Chip packaging method and packaging structure
By setting a protrusion on the second metal layer of the metal bump and allowing the solder to surround the protrusion, the problem of air bubble retention in the solder is solved, improving the stability of the package structure and chip performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-15
- Publication Date
- 2026-03-27
AI Technical Summary
In existing technologies, cavities are generated within the solder after chip packaging, affecting the stability of the packaging structure and chip performance.
A protrusion is provided on the second metal layer of the metal bump, and the solder surrounds the protrusion during welding to prevent air bubbles from being trapped. The air bubbles are then allowed to escape to both sides during the welding heating process.
It significantly reduces the probability of air bubbles trapped in the solder, improves the stability of the packaging structure, avoids problems such as excessive parasitic resistance, and ensures the performance of the chip.
Smart Images
Figure CN121752090A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of chip manufacturing, and more particularly to a chip packaging method and packaging structure. Background Technology
[0002] When chips are flip-chip packaged, their metal bumps need to be soldered to the substrate. In some existing chips, due to manufacturing processes, grooves are formed on the side of the metal bumps facing the substrate. During soldering, air bubbles are generated inside the solder. These bubbles accumulate in the grooves of the metal bumps and cannot escape, creating cavities in the grooved area of the solder after soldering. The presence of these cavities affects the stability of the package structure and can cause problems such as excessive parasitic resistance, thus impacting chip performance. Summary of the Invention This invention provides a chip packaging method and packaging structure, the purpose of which is to solve the problem that cavities are generated in the solder after chip packaging in the prior art.
[0003] To achieve the above objectives, the present invention provides a chip packaging method, comprising the following steps: A chip is provided, the chip including a substrate layer and functional components disposed on the substrate layer; A conductive layer is formed, the conductive layer having a first surface and a second surface disposed opposite to each other, the first surface contacting the functional component, and the conductive layer having a recessed portion formed from the second surface; A metal bump is formed, the metal bump having a first metal layer and a second metal layer connected together, at least a portion of the first metal layer filling the recess, the second metal layer protruding from the second surface, and a protrusion forming on the side of the second metal layer opposite to the first metal layer. Provide substrate; The second metal layer is soldered to the substrate using solder, and during soldering, the solder surrounds the protrusion.
[0004] As a further improvement of the present invention, the step of "forming a metal bump" includes the following steps: A first metal layer is formed, the first metal layer including a connected filling portion and a protruding portion, the filling portion filling the recessed portion, and the protruding portion protruding from the second surface; A second metal layer is formed by depositing material on the side of the protrusion opposite to the filling portion and on the second surface near the protrusion, the protrusion corresponding to the protrusion.
[0005] As a further improvement of the present invention, the step of "forming the first metal layer" includes the following steps: A first mold layer is formed on the second surface; Remove a portion of the material from the first mold layer to form a first groove communicating with the recess; Material is deposited in the recess and the first groove to form the first metal layer; Remove the first mold layer.
[0006] As a further improvement of the present invention, the first slot is provided not beyond the recess in the width direction of the chip.
[0007] As a further improvement of the present invention, the step of "forming a second metal layer" includes the following steps: A second mold layer is formed on the second surface; A portion of the material of the second mold layer is removed to form a second groove, the protrusion being located within the second groove, and the width of the second groove being greater than the width of the protrusion; Material is deposited from the bottom wall of the second slot to form the second metal layer, the bottom wall of the second slot including the protrusion on the side opposite to the filling portion and a portion of the second surface near the protrusion; Remove the second mold layer.
[0008] As a further improvement of the present invention, in the step of "depositing material in the recess and the first groove to form the first metal layer", the material is deposited using an electroplating process. In the step of "depositing material from the bottom wall of the second groove to form the second metal layer", the material is deposited using an electroplating process.
[0009] As a further improvement of the present invention, the step of "forming a conductive layer" includes the following steps: A protective layer is formed, which covers the substrate layer and the functional component; A portion of the material of the protective layer is removed to form a window that extends through the functional component and the protective layer to the side opposite to the substrate layer. The window has a bottom wall located on the functional component and a side wall located on the protective layer. A conductive layer is formed, which covers the bottom and side walls of the window and the side of the protective layer opposite to the substrate layer, and the recess is located between the conductive layers covering the bottom and side walls of the window.
[0010] As a further improvement of the present invention, the second slot is higher than the second metal layer, and before the step of "removing the second mold layer", the encapsulation method further includes the following steps: Material is deposited further within the second groove to form the solder surrounding the protrusion.
[0011] As a further improvement of the present invention, the packaging method further includes the following steps: The solder is shaped so that the side of the solder away from the second metal layer is hemispherical.
[0012] The present invention also provides a chip packaging structure, the packaging structure comprising: The chip includes a substrate layer and functional components disposed on the substrate layer; A conductive layer having a first surface and a second surface disposed opposite to each other, the first surface contacting the functional component, and the conductive layer having a recessed portion formed from the second surface; A metal bump having a first metal layer and a second metal layer connected together, at least a portion of the first metal layer filling the recess, the second metal layer protruding from the second surface, and a protrusion forming on the side of the second metal layer opposite to the first metal layer. The substrate, the second metal layer and the substrate are soldered together by solder, the solder surrounding the protrusion. Beneficial effects: In the chip packaging method and structure provided by this invention, a raised portion is provided on the second metal layer of the metal bump. When the metal bump is soldered to the substrate using solder, the solder surrounds the raised portion. During the soldering heating process, bubbles inevitably form inside the solder. As the bubbles move upward, they are obstructed by the raised portion and tend to move to both sides of the solder, thus escaping from the solder. The chip packaging method and structure provided by this invention can significantly reduce the probability of bubbles remaining inside the solder, avoid cavities in the solder after soldering, improve the stability of the packaging structure, avoid problems such as excessive parasitic resistance, and ensure chip performance. Attached Figure Description
[0013] Figure 1 A flowchart illustrating a chip packaging method according to an embodiment of the present invention; Figure 2-20 This is a schematic diagram illustrating the steps of a chip packaging method according to an embodiment of the present invention; Figure 21 This is a schematic diagram of the chip packaging structure provided in an embodiment of the present invention.
[0014] In the picture: 100. Packaging structure; 10. Chip; 11. Substrate; 12. Functional component; 20. Conductive layer; 111. First surface; 112. Second surface; 113. Recess; 30. Protective layer; 31. Window opening; 32. Third non-exposure area; 33. Third exposure area; 40. Metal bump; 41. First metal layer; 411. Filler portion; 412. Protrusion; 42. Second metal layer; 421. Raised portion; 50. Substrate; 60. Solder; 70. First mold layer; 71. First slot; 72. First non-exposure area; 73. First exposure area; 80. Second mold layer; 81. Second slot; 82. Second non-exposure area; 83. Second exposure area. Detailed Implementation
[0015] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any modifications to the mechanism, method, or function made by those skilled in the art based on these embodiments are included within the scope of protection of the present invention.
[0016] The terms used herein, such as "up," "down," "left," "right," "front," and "back," indicating spatial relative position, are for illustrative purposes to describe the relationship of one feature relative to another, as shown in the accompanying drawings. It is understood that, depending on the product's placement, these terms may be intended to include different orientations besides those shown in the figures, and should not be construed as limiting the claims. Furthermore, the descriptive term "horizontal" used herein is not entirely equivalent to being perpendicular to the direction of gravity, and allows for a certain angle of inclination.
[0017] like Figure 1 As shown, an embodiment of the present invention provides a packaging method for a chip 10, the packaging method comprising the following steps: like Figure 2 As shown, a chip 10 is provided, which includes a substrate 11 and functional components 12 disposed on the substrate 11. The substrate 11 can be made of materials such as gallium arsenide or silicon, as needed. The functional components 12 are structural elements that need to be electrically connected to other structures during the subsequent packaging process of the chip 10. For example, the functional components 12 can be connection lines of the chip 10.
[0018] like Figure 6 As shown, a conductive layer 20 is formed, having a first surface 111 and a second surface 112 disposed opposite to each other. The first surface 111 faces and contacts the functional member 12, enabling the conductive layer 20 to achieve a conductive connection with the functional member 12. The second surface 112 is located on the side of the conductive layer 20 away from the functional member 12, and the conductive layer 20 has a recess 113 formed from the second surface 112. In this embodiment, the recess 113 is trapezoidal in shape, wider at the top and narrower at the bottom.
[0019] like Figure 15 As shown, a metal bump 40 is formed, having a first metal layer 41 and a second metal layer 42 connected together. At least a portion of the first metal layer 41 fills the recess 113, and the second metal layer 42 protrudes from the second surface 112. Furthermore, a protrusion 421 is formed on the side of the second metal layer 42 opposite to the first metal layer 41. The first metal layer 41 fills the recess 113 and contacts the conductive layer 20, enabling conductive connection with the conductive layer 20.
[0020] like Figure 20-21 As shown, a substrate 50 is provided. In the subsequent packaging process of the chip 10, the substrate 50 is electrically connected to the chip 10 through metal bumps 40.
[0021] The second metal layer 42 is soldered to the substrate 50 using solder 60. During soldering, the solder 60 surrounds the protrusion 421. After the second metal layer 42 is soldered to the substrate 50, the solder 60 connects the second metal layer 42 and the substrate 50. After soldering, the substrate 50 can be electrically connected to the functional component 12 via the metal bumps 40 and the conductive layer 20. It can be seen that the packaging method provided in this embodiment uses a flip-chip process to package the chip 10.
[0022] In the chip 10 packaging method provided in this embodiment, a protrusion 421 is provided on the second metal layer 42 of the metal bump 40. When the metal bump 40 is soldered to the substrate 50 using solder 60, the solder 60 surrounds the protrusion 421. During the soldering heating process, bubbles inevitably form inside the solder 60. As the bubbles move upward, they tend to move to both sides of the solder 60 due to the obstruction of the protrusion 421, thus escaping from the solder 60. The chip 10 packaging method provided in this embodiment can significantly reduce the probability of bubbles remaining inside the solder 60, avoid cavities in the solder 60 after soldering, improve the stability of the packaging structure 100, avoid problems such as excessive parasitic resistance, and ensure the performance of the chip 10.
[0023] like Figure 11 , 15 As shown, in this embodiment, the step "forming the metal bump 40" includes the following steps: A first metal layer 41 is formed. The first metal layer 41 includes a connected filling portion 411 and a protrusion 412, wherein the filling portion 411 fills the recess 113, and the protrusion 412 protrudes from the second surface 112. The filling portion 411 contacts the conductive layer 20, enabling a conductive connection between the conductive layer 20 and the metal bump 40.
[0024] A second metal layer 42 is formed by depositing material on the side of the protrusion 412 away from the filling portion 411 and on a portion of the second surface 112 near the protrusion 412. Since the side of the protrusion 412 away from the filling portion 411 is higher than the second surface 112, the material deposited on the protrusion 412 is higher than the material deposited on the portion of the second surface 112 during the formation of the second metal layer 42. After the second metal layer 42 is formed, a protrusion 421 corresponding to the protrusion 412 is formed on it. In this embodiment, the side of the protrusion 412 away from the filling portion 411 is planar, and the protrusion 421 is rectangular and located in the middle of the second metal layer 42.
[0025] As can be imagined, after the second metal layer 42 is formed, its width is greater than the width of the protrusion 412. The second metal layer 42 surrounds the protrusion 412, and the widths of the protrusion 412 and the raised portion 421 are equal.
[0026] The first metal layer 41 and the second metal layer 42 can be made of the same material; for example, both the first metal layer 41 and the second metal layer 42 can be made of copper. Alternatively, the first metal layer 41 and the second metal layer 42 can be made of different materials; for example, the first metal layer 41 can be made of aluminum, and the second metal layer 42 can be made of copper.
[0027] By using the above steps, a first metal layer 41 and a second metal layer 42 can be formed respectively. Furthermore, by utilizing the protrusion 412 of the first metal layer 41, the protrusion 421 of the second metal layer 42 can be controllably formed, making the fabrication of the metal bump 40 easy to achieve in terms of process steps and ensuring the accuracy of the structural dimensions of the metal bump 40.
[0028] like Figure 7-11 As shown, in this embodiment, the step "forming the first metal layer 41" includes the following steps: A first mold layer 70 is formed on the second surface 112; A portion of the material in the first mold layer 70 is removed to form a first groove 71, which connects to the recess 113. The shape of the first groove 71 matches the shape of the protrusion 412. Material is deposited in the recess 113 and the first groove 71 to form a first metal layer 41; Remove the first mold layer 70.
[0029] In the above steps, a first mold layer 70 is first formed on the second surface 112, and then a portion of the material of the first mold layer 70 is removed to form the first groove 71. It is conceivable that the material deposited in the recess 113 will form a filling portion 411 of the first metal layer 41, filling the recess 113 completely. The material deposited in the first groove 71 will form a protrusion 412 of the first metal layer 41, the width of which is defined by the width of the first groove 71. After the first metal layer 41 is formed, the first mold layer 70 has fulfilled its function and can be removed.
[0030] By adopting the above steps, the shape of the first metal layer 41 can be effectively controlled, and when forming the first metal layer 41, the first mold layer 70 will cover the part of the second surface 112 that does not correspond to the recess 113, which can prevent material from being deposited on the part of the second surface 112 that does not correspond to the recess 113.
[0031] In the above steps, the first notch 71 is provided without extending beyond the recess 113 in the width direction of the chip 10, so that the formed protrusion 412 is also provided without extending beyond the recess 113 in the width direction of the chip 10. The width direction of the chip 10 is where the chip 10 is located. Figure 1 The left and right directions in the state shown.
[0032] If the first notch 71 extends beyond the recess 113 in the width direction of the chip 10, when depositing material to form the first metal layer 41, the material will be deposited upwards from the bottom of the recess 113 and the portion of the second surface 112 near the recess 113. After deposition, a large depression will appear in the middle of the protrusion 412. When the second metal layer 42 is subsequently formed, a large depression will also appear in the middle of the protrusion 421 corresponding to the protrusion 412 on the second metal layer 42. If there is a depression in the middle of the protrusion 421, when the second metal layer 42 is subsequently soldered to the substrate 50, air bubbles generated in the solder 60 are likely to remain in the depression in the middle of the protrusion 421. In this embodiment, the first notch 71 is provided not to extend beyond the recess 113 in the width direction of the chip 10. When depositing material to form the first metal layer 41, the material will only be deposited upwards from the bottom of the recess 113, which can avoid a large depression in the middle of the formed protrusion 412, thereby avoiding the above-mentioned problems.
[0033] In this embodiment, the first mold layer 70 is made of a negative photosensitive material. When exposed to light, the negative photosensitive material undergoes internal denaturation, and the unexposed areas can be dissolved and removed using a developing solution.
[0034] like Figure 8-9 As shown, the step "removing a portion of the material from the first mold layer 70 to form the first groove 71" specifically includes the following steps: A mask is used to partially cover the first mold layer 70. The first mold layer 70 has a first non-exposed area 72 and a first exposed area 73. The area of the first mold layer 70 covered by the mask is the first non-exposed area 72, and the area of the first mold layer 70 not covered by the mask is the first exposed area 73. The position of the first slot 71 coincides with the position of the first non-exposed area 72. The first mold layer 70 is exposed to cause the first exposure area 73 to undergo denaturation. The first non-exposed area 72 is dissolved using a developing solution to form the first groove 71.
[0035] In the above steps, a mask is used to cover the first non-exposed area 72 corresponding to the position of the first slot 71, so that when the first mold layer 70 is exposed later, only the first exposed area 73, which is not covered by the mask, will be denatured. After denaturation, the first exposed area 73 is not easily dissolved in the developer. Therefore, the developer will only dissolve the first non-exposed area 72, so only the material corresponding to the position of the first slot 71 on the first mold layer 70 will be removed.
[0036] In other embodiments of the present invention, the material of the first mold layer 70 may be a positive photosensitive material. The area of the positive photosensitive material exposed can be removed by a developing solution. In this case, the position of the first groove 71 should coincide with the first exposure area 73.
[0037] like Figure 12-17 As shown, in this embodiment, the step "forming the second metal layer 42" includes the following steps: A second mold layer 80 is formed on the second surface 112; A portion of the material of the second mold layer 80 is removed to form a second groove 81. The protrusion 412 is located inside the second groove 81, and the width of the second groove 81 is greater than the width of the protrusion 412. Material is deposited from the bottom wall of the second slot 81 to form a second metal layer 42. It is conceivable that the bottom wall includes a protrusion 412 on the side opposite to the filling portion 411 and a portion of the second surface 112 near the protrusion 412; Remove the second mold layer 80.
[0038] In the above steps, a second mold layer 80 is first formed on the second surface 112, and then a portion of the material of the second mold layer 80 is removed to form a second groove 81. Next, material is deposited on the bottom wall of the second groove 81 to form a second metal layer 42. The width of the second metal layer 42 is defined by the width of the second groove 81. After the second metal layer 42 is formed, the second mold layer 80 has fulfilled its function and can be removed.
[0039] By adopting the above steps, the shape of the formed second metal layer 42 can be effectively controlled, and when forming the second metal layer 42, the second mold layer 80 will cover the part of the second surface 112 that does not correspond to the second slot 81, which can prevent material from being deposited on the part of the second surface 112 that does not correspond to the second slot 81.
[0040] In this embodiment, the material of the second mold layer 80 is a negative photosensitive material. For example... Figure 12-14 As shown, the step "removing a portion of the material from the second mold layer 80 to form the second groove 81" includes the following steps: A mask is used to partially cover the second mold layer 80. The second mold layer 80 has a second non-exposed area 82 and a second exposed area 83. The area of the second mold layer 80 covered by the mask is the second non-exposed area 82, and the area of the second mold layer 80 not covered by the mask is the second exposed area 83. The position of the second slot 81 coincides with the position of the second non-exposed area 82. The second mold layer 80 is exposed to cause the second exposure area 83 to undergo denaturation. The second unexposed area 82 is dissolved using a developer to form the second groove 81.
[0041] In the above steps, a mask is used to cover the second non-exposed area 82 corresponding to the position of the second slot 81, so that when the second mold layer 80 is exposed later, only the second exposed area 83, which is not covered by the mask, will be denatured. After denaturation, the second exposed area 83 is not easily dissolved in the developer. Therefore, the developer will only dissolve the second non-exposed area 82, so only the material corresponding to the position of the second slot 81 on the second mold layer 80 will be removed.
[0042] In other embodiments of the present invention, the material of the second mold layer 80 may be a positive photosensitive material. In this case, the position of the second slot 81 should coincide with the second exposure area 83.
[0043] like Figure 3-6 As shown, in the encapsulation method provided in this embodiment, the step "forming conductive layer 20" includes the following steps: A protective layer 30 is formed, which covers the substrate 11 and the functional component 12 disposed on the substrate 11. A portion of the material of the protective layer 30 is removed to form a window 31, which extends through the functional member 12 and the side of the protective layer 30 away from the substrate layer 11. The window 31 has a bottom wall located on the functional member 12 and a side wall located on the protective layer 30. A conductive layer 20 is formed, which covers the bottom and side walls of the opening 31 and the side of the protective layer 30 facing away from the substrate layer 11. The recess 113 is located between the portion of the conductive layer 20 covering the bottom and side walls of the opening 31.
[0044] The protective layer 30 protects the chip 10 and supports the conductive layer 20, stabilizing its shape. The conductive layer 20 extends into the opening 31 of the protective layer 30 and can contact the functional component 12, thus enabling an electrical connection between the conductive layer 20 and the functional component 12.
[0045] The protective layer 30 can be made of polyimide (PI). Polyimide has excellent heat resistance, chemical stability and mechanical strength, which can reliably support the conductive layer 20 and protect the chip 10.
[0046] The conductive layer 20 can be formed by metal sputtering. The conductive layer 20 is continuously distributed on the bottom and side walls of the window 31 and on the side of the protective layer 30 opposite to the substrate layer 11.
[0047] In this embodiment, the protective layer 30 is made of a negative photosensitive material. For example... Figure 4-5 As shown, the step "removing part of the material of the protective layer 30 to form the window 31" specifically includes the following steps: A mask is used to partially cover the protective layer 30. The protective layer 30 has a third non-exposed area 32 and a third exposed area 33. The area of the protective layer 30 covered by the mask is the third non-exposed area 32, and the area of the protective layer 30 not covered by the mask is the third exposed area 33. The position of the window 31 coincides with the position of the third non-exposed area 32. The protective layer 30 is exposed to cause the third exposure area 33 to undergo denaturation. The third unexposed area 32 is dissolved using a developing solution to form a window 31.
[0048] In the above steps, a mask is used to cover the third non-exposed area 32 corresponding to the position of the window 31, so that when the protective layer 30 is exposed later, only the third exposed area 33, which is not covered by the mask, will be denatured. After denaturation, the third exposed area 33 is not easily dissolved in the developer. Therefore, the developer will only dissolve the third non-exposed area 32, so only the material corresponding to the position of the window 31 on the protective layer 30 will be removed.
[0049] In other embodiments of the present invention, the protective layer 30 may be made of a positive photosensitive material. In this case, the position of the window 31 should coincide with the first exposure area 33.
[0050] In this embodiment, in the step of "depositing material in the recess 113 and the first groove 71 to form the first metal layer 41", the material is deposited using an electroplating process.
[0051] In the step of "depositing material from the bottom wall of the second slot 81 to form the second metal layer 42", the material is also deposited using an electroplating process.
[0052] By using electroplating to deposit materials to form a first metal layer 41 and a second metal layer 42, the forming area and thickness of the first metal layer 41 and the second metal layer 42 can be effectively controlled. Furthermore, the electroplating process has a high deposition rate, and the formed first metal layer 41 and the second metal layer 42 have a dense structure and excellent electrical conductivity.
[0053] like Figure 16 As shown, in this embodiment, the second slot 81 is higher than the second metal layer 42. Before the step of "removing the second mold layer 80", the encapsulation method further includes the following steps: Material continues to be deposited in the second slot 81 to form solder 60 surrounding the protrusion 421.
[0054] In the above steps, before removing the second mold layer 80, material is deposited in the second slot 81 to form solder 60. Solder 60 can be reliably connected to the second metal layer 42, and the width of solder 60 is conveniently defined by the second slot 81, so that solder 60 can be shaped into the required shape, simplifying the packaging method.
[0055] like Figure 19 As shown, in this embodiment, the encapsulation method further includes the following steps: Shape the solder 60 so that the side of the solder 60 facing away from the second metal layer 42 is hemispherical. This step can be performed after the second mold layer 80 is removed.
[0056] In the above steps, after the side of the solder 60 away from the second metal layer 42 is shaped into a hemispherical shape, the middle area of the solder 60 corresponding to the protrusion 421 is thinner, while the sides are thicker. During soldering, fewer bubbles are generated in the middle of the solder 60, and the bubbles generated in the solder 60 are more likely to move to the sides of the solder 60 and escape from the solder 60.
[0057] When the second metal layer 42 is soldered to the substrate 50 using solder 60, flux or solder may be provided on the substrate 50 to help solder the second metal layer 42 and the substrate 50 together.
[0058] In this embodiment, two functional components 12 are provided on the substrate, and the conductive layer 20 contacts both functional components 12 simultaneously during its formation. Two metal bumps 40 are also formed corresponding to the two functional components 12. For example... Figure 18 As shown, after step "forming metal bump 40", the encapsulation method further includes the following steps: Remove a portion of the conductive layer 20 located between the two metal bumps 40.
[0059] Using the above steps, the two functional components 12 cannot be electrically connected through the conductive layer 20, but both can be independently electrically connected to other structures to achieve their respective functions.
[0060] like Figure 21 As shown, an embodiment of the present invention also provides a packaging structure 100 for a chip 10, which is obtained by the above-described packaging method. The packaging structure 100 includes a chip 10, a conductive layer 20, metal bumps 40, and a substrate 50.
[0061] Chip 10 includes a substrate layer 11 and a functional component 12 disposed on the substrate layer 11. A conductive layer 20 has a first surface 111 and a second surface 112 disposed opposite to each other. The first surface 111 faces and contacts the functional component 12, enabling the conductive layer 20 to achieve a conductive connection with the functional component 12. The second surface 112 is located on the side of the conductive layer 20 away from the functional component 12, and the conductive layer 20 has a recess 113 formed from the second surface 112.
[0062] The metal bump 40 has a first metal layer 41 and a second metal layer 42 connected together. At least a portion of the first metal layer 41 fills the recess 113. The second metal layer 42 protrudes from the second surface 112, and a protrusion 421 is formed on the side of the second metal layer 42 opposite to the first metal layer 41. The first metal layer 41 fills the recess 113 and contacts the conductive layer 20, enabling conductive connection with the conductive layer 20.
[0063] The second metal layer 42 and the substrate 50 are soldered together by solder 60, and the solder 60 surrounds the protrusion 421. The substrate 50 can be electrically connected to the functional component 12 through the metal bump 40 and the conductive layer 20.
[0064] In the chip 10 packaging structure 100 provided in this embodiment, a protrusion 421 is provided on the second metal layer 42 of the metal bump 40. When the metal bump 40 is soldered to the substrate 50 using solder 60, the solder 60 surrounds the protrusion 421. During the soldering heating process, bubbles inevitably form inside the solder 60. As the bubbles move upward, they tend to move to both sides of the solder 60 due to the obstruction of the protrusion 421, thus escaping from the solder 60. During the manufacturing process, the chip 10 packaging structure 100 provided in this embodiment can significantly reduce the probability of bubbles remaining inside the solder 60, avoid cavities in the solder 60 after soldering, improve the stability of the packaging structure 100, avoid problems such as excessive parasitic resistance, and ensure the performance of the chip 10.
[0065] The packaging structure 100 also includes a protective layer 30, which covers the substrate layer 11 and the functional components 12 disposed on the substrate layer 11, and protects the chip 10.
[0066] A window 31 is provided on the protective layer 30. The window 31 extends through the functional component 12 and the side of the protective layer 30 opposite to the substrate layer 11. The window 31 has a bottom wall located on the functional component 12 and a side wall located on the protective layer 30. A conductive layer 20 covers the bottom wall and side wall of the window 31, and the first metal layer 41 can be electrically connected to the functional component 12 through the conductive layer 20. The conductive layer 20 extends from the window 31 to the side of the protective layer 30 opposite to the chip 10, so that the second metal layer 42 can also contact the conductive layer 20.
[0067] The protective layer 30 can protect the chip 10 and support the conductive layer 20, so that the shape of the conductive layer 20 can be stabilized.
[0068] Other features of the packaging structure 100 in this embodiment can be found in the embodiments of the packaging method described above.
[0069] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
[0070] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application.
Claims
1. A chip packaging method, characterized in that, Includes the following steps: A chip is provided, the chip including a substrate layer and functional components disposed on the substrate layer; A conductive layer is formed, the conductive layer having a first surface and a second surface disposed opposite to each other, the first surface contacting the functional component, and the conductive layer having a recessed portion formed from the second surface; A metal bump is formed, the metal bump having a first metal layer and a second metal layer connected together, at least a portion of the first metal layer filling the recess, the second metal layer protruding from the second surface, and a protrusion forming on the side of the second metal layer opposite to the first metal layer. Provide substrate; The second metal layer is soldered to the substrate using solder, and during soldering, the solder surrounds the protrusion.
2. The packaging method according to claim 1, characterized in that, The step of "forming metal bumps" includes the following steps: A first metal layer is formed, the first metal layer including a connected filling portion and a protruding portion, the filling portion filling the recessed portion, and the protruding portion protruding from the second surface; A second metal layer is formed by depositing material on the side of the protrusion opposite to the filling portion and on the second surface near the protrusion, the protrusion corresponding to the protrusion.
3. The packaging method according to claim 2, characterized in that, The step of "forming the first metal layer" includes the following steps: A first mold layer is formed on the second surface; Remove a portion of the material from the first mold layer to form a first groove communicating with the recess; Material is deposited in the recess and the first groove to form the first metal layer; Remove the first mold layer.
4. The packaging method according to claim 3, characterized in that, The first slot is provided not beyond the recess in the width direction of the chip.
5. The packaging method according to claim 4, characterized in that, The step of "forming a second metal layer" includes the following steps: A second mold layer is formed on the second surface; A portion of the material of the second mold layer is removed to form a second groove, the protrusion being located within the second groove, and the width of the second groove being greater than the width of the protrusion; Material is deposited from the bottom wall of the second slot to form the second metal layer, the bottom wall of the second slot including the protrusion on the side opposite to the filling portion and a portion of the second surface near the protrusion; Remove the second mold layer.
6. The packaging method according to claim 5, characterized in that, In the step of "depositing material in the recess and the first groove to form the first metal layer", the material is deposited using an electroplating process. In the step of "depositing material from the bottom wall of the second groove to form the second metal layer", the material is deposited using an electroplating process.
7. The packaging method according to claim 1, characterized in that, The step of "forming a conductive layer" includes the following steps: A protective layer is formed, which covers the substrate layer and the functional component; A portion of the material of the protective layer is removed to form a window that extends through the functional component and the protective layer to the side opposite to the substrate layer. The window has a bottom wall located on the functional component and a side wall located on the protective layer. A conductive layer is formed, which covers the bottom and side walls of the window and the side of the protective layer opposite to the substrate layer, and the recess is located between the conductive layers covering the bottom and side walls of the window.
8. The packaging method according to claim 5, characterized in that, The second slot is higher than the second metal layer. Before the step of "removing the second mold layer", the encapsulation method further includes the following steps: Material is deposited further within the second groove to form the solder surrounding the protrusion.
9. The packaging method according to claim 8, characterized in that, The encapsulation method further includes the following steps: The solder is shaped so that the side of the solder away from the second metal layer is hemispherical.
10. A chip packaging structure, characterized in that, The packaging structure includes: The chip includes a substrate layer and functional components disposed on the substrate layer; A conductive layer having a first surface and a second surface disposed opposite to each other, the first surface contacting the functional component, and the conductive layer having a recessed portion formed from the second surface; A metal bump having a first metal layer and a second metal layer connected together, at least a portion of the first metal layer filling the recess, the second metal layer protruding from the second surface, and a protrusion forming on the side of the second metal layer opposite to the first metal layer. The substrate, the second metal layer and the substrate are soldered together by solder, the solder surrounding the protrusion.