Packaging structure for protecting metal fuse in chip
By introducing a polyimide (PI) layer to protect the metal fuse during the chip packaging process, the problem of physical damage to the metal fuse by molding compound filler particles is solved, the final test yield is improved and the improvement cost is reduced, while maintaining process compatibility.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SUZHOU LEIGE SEMICON CO LTD
- Filing Date
- 2025-04-24
- Publication Date
- 2026-05-15
AI Technical Summary
During the chip packaging process, metal fuses are susceptible to physical damage from the plastic filler particles, which can lead to poor contact or breakage after packaging, affecting the final test yield.
A polyimide (PI) layer is introduced between the chip and the molding compound as a protective layer. Its high-temperature insulation properties and mechanical stability are used to isolate the metal fuse from the molding compound filler particles and prevent physical damage.
It effectively prevents physical damage to the metal fuse by the plastic sealant filler particles during the packaging process, improves the final test yield, reduces improvement costs, and maintains process compatibility.
Smart Images
Figure CN224250166U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to chip packaging technology, and more particularly to a packaging structure for protecting metal fuses in chips. Background Technology
[0002] In the field of integrated circuits, for products that require adjustment of reference voltage and reference frequency, adjustable resistor structures called trim resistors need to be designed into the chip. These trim resistor structures are layout-designed according to the required circuit performance, and after manufacturing, they form a functional chip. During chip testing, appropriate test procedures are used to selectively burn out the trim resistors. The burned-out structures and modules will not be used in the chip, thus achieving the performance required by the circuit designer by selecting and modifying the trim resistors.
[0003] Adjustable resistors are generally classified into three categories: fuse-type, Zener diode-type, and thin-film resistor laser-adjustable type. Among them, fuse-type adjustable resistors are widely used because the burning technology has relatively simple requirements for process level and testing accuracy, which is conducive to production control and the technology is relatively mature.
[0004] In the semiconductor chip packaging process, such as Figures 1 to 2 As shown, since the chip needs to be filled and wrapped with molding compound, problems such as physical deformation, breakage or poor contact of metal fuses often occur after packaging. The reason for this is that the filler particles (such as silicon dioxide and aluminum oxide) in the molding compound (such as epoxy resin and silicone resin) may be displaced or stressed during curing or subsequent processes, thus causing the above problems.
[0005] Traditional solutions, while improving upon these issues by increasing the spacing between metal fuses or optimizing molding compound formulations, also suffer from problems such as high cost and poor process compatibility. Utility Model Content
[0006] Therefore, the main objective of this utility model is to provide a packaging structure for protecting the metal fuse in a chip, so as to solve the problems mentioned in the background art.
[0007] To achieve the above objectives, according to one aspect of the present invention, a packaging structure for protecting a metal fuse in a chip is provided, comprising: a PI layer covering the surface of the chip, and a molding compound layer covering the chip and the PI layer.
[0008] Preferably, the thickness of the PI layer is 5~10 μm.
[0009] Preferably, the PI layer completely covers the metal fuse and its surrounding area.
[0010] Preferably, the chip comprises any one of a semiconductor wafer or module with an integrated metal fuse.
[0011] The packaging structure of the metal fuse in the protection chip provided by this utility model cleverly incorporates a PI layer between the chip and the molding compound. Utilizing the excellent mechanical properties and chemical stability of polyimide (PI) high-temperature insulating material, it provides sufficient protection for the metal fuse during the packaging process, preventing physical impact from filler particles. This effectively solves the problem of physical damage to the metal fuse caused by molded material filler particles during packaging. Furthermore, since the PI layer coating process can be completed after the metal fuse is formed but before molding, there is no need to modify existing production line equipment or fuse structure, nor to adjust the molding compound formulation. Therefore, the implementation cost is low, the process compatibility is extremely high, and it effectively solves the problem of final test failure caused by metal fuse damage, improving the final test yield. Attached Figure Description
[0012] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:
[0013] Figure 1 This is a cross-sectional structural diagram of an existing solution that directly encapsulates chips using molding compound;
[0014] Figure 2 This is a top view diagram of an existing solution that directly encapsulates chips using molding compound.
[0015] Figure 3 This is a cross-sectional schematic diagram of the packaging structure of the metal fuse in the protection chip of this utility model. Detailed Implementation
[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0017] Therefore, the following detailed description of the embodiments of the present 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 present invention without inventive effort are within the scope of protection of the present invention.
[0018] 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.
[0019] In the description of this utility model, 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 utility model product is in use. They are used only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. The terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.
[0020] 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.
[0021] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "lay out," "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 utility model according to the specific circumstances and in conjunction with existing technology. Furthermore, without conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. One or more of the components shown in the figures may be necessary or not, and the relative positional relationships between the components shown in the figures can be adjusted according to actual needs.
[0022] To address the issue of low final yield rates in existing chip packaging structures, such as... Figure 3 As shown, this utility model provides a packaging structure for protecting the metal fuse in a chip. The example structure includes: a PI layer covering the chip surface, and a plastic encapsulation layer covering the chip and the PI layer.
[0023] Specifically, due to the random distribution of molding compound filler particles, it is difficult to completely avoid impact on the metal fuse (sensitive device). Therefore, this solution introduces a polyimide (PI) covering layer to physically isolate the metal fuse from the molding compound filler, thereby effectively solving the problem of physical damage to the metal fuse caused by the molding compound filler particles during the encapsulation process.
[0024] The reasons are twofold. First, polyimide can operate stably in high-temperature environments of 200℃~300℃ for extended periods, and its short-term tolerance temperature can reach over 400℃, making it suitable for high-temperature processes such as reflow soldering and etching in semiconductor manufacturing. Second, its coefficient of thermal expansion is close to that of silicon wafers, thus reducing the risk of interface delamination caused by thermal stress and significantly improving the reliability of the packaging structure.
[0025] Furthermore, polyimide possesses high abrasion resistance and flexibility, resisting mechanical damage during wafer dicing and grinding processes while buffering external vibration stress. It also exhibits strong resistance to chemical corrosion, such as resistance to acids, alkalis, and organic solvents, thus protecting the wafer from moisture and contaminant penetration. Considering these characteristics, the addition of a PI layer can effectively improve the final test yield of metal fuses after chip packaging.
[0026] In a further preferred embodiment, reference is made to Figure 3 As shown, the polyimide (PI) layer can preferably be formed on the surface of the metal fuse through processes such as spin coating, spraying, or deposition to form a uniform PI layer. After that, it is subjected to thermosetting treatment (such as curing at 250–350°C) to ensure that the PI layer is completely cross-linked, thereby covering the chip surface and forming an insulating protective layer with a thickness of 5~10µm to completely cover the metal fuse and its surrounding area. Then, a molding compound is applied on the PI layer. After curing, the chip encapsulation is completed. This setup can effectively ensure the isolation of the physical influence of filler particles in the molding compound on the metal fuse. At the same time, since the PI layer coating process can be completed after the metal fuse is formed and before molding, it is compatible with existing equipment production lines, with low improvement costs and extremely high process compatibility.
[0027] Furthermore, in other alternative embodiments, the chip may include any of the following: a semiconductor wafer or module with an integrated metal fuse. Therefore, those skilled in the art, based on an understanding of the above examples, can choose to implement the package structure containing such a metal fuse, and thus the solution of this example, according to the actual situation. Therefore, other equivalent alternative embodiments without departing from the inventive concept are all within the scope of this invention.
[0028] In summary, the packaging structure of the metal fuse in the protection chip provided by this utility model cleverly incorporates a PI layer between the chip and the molding compound. This utilizes the excellent mechanical properties and chemical stability of polyimide (PI) high-temperature insulating material to provide sufficient protection for the metal fuse during the packaging process, preventing physical impact from filler particles. This effectively solves the problem of physical damage to the metal fuse caused by molded material filler particles during packaging. Furthermore, since the PI layer coating process can be completed after the metal fuse is formed but before molding, there is no need to modify existing production line equipment or fuse structure, nor is it necessary to adjust the molding compound formulation. Therefore, the implementation cost is low, the process compatibility is extremely high, and the problem of final test failure caused by metal fuse damage is effectively solved, improving the final test yield.
[0029] The preferred embodiments of this utility model disclosed above are merely illustrative of the present utility model. These preferred embodiments do not exhaustively describe all details, nor do they limit the utility model to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
[0030] Furthermore, various different implementation methods of this utility model can be arbitrarily combined, as long as they do not violate the spirit of this utility model, they should also be regarded as the content disclosed by this utility model.
Claims
1. A packaging structure for a metal fuse in a protection chip, characterized in that... include: A chip on which a metal fuse is formed; A PI layer, wherein the PI layer covers at least the surface of the metal fuse of the chip and has a thickness of 5~10μm; A molding compound layer, wherein the molding compound layer covers the chip and the PI layer; The PI layer is used to provide insulation protection for the metal fuse and to isolate the physical influence of the filler particles in the encapsulation layer on the metal fuse.
2. The packaging structure of the metal fuse in the protection chip according to claim 1, characterized in that, The PI layer completely covers the metal fuse and its surrounding area.
3. The packaging structure of the metal fuse in the protection chip according to claim 1, characterized in that, The chip includes any one of a semiconductor wafer or module with an integrated metal fuse.