Substrate for packaging redistribution layer and manufacturing method thereof
By using glass, ceramic, or high-temperature polymer substrate materials and selective laser etching technology to form a redistribution layer with rounded corners, the high cost and complexity of traditional redistribution layers are solved, achieving high-density interconnection and efficient heat dissipation.
Patent Information
- Application Number
- CN202411216747.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-07-03
- Filing Date
- 2024-09-02
- Publication Date
- 2026-01-13
AI Technical Summary
In existing semiconductor packaging technologies, traditional redistribution layer formation methods face challenges such as high cost, complexity, low thermal management efficiency, and high-density interconnection. In particular, redistribution layers formed on nonwoven or polyimide substrates present challenges related to resistance points and fine line/spacing resolution.
Glass, ceramic, or high-temperature polymers are used as substrate materials. Selective laser etching and 3D printing technologies are combined to form a redistribution layer with rounded corners, and conductive adhesives such as copper or silver paste are used for filling. The manufacturing process includes an annealing step to cure the conductive adhesive.
It improves electrical and thermal performance, simplifies the manufacturing process, reduces resistance points, enables high-density interconnection and signal integrity, and meets the high-performance requirements of modern electronic devices.
Smart Images
Figure CN121335570A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present invention relates to semiconductor packaging technology, and more particularly, to a substrate for packaging redistribution layers (RDL) in semiconductor devices and a method of manufacturing the same. BACKGROUND
[0002] Semiconductor devices are becoming increasingly complex, requiring efficient packaging solutions that can accommodate high-density interconnects, while also managing the demands of modern electronic devices for thermal and electrical performance. Conventional packaging techniques, such as flip-chip and wire-bonding, have reached their limits in terms of scalability and performance. Fan-Out Wafer Level Packaging (FOWLP) has emerged as a promising alternative, as it offers higher I / O density and improved thermal characteristics. However, conventional methods of forming redistribution layers involve the stacking of insulating and conductive layers, which are costly and complex, especially for small batch production or diverse product portfolios.
[0003] Typically, redistribution layers in these packaging techniques are formed on substrates such as non-woven cloth or polyimide. These materials have certain limitations in terms of heat dissipation and electrical performance. Furthermore, standard methods of forming redistribution layers involve abrupt right-angle turns, which can create resistance points, hinder the filling capacity of conductive materials, and result in inefficient thermal management. Additionally, these substrates and methods present challenges in achieving the fine line / pitch resolution required for high-density interconnects.
[0004] Therefore, there is a need to develop a packaging technology that overcomes the limitations of conventional substrates and redistribution layer formation methods. A solution that can accommodate high-density interconnects and improve thermal and electrical performance, while also simplifying the manufacturing process, would greatly benefit the semiconductor industry. SUMMARY
[0005] To address the aforementioned problems, it is an object of the present invention to provide a substrate for packaging redistribution layers and a method of manufacturing the same.
[0006] The present invention addresses the aforementioned challenges by providing a substrate for packaging redistribution layers that incorporates novel materials and designs to enhance electrical and thermal performance and simplify the manufacturing process. The substrate utilizes materials such as glass, ceramic, or high-temperature polymers, which offer superior thermal properties compared to conventional materials. The redistribution layer is filled with conductive pastes, such as copper or silver paste, which are selected for their excellent electrical conductivity and compatibility with the substrate material.
[0007] One key innovation of the present invention is the design of the redistribution layer, which has a rounded corner at the turn of the line, which facilitates a smooth structure at the turn. This design significantly reduces the resistance points and allows smoother filling of conductive material. The angle between the extended parts of the redistribution layer is set between 90 to 180 degrees, optimizing the electrical performance and making manufacturing easier.
[0008] The present invention also includes a method of manufacturing the substrate, which utilizes advanced techniques such as selective laser induced etching (SLE) and 3D printing technology to form the redistribution via with the required rounded corner. These techniques enable precise control of the via geometry and can be applied to various substrate materials. In addition, the method includes a step of annealing the substrate to solidify the conductive paste, ensuring the robustness of the finished product.
[0009] In summary, the present invention provides a substrate and manufacturing method that offers enhanced performance, reduced complexity, and increased adaptability for high-density semiconductor packaging applications.
[0010] To make the above objects, features and advantages of the present invention more obvious and easy to understand, the following will be described in detail with examples and in conjunction with the accompanying drawings. It should be noted that the components in the accompanying drawings are only schematic and not drawn according to the actual proportions of the components. BRIEF DESCRIPTION OF DRAWINGS
[0011] Figure 1 An embodiment of the substrate of the present invention is shown;
[0012] Figure 2 An enlarged schematic view of the redistribution layer of Figure 1 is shown;
[0013] Figure 3 A manufacturing process of an embodiment of the substrate of the present invention is shown;
[0014] Figure 4 Another embodiment of the substrate of the present invention is shown;
[0015] Figure 5 An enlarged schematic view of the redistribution layer of Figure 4 is shown. DETAILED DESCRIPTION
[0016] Please refer to Figure 1 and Figure 2 , Figure 1 An embodiment of the substrate of the present invention is shown, Figure 2 An enlarged schematic view of the redistribution layer of Figure 1FIG. 6 is a magnified schematic view of the redistribution layer of FIG. 5. The present embodiment introduces a novel substrate 100 for encapsulating the redistribution layer 110, which includes a first surface 102, a second surface 104, and the redistribution layer 110. The material of the substrate 100 is required to use glass, ceramic, or high-temperature polymer as the main material of the substrate. Among them, glass has excellent thermal stability and insulation performance, and compared with the traditional substrate, it provides superior heat dissipation performance. In addition, the inherent rigidity and dimensional stability of glass help to improve the mechanical strength of the semiconductor package. Ceramic has high thermal conductivity and good insulation capacity, and can withstand high temperature, and its chemical stability and mechanical strength further improve the durability and life of the semiconductor package. The substrate made of high-temperature polymer can withstand high temperature without degradation, and has the advantages of light weight and complex shape. In the present embodiment, since the material of the substrate 100 is selected from the group of glass, ceramic, and high-temperature polymer, these materials have high thermal conductivity, thereby improving the heat dissipation capacity of the substrate 100.
[0017] The redistribution layer 110 is mainly used for electrically connecting the wafer and the external circuit in the semiconductor package. In the present embodiment, each redistribution of the redistribution layer 110 includes a first redistribution 112 and a second redistribution 114. Among them, the first end point 1122 of the first redistribution 112 is connected with the electronic element contact pad 130 of the first surface 102 of the substrate 100, and extends outwardly via the first extension part 1124, and ends at the second end point 1126. Among them, the second end point 1126 can serve as the starting point for connecting with the second redistribution 114. The second redistribution 114 is electrically connected with the second end point 1126 of the first redistribution 112 via the third end point 1142, and the second redistribution 114 further extends the path to the printed circuit board contact pad 140 on the second surface 104 of the substrate 100 via the second extension part 1144, that is, the fourth end point 1146 of the second redistribution 114 is connected with the printed circuit board contact pad 140. In the present embodiment, the cross-sectional area of the printed circuit board contact pad 140 is larger than the cross-sectional area of the electronic element contact pad 130, and the cross-section of the fourth end point 1146 of the second redistribution 114 is elliptical.
[0018] It is noted that the redistribution layer 110 of the present embodiment features a rounded corner at the turn between the redistribution lines. That is, the angle between the first extension 1124 of the first redistribution line 112 and the second extension 1144 of the second redistribution line 114 is between 90 and 180 degrees. This rounded corner feature avoids stress concentration and facilitates the flow of conductive material in the redistribution layer 110 during the fabrication of the substrate 100, thereby improving the reliability of the electrical connections and achieving the advantages of minimizing signal loss and ensuring high-speed signal transmission. During the process of filling the redistribution layer 110 with conductive material such as conductive paste, the rounded corner facilitates more uniform and efficient flow of the conductive material. This ensures complete filling without air gaps or voids, thereby achieving better electrical connections in the redistribution layer 110. In addition, the rounded corner provides a smoother turn to minimize reflections and impedance discontinuities on the signal path. This improvement is important for maintaining signal integrity, especially at higher frequencies where signal attenuation can severely affect device performance.
[0019] In the following, the fabrication process of the substrate will be described in detail. Please refer to Figure 3 , Figure 3 The fabrication process of one embodiment of the substrate of the present application is shown. First, step S110 is performed to provide a substrate 100 for the redistribution layer. Those skilled in the art select the substrate 100 according to the required performance and the type of material, such as glass, ceramic or high-temperature polymer. Next, step S120 is performed to form a plurality of redistribution channels in the substrate 100, wherein the redistribution channels are formed with a rounded corner at the turn to form a smooth structure. In the present embodiment, the redistribution channels are formed by selective laser etching. Selective laser etching works by focusing a high-power laser light at a specific location of a transparent material substrate, the laser light having sufficient intensity to change the structure of the material at the focal point without significantly affecting the surrounding material, and then selectively removing the changed material in a subsequent etching step.
[0020] In other embodiments, steps S110 and S120 described above can be combined into one step, i.e. using 3D printing technology. In this way, the redistribution channels can be formed at the same time as the substrate 100 is formed.
[0021] Next, step S130 is performed, filling the redistribution channels with a conductive material (e.g., conductive adhesive) to form the redistribution layer 110. In this embodiment, the conductive adhesive can be copper paste or silver paste. Copper paste has low impedance, high thermal conductivity, and good cost-effectiveness. Silver paste has the lowest impedance among all metal pastes, making it ideal for applications requiring minimal signal loss. Furthermore, filling the redistribution channels can be mainly divided into two steps. First, the redistribution channels are evacuated, which helps remove air from the channels and prevents air pockets from forming during the filling process. Next, the conductive adhesive is injected into the redistribution channels under controlled pressure. The pressure is adjusted according to the viscosity of the conductive adhesive and the characteristics of the redistribution channels to achieve complete and uniform filling.
[0022] After filling with conductive adhesive, step S140 is performed to anneal the redistribution layer substrate 100. This step involves heating the substrate 100 to a specific temperature for a predetermined time to allow the conductive adhesive to cure within the redistribution channels. The annealing conditions are optimized based on the type of conductive adhesive used and the substrate material to enhance the adhesive strength and reduce the conductive resistance.
[0023] Next, step S150 is performed to form electronic component contact pads 130 on the first surface 102 of the redistribution layer substrate 100. These electronic component contact pads 130 are where semiconductor devices will be connected. Then, step S160 is performed to form a plurality of printed circuit board contact pads 140 on the second surface 104 of the redistribution layer substrate 100. These printed circuit board contact pads 140 are to be matched with contact pads on the printed circuit board of the test device to ensure reliable electrical connection.
[0024] After completing the above steps, the fabrication of the redistribution layer substrate 100 of this embodiment is essentially complete. However, those skilled in the art can continue to perform quality control and functional testing. For example, techniques such as microscopy, electrical testing, and thermal analysis can be used to evaluate the quality and function of the redistribution layer substrate 100 and the redistribution layer 110.
[0025] Please refer to Figure 4 and Figure 5 , Figure 4 The illustration shows another embodiment of the substrate of the present invention. Figure 5 The drawing is shown as Figure 4 An enlarged schematic diagram of the redistribution layer. Compared to Figure 1In the illustrated embodiment, each redistribution layer 210 of this embodiment includes an additional third redistribution 116. In the substrate 200 of this embodiment, the third redistribution 116 is connected to the second redistribution 114. The fifth endpoint 1162 of the third redistribution 116 is connected to the fourth endpoint 1146 of the second redistribution 114, and the third extension portion 1164 of the third redistribution 116 further extends the circuit. The angle between the second extension portion 1144 of the second redistribution 114 and the third extension portion 1164 of the third redistribution 116 is between 90 and 180 degrees, and the fifth endpoint 1166 of the third redistribution 116 is connected to the printed circuit board contact pad 140. Figure 1 Similar to the previous embodiment, this embodiment also features rounded corners at line bends, which promotes a smooth structure at the bends. This design significantly reduces resistance points and allows for more efficient filling of conductive material.
[0026] To explain in detail the technical content, structural features, objectives, and effects of the technical solution, the following detailed description is provided in conjunction with specific embodiments and accompanying drawings.
[0027] The above embodiments are merely illustrative examples for ease of explanation. Although they may be modified by those skilled in the art, they will not depart from the scope of protection intended in the claims.
Claims
1. A substrate for encapsulating a redistribution layer, characterized in that, include: A first surface and a second surface, the first surface and the second surface being opposite to each other; Multiple electronic component contact pads are disposed on the first surface; Multiple first wirings, each first wiring having a first endpoint, a first extension portion and a second endpoint, wherein the first endpoint is electrically connected to the electronic component contact pad; Multiple second-level wirings, each second-level wiring having a third endpoint, a second extension portion and a fourth endpoint, the third endpoint being electrically connected to the second endpoint of the first-level wiring; Multiple printed circuit board contact pads are located on the second surface of the substrate, and the printed circuit board contact pads are electrically connected to the fourth terminal of the second rewiring. The connection between the first and second overlays includes a rounded corner to facilitate a smooth transition between them.
2. The substrate according to claim 1, characterized in that, The angle between the first extension of the first rewiring and the second extension of the second rewiring is between 90 and 180 degrees.
3. The substrate according to claim 1, characterized in that, The cross-sectional area of the printed circuit board contact pad is larger than that of the electronic component contact pad.
4. The substrate according to claim 1, characterized in that, It further includes a third wiring having a fifth endpoint, a third extension, and a sixth endpoint, wherein the fifth endpoint is connected to the fourth endpoint of the second wiring, and the sixth endpoint is electrically connected to the printed circuit board contact pad.
5. The substrate according to claim 4, characterized in that, The angle between the second extension of the second rewiring and the third extension of the third rewiring is between 90 and 180 degrees.
6. The substrate according to claim 1, characterized in that, The substrate is made of glass, ceramic or high-temperature polymer.
7. The substrate according to claim 1, characterized in that, The first and second layers of wiring are filled with conductive adhesive.
8. The substrate according to claim 7, characterized in that, The conductive adhesive is selected from the group consisting of copper adhesive and silver adhesive.
9. A method for manufacturing a substrate for encapsulating a redistribution layer, characterized in that, include: Provide a substrate for a redistribution layer; Multiple redistribution channels are formed in the substrate, wherein the redistribution channels form a smooth structure with rounded corners at the turning points. The redistribution channel is filled with conductive material.
10. The manufacturing method according to claim 9, characterized in that, The conductive material is a conductive adhesive.
11. The manufacturing method according to claim 10, characterized in that, Further includes: The substrate is annealed to cure the conductive adhesive.
12. The manufacturing method according to claim 9, characterized in that, Further includes: Multiple electronic component contact pads are formed on the first surface of the substrate; A plurality of printed circuit board contact pads are formed on the second surface of the substrate; Wherein, the cross-sectional area of the electronic component contact pad is smaller than the cross-sectional area of the printed circuit board contact pad.
13. The manufacturing method according to claim 9, characterized in that, The rewiring channels are formed using selective laser etching technology.
14. The manufacturing method according to claim 9, characterized in that, The rewire channel is formed using 3D printing technology.
15. The manufacturing method according to claim 9, characterized in that, The substrate is made of glass, ceramic, high-temperature polymer, or a combination thereof.