Method for manufacturing a packaging substrate and packaging substrate
By using laser drilling and filling with solid copper pillars, the problems of limited via density and stress difference in thick core boards were solved, forming a high dielectric thickness packaging substrate, which improved reliability and stress resistance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHUHAI ACCESS SEMICONDUCTOR CO LTD
- Filing Date
- 2022-04-11
- Publication Date
- 2026-05-12
AI Technical Summary
In the existing technology, the density of vias in thick core boards is limited. Non-solid vias are prone to copper layer brush marks during the grinding process and are easily broken under stress, affecting reliability.
Through holes are formed by laser drilling, solid copper pillars are filled, and conductive copper pillars are formed at both ends. After etching copper foil, dielectric layers are set on both sides of the substrate to expose the end faces of the conductive copper pillars, forming a high dielectric thickness core board.
It improves the density and reliability of the through holes, alleviates the problems of limited hole density and stress difference, and enhances the stress resistance of the core board.
Smart Images
Figure CN114900960B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor packaging technology, and in particular to a method for manufacturing a packaging substrate and the packaging substrate itself. Background Technology
[0002] As electronic products evolve towards miniaturization and multi-functional integration, the line density and via density of packaging substrates are continuously increasing, leading to higher demands on substrate reliability. In existing technologies, to create vias on thick core boards (typically 150μm or more thick), non-solid vias are typically electroplated, then filled with resin, and finally the entire board is ground after the resin cures. The disadvantages of this method are: firstly, the via density is easily limited by the via-filling and grinding processes; higher via density introduces more manufacturing problems and difficulties, making it difficult to further increase the via density; secondly, the grinding process after resin filling can cause brush marks on the copper layer, which is often difficult to completely resolve, leading to open circuits and scrapping issues in subsequent circuit fabrication, and even reliability risks; furthermore, the copper thickness inside non-solid vias is typically 10-15μm, with a high vertical depth, making them weaker in resisting stress and preventing copper fracture compared to solid vias (typically ≥40μm thick). Summary of the Invention
[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a method for manufacturing a packaging substrate and a packaging substrate, which can realize a core board with high dielectric thickness and solid vias.
[0004] On one hand, the method for manufacturing a packaging substrate according to an embodiment of the present invention includes the following steps: preparing a substrate with double-sided copper cladding; laser drilling the substrate to form through holes; performing hole-filling electroplating on the substrate to form solid copper pillars in the through holes; forming conductive copper pillars at both ends of the solid copper pillars; etching copper foil on the surface of the substrate; and setting a first dielectric layer on both sides of the substrate and exposing the end faces of the conductive copper pillars to form a core board.
[0005] According to some embodiments of the present invention, the method further includes the following steps: forming a first seed layer on both sides of the core board; fabricating a first circuit on the first seed layer, the first circuit being in communication with the conductive copper pillar; and etching the first seed layer exposed on the surface of the first dielectric layer.
[0006] According to some embodiments of the present invention, the method further includes the following steps: forming a second dielectric layer on both sides of the core board, the second dielectric layer covering the first circuit; forming a second laser blind via on the second dielectric layer; forming a second seed layer on the surface of the second dielectric layer and the inner wall of the second laser blind via; performing a hole-filling electroplating on the second laser blind via and forming a second circuit on the surface of the second dielectric layer, the second circuit being conductive to the first circuit; and etching the second seed layer exposed on the surface of the second dielectric layer.
[0007] According to some embodiments of the present invention, the step of laser drilling the substrate to form a through hole specifically includes: laser drilling on both sides of the substrate to form the through hole, which gradually narrows from both ends to the middle.
[0008] According to some embodiments of the present invention, the via-filling electroplating of the substrate to form solid copper pillars within the vias specifically includes: depositing chemical copper on the walls of the vias; attaching a first dry film to both sides of the substrate; exposing and developing the first dry film to expose the positions corresponding to the vias; and performing via-filling electroplating on the substrate to form solid copper pillars within the vias.
[0009] According to some embodiments of the present invention, the step of forming conductive copper pillars at both ends of the solid copper pillar specifically includes: attaching a second dry film to both sides of the substrate; exposing and developing the second dry film to expose the positions corresponding to the conductive copper pillars; electroplating the substrate to form the conductive copper pillars at both ends of the solid copper pillar; and removing the first dry film and the second dry film.
[0010] According to some embodiments of the present invention, the step of forming a core board by depositing a first dielectric layer on both sides of the substrate and exposing the end faces of the conductive copper pillars specifically includes: depositing the first dielectric layer on both sides of the substrate; polishing the first dielectric layer so that the first dielectric layer is flush with the end faces of the conductive copper pillars to form the core board; or, depositing a first laser blind via on the first dielectric layer to expose the end faces of the conductive copper pillars to form the core board.
[0011] On the other hand, the packaging substrate according to the embodiments of the present invention is prepared by the packaging substrate manufacturing method described in the above embodiments of the present invention.
[0012] On the other hand, according to an embodiment of the present invention, the packaging substrate includes: a substrate; a solid copper pillar penetrating the substrate, wherein conductive copper pillars are respectively disposed at both ends of the solid copper pillar; and a first dielectric layer disposed on both sides of the substrate, wherein the end faces of the conductive copper pillars are exposed to the first dielectric layer.
[0013] According to some embodiments of the present invention, a first seed layer is disposed on the surface of the first dielectric layer, and a first line is disposed on the surface of the first seed layer, the first line being connected to the conductive copper pillar.
[0014] The method for manufacturing the packaging substrate and the packaging substrate of the present invention have at least the following beneficial effects: they can form a core board with high dielectric thickness and solid vias, which solves the process defects of non-solid vias in existing thick core boards and improves the problems of limited hole density and stress difference of non-solid vias in existing processes.
[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:
[0017] Figure 1 This is a flowchart illustrating the steps of a method for fabricating a packaging substrate according to an embodiment of the present invention.
[0018] Figures 2-17 This is a schematic diagram of the intermediate process of the packaging substrate manufacturing method according to an embodiment of the present invention.
[0019] Figure label:
[0020] Substrate 100, copper foil 101, through hole 200, chemical copper 210, first dry film 300, solid copper pillar 400, second dry film 500, conductive copper pillar 600, first dielectric layer 700, core board 800, first laser blind hole 900, first seed layer 1000, third dry film 1100, first circuit 1200, second dielectric layer 1300, second laser blind hole 1400, second circuit 1500, second seed layer 1600. Detailed Implementation
[0021] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.
[0022] 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.
[0023] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
[0024] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.
[0025] On the one hand, such as Figure 1 As shown, the method for manufacturing a packaging substrate according to an embodiment of the present invention includes the following steps:
[0026] Step S100: Prepare a double-sided copper-clad substrate 100.
[0027] Specifically, such as Figure 2 As shown, both sides of the substrate 100 are covered with copper foil 101. The substrate 100 can be a CCL (Copper Clad Laminate) with built-in ultra-thin copper foil (about 3μm).
[0028] Step S200: Laser drilling is performed on the substrate 100 to form through holes 200.
[0029] Specifically, in this embodiment of the invention, the drilling method used is: laser drilling is performed on both sides of the substrate 100 to form a through hole 200 that gradually narrows from both ends to the middle. For example... Figure 3 As shown, the through hole 200 is in the shape of an "X", with large openings at both ends and a small opening in the middle. The X-shaped through hole 200 is formed so that in the subsequent hole-filling electroplating operation, it can achieve the effect of filling without voids and avoiding excessive recesses at the hole opening.
[0030] Step S300: Perform hole-filling electroplating on the substrate 100 to form a solid copper pillar 400 inside the through hole 200.
[0031] Specifically, in this embodiment of the invention, in order to fill the through hole 200 and form a solid copper pillar 400, such as... Figure 4 As shown, firstly, chemical copper 210 is deposited on the wall of the through-hole 200. This can be achieved by depositing a thin layer of chemical copper 210 on the hole wall using a chemical solution, typically with a thickness of 0.6–1.2 μm. Alternatively, titanium copper can be sputtered onto the hole wall using a sputtering process to provide current conduction for subsequent hole-filling electroplating. Then, as… Figure 5 As shown, a first dry film 300 is laminated on both sides of the substrate 100. This first dry film 300 can be a photosensitive dry film with anti-plating properties. The first dry film 300 is exposed and developed to expose the positions corresponding to the vias 200. That is, through exposure and development, the positions where solid copper pillars 400 will subsequently be formed are exposed, while the remaining positions of the first dry film 300 are retained. Finally, as... Figure 6 As shown, the substrate 100 is subjected to hole-filling electroplating to form solid copper pillars 400 inside the through holes 200, thus filling and leveling the through holes 200.
[0032] Step S400: Form conductive copper pillars 600 at both ends of the solid copper pillar 400.
[0033] Specifically, in this embodiment of the invention, in order to form conductive copper pillars 600 at both ends of the solid copper pillar 400, such as... Figure 7 As shown, firstly, a second dry film 500 is laminated to both sides of the substrate 100. The second dry film 500 can be a photosensitive dry film with anti-plating properties. The first dry film 300 and the second dry film 500 can be of the same or different type. Then, the second dry film 500 is exposed and developed to expose the positions corresponding to the conductive copper pillars 600; that is, through exposure and development, the positions where the conductive copper pillars 600 need to be electroplated are exposed, while the second dry film 500 at other positions is retained. Subsequently, as... Figure 7 and Figure 8 As shown, the substrate 100 is electroplated to form conductive copper pillars 600. Finally, as... Figure 8 As shown, the first dry film 300 and the second dry film 500 on the surface of the substrate 100 are completely removed. It should be noted that in some embodiments of the present invention, the first dry film 300 may be removed first and then the second dry film 500 may be applied; alternatively, the first dry film 300 may not be removed first, and the second dry film 500 may be applied directly on the first dry film 300 until the conductive copper pillar 600 is formed, and then the first dry film 300 and the second dry film 500 are removed together.
[0034] Step S500: Etch the copper foil 101 on the surface of the substrate 100.
[0035] like Figure 9 As shown, after removing the first dry film 300 and the second dry film 500, the copper foil 101 on the surface of the substrate 100 is etched away to facilitate the subsequent operation of the laminated dielectric layer.
[0036] Step S600: A first dielectric layer 700 is formed on both sides of the substrate 100, and the end face of the conductive copper pillar 600 is exposed to form a core board 800.
[0037] Specifically, in the embodiments of the present invention, such as Figure 10 As shown, firstly, a first dielectric layer 700 is laminated on both sides of the substrate 100. The first dielectric layer 700 can be made of materials such as PP (Prepreg) or ABF (Ajinomoto Build-up Film). Then, as... Figure 11 As shown, the first dielectric layer 700 is polished so that it is flush with the end face of the conductive copper pillar 600, forming a core board 800 with high dielectric thickness and solid through holes; or, as shown... Figure 12 As shown, a first laser blind via 900 is provided on the first dielectric layer 700 to expose the end face of the conductive copper pillar 600, so that the outer layer circuit can be connected with the inner layer conductive copper pillar 600 to form a core board 800 with high dielectric thickness and solid conductive via.
[0038] According to the method for manufacturing a packaging substrate according to an embodiment of the present invention, a core board 800 with high dielectric thickness and solid vias can be formed, which solves the process defects of non-solid vias in existing thick core boards and improves the problems of limited hole density and stress difference of non-solid vias in existing processes.
[0039] In this embodiment of the invention, in the practical application of the core board 800, the method for manufacturing the packaging substrate further includes the following steps:
[0040] A first seed layer 1000 is set on both sides of the core board 800;
[0041] A first line 1200 is fabricated on the first seed layer 1000, and the first line 1200 is connected to the conductive copper pillar 600.
[0042] The first seed layer 1000 is exposed by etching the surface of the first dielectric layer 700.
[0043] Specifically, such as Figure 13 As shown, firstly, a first seed layer 1000 is formed on both sides of the core board 800 using processes such as sputtering. Then, as... Figure 14 As shown, a third dry film 1100 is attached to the first seed layer 1000, and the third dry film 1100 is subjected to exposure and development operations to expose the location where the first line 1200 needs to be fabricated. Subsequently, as... Figure 15 As shown, the core board 800 undergoes an electroplating operation to form the first circuit 1200. Finally, as... Figure 16 As shown, the third dry film 1100 is removed, and the first seed layer 1000 exposed on the surface of the first dielectric layer 700 is etched away.
[0044] like Figure 17 As shown, in this embodiment of the invention, in order to perform outer layer addition and circuit fabrication on the core board 800 according to the needs of the actual product, the method for manufacturing the packaging substrate further includes the following steps:
[0045] A second dielectric layer 1300 is provided on both sides of the core board 800, and the second dielectric layer 1300 covers the first line 1200;
[0046] A second laser blind hole 1400 is provided on the second dielectric layer 1300;
[0047] A second seed layer 1600 is formed on the surface of the second dielectric layer 1300 and on the inner wall of the second laser blind hole 1400;
[0048] The second laser blind hole 1400 is filled by electroplating, and a second line 1500 is formed on the surface of the second dielectric layer 1300. The second line 1500 is connected to the first line 1200.
[0049] The second seed layer 1600 is exposed by etching the surface of the second dielectric layer 1300.
[0050] Specifically, such as Figure 17 As shown, firstly, a second dielectric layer 1300 is laminated on both sides of the core board 800, and a second laser blind via 1400 is formed on the second dielectric layer 1300 using laser drilling technology. Then, a second seed layer 1600 is formed on the surface of the second dielectric layer 1300 and the inner wall of the second laser blind via 1400 using processes such as sputtering. Subsequently, after operations such as applying a photosensitive dry film, exposure, and development, the second laser blind via 1400 is electroplated to fill the vias. Simultaneously, a second circuit 1500 is formed on the surface of the second dielectric layer 1300, and the second circuit 1500 is connected to the first circuit 1200 through the second laser blind via 1400. Finally, the photosensitive dry film is removed, and the exposed second seed layer 1600 on the surface of the second dielectric layer 1300 is etched away.
[0051] On the other hand, the packaging substrate according to the embodiments of the present invention is prepared by the packaging substrate manufacturing method described in the above embodiments of the present invention.
[0052] On the other hand, according to embodiments of the present invention, such as... Figure 11 As shown, it includes a substrate 100, a solid copper pillar 400 and a first dielectric layer 700; the solid copper pillar 400 penetrates through the substrate 100, and conductive copper pillars 600 are respectively provided at both ends of the solid copper pillar 400; the first dielectric layer 700 is disposed on both sides of the substrate 100, and the end faces of the conductive copper pillars 600 are exposed to the first dielectric layer 700.
[0053] According to the packaging substrate of the present invention, by adopting the above-described packaging substrate manufacturing method, a core board 800 with high dielectric thickness and solid vias is formed, which improves the defects of non-solid vias in existing thick core boards, has a strong ability to resist stress without causing copper hole fracture, and has high reliability.
[0054] like Figure 16 As shown, in some embodiments of the present invention, a first seed layer 1000 is disposed on the surface of the first dielectric layer 700, and a first line 1200 is disposed on the surface of the first seed layer 1000, and the first line 1200 is connected to the conductive copper pillar 600.
[0055] 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 manufacturing a packaging substrate, characterized in that, Includes the following steps: Prepare a double-sided copper-clad substrate; Laser drilling is performed on the substrate to form through holes; Chemical copper is deposited on the wall of the through hole; A first dry film is applied to both sides of the substrate; The first dry film is exposed and developed to expose the positions corresponding to the through holes; The substrate is subjected to through-hole electroplating to form solid copper pillars inside the through holes; A second dry film is attached to both sides of the substrate; The second dry film is exposed and developed to expose the positions corresponding to the conductive copper pillars; The substrate is electroplated to form the conductive copper pillars at both ends of the solid copper pillar; Remove the first dry film and the second dry film; Etch the copper foil on the surface of the substrate; A first dielectric layer is disposed on both sides of the substrate, and the end faces of the conductive copper pillars are exposed to form a core board; The step of laser drilling the substrate to form through holes specifically includes: Laser drilling is performed on both sides of the substrate to form the through hole, which gradually narrows from both ends to the middle.
2. The method for manufacturing a packaging substrate according to claim 1, characterized in that, It also includes the following steps: A first seed layer is provided on both sides of the core plate; A first circuit is fabricated on the first seed layer, and the first circuit is connected to the conductive copper pillar; The first seed layer exposed on the surface of the first dielectric layer is etched.
3. The method for manufacturing a packaging substrate according to claim 2, characterized in that, It also includes the following steps: A second dielectric layer is provided on both sides of the core board, and the second dielectric layer covers the first circuit. A second laser blind hole is formed on the second dielectric layer; A second seed layer is formed on the surface of the second dielectric layer and on the inner wall of the second laser blind hole; The second laser blind hole is filled by electroplating, and a second circuit is formed on the surface of the second dielectric layer. The second circuit is connected to the first circuit. The second seed layer is exposed by etching the surface of the second dielectric layer.
4. The method for manufacturing a packaging substrate according to claim 1, characterized in that, The step of forming a core board by depositing a first dielectric layer on both sides of the substrate and exposing the end faces of the conductive copper pillars specifically includes: The first dielectric layer is disposed on both sides of the substrate; The first dielectric layer is polished to make it flush with the end face of the conductive copper pillar, forming the core board; or, A first laser blind via is provided in the first dielectric layer to expose the end face of the conductive copper pillar, thereby forming the core board.
5. A packaging substrate, characterized in that, The substrate is prepared by the method of any one of claims 1-4.