A very large scale bga package
Patent Information
- Application Number
- CN202522202026.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-17
- Publication Date
- 2026-09-22
- Estimated Expiration
- 2035-10-17
AI Technical Summary
超大尺寸BGA封装产品的一个共同特点是在完成封装制程后产品重量大、翘曲不规律且普遍存在，在产品组装到PCB（Printed Circuit Board，印刷电路板）回流过程中，因为大翘曲导致局部（尤其是封装体的边缘）焊球上的受力过大而引起桥接，导致产品的良率降低
[0014]本申请实施例中，当第一距离大于第二距离时，基板的翘曲程度较高，继而使得基板的波谷部通过焊接件与PCB的接触面积较小，导致焊接件在此位置的压强较大，在此位置设置支撑能力较强的铜核球将基板与PCB连接，能够对基板起到较好的支撑作用，以降低铜核球之间或铜核球和焊球之间因为重量超过自身表面的张力而发生桥接的可能性，以提高封装的良品率，使得本申请的技术方案无需试错，只需根据基板翘曲复杂多变的特性，在波谷部的范围内在基板上植入铜核球，便可避免反复试错导致的产品成本和产品开发周期长等问题。再者，本申请在波谷部范围内植入铜核球的技术方案可以基于成熟的工艺，技术难度较低，使得铜核球的植入可以通过正常的工艺完成，不增加额外的工序环节。此外，本申请的技术方案有针对性地焊接铜核球，节省了基板和PCB组装过程中频繁更换治具以及调整工艺的时间，有利于降低产品的开发周期。综上，本申请的技术方案无论在工艺、材料，还是在开发难度上，均远低于相关技术方案，具有低成本的技术优势。
Smart Images
Figure CN224791089U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of microelectronic chip packaging technology, and in particular to an ultra-large size BGA package. Background Technology
[0002] To meet the ever-increasing computing power and performance demands of fields such as artificial intelligence and high-performance computing, more and more chips, dies, and devices are being integrated into a single package to improve performance, driving the development of BGA (Ball Grid Array) packages for such products towards larger sizes. For example, in 2022, a product integrating 47 dies with a package size of 77.5mm × 62.5mm was released overseas; in 2024, a product integrating more than 10 chips with a package size of 85mm × 85mm and a product integrating more than 10 chips with a package size of 120mm × 120mm (currently the largest BGA product in terms of package size) were released. In 2024, a product integrating 4 chips with a package size of 102mm × 102mm was released domestically. A common characteristic of ultra-large BGA packaged products is that they are heavy and have irregular and widespread warpage after the packaging process is completed. During the reflow process of the product assembly to PCB (Printed Circuit Board), the large warpage causes excessive stress on the solder balls in some areas (especially the edges of the package), which leads to bridging and reduces the yield of the product.
[0003] To address these issues, packaging companies strive to reduce warpage, especially deformation during high-temperature processes. However, due to the ultra-large size of the products and the mismatch in thermal expansion coefficients between the chip and the organic substrate, warpage control for ultra-large products remains an industry challenge. The core technology concept involves matching the warpage of the PCB and the package at the surface mount reflow stage to improve bridging. This typically involves customizing PCB fixtures to reduce warpage at high temperatures, using low-temperature solder paste / balls to lower reflow temperatures, or adding shims to the PCB. While these methods can reduce the likelihood of bridging to some extent, they require repeated trial and error, resulting in high costs and long lead times. Furthermore, ultra-large packaged products are currently rare, and mature solutions are also scarce. Utility Model Content
[0004] This invention provides an ultra-large BGA package, the purpose of which is to reduce the possibility of high product costs and long product development cycles caused by repeated trial and error.
[0005] To achieve the above objectives, this utility model provides an ultra-large size BGA package, comprising:
[0006] The substrate is warped, forming concave troughs and convex crests. When the substrate is flat, the plane on which the substrate is located is the first reference plane, the plane passing through the highest point of the crest and parallel to the first reference plane is the second reference plane, and the plane passing through the lowest point of the trough and parallel to the first reference plane is the third reference plane. The distance between the second reference plane and the third reference plane is the warping amplitude.
[0007] The chip is multiple, and all of the chips are electrically connected to the substrate.
[0008] A solder joint is disposed on the side of the substrate opposite to the chip. The solder joint includes solder balls and copper core balls. When the warpage amplitude is greater than a threshold, the copper core balls are disposed within the range of the trough and the solder balls are disposed outside the range of the trough. When the warpage amplitude is less than or equal to the threshold, either the copper core balls or the solder balls are disposed within the range of the trough and the solder balls are disposed outside the range of the trough.
[0009] In one embodiment, when the substrate is in a warped state, the substrate forms a wave shape, the number of wave troughs is multiple, the number of copper core balls is multiple, and the multiple copper core balls are respectively disposed in the corresponding wave troughs.
[0010] In one embodiment, when the substrate is in a warped state, the substrate forms a convex warp with four apex corners warped upwards, and the copper core ball is located at the center of the substrate.
[0011] In one embodiment, when the substrate is in a warped state, the substrate forms a concave warp with the center position warped upwards, and the copper core ball is located in the circumferential direction of the substrate.
[0012] In one embodiment, the package further includes a reinforcing ring disposed on the side of the substrate opposite to the solder joint, the reinforcing ring being circumferentially disposed around the substrate, and the reinforcing ring being made of copper or stainless steel.
[0013] The above-mentioned solution of this utility model has the following beneficial effects:
[0014] In this embodiment, when the first distance is greater than the second distance, the substrate warps more significantly, resulting in a smaller contact area between the substrate's trough and the PCB via the solder joint. This leads to higher pressure on the solder joint at this location. Placing a strong copper core ball at this location to connect the substrate and PCB provides better support, reducing the possibility of bridging between copper core balls or between copper core balls and solder balls due to their weight exceeding their surface tension. This improves the package yield. The technical solution of this application eliminates the need for trial and error; it only requires implanting copper core balls within the trough area of the substrate, taking into account the complex and variable warping characteristics. This avoids the problems of increased product costs and long product development cycles caused by repeated trial and error. Furthermore, the technical solution of implanting copper core balls within the trough area can be based on mature processes with low technical difficulty, allowing the implantation of copper core balls to be completed through normal processes without adding extra steps. In addition, the targeted soldering of copper core balls in this application saves time spent on frequent fixture changes and process adjustments during substrate and PCB assembly, thus reducing the product development cycle. In summary, the technical solution of this application is far inferior to related technical solutions in terms of process, materials, and development difficulty, and has the technical advantage of low cost.
[0015] Other beneficial effects of this invention will be described in detail in the following detailed description section. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the assembly of the package and the PCB in one embodiment of the present invention;
[0017] Figure 2 This is a schematic diagram of the structure of the copper core sphere in one embodiment of the present invention;
[0018] Figure 3 This is a schematic diagram of the assembly of a substrate and a chip in a warped state according to one embodiment of the present invention.
[0019] Figure 4 In one embodiment of this utility model, when the substrate is in the form of Figure 1 The diagram shows the structural arrangement of the welded components on the substrate when the substrate is in a warped state.
[0020] Figure 5 This is a schematic diagram of the structure of the package in a warped state according to another embodiment of the present invention;
[0021] Figure 6 In one embodiment of this utility model, when the substrate is in the form of Figure 5 The diagram shows the structural arrangement of the welded components on the substrate when the substrate is in a warped state.
[0022] Figure 7This is a schematic diagram of the structure of the package in a warped state according to another embodiment of the present invention;
[0023] Figure 8 In one embodiment of this utility model, when the substrate is in the form of Figure 7 The diagram shows the structural arrangement of the welded components on the substrate when the substrate is in a warped state.
[0024] Figure 9 This is a measurement result diagram of a substrate in a warped state according to one embodiment of the present invention.
[0025] [Explanation of Labels in the Attached Images]
[0026] 100. Package; 101. First reference plane; 102. Second reference plane; 103. Third reference plane; 1. Substrate; 11. Valley; 12. Peak; 2. Chip; 3. Solder; 31. Copper core ball; 311. Copper ball core; 312. Solder; 32. Solder ball; 4. Reinforcing ring; 200. PCB. Detailed Implementation
[0027] To make the technical problems, solutions, and advantages of this utility model clearer, a detailed description will be provided below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.
[0028] 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., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are 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, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a locking 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 based on the specific circumstances.
[0030] This application addresses the problem of warping easily occurring on the substrate 1 of an ultra-large size package 100 by providing an ultra-large size BGA package 100. For details, please refer to... Figure 1 The package 100 of this application includes a substrate 1, a chip 2, and a solder joint 3.
[0031] Please see Figure 1 The larger substrate 1 is prone to deformation due to temperature changes, resulting in a warped state with multiple peaks and valleys, giving the substrate 1 concave valleys 11 and convex peaks 12. When the substrate 1 is flat, the plane containing the substrate 1 is the first reference plane 101. Please refer to... Figure 3 The plane passing through the highest point of the crest 12 and parallel to the first reference plane 101 is the second reference plane 102, and the plane passing through the lowest point of the trough 11 and parallel to the first reference plane 101 is the third reference plane 103. The distance between the second reference plane 102 and the third reference plane 103 is the warpage amplitude. It should be noted that the dimensions of the substrate 1 in the length and width directions are much larger than the thickness of the substrate 1, making the thickness of the substrate 1 negligible. For example, Figure 3 The sum of distances h1 and h2 represents the warpage amplitude. For example, the warpage amplitude of a warped substrate 1 can be measured using methods such as a shadow moire (warpage meter) or DIC (digital image correlation). The temperature of substrate 1 can vary from 25°C to 260°C. This is a mature technology in the industry, and its measurement principle will not be elaborated here. For example, Figure 9 The results of measuring the warp amplitude of substrate 1 in a warped state using shadow moire are shown.
[0032] There are multiple chips 2, and all of the chips 2 are electrically connected to the substrate 1.
[0033] The solder joint 3 is disposed on the side of the substrate 1 opposite to the chip 2, so as to electrically connect the substrate 1 to the PCB 200. The solder joint 3 includes solder balls 32 and copper core balls 31. For example, please refer to Figure 2The copper core ball 31 includes a copper core 311 and solder 312, with the solder 312 covering the outer periphery of the copper core 311. Compared to ordinary solder balls 32, the copper core 311 within the copper core ball 31 is more rigid, enabling the copper core ball 31 to provide better support for the substrate 1. This reduces the possibility of bridging between copper core balls 31 or between copper core balls 31 and solder balls 32 due to their weight exceeding their surface tension, thereby improving the yield of the package 100. On the other hand, by setting the diameter of the copper core ball 31, the contact height between the copper core ball 31 and the PCB 200 can be adjusted to ensure wetting and prevent open circuits in the copper core ball 31. For example, the material of the solder ball 32 can be tin-lead alloy solder or lead-free solder. For example, the diameter of the copper core ball 31 can be selected according to the warpage amplitude. When the warpage amplitude exceeds a threshold, the warpage of substrate 1 becomes significant. Consequently, the contact area between the trough portion 11 of substrate 1 and the PCB 200 via the solder joint 3 is small, resulting in higher pressure on the solder joint 3 at this location. Therefore, the solder joint 3 in this area is configured as a copper core ball 31 with stronger support capacity. That is, the copper core ball 31 is located within the trough portion 11. The solder joint 3 at other locations can be configured as solder balls 32, that is, the solder balls 32 are located outside the trough portion 11. It should be noted that... Figure 1 The middle represents the degree of warpage of the protruding substrate 1. The degree of warpage of substrate 1 is amplified, making... Figure 1 The solder ball 32 is not connected to the PCB 200. In practice, the solder ball 32 at this position remains connected to the PCB 200. When the warpage amplitude is less than or equal to the threshold, the warpage of the substrate 1 is relatively low, but the contact area between the trough 11 of the substrate 1 and the PCB 200 through the solder joint 3 is still small, resulting in a relatively high pressure on the solder joint 3 at this position. A copper core ball 31 with strong support capacity is set at this position to connect the substrate 1 and the PCB 200, that is, the copper core ball 31 is set within the range of the trough 11. It can be understood that the solder ball 32 can also be set within the range of the trough 11. Under this condition, the solder ball 32 is still set outside the range of the trough 11.
[0034] In this embodiment, when the warpage amplitude exceeds a threshold, the warpage of substrate 1 is high, resulting in a smaller contact area between the trough portion 11 of substrate 1 and PCB 200 via solder joint 3. This leads to higher pressure on solder joint 3 at this location. Placing a copper core ball 31 with strong support at this location connects substrate 1 to PCB 200, providing better support for substrate 1. This reduces the possibility of bridging between copper core balls 31 or between copper core balls 31 and solder balls 32 due to their weight exceeding their surface tension, thereby improving the yield of package 100. This technical solution eliminates the need for trial and error; it simply involves implanting copper core balls 31 within the trough portion 11 of substrate 1, taking into account the complex and variable warpage characteristics of substrate 1. This avoids problems such as increased product costs and long product development cycles caused by repeated trial and error. Furthermore, the technical solution of implanting copper core balls 31 within the trough portion 11 of this application can be based on mature processes with low technical difficulty, allowing the implantation of copper core balls 31 to be completed through normal processes without adding additional steps. Furthermore, the technical solution of this application specifically welds the copper core balls 31, saving time spent on frequent fixture changes and process adjustments during the assembly of the substrate 1 and PCB 200, which helps to shorten the product development cycle. In summary, the technical solution of this application is far inferior to related technical solutions in terms of process, materials, and development difficulty, and has a low-cost technical advantage.
[0035] In one embodiment, please refer to Figure 1 and Figure 4 When the substrate 1 is warped, it forms a wave-like shape with multiple troughs 11 and multiple copper core balls 31. Each copper core ball 31 is disposed within a corresponding trough 11, ensuring that all troughs 11 are connected to the PCB 200 via the copper core balls 31. This reduces the possibility of bridging between copper core balls 31 or between copper core balls 31 and solder balls 32 due to their weight exceeding surface tension, thereby improving the yield of the package 100. This approach eliminates the need for trial and error; by simply embedding copper core balls 31 within the troughs 11 based on the complex and variable warping characteristics of the substrate 1, problems such as increased product costs and long product development cycles caused by repeated trial and error can be avoided. For example, Figure 4 The arrangement of the copper core balls 31 is shown when the substrate 1 has a relatively complex warped shape. The substrate 1 is wavy in both mutually perpendicular directions of the first reference plane 101, so that the substrate 1 has multiple troughs 11.
[0036] In one embodiment, please refer to Figure 5 and Figure 6When the substrate 1 is in a warped state, the substrate 1 is formed as a convex warp with four apex corners warped upwards, so that the trough portion 11 is located at the center of the substrate 1 and the copper core ball 31 is located at the center of the substrate 1, so that the trough portion 11 can be connected to the PCB 200 through the copper core ball 31, thereby reducing the possibility of bridging between the copper core balls 31 or between the copper core balls 31 and the solder balls 32 due to the weight exceeding the tension of their own surfaces, thereby improving the yield of the package 100.
[0037] In one embodiment, please refer to Figure 7 and Figure 8 When the substrate 1 is in a warped state, the substrate 1 is formed as a concave warp with the center warped upward, so that the trough portion 11 surrounds the circumference of the substrate 1, and the copper core ball 31 is located in the circumference of the substrate 1, so that the trough portion 11 can be connected to the PCB 200 through the copper core ball 31, thereby reducing the possibility of bridging between the copper core balls 31 or between the copper core balls 31 and the solder balls 32 due to the weight exceeding the tension of their own surfaces, thereby improving the yield of the package 100.
[0038] In one embodiment, please refer to Figure 1 , Figure 3 , Figure 5 and Figure 7 The package 100 also includes a reinforcing ring 4, which is disposed on the side of the substrate 1 away from the solder joint 3. The reinforcing ring 4 is disposed around the substrate 1 in the circumferential direction. The material of the reinforcing ring 4 is configured to be copper or stainless steel to increase the rigidity of the substrate 1, thereby helping to reduce the possibility of the substrate 1 warping during temperature changes.
[0039] The above are preferred embodiments of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.
Claims
1. An ultra-large BGA package, characterized in that, include: The substrate is warped, forming concave troughs and convex crests. When the substrate is flat, the plane on which the substrate is located is the first reference plane, the plane passing through the highest point of the crest and parallel to the first reference plane is the second reference plane, and the plane passing through the lowest point of the trough and parallel to the first reference plane is the third reference plane. The distance between the second reference plane and the third reference plane is the warping amplitude. The chip is multiple, and all of the chips are electrically connected to the substrate. A solder joint is disposed on the side of the substrate opposite to the chip. The solder joint includes solder balls and copper core balls. When the warpage amplitude is greater than a threshold, the copper core balls are disposed within the range of the trough and the solder balls are disposed outside the range of the trough. When the warpage amplitude is less than or equal to the threshold, either the copper core balls or the solder balls are disposed within the range of the trough and the solder balls are disposed outside the range of the trough.
2. The ultra-large size BGA package according to claim 1, characterized in that, When the substrate is in a warped state, the substrate forms a wave shape, and there are multiple troughs and multiple copper core balls, with each copper core ball being disposed in a corresponding trough.
3. The ultra-large size BGA package according to claim 1, characterized in that, When the substrate is in a warped state, the substrate forms a convex warp with four apex corners warped upwards, and the copper core ball is located at the center of the substrate.
4. The ultra-large size BGA package according to claim 1, characterized in that, When the substrate is in a warped state, the substrate forms a concave warp with the center position warped upwards, and the copper core ball is located in the circumferential direction of the substrate.
5. The ultra-large size BGA package according to claim 1, characterized in that, The package further includes a reinforcing ring disposed on the side of the substrate away from the solder joint, the reinforcing ring being arranged circumferentially around the substrate, and the material of the reinforcing ring being configured as copper or stainless steel.