High-copper thick-copper pillar process package substrate structure and manufacturing method thereof

Abstract

The application discloses a high-copper thick-copper-column packaging substrate structure and a manufacturing method thereof, and relates to the technical field of packaging substrates. The method comprises the following steps: preparing a carrier substrate; manufacturing a first circuit on the surface of the carrier substrate; manufacturing a first copper column on the surface of the first circuit; pressing a first dielectric layer on the surface of the carrier substrate; manufacturing a second circuit on the surface of the first copper column; removing the carrier substrate to obtain a first substrate; manufacturing a first thickened circuit at the bottom of the first circuit; manufacturing a second thickened circuit on the surface and the peripheral side of the second circuit; manufacturing a second copper column on the surface of the first thickened circuit and manufacturing a third copper column on the surface of the second thickened circuit; pressing a second dielectric layer on the first surface of the first dielectric layer; pressing a third dielectric layer on the second surface of the first dielectric layer; manufacturing a third circuit on the surface of the second copper column and manufacturing a fourth circuit on the surface of the third copper column to obtain a packaging substrate. The method can manufacture high-copper thick circuits and meet the manufacturing requirements of fine circuits.

Description

Technical Field

[0001] This invention relates to the field of packaging substrate technology, and in particular to a high-copper, thick-copper pillar process packaging substrate structure and its manufacturing method. Background Technology

[0002] As chip power consumption continues to rise, traditional thin copper wiring structures can no longer meet the demands of high current transmission and efficient heat dissipation, resulting in performance and reliability bottlenecks due to high conduction losses and excessive thermal resistance. Existing thickness enhancement technologies often present a trade-off between process complexity, circuit fineness, and interlayer bonding reliability, such as difficulties in controlling plating uniformity and reduced pattern transfer accuracy. The market has an urgent need for packaging substrates that combine high current capacity, excellent thermal management, and stable interconnect performance, driving the continuous evolution of high conductor thickness manufacturing processes and material systems. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a high-copper-thickness copper pillar process packaging substrate structure and its fabrication method, which can fabricate high-copper-thickness circuits to meet the requirements of fine circuit fabrication.

[0004] In a first aspect, a method for fabricating a high-copper, thick-copper pillar process packaging substrate structure according to an embodiment of the present invention includes: Prepare the carrier substrate; A first circuit is fabricated on the surface of the carrier substrate; A first copper pillar is fabricated on the surface of the first line; A first dielectric layer is laminated onto the surface of the carrier substrate, such that the first dielectric layer covers the first circuit and the first copper pillar, and the surface of the first dielectric layer is flush with the surface of the first copper pillar. A second circuit is fabricated on the surface of the first copper pillar; Remove the carrier substrate to obtain a first substrate including the first line, the first copper pillar and the second line; A first thickened line is made at the bottom of the first line; A second thickened line is made surrounding the second line on the surface and around the second line; A second copper pillar is fabricated on the surface of the first thickened circuit, and a third copper pillar is fabricated on the surface of the second thickened circuit. A second dielectric layer is pressed onto the first surface of the first dielectric layer, so that the second dielectric layer covers the first thickened circuit and the second copper pillar, and the surface of the second dielectric layer is flush with the surface of the second copper pillar. A third dielectric layer is pressed onto the second surface of the first dielectric layer, so that the third dielectric layer covers the second circuit, the second thickened circuit and the third copper pillar, and the surface of the third dielectric layer is flush with the surface of the third copper pillar; A third circuit is fabricated on the surface of the second copper pillar, and a fourth circuit is fabricated on the surface of the third copper pillar to obtain a packaging substrate.

[0005] According to some embodiments of the present invention, the carrier substrate includes a support layer, a carrier copper foil is disposed on at least one side of the support layer, a seed layer copper foil is disposed on the surface of the carrier copper foil, and the first line is disposed on the surface of the seed layer copper foil.

[0006] According to some embodiments of the present invention, the fabrication of the first circuit on the surface of the carrier substrate includes: A first photosensitive dry film is disposed on the surface of the copper foil in the seed layer; The first photosensitive dry film is exposed and developed to form a first pattern corresponding to the first circuit. The first line is formed by electroplating at the first pattern; The process of fabricating a first copper pillar on the surface of the first line includes: A second photosensitive dry film is disposed on the surface of the first photosensitive dry film, and the second photosensitive dry film is exposed and developed to form a second pattern corresponding to the first copper pillar. The first copper pillar is formed by electroplating at the second pattern. Remove the first photosensitive dry film and the second photosensitive dry film.

[0007] According to some embodiments of the present invention, fabricating a second circuit on the surface of the first copper pillar includes: A first seed layer is formed on the surface of the first medium layer; A third photosensitive dry film is disposed on the surface of the first seed layer; The third photosensitive dry film is exposed and developed to form a third pattern corresponding to the second circuit; A second circuit is formed by electroplating at the third pattern; Remove the third photosensitive dry film.

[0008] According to some embodiments of the present invention, removing the carrier substrate to obtain a first substrate including the first line, the first copper pillar, and the second line includes: Remove the support layer and the carrier copper foil, and retain the seed layer copper foil; A first substrate comprising the first line, the first copper pillar, the second line, and the seed layer copper foil is obtained.

[0009] According to some embodiments of the present invention, the step of fabricating a first thickened circuit at the bottom of the first circuit includes: A thickened metal layer is formed by electroplating on the side of the seed layer copper foil away from the first line; A fourth photosensitive dry film is disposed on the surface of the thickened metal layer; The fourth photosensitive dry film is exposed and developed to protect the position of the thickened metal layer corresponding to the first thickened circuit, while exposing the remaining position of the thickened metal layer. The thickened metal layer and the corresponding seed layer copper foil are etched to expose the thickened metal layer; Remove the fourth photosensitive dry film to obtain the first thickened circuit.

[0010] According to some embodiments of the present invention, the step of fabricating a third circuit on the surface of the second copper pillar and fabricating a fourth circuit on the surface of the third copper pillar includes: A second seed layer is disposed on the surface of the second medium layer, and a third seed layer is disposed on the surface of the third medium layer; A fifth photosensitive dry film is disposed on the surface of the second seed layer, and a sixth photosensitive dry film is disposed on the surface of the third seed layer; The fifth photosensitive dry film is exposed and developed to form a fourth pattern corresponding to the third circuit; the sixth photosensitive dry film is exposed and developed to form a fifth pattern corresponding to the fourth circuit. The third circuit is formed by electroplating at the fourth pattern, and the fourth circuit is formed by electroplating at the fifth pattern; Remove the fifth and sixth photosensitive dry films.

[0011] According to some embodiments of the present invention, after the steps of fabricating a third circuit on the surface of the second copper pillar and fabricating a fourth circuit on the surface of the third copper pillar, the method further includes: A first solder resist layer is formed on the surface of the second dielectric layer, and a window is made in the first solder resist layer to form a first pad corresponding to the third circuit. A second solder resist layer is formed on the surface of the third dielectric layer, and a window is made in the second solder resist layer to form a second pad corresponding to the fourth circuit.

[0012] Secondly, the high-copper-thickness copper pillar process packaging substrate structure according to embodiments of the present invention is manufactured by the manufacturing method of the high-copper-thickness copper pillar process packaging substrate structure as described in the first aspect embodiment, the structure comprising: The first substrate includes a first dielectric layer, a first circuit and a first copper pillar disposed within the first dielectric layer, and a second circuit disposed on the surface of the first copper pillar. The first surface of the first circuit is flush with the first surface of the first dielectric layer, and the first copper pillar is disposed on the second surface of the first circuit. The surface of the first copper pillar is flush with the second surface of the first dielectric layer. A first thickened line is disposed on the first surface of the first line; The second thickened line is disposed on the surface and periphery of the second line; The second copper pillar is set on the surface of the first thickened circuit; The third copper pillar is installed on the surface of the second thickened circuit. A second dielectric layer is disposed on the first surface of the first dielectric layer. The second dielectric layer covers the first thickened line and the second copper pillar, and the surface of the second dielectric layer is flush with the surface of the second copper pillar. A third dielectric layer is disposed on the second surface of the first dielectric layer. The third dielectric layer covers the second line, the second thickened line, and the third copper pillar, and the surface of the third dielectric layer is flush with the surface of the third copper pillar. The third circuit is installed on the surface of the second copper pillar. The fourth line is located on the surface of the third copper pillar.

[0013] According to some embodiments of the present invention, it further includes: A first solder mask layer is disposed on the surface of the second dielectric layer, and the first solder mask layer has an opening to expose the third circuit. A second solder mask layer is disposed on the surface of the third dielectric layer, and the second solder mask layer has an opening to expose the fourth circuit.

[0014] The high-copper-thickness copper pillar process packaging substrate structure according to embodiments of the present invention has at least the following beneficial effects: The target copper thickness is divided into two electroplating processes. A coreless process is used to initially fabricate the first and second layer circuits. Then, a method of separate board-by-board electroplating is adopted to fabricate the first and second thickened circuits, thickening them to achieve the target copper thickness. Finally, the outer layer circuits are fabricated. This method solves the problem of insufficient fine-line fabrication capability caused by the need for thicker photosensitive dry films when fabricating high-copper-thickness circuits. By performing a secondary thickening process on the circuit layers, the impact of high-copper-thickness electroplating on circuit fabrication is avoided, thereby improving the fine-line fabrication capability and increasing the current-carrying capacity of the packaging substrate.

[0015] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a flowchart illustrating the steps of a method for fabricating a high-copper, thick-copper pillar process packaging substrate structure according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of the carrier substrate according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure after the first circuit is fabricated on the surface of the carrier substrate according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure after the first copper pillar is fabricated on the surface of the first circuit according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure after the first dielectric layer is laminated onto the surface of the carrier substrate according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure after the second circuit is fabricated on the surface of the first copper pillar according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of the first substrate according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure after electroplating to form a thickened metal layer and a second thickened circuit, according to an embodiment of the present invention. Figure 9 This is a schematic diagram of the structure after the fourth dielectric layer is pressed in according to an embodiment of the present invention; Figure 10 This is a schematic diagram of the structure after the first thickened circuit is formed according to an embodiment of the present invention; Figure 11 This is a schematic diagram of the structure after removing the fourth photosensitive dry film according to an embodiment of the present invention; Figure 12 This is a schematic diagram of the structure after the second and third copper pillars were fabricated according to an embodiment of the present invention; Figure 13 This is a schematic diagram of the structure after the fifth and second dielectric layers are pressed together according to an embodiment of the present invention; Figure 14 This is a schematic diagram of the structure after setting the second seed layer and the third seed layer in an embodiment of the present invention; Figure 15 This is a schematic diagram of the structure after fabricating the third and fourth lines in an embodiment of the present invention; Figure 16 This is a schematic diagram of the structure after removing the fifth and sixth photosensitive dry films in an embodiment of the present invention; Figure 17 This is a schematic diagram of the structure after the first and second solder resist layers are fabricated according to an embodiment of the present invention. Detailed Implementation

[0017] The embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. The step numbers in the following embodiments are set only for ease of explanation, and there is no limitation on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0018] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0019] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0020] In this invention, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0021] As chip power consumption continues to rise, traditional thin copper wiring structures can no longer meet the demands of high current transmission and efficient heat dissipation, resulting in performance and reliability bottlenecks due to high conduction losses and excessive thermal resistance. Existing thickness enhancement technologies often present a trade-off between process complexity, circuit fineness, and interlayer bonding reliability, such as difficulties in controlling plating uniformity and reduced pattern transfer accuracy. The market has an urgent need for packaging substrates that combine high current capacity, excellent thermal management, and stable interconnect performance, driving the continuous evolution of high conductor thickness manufacturing processes and material systems.

[0022] To address this issue, this invention proposes a high-copper-thickness copper pillar process for packaging substrate structure and its fabrication method. The target copper thickness is achieved through two electroplating processes. A coreless process is used to initially fabricate the first and second layer circuits. Then, a board-by-board electroplating method is employed to fabricate the first and second thickened circuits, increasing their copper thickness to the target level. Finally, the outer layer circuits are fabricated. This method solves the problem of insufficient fine-line fabrication capability caused by the need for thicker photosensitive dry films when fabricating high-copper-thickness circuits. By performing a secondary thickening process on the circuit layers, the impact of high-copper-thickness electroplating on circuit fabrication is avoided, thereby improving the ability to fabricate fine circuits and enhancing the current-carrying capacity of the packaging substrate.

[0023] The following description, in conjunction with the accompanying drawings, details the structure and fabrication method of the high-copper, thick-copper pillar process packaging substrate according to embodiments of the present invention.

[0024] Firstly, such as Figure 1 As shown, the method for fabricating a high-copper, thick-copper pillar process packaging substrate structure according to an embodiment of the present invention includes, but is not limited to, steps S100-S1200: Step S100: Prepare the carrier substrate 100; It should be noted that the carrier substrate 100 serves as the basis for fabricating subsequent circuitry; once the subsequent circuitry is fabricated, the carrier substrate 100 can be removed. For example... Figure 2As shown, in this example, the carrier substrate 100 includes a support layer 110, a carrier copper foil 120 is disposed on at least one side of the support layer 110, and a seed layer copper foil 130 is disposed on the surface of the carrier copper foil 120. It should be noted that in this example, carrier copper foils 120 can be disposed on both sides of the support layer 110, and the seed layer copper foil 130 is disposed on the surface of the carrier copper foils 120 on both sides, meaning the structure on both sides of the support layer 110 is completely symmetrical, allowing two first substrates 2500 to be fabricated simultaneously. Alternatively, the carrier copper foil 120 and seed layer copper foil 130 can be disposed only on the upper or lower side of the support layer 110, thus fabricating one first substrate 2500 at a time. To facilitate subsequent removal of the carrier substrate 100, the carrier copper foil 120 and the seed layer copper foil 130 can be physically separated. It should be noted that... Figure 2 The carrier substrate 100 shown is only one example and is not a specific limitation on the structure of the carrier substrate 100. The carrier substrate 100 can be structurally modified, for example, by setting more different metal layers.

[0025] Step S200: Fabricate a first line 200 on the surface of the carrier substrate 100; It should be noted that when fabricating the first line 200, common methods such as subtractive layering, semi-additive layering, and electroplating can be used. In this example, as... Figure 3 As shown, step S200 above specifically includes the following three steps: Step S210: A first photosensitive dry film 140 is formed on the surface of the seed layer copper foil 130; Step S220: Expose and develop the first photosensitive dry film 140 to form a first pattern corresponding to the first line 200; Step S230: Electroplating is performed on the first pattern to form the first line 200.

[0026] Specifically, such as Figure 3 As shown, a first photosensitive dry film 140 is first applied to the surface of the seed layer copper foil 130. By exposing and developing the first photosensitive dry film 140, the area where the first line 200 needs to be electroplated can be exposed, while the remaining areas are protected by the first photosensitive dry film 140 to prevent them from being affected during the electroplating of the first line 200. The seed layer copper foil 130 serves as the basis for electroplating the first line 200.

[0027] Step S300: Fabricate the first copper pillar 400 on the surface of the first line 200; Specifically, the first copper pillar 400 can be formed by electroplating. In this example, such as Figure 4 As shown, step S300 includes the following three steps: Step S310: A second photosensitive dry film 300 is disposed on the surface of the first photosensitive dry film 140, and the second photosensitive dry film 300 is exposed and developed to form a second pattern corresponding to the first copper pillar 400. Step S320: Electroplating is performed on the second pattern to form the first copper pillar 400; Step S330: Remove the first photosensitive dry film 140 and the second photosensitive dry film 300.

[0028] like Figure 4 As shown, after the first circuit 200 is fabricated, a second photosensitive dry film 300 is applied to the surface of the first photosensitive dry film 140. The second photosensitive dry film 300 is then exposed and developed to expose the area where the first copper pillar 400 needs to be electroplated. The remaining areas are protected by the second photosensitive dry film 300 to prevent damage during the electroplating of the first copper pillar 400. After the fabrication of the first copper pillar 400 and the first circuit 200 is completed, the first photosensitive dry film 140 and the second photosensitive dry film 300 can be removed.

[0029] Step S400: Press the first dielectric layer 500 onto the surface of the carrier substrate 100 so that the surface of the first dielectric layer 500 is flush with the surface of the first copper pillar 400. Specifically, such as Figure 5 As shown, after the fabrication of the first copper pillar 400 and the first circuit 200 is completed, a first dielectric layer 500 is laminated onto the surface of the carrier substrate 100, so that the first dielectric layer 500 covers the first circuit 200 and the first copper pillar 400. After laminating the first dielectric layer 500, the first dielectric layer 500 is ground so that the surface of the first dielectric layer 500 is flush with the surface of the first copper pillar 400.

[0030] Step S500: Fabricate a second circuit 800 on the surface of the first copper pillar 400; Specifically, such as Figure 6 As shown, by fabricating a second circuit 800 on the surface of the first copper pillar 400, the second circuit 800 can be connected to the first circuit 200 through the first copper pillar 400. In this example, step S500 includes the following five steps: Step S510: A first seed layer 600 is formed on the surface of the first dielectric layer 500; Step S520: Deposit a third photosensitive dry film 700 on the surface of the first seed layer 600; Step S530: Expose and develop the third photosensitive dry film 700 to form a third pattern corresponding to the second circuit 800; Step S540: Electroplating is performed at the third pattern to form the second line 800; Step S550: Remove the third photosensitive dry film 700.

[0031] like Figure 6 As shown, a first seed layer 600 is first formed on the surface of the first dielectric layer 500 by means of metal sputtering or chemical deposition, which serves as the basis for subsequent electroplating of the second line 800. Then, a third photosensitive dry film 700 is covered on the surface of the first seed layer 600, and the third photosensitive dry film 700 is exposed and developed to expose the position where the second line 800 needs to be electroplated, while protecting other positions. Then, the second line 800 is formed by electroplating. Finally, the third photosensitive dry film 700 is removed, and the first seed layer 600 not covered by the second line 800 is etched away.

[0032] Step S600: Remove the carrier substrate 100 to obtain a first substrate 2500 including a first line 200, a first copper pillar 400 and a second line 800; like Figure 7 As shown, after the fabrication of the second line 800 is completed, the carrier substrate 100 can be removed, leaving only the first substrate 2500, which consists of the first line 200, the first copper pillar 400, and the second line 800. Figure 6 As shown, since the carrier substrate 100 is fabricated simultaneously on both sides, two first substrates 2500 can be obtained simultaneously after removing the carrier substrate 100, thereby improving production efficiency. In this example, step S600 above includes the following two steps: Step S610: Remove the support layer 110 and the carrier copper foil 120, and retain the seed layer copper foil 130; Step S620: Obtain a first substrate 2500 including a first line 200, a first copper pillar 400, a second line 800, and a seed layer copper foil 130.

[0033] It should be noted that since the carrier copper foil 120 and the seed layer copper foil 130 can be physically separated, the support layer 110 and the carrier copper foil 120 can be removed by splitting the carrier copper foil 120 and the seed layer copper foil 130, while the seed layer copper foil 130 can be retained and used as the base for subsequent electroplating circuits.

[0034] Step S700: Create a first thickened line 1300 at the bottom of the first line 200; By fabricating a first thickened line 1300 at the bottom of the first line 200, the copper thickness of the first line 200 can reach the target design copper thickness, meeting the design requirements for finer line spacing. In this example, the above step S700 includes the following five steps: Step S710: Electroplating a thickened metal layer 1000 on the side of the seed layer copper foil 130 away from the first line 200; Step S720: A fourth photosensitive dry film 1200 is deposited on the surface of the thickened metal layer 1000; Step S730: Expose and develop the fourth photosensitive dry film 1200 to protect the position of the thickened metal layer 1000 corresponding to the first thickened line 1300, and expose the remaining position of the thickened metal layer 1000. Step S740: Etch the exposed thickened metal layer 1000 and the corresponding seed layer copper foil 130; Step S750: Remove the fourth photosensitive dry film 1200 to obtain the first thickened circuit 1300.

[0035] like Figure 8 As shown, a thickened metal layer 1000 is formed by electroplating on the side of the seed layer copper foil 130 away from the first line 200. Then, a fourth photosensitive dry film 1200 is deposited on the surface of the thickened metal layer 1000, and the fourth photosensitive dry film 1200 is exposed and developed to expose the areas to be etched, while the remaining areas are protected. The unexposed areas correspond to the pattern of the first line 200. Then, the exposed areas are etched using an etching solution, and finally the fourth photosensitive dry film 1200 is removed to obtain the first thickened line 1300. Figure 10 and Figure 11 As shown.

[0036] Step S800: Create a second thickened line 900 surrounding the second line 800 on the surface and periphery of the second line 800; like Figure 8 As shown, by fabricating a second thickened line 900 on the surface and periphery of the second line 800, the copper thickness of the second line 800 is increased to meet the target design copper thickness and the requirements for manufacturing finer lines. Figure 8 As shown, the thickened metal layer 1000 and the second thickened line 900 can be electroplated simultaneously, and the entire board can be electroplated to form the thickened metal layer 1000 and the second thickened line 900 at the same time.

[0037] Step S900: Fabricate a second copper pillar 1700 on the surface of the first thickened circuit 1300, and fabricate a third copper pillar 1600 on the surface of the second thickened circuit 900. It should be noted that, as Figure 13 As shown, by fabricating a third copper pillar 1600 on the surface of the second thickened line 900 and a second copper pillar 1700 on the surface of the first thickened line 1300, the second thickened line 900 can be connected to external lines through the third copper pillar 1600, and the first thickened line 1300 can be connected to external lines through the second copper pillar 1700. The same method as for fabricating the first copper pillar 400 can be used when fabricating the second copper pillar 1700 and the third copper pillar 1800.

[0038] Step S1000: Press the second dielectric layer 1500 onto the first surface of the first dielectric layer 500, so that the second dielectric layer 1500 covers the first thickened line 1300 and the second copper pillar 1700, and the surface of the second dielectric layer 1500 is flush with the surface of the second copper pillar 1700. Step S1100: Press the third dielectric layer 1100 onto the second surface of the first dielectric layer 500, so that the third dielectric layer 1100 covers the second line 800, the second thickened line 900 and the third copper pillar 1600, and the surface of the third dielectric layer 1100 is flush with the surface of the third copper pillar 1600. Specifically, such as Figure 12 and 13 As shown, in this example, the third dielectric layer 1100 includes a fourth dielectric layer 1110 and a fifth dielectric layer 1120. When pressing the third dielectric layer 1100, it can be pressed in two stages. First, the fourth dielectric layer 1110 is pressed, as shown... Figure 9 As shown, after completing the fabrication of the second thickened circuit 900, the fourth dielectric layer 1110 can be laminated first, and then as follows... Figure 10 and Figure 11 As shown, after the fabrication of the first thickened circuit 1300 is completed, the fourth dielectric layer 1110 is ground to make its surface flush with the surface of the first thickened circuit 1300. Then, as... Figure 12 As shown, in fabricating the second copper pillar 1700 and the third copper pillar 1600, a seventh photosensitive dry film 1400 is deposited on the surface of the fourth dielectric layer 1110, and an eighth photosensitive dry film 2700 is deposited on the second surface of the first dielectric layer 500. After exposing and developing the seventh photosensitive dry film 1400 and the eighth photosensitive dry film 2700, the second copper pillar 1700 and the third copper pillar 1600 are formed by electroplating. Then, the seventh photosensitive dry film 1400 and the eighth photosensitive dry film 2700 are removed. Figure 13 As shown, after the fabrication of the second copper pillar 1700 and the third copper pillar 1600 is completed, the second dielectric layer 1500 and the fifth dielectric layer 1120 are simultaneously laminated, so that the second dielectric layer 1500 covers the first thickened circuit 1300 and the second copper pillar 1700, and the surface of the second dielectric layer 1500 is flush with the surface of the second copper pillar 1700; the fourth dielectric layer 1110 and the fifth dielectric layer 1120 constitute the third dielectric layer 1100, which covers the second circuit 800, the second thickened circuit 900, and the third copper pillar 1600, and the surface of the third dielectric layer 1100 is flush with the surface of the third copper pillar 1600. It should be noted that the third dielectric layer 1100 can also be laminated in one go after the fabrication of the second copper pillar 1700 and the third copper pillar 1600, instead of being laminated in two separate processes, the fourth dielectric layer 1110 and the fifth dielectric layer 1120.

[0039] Step S1200: Fabricate a third circuit 2100 on the surface of the second copper pillar 1700, and fabricate a fourth circuit 2300 on the surface of the third copper pillar 1600 to obtain a packaging substrate.

[0040] like Figure 15 As shown, the third line 2100 is interconnected with the first thickened line 1300 via the second copper pillar 1700, and the first thickened line 1300 is interconnected with the first line 200, thus the third line 2100 and the first line 200 are interconnected. The fourth line 2300 is interconnected with the second thickened line 900 via the third copper pillar 1600, and the second thickened line 900 is interconnected with the second line 800, thus the fourth line 2300 and the second line 800 are interconnected. The first line 200 and the second line 800 are interconnected via the first copper pillar 400, thereby achieving interconnection between the various layers of the packaging substrate. In this example, as... Figures 14 to 16 As shown, step S1200 above specifically includes the following five steps: Step S1210: A second seed layer 1900 is provided on the surface of the second dielectric layer 1500, and a third seed layer 1800 is provided on the surface of the third dielectric layer 1400; Step S1220: A fifth photosensitive dry film 2000 is disposed on the surface of the second seed layer 1900, and a sixth photosensitive dry film 2200 is disposed on the surface of the third seed layer; Step S1230: Expose and develop the fifth photosensitive dry film 2000 to form the fourth pattern corresponding to the third line 2100; expose and develop the sixth photosensitive dry film 2200 to form the fifth pattern corresponding to the fourth line 2300. Step S1240: Electroplating is performed on the fourth pattern to form the third line 2100, and electroplating is performed on the fifth pattern to form the fourth line 2300; Step S1250: Remove the fifth photosensitive dry film 2000 and the sixth photosensitive dry film 2200.

[0041] like Figure 14 As shown, a second seed layer 1900 is formed on the surface of the second dielectric layer 1500, and a third seed layer 1800 is formed on the surface of the third dielectric layer 1400, serving as the basis for subsequent electroplating of the third line 2100 and the fourth line 2300. Then, a fifth photosensitive dry film 2000 and a sixth photosensitive dry film 2200 are formed, and the fifth photosensitive dry film 2000 and the sixth photosensitive dry film 2200 are exposed and developed, thereby electroplating to form the third line 2100 and the fourth line 2300, as shown. Figure 15 As shown. Finally, the fifth photosensitive dry film 2000 and the sixth photosensitive dry film 2200 are removed to obtain the packaging substrate, as shown. Figure 16 As shown.

[0042] like Figure 17 As shown, in some embodiments of this application, after the fabrication of the third line 2100 and the fourth line 2300 is completed, the method of this application further includes the following two steps: A first solder mask layer 2600 is formed on the surface of the second dielectric layer 1500, and a window is made in the first solder mask layer 2600 to form a first pad corresponding to the third circuit 2100. A second solder mask layer 2400 is provided on the surface of the third dielectric layer 1100, and a window is made in the second solder mask layer 2400 to form a second pad corresponding to the fourth circuit 2300.

[0043] By setting the first solder mask layer 2600 and the second solder mask layer 2400, the packaging substrate is protected against soldering, ensuring the soldering effect during subsequent component soldering. At the same time, the first and second solder pads are exposed, facilitating subsequent component soldering.

[0044] According to the fabrication method of the high-copper-thickness copper pillar process packaging substrate structure of the embodiments of this application, the target copper thickness is divided into two electroplating processes. The first line 200 and the second layer line 800 are initially fabricated using a coreless process. Then, the first thickened line 1300 and the second thickened line 900 are fabricated by performing whole-board electroplating on separate boards, thus thickening the first line 200 and the second line 800 to the target copper thickness. Finally, the outer layer lines are fabricated. This method solves the problem of insufficient fine line fabrication capability caused by the need to use a correspondingly thicker photosensitive dry film when fabricating high-copper-thickness lines. By performing a secondary thickening process on the line layers, the impact of high-copper-thickness electroplating on line fabrication is avoided, thereby improving the fine line fabrication capability and increasing the current carrying capacity of the packaging substrate.

[0045] Secondly, embodiments of the present invention also propose a high-copper, thick-copper-pillar process packaging substrate structure, which is fabricated using the high-copper, thick-copper-pillar process packaging substrate structure fabrication method described in the above-mentioned embodiments. This structure is as follows... Figure 16 As shown. The structure includes: The first substrate 2500 includes a first dielectric layer 500, a first circuit 200 and a first copper pillar 400 disposed within the first dielectric layer 500, and a second circuit 800 disposed on the surface of the first copper pillar 400. The first surface of the first circuit 200 is flush with the first surface of the first dielectric layer 500, and the first copper pillar 400 is disposed on the second surface of the first circuit 200. The surface of the first copper pillar 400 is flush with the second surface of the first dielectric layer 500. The first thickened line 1300 is disposed on the first surface of the first line 200; The second thickened line 900 is disposed on the surface and periphery of the second line 800; The second copper pillar 1700 is set on the surface of the first thickened line 1300; The third copper pillar 1600 is installed on the surface of the second thickened line 900; The second dielectric layer 1500 is disposed on the first surface of the first dielectric layer 500. The second dielectric layer 1500 covers the first thickened line 1300 and the second copper pillar 1700, and the surface of the second dielectric layer 1500 is flush with the surface of the second copper pillar 1700. The third dielectric layer 1100 is disposed on the second surface of the first dielectric layer 500. The third dielectric layer 1100 covers the second line 800, the second thickened line 900 and the third copper pillar 1600, and the surface of the third dielectric layer 1100 is flush with the surface of the third copper pillar 1600. The third line 2100 is located on the surface of the second copper pillar 1700. The fourth line, 2300, is located on the surface of the third copper pillar, 1600.

[0046] According to the high-copper-thickness copper pillar process packaging substrate structure of this application embodiment, the first line 200 and the second line 800 are thickened by the first thickened line 1300 and the second thickened line 900, so that the copper thickness of the first line 200 and the second line 800 is increased to the target copper thickness. This structure can improve the fine circuit fabrication capability and increase the current carrying capacity of the packaging substrate.

[0047] In some embodiments of this application, such as Figure 17 As shown, the high-copper, thick-copper pillar process packaging substrate structure also includes: The first solder mask layer 2600 is disposed on the surface of the second dielectric layer 1500, and the first solder mask layer 2600 has an opening to expose the third circuit 2100. The second solder mask layer 2400 is disposed on the surface of the third dielectric layer 1100, and the second solder mask layer 2400 has an opening to expose the fourth circuit 2300.

[0048] By setting the first solder mask layer 2600 and the second solder mask layer 2400, the packaging substrate is protected against soldering, ensuring the soldering effect during subsequent component soldering. At the same time, the first and second solder pads are exposed, facilitating subsequent component soldering.

[0049] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for fabricating a high-copper, thick-copper pillar process packaging substrate structure, characterized in that, include: Prepare the carrier substrate; A first circuit is fabricated on the surface of the carrier substrate; A first copper pillar is fabricated on the surface of the first line; A first dielectric layer is laminated onto the surface of the carrier substrate, such that the first dielectric layer covers the first circuit and the first copper pillar, and the surface of the first dielectric layer is flush with the surface of the first copper pillar. A second circuit is fabricated on the surface of the first copper pillar; Remove the carrier substrate to obtain a first substrate including the first line, the first copper pillar and the second line; A first thickened line is made at the bottom of the first line; A second thickened line is made surrounding the second line on the surface and around the second line; A second copper pillar is fabricated on the surface of the first thickened circuit, and a third copper pillar is fabricated on the surface of the second thickened circuit. A second dielectric layer is pressed onto the first surface of the first dielectric layer, so that the second dielectric layer covers the first thickened circuit and the second copper pillar, and the surface of the second dielectric layer is flush with the surface of the second copper pillar. A third dielectric layer is pressed onto the second surface of the first dielectric layer, so that the third dielectric layer covers the second circuit, the second thickened circuit and the third copper pillar, and the surface of the third dielectric layer is flush with the surface of the third copper pillar; A third circuit is fabricated on the surface of the second copper pillar, and a fourth circuit is fabricated on the surface of the third copper pillar to obtain a packaging substrate.

2. The method for fabricating a high-copper, thick-copper pillar process packaging substrate structure according to claim 1, characterized in that, The carrier substrate includes a support layer, at least one side of which is provided with a carrier copper foil, and a seed layer copper foil is provided on the surface of the carrier copper foil, and the first line is provided on the surface of the seed layer copper foil.

3. The method for fabricating a high-copper, thick-copper pillar process packaging substrate structure according to claim 2, characterized in that, The fabrication of the first line on the surface of the carrier substrate includes: A first photosensitive dry film is disposed on the surface of the copper foil in the seed layer; The first photosensitive dry film is exposed and developed to form a first pattern corresponding to the first circuit. The first line is formed by electroplating at the first pattern; The process of fabricating a first copper pillar on the surface of the first line includes: A second photosensitive dry film is disposed on the surface of the first photosensitive dry film, and the second photosensitive dry film is exposed and developed to form a second pattern corresponding to the first copper pillar. The first copper pillar is formed by electroplating at the second pattern. Remove the first photosensitive dry film and the second photosensitive dry film.

4. The method for fabricating a high-copper, thick-copper pillar process packaging substrate structure according to claim 1, characterized in that, The fabrication of the second circuit on the surface of the first copper pillar includes: A first seed layer is formed on the surface of the first medium layer; A third photosensitive dry film is disposed on the surface of the first seed layer; The third photosensitive dry film is exposed and developed to form a third pattern corresponding to the second circuit; A second circuit is formed by electroplating at the third pattern; Remove the third photosensitive dry film.

5. The method for fabricating a high-copper, thick-copper pillar process packaging substrate structure according to claim 2, characterized in that, The process of removing the carrier substrate to obtain a first substrate including the first line, the first copper pillar, and the second line includes: Remove the support layer and the carrier copper foil, and retain the seed layer copper foil; A first substrate comprising the first line, the first copper pillar, the second line, and the seed layer copper foil is obtained.

6. The method for fabricating a high-copper, thick-copper pillar process packaging substrate structure according to claim 5, characterized in that, The step of fabricating a first thickened circuit at the bottom of the first circuit includes: A thickened metal layer is formed by electroplating on the side of the seed layer copper foil away from the first line; A fourth photosensitive dry film is disposed on the surface of the thickened metal layer; The fourth photosensitive dry film is exposed and developed to protect the position of the thickened metal layer corresponding to the first thickened circuit, while exposing the remaining position of the thickened metal layer. The thickened metal layer and the corresponding seed layer copper foil are etched to expose the thickened metal layer; Remove the fourth photosensitive dry film to obtain the first thickened circuit.

7. The method for fabricating a high-copper, thick-copper pillar process packaging substrate structure according to claim 5, characterized in that, The process of fabricating a third circuit on the surface of the second copper pillar and a fourth circuit on the surface of the third copper pillar includes: A second seed layer is disposed on the surface of the second medium layer, and a third seed layer is disposed on the surface of the third medium layer; A fifth photosensitive dry film is disposed on the surface of the second seed layer, and a sixth photosensitive dry film is disposed on the surface of the third seed layer; The fifth photosensitive dry film is exposed and developed to form a fourth pattern corresponding to the third circuit; the sixth photosensitive dry film is exposed and developed to form a fifth pattern corresponding to the fourth circuit. The third circuit is formed by electroplating at the fourth pattern, and the fourth circuit is formed by electroplating at the fifth pattern; Remove the fifth and sixth photosensitive dry films.

8. The method for fabricating a high-copper, thick-copper pillar process packaging substrate structure according to claim 1, characterized in that, After the steps of fabricating a third circuit on the surface of the second copper pillar and fabricating a fourth circuit on the surface of the third copper pillar, the method further includes: A first solder resist layer is formed on the surface of the second dielectric layer, and a window is made in the first solder resist layer to form a first pad corresponding to the third circuit. A second solder resist layer is formed on the surface of the third dielectric layer, and a window is made in the second solder resist layer to form a second pad corresponding to the fourth circuit.

9. A high-copper, thick-copper pillar process packaging substrate structure, characterized in that, The structure is manufactured using the high-copper, thick-copper pillar process packaging substrate structure as described in any one of claims 1-8, and the structure includes: The first substrate includes a first dielectric layer, a first circuit and a first copper pillar disposed within the first dielectric layer, and a second circuit disposed on the surface of the first copper pillar. The first surface of the first circuit is flush with the first surface of the first dielectric layer, and the first copper pillar is disposed on the second surface of the first circuit. The surface of the first copper pillar is flush with the second surface of the first dielectric layer. A first thickened line is disposed on the first surface of the first line; The second thickened line is disposed on the surface and periphery of the second line; The second copper pillar is set on the surface of the first thickened circuit; The third copper pillar is installed on the surface of the second thickened circuit. A second dielectric layer is disposed on the first surface of the first dielectric layer. The second dielectric layer covers the first thickened line and the second copper pillar, and the surface of the second dielectric layer is flush with the surface of the second copper pillar. A third dielectric layer is disposed on the second surface of the first dielectric layer. The third dielectric layer covers the second line, the second thickened line, and the third copper pillar, and the surface of the third dielectric layer is flush with the surface of the third copper pillar. The third circuit is installed on the surface of the second copper pillar. The fourth line is located on the surface of the third copper pillar.

10. The high-copper, thick-copper pillar process packaging substrate structure according to claim 9, characterized in that, Also includes: A first solder mask layer is disposed on the surface of the second dielectric layer, and the first solder mask layer has an opening to expose the third circuit. A second solder mask layer is disposed on the surface of the third dielectric layer, and the second solder mask layer has an opening to expose the fourth circuit.

Images