stepped groove form the second channel, and the encapsulant fills a portion of the first channel.

[0018] In an optional embodiment, the encapsulation body is flush with the metal layer on the side of the base island away from the encapsulation body, or the metal layer on the side of the base island away from the encapsulation body protrudes from the surface of the encapsulation body.

[0019] Secondly, the present invention provides a packaging method, comprising: A substrate is provided, the substrate including a first surface and a second surface disposed opposite to each other; A first isolation groove is formed on the first surface of the substrate to separate the base island and the pin; A metal layer is formed within the first isolation groove and on the surface of the substrate; Cut the metal layer and the substrate along the first isolation groove to separate the base island and the pin; Chips are mounted on the base island of the second surface; The chip is encapsulated to form an encapsulation; the encapsulation at least partially or completely fills the first isolation trench.

[0020] In an optional embodiment, the step of forming a first isolation groove on the first surface of the substrate to separate the base island and the pin further includes: A second isolation groove is formed on the first surface of the substrate to form a connecting rib between the pin and the pin; Cut the end of the connecting rib near the pin to form a groove; The step of forming a metal layer within the first isolation groove and on the surface of the substrate further includes: The metal layer is formed on the surface of the groove and the connecting rib.

[0021] In an optional implementation, prior to the step of mounting the chip on the base island of the second surface, the method further includes: The base island is stamped from the second surface to form a first fence at the edge of the base island.

[0022] In an optional embodiment, the step of stamping the base island from the second surface to form a first fence at the edge of the base island further includes: The pin is stamped from the second surface to form a second fence at the edge of the pin.

[0023] In an optional embodiment, the step of forming a first isolation groove on the first surface of the substrate to separate the base island and the pin further includes: A first step portion is formed in the wall of the first isolation groove to form a first step groove on the base island and a second step groove on the pin.

[0024] The semiconductor packaging structure and packaging method provided in this invention have the following beneficial effects: The metal layers on the inner sides of the base island and pins help reduce the surface energy of the bare copper and decrease the wetting angle. During molding, the molding fluid spreads more easily in the inner areas of the base island and pins, penetrating narrow gaps and reducing voids caused by incomplete filling in dead corners. This improves bonding, prevents structural delamination, and also enhances heat dissipation and the wettable side creep performance of soldering, thereby improving package quality. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of a first type of semiconductor packaging structure provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a second semiconductor packaging structure provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a third type of semiconductor packaging structure provided in an embodiment of the present invention; Figure 4 A schematic diagram of a first fence of a semiconductor packaging structure provided in an embodiment of the present invention; Figure 5 Another schematic diagram of the first fence of the semiconductor packaging structure provided in the embodiment of the present invention; Figure 6 A schematic diagram of the distribution structure of the first fence of the semiconductor packaging structure provided in an embodiment of the present invention from a top view. Figure 7 This is a schematic diagram of a fourth semiconductor packaging structure provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the connection between the semiconductor packaging structure and the substrate provided in an embodiment of the present invention; Figure 9 This is one of the process diagrams of the packaging method provided in the embodiments of the present invention; Figure 10 A second schematic diagram of the manufacturing process of the packaging method provided in an embodiment of the present invention; Figure 11 The third schematic diagram of the packaging method provided in the embodiment of the present invention; Figure 12 This is another process diagram of the packaging method provided in an embodiment of the present invention.

[0027] Icons: 110-Base island; 111-First isolation trench; 1111-First channel; 112-First step trench; 113-Third step trench; 114-First fence; 115-Second step section; 120-Pin; 121-Second step trench; 122-Fourth step trench; 123-Second fence; 130-Chip; 131-Wire bonding structure; 132-Colloid; 140-Metal layer; 150-Encapsulation body; 161-Second isolation trench; 160-Connecting rib; 162-Groove; 171-Protective adhesive layer; 170-Coating; 200-Substrate. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0030] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0031] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0032] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0033] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0035] Please combine Figure 1 This invention discloses a semiconductor packaging structure comprising a base island 110, leads 120, a chip 130, a molding compound 150, and a metal layer 140. The leads 120 are distributed along the outer periphery of the base island 110. The chip 130 is mounted on the base island 110. The chip 130 and the leads 120 are electrically connected by a wire bonding structure 131. The molding compound 150 covers the chip 130 and the wire bonding structure 131. The metal layer 140 is respectively disposed on the outer peripheral surface of the base island 110, the outer peripheral surface of the leads 120, the surface of the base island 110 away from the molding compound 150, and the surface of the leads 120 away from the molding compound 150. Because the metal layer 140 is respectively coated on the inner sides of the base island 110 and the leads 120, it is beneficial to reduce the surface energy of the bare copper and decrease the wetting angle. During molding, the mold flow of the molding body 150 spreads more easily and penetrates into narrow gaps in the inner areas of the base island 110 and pins 120, reducing the occurrence of voids due to incomplete filling of dead corners. This is beneficial for improving bonding and preventing structural delamination. In addition, it is also beneficial for improving heat dissipation performance and the wettable side creep performance of soldering, thereby improving the packaging quality.

[0036] Optionally, a first isolation trench 111 is formed between the base island 110 and the pin 120 to ensure that the base island 110 and the pin 120 are separated and to avoid circuit bridging. One end of the wire bonding structure 131 is soldered to the chip 130, and the other end is soldered across the first isolation trench 111 to the pin 120.

[0037] Optionally, the first isolation groove 111 has a first stepped portion on its wall to form a first stepped groove 112 on the base island 110 and a second stepped groove 121 on the pin 120; the first stepped groove 112 and the second stepped groove 121 are arranged opposite to each other. This arrangement changes the cross-sectional area of ​​the first isolation groove 111, which helps to improve the flowability of the molding compound 150 during filling, prevents problems such as voids caused by incomplete filling in dead corners, and increases the contact area between the molding compound 150 and the base island 110 and the pin 120 respectively, improving the bonding and preventing structural delamination.

[0038] Optionally, the walls of the first isolation groove 111, the first stepped groove 112, and the second stepped groove 121 are respectively covered with a metal layer 140. This can increase the contact area between the metal layer 140 and the base island 110, as well as between the metal layer 140 and the pin 120, and improve the problems of "high surface energy, easy oxidation, large wetting angle and poor spreading of the inner bare copper of the base island 110 and the pin 120". This is beneficial to improving the filling fluidity and bonding of the molding compound 150, and preventing filling voids and delamination.

[0039] Please combine Figure 2 Optionally, the first isolation groove 111 has a second stepped portion 115 on its wall to form a third stepped groove 113 on the base island 110 and a fourth stepped groove 122 on the pin 120. The walls of the third stepped groove 113 and the fourth stepped groove 122 are respectively covered with a metal layer 140. The second stepped portion 115 further improves the flow performance of the molding compound 150, increases the contact area between the metal layer 140 and the molding compound 150, improves the bonding performance of the structure, and prevents structural delamination.

[0040] It should be noted that the number, shape, and distribution of the steps on the first isolation groove 111 can be designed flexibly, and no specific limitations are made here.

[0041] Optionally, the metal layer 140 may be made of any one or more metals such as tin, gold, silver, palladium and nickel, which is beneficial to improving the wettable side soldering performance of the back of the pin 120 and the back of the base island 110.

[0042] Please combine Figure 3 and Figure 4 Optionally, a first fence 114 is provided on the edge of the base island 110. The first fence 114 is located on the side of the base island 110 where the chip 130 is mounted. The chip 130 is bonded to the base island 110 by adhesive 132. The first fence 114 helps prevent adhesive 132 from overflowing and contaminating the pins 120. It also improves thermal conductivity and enhances the bonding performance between the base island 110 and the molding compound 150.

[0043] Optionally, in some implementations, the following can be done: Figure 2 The second step portion 115 is stamped from the non-mounting surface of the base island 110 toward the mounted chip 130 to form a first fence 114. In this way, the surface of the first fence 114 away from the base island 110 is higher than the surface of the pin 120, that is, the upper surface of the first fence 114 is higher than the surface of the mounted chip 130 of the base island 110. This not only serves to block the adhesive layer, but also guides the molding compound flow into the first isolation groove 111, improving the flowability and filling performance of the molding compound 150.

[0044] Optionally, the outer wall of the first enclosure 114 is covered with a metal layer 140, which helps to reduce the surface energy of the bare copper and reduce the wetting angle. During molding, the mold flow of the molding body 150 is more likely to spread and penetrate into narrow gaps in the inner areas of the base island 110 and the pins 120, reducing the occurrence of voids due to incomplete filling of dead corners, which helps to improve bonding and prevent structural delamination.

[0045] Please combine Figure 5 and Figure 6 In some embodiments, the first enclosure 114 comprises multiple segments, which are spaced apart along the edge of the base island 110. This arrangement creates flow channels between adjacent segments of the first enclosure 114, allowing for more flow channels to be formed along the edge of the base island 110, thus improving the flowability and filling properties of the molding compound 150. The illustration shows the first enclosure 114 only located at the four corners of the base island 110, meaning the first enclosure 114 comprises four segments. In some embodiments, the number of segments, their distribution, and cross-sectional shape can be flexibly designed according to actual needs, and are not specifically limited here. For example, only the second step portion 115 may be partially stamped, forming the first enclosure 114 at the stamped area, while the unstamped area retains the structure of the second step portion 115.

[0046] Please combine Figure 7 Optionally, a second fence 123 is provided at the edge of the pin 120. It is understood that after stamping the second stepped portion 115, the second fence 123 is formed at the edge of the pin 120. The edge of the second fence 123 is covered with a metal layer 140, which helps guide the molding flow into the first isolation groove 111, improves the flow uniformity of the molding flow in the first isolation groove 111, and improves the filling performance of the molding compound 150. Optionally, the upper surface of the second fence 123 is higher than the upper surface of the pin 120. The second fence 123 helps to slow down the flow rate of the molding flow during molding, reduces the impact of the molding flow on the tail end of the wire bonding structure 131, avoids welding failure of the wire bonding structure 131, and improves the reliability of the electrical connection. In addition, the setting of the second fence 123 also helps to increase the bonding performance between the pin 120 and the molding compound 150.

[0047] Optionally, the metal layer 140 on the side of pin 120 away from base island 110 protrudes from the edge of the molding compound 150, which helps to improve the wettable sidewall performance of the outer side of pin 120.

[0048] Optionally, the molding compound 150 at least partially or completely fills the first isolation groove 111. It is understood that, along the thickness direction of the base island 110, the molding compound 150 enters from the side with the chip 130 and gradually fills the first isolation groove 111. Its filling height within the first isolation groove 111 can be flexibly controlled according to actual needs.

[0049] Optionally, along the thickness direction of the base island 110, the encapsulant 150 at least partially or completely fills the first step groove 112 and the second step groove 121. In this embodiment, the encapsulant 150 fills to the bottom of the first step groove 112, and the surface of the encapsulant 150 is flush with the bottom of the first step groove 112.

[0050] In some embodiments, the surface of the molding compound 150 is filled to half the height of the sidewall of the first stepped groove 112. This unfilled portion helps improve heat dissipation. Furthermore, the exposed metal layer 140 in the unfilled portion improves the wettable sidewall climbing performance of the weld, thus enhancing weld reliability.

[0051] Please combine Figure 8 Optionally, when the semiconductor package structure is mounted to the substrate 200, the base island 110 and the leads 120 are soldered to pads on the substrate 200, respectively. The first isolation trench 111 includes a first channel 1111 and a second channel along the thickness direction of the base island 110. A first stepped trench 112 and a second stepped trench 121 form the second channel. In the figure, the upper portion of the first isolation trench 111 is the first channel 1111. The molding compound 150 fills a portion of the first channel 1111. For example, the height of the first channel 1111 is H, and the molding compound 150 fills half or two-thirds of the height H. The unfilled portion helps improve heat dissipation performance. Furthermore, the exposed metal layer 140 in the unfilled portion helps improve the wettable sidewall climbing performance for soldering to the substrate 200, thus improving soldering reliability.

[0052] Optionally, the molding compound 150 is flush with the metal layer 140 on the side of the base island 110 away from the chip 130, such as... Figure 3 As shown, this maximizes the contact area between the molding compound 150 and the metal layer 140, which improves the filling flow of the molding compound, enhances bonding performance, and prevents structural delamination. Furthermore, the back metal layer 140 is flush with the molding compound 150, allowing the molding compound 150 to provide protection during welding.

[0053] Similarly, the molding compound 150 is flush with the metal layer 140 (the metal layer 140 on the back side) on the side of the pins 120 away from the chip 130.

[0054] Alternatively, in some embodiments, the metal layer 140 on the side of the base island 110 away from the chip 130 protrudes from the surface of the molding compound 150, such as... Figure 7 As shown. This configuration allows the metal layer 140 to improve the wettable side wing climbability. Similarly, the metal layer 140 on the back of the pin 120 protrudes from the surface of the molding compound 150.

[0055] Please combine Figures 9 to 11 This invention also provides a packaging method, which mainly includes the following steps: Step S1: Provide a substrate, which includes a first surface and a second surface disposed opposite to each other. The substrate may be a copper frame.

[0056] Step S2: A first isolation groove 111 is formed on the first surface of the substrate to separate the base island 110 and the pin 120. In this embodiment, the depth of the first isolation groove 111 is less than the thickness of the substrate.

[0057] Optionally, the substrate can be divided into sections using a cutting process such as laser cutting or mechanical cutting to form the base island 110 and the pins 120.

[0058] Optionally, a second isolation groove 161 is formed on the first surface of the substrate to form a connecting rib 160 between the pins 120; the depth of the second isolation groove 161 is less than the thickness of the substrate, and the bottom of the second isolation groove 161 serves as the connecting rib 160. It is understood that multiple lead frame structures can be separated on the substrate, each lead frame structure including a base island 110 and pins 120 located around the base island 110. The connecting rib 160 is located between two adjacent lead frame structures.

[0059] Optionally, a groove 162 is formed by cutting the end of the connecting rib 160 near the pin 120. That is, a groove 162 is cut at the end of the connecting rib 160, so that the connecting rib 160 is separated from the pin 120.

[0060] Optionally, when forming the first isolation groove 111 on the first surface of the substrate, a first step portion can be formed on the groove wall of the first isolation groove 111 to form a first step groove 112 on the base island 110 and a second step groove 121 on the lead 120. This is beneficial to improving the filling performance and bonding of the molding compound 150.

[0061] Step S3: A metal layer 140 is formed in the first isolation groove 111 and on the surface of the substrate.

[0062] Using an electroplating process, the substrate is immersed in an electroplating solution, and the substrate is electrically coupled to the negative electrode of the electroplating equipment, while the positive electrode is coupled to the electroplating material, which is also immersed in the electroplating solution. An electric current is applied to the substrate, and the electroplating material is deposited on the bare copper surface of the substrate. In this embodiment, a metal layer 140 is formed on the side surface of the substrate with the first isolation trench 111, including the upper surface of the pin 120 and the base island 110, the bottom and wall of the first isolation trench 111, the bottom and wall of the second isolation trench 161, and the bottom and wall of the groove 162.

[0063] Step S4: Cut the metal layer 140 and the substrate along the first isolation groove 111 to separate the base island 110 and the pin 120.

[0064] Optionally, the bottom of the first isolation groove 111 can be removed using a cutting process, completely separating the base island 110 and the pin 120. It is understood that removing only the bottom of the first isolation groove 111 allows the connecting rib 160 to connect the various parts of the substrate together without them scattering. In some embodiments, the bottom of the second isolation groove 161 can also be removed, i.e., the connecting rib 160 can be cut and removed. If the connecting rib 160 is removed, the adhesive film can be used to prevent the multiple pins 120 and base island 110 on the substrate from scattering.

[0065] Optionally, the sidewall of the first isolation groove 111 on the base island 110 is stamped from one side of the first surface, such as by stamping. Figure 2 The second step portion 115 forms a first fence 114 at the edge of the base island 110. In some embodiments, the pin 120 may be stamped simultaneously to form a second fence 123 at the edge of the pin 120. Both the first fence 114 and the second fence 123 are higher than the second surface.

[0066] Step S5: Mount chip 130 on base island 110 on the second surface.

[0067] Optionally, using a back-mounting process, the film 170 is attached to the back of the lead frame (the first surface of the substrate) through a protective adhesive layer 171, wherein the metal layer 140 is embedded in the protective adhesive layer 171, and the protective adhesive layer 171 protects the metal layer 140.

[0068] Using the chip mounting process 130, a standard chip 130 is mounted. The chip 130 is bonded using adhesive 132 and then fixed onto the base island 110 after baking. The chip 130 pads are then connected to the pins 120 using a wire bonding process, forming a wire bonding structure 131.

[0069] Step S6: The encapsulated chip 130 forms an encapsulated body 150; the encapsulated body 150 at least partially or completely fills the first isolation groove 111.

[0070] Optionally, a molding process is used to form a molding compound 150 to protect the wire bonding structure 131 and the chip 130. The overlay 170 and adhesive layer are then removed. Finally, a cutting process is used to cut along the connecting ribs 160 to separate them into individual products.

[0071] It should be noted that when the metal layer 140 is embedded in the protective adhesive layer 171 and then molded, the surface of the resulting molded body 150 is lower than the surface of the metal layer 140 on one side of the first surface, meaning the metal layer 140 is exposed on the surface of the molded body 150. If the metal layer 140 is not embedded in the protective adhesive layer 171, after molding, the surface of the resulting molded body 150 is flush with the surface of the metal layer 140 on one side of the first surface, such as... Figure 12 As shown.

[0072] Alternatively, in some other embodiments, the filling height of the encapsulant 150 in the first isolation groove 111 can be controlled by controlling the height of the protective adhesive layer 171 at the first isolation groove 111, thereby achieving different heights of encapsulant 150 filling in the first isolation groove 111 according to actual needs.

[0073] In summary, the semiconductor packaging structure and packaging method provided by the embodiments of the present invention have the following beneficial effects, including: Metal layers 140 are applied to the inner sides of the base island 110 and the pin 120, which helps reduce the surface energy of the bare copper and decrease the wetting angle. During molding, the molding flow of the molding compound 150 spreads more easily and penetrates into narrow gaps in the inner areas of the base island 110 and the pin 120, reducing voids caused by incomplete filling in dead corners. This improves bonding and prevents structural delamination. In addition, it also improves heat dissipation and the wettability and creepage properties of the solder, thereby improving the package quality. By setting a first fence 114 and a second fence 123 on the base island 110 and the pin 120 respectively, the impact of the molding flow on the wire bonding structure 131 is reduced, bonding performance is improved, and adhesive overflow is prevented from contaminating the pin 120. The metal layer 140 also helps improve the wettability and creepage properties of the solder, improving soldering reliability.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; any modifications, equivalent substitutions, improvements, etc., should be included within the protection scope of the present invention.

Claims

1. A semiconductor packaging structure, characterized in that, include: Base Island; Pins, which are distributed along the outer periphery of the base island; The chip is mounted on the base island; the chip and the pins are electrically connected by a wire bonding structure. A molding compound that encapsulates the chip and the wire bonding structure; Metal layers are respectively disposed on the outer peripheral surface of the base island, the outer peripheral surface of the pin, the side surface of the base island away from the molding compound, and the side surface of the pin away from the molding compound.

2. The semiconductor packaging structure according to claim 1, characterized in that, A first isolation groove is formed between the base island and the pin. The wall of the first isolation groove is provided with a first step portion to form a first step groove on the base island and a second step groove on the pin. The first step groove and the second step groove are arranged opposite to each other.

3. The semiconductor packaging structure according to claim 2, characterized in that, The walls of the first isolation groove, the first stepped groove, and the second stepped groove are respectively covered with the metal layer.

4. The semiconductor packaging structure according to claim 2, characterized in that, The first isolation groove has a second stepped portion on its wall to form a third stepped groove on the base island and a fourth stepped groove on the pin.

5. The semiconductor packaging structure according to claim 4, characterized in that, The walls of the third and fourth stepped grooves are respectively covered with the metal layer.

6. The semiconductor packaging structure according to claim 1, characterized in that, The edge of the base island is equipped with a first fence.

7. The semiconductor packaging structure according to claim 6, characterized in that, The first fence comprises multiple sections, which are spaced apart along the edge of the base island.

8. The semiconductor packaging structure according to claim 6, characterized in that, The surface of the first fence on the side away from the base island is higher than the surface of the pin.

9. The semiconductor packaging structure according to claim 6, characterized in that, The metal layer covers the outside of the first fence.

10. The semiconductor packaging structure according to claim 1, characterized in that, The edge of the pin is provided with a second fence.

11. The semiconductor packaging structure according to claim 1, characterized in that, The metal layer on the side of the pin away from the base island protrudes from the edge of the molding compound.

12. The semiconductor packaging structure according to claim 2, characterized in that, The encapsulation body at least partially or completely fills the first isolation groove.

13. The semiconductor packaging structure according to claim 12, characterized in that, Along the thickness direction of the base island, the encapsulation body at least partially or completely fills the first stepped groove and the second stepped groove; Alternatively, the first isolation groove includes a first channel and a second channel along the thickness direction of the base island, the first stepped groove and the second stepped groove form the second channel, and the encapsulant fills a portion of the first channel.

14. The semiconductor packaging structure according to claim 12, characterized in that, The metal layer of the molding compound is flush with the metal layer of the base island on the side away from the molding compound, or the metal layer of the base island on the side away from the molding compound protrudes from the surface of the molding compound.

15. A packaging method, characterized in that, include: A substrate is provided, the substrate including a first surface and a second surface disposed opposite to each other; A first isolation groove is formed on the first surface of the substrate to separate the base island and the pin; A metal layer is formed within the first isolation groove and on the surface of the substrate; Cut the metal layer and the substrate along the first isolation groove to separate the base island and the pin; Chips are mounted on the base island of the second surface; The chip is encapsulated to form an encapsulation; the encapsulation at least partially or completely fills the first isolation trench.

16. The packaging method according to claim 15, characterized in that, The step of forming a first isolation groove on the first surface of the substrate to separate the base island and the pins further includes: A second isolation groove is formed on the first surface of the substrate to form a connecting rib between the pin and the pin; Cut the end of the connecting rib near the pin to form a groove; The step of forming a metal layer within the first isolation groove and on the surface of the substrate further includes: The metal layer is formed on the surface of the groove and the connecting rib.

17. The packaging method according to claim 15, characterized in that, Prior to the step of mounting the chip on the base island of the second surface, the method further includes: The base island is stamped from the second surface to form a first fence at the edge of the base island.

18. The packaging method according to claim 17, characterized in that, The step of stamping the base island from the second surface to form a first fence at the edge of the base island further includes: The pin is stamped from the second surface to form a second fence at the edge of the pin.

19. The packaging method according to claim 15, characterized in that, The step of forming a first isolation groove on the first surface of the substrate to separate the base island and the pins further includes: A first step portion is formed in the wall of the first isolation groove to form a first step groove on the base island and a second step groove on the pin.

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