Packaging substrate and preparation method thereof
By setting SiOx isolation rings and/or regional isolation pillars in front of the glass vias, the problem of microcracks around the glass vias was solved, improving the reliability and yield of the packaging substrate.
Patent Information
- Application Number
- CN202511746817.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-25
- Publication Date
- 2026-01-27
AI Technical Summary
During chip packaging, microcracks are easily generated around glass vias due to heat, which is difficult to effectively solve with existing technologies.
Before fabricating the glass through-hole, a pre-surrounding isolation ring and/or regional isolation pillar are set up. The isolation structure is made of SiOx material. The isolation ring and/or regional isolation pillar block the thermally induced cracks and their deterioration and propagation.
It effectively blocks and prevents the propagation of cracks caused by thermal effects on the packaging substrate, thereby improving the single-hole yield and overall reliability of the packaging substrate.
Smart Images
Figure CN121419652A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of integrated circuit board technology, and in particular to a packaging substrate and its preparation method. Background Technology
[0002] Currently, in the field of chip packaging, through-glass via (TGV) technology and redistribution layer (RDL) technology are typically required to achieve electrical interconnection of glass substrates. However, due to the typically small hole size of TGV and the use of TGV laser-induced and HF etching processes for drilling, the high density of glass vias leads to significant microcracks around the periphery due to thermal effects.
[0003] Therefore, a new technical solution is urgently needed. Summary of the Invention
[0004] In view of this, the purpose of this disclosure is to provide a packaging substrate and its preparation method to solve the problem of microcracks easily occurring when drilling holes in the packaging substrate.
[0005] For the purposes described above, this disclosure discloses a packaging substrate, comprising:
[0006] The substrate body has a plurality of through holes in a direction perpendicular to the substrate body.
[0007] An isolation structure is disposed on one side of the substrate body; the isolation structure includes an isolation ring and / or a regional isolation pillar; the orthographic projection of the isolation ring on the substrate body surrounds the orthographic projection of a single through hole on the substrate body and / or the orthographic projection of the regional isolation pillar on the substrate body surrounds the orthographic projection of a plurality of through holes on the substrate body.
[0008] Furthermore, the material of the isolation structure is SiOx;
[0009] Preferably, the isolation structure is made of multiple layers of SiOx with different densities, and the SiOx density is smaller along the direction away from the through hole.
[0010] Furthermore, the substrate body is made of inorganic materials;
[0011] Preferably, the substrate body is made of glass.
[0012] Furthermore, each of the through holes corresponds to at least one of the isolation rings;
[0013] The orthographic projection of the isolation ring on the substrate body is concentric with the orthographic projection of the corresponding through hole on the substrate body.
[0014] Furthermore, in the thickness direction of the substrate body, the thickness of the isolation structure is 200-600 nm;
[0015] Preferably, the thickness of the isolation structure is 300-500 nm in the thickness direction of the substrate body.
[0016] Furthermore, the spacing between the isolation structure and the adjacent through-hole is 10-30 nm.
[0017] Furthermore, the isolation ring is ring-shaped.
[0018] Furthermore, the regional isolation pillars are rectangular in shape.
[0019] Based on the same inventive concept, this application discloses a method for preparing a packaging substrate, comprising the following steps:
[0020] A substrate body is provided, and at least one isolation film layer is stacked on one side of the substrate body;
[0021] Photoresist is coated onto the isolation film layer to form a photoresist layer;
[0022] After the photoresist layer is exposed and developed in sequence, an isolation structure pattern is obtained, and the isolation film layer is dry-etched according to the pattern to form an isolation structure;
[0023] The residual photoresist layer on the substrate body is peeled off to create through-holes, thus completing the preparation of the packaging substrate.
[0024] Furthermore, the material of the isolation membrane layer is SiOx.
[0025] Compared with the prior art, this application has the following technical effects:
[0026] This application achieves the effect of blocking thermally-induced cracks in the packaging substrate and their continuous deterioration and growth by setting a pre-surrounding isolation ring and / or regional isolation pillars before fabricating the glass through-hole. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in this disclosure or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0028] Figure 1 This is a schematic diagram of a crack in a related packaging substrate;
[0029] Figure 2This is a schematic cross-sectional view of the packaging substrate in one embodiment of this application;
[0030] Figure 3 This is a top view of the isolation ring of the packaging substrate in one embodiment of this application;
[0031] Figure 4 This is a top view of the multilayer isolation ring of the packaging substrate in one embodiment of this application;
[0032] Figure 5 This is a top view of the area isolation pillars of the packaging substrate in one embodiment of this application;
[0033] Figure 6 This is a top view of the isolation ring and regional isolation pillars of the packaging substrate in one embodiment of this application;
[0034] Figure 7 This is a flowchart of a method for preparing a packaging substrate according to an embodiment of this application. Detailed Implementation
[0035] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.
[0036] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this disclosure should have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in the embodiments of this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0037] The packaging substrate is a crucial support carrier for the stable operation of a chip, providing support, heat dissipation, and protection. Currently, the most commonly used packaging substrate is the glass substrate. As a new generation of inorganic packaging substrates, glass substrates offer advantages over traditional organic substrates, including lower dielectric loss, better high-frequency signal transmission, better heat dissipation, greater flexibility, and higher light transmittance. To achieve electrical interconnection on glass packaging substrates, overlapping glass via technology and redistribution layer technology are typically required.
[0038] The inventors of this application have discovered the following problems in the relevant technology during long-term practical work:
[0039] In practical applications, due to the relatively low maturity of current glass packaging substrates using TVG and RDL technologies, some problems still exist. For example... Figure 1 As shown, due to the small diameter of the drilled holes, typically around 50 μm, it is easy to generate noticeable microcracks during the drilling process. In addition, the TVG process using laser-induced and hydrofluoric acid etching generates heat effects, and the glass substrate is prone to microcracks due to thermal stress and other factors in the area surrounding the high-density glass vias.
[0040] For the reasons stated above, this application provides a packaging substrate, including a substrate body and an isolation structure. The isolation structure is disposed on one side of the substrate body; the isolation structure includes an isolation ring and / or regional isolation pillars; the orthographic projection of the isolation ring on the substrate body surrounds the orthographic projection of a single through-hole on the substrate body and / or the orthographic projection of the regional isolation pillars on the substrate body surrounds the orthographic projection of multiple through-holes on the substrate body.
[0041] This application achieves the effect of blocking thermally-induced cracks in the packaging substrate and their continuous deterioration and growth by setting a pre-surrounding isolation ring and / or regional isolation pillars before fabricating the glass through-hole.
[0042] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.
[0043] Specifically, Figure 1 This is a schematic diagram of a crack in a related packaging substrate; Figure 2 This is a schematic cross-sectional view of the packaging substrate in one embodiment of this application; Figure 3 This is a top view of the isolation ring of the packaging substrate in one embodiment of this application; Figure 4 This is a top view of the multilayer isolation ring of the packaging substrate in one embodiment of this application; Figure 5 This is a top view of the area isolation pillars of the packaging substrate in one embodiment of this application; Figure 6 This is a top view of the isolation ring and regional isolation pillars of the packaging substrate in one embodiment of this application; Figure 7 This is a flowchart of a method for preparing a packaging substrate according to an embodiment of this application.
[0044] Please refer to Figure 2This application provides a packaging substrate, including a substrate body 100 and an isolation structure 200. Along a direction perpendicular to the substrate body 100, a plurality of through holes 110 are provided on the substrate body 100. The isolation structure 200 is disposed on one side of the substrate body 100. The isolation structure 200 includes an isolation ring 210 and / or regional isolation pillars 220. The orthographic projection of the isolation ring 210 on the substrate body 100 surrounds the orthographic projection of a single through hole 110 on the substrate body 100, and / or the orthographic projection of the regional isolation pillars 220 on the substrate body 100 surrounds the orthographic projection of the plurality of through holes 110 on the substrate body 100.
[0045] The substrate body 100 is the base of the encapsulation substrate and is used to support the redistribution layer. In this embodiment, the substrate body 100 is a glass substrate. In other embodiments, the substrate body 100 of the encapsulation substrate may also be other insulating substrates, such as ceramic substrates or silicon substrates, without specific limitations. Compared with silicon substrates, glass substrates have better mechanical strength and high-temperature resistance, reducing warpage of the encapsulation substrate body 100 during the encapsulation process; moreover, the glass material makes the fabrication of large-size ultra-thin encapsulation substrates easier than silicon-based adapters, eliminating the need for insulating layer deposition, resulting in lower manufacturing costs and difficulty.
[0046] In some embodiments, the substrate body 100 may adopt a rectangular plate-like structure. Of course, the substrate body 100 may also adopt a circular, irregular, or other shaped plate-like structure, without specific limitation.
[0047] As one possible implementation, the thickness of the substrate body 100 ranges from 5 μm to 10 mm. Optionally, the thickness of the substrate body 100 ranges from 200 μm to 500 μm, for example, the thickness range of the substrate body 100 is 200 μm, 300 μm, 350 μm, 400 μm, 500 μm, etc., and is not limited.
[0048] In this embodiment, a plurality of through holes 110 are provided on the substrate body 100. These through holes 110 are TGV vias, enabling vertical electrical interconnection through the substrate body 100, allowing circuits or components on both sides of the substrate body 100 to be electrically connected via the through holes 110. The through holes 110 are filled with a metallic material to achieve electrical connection. In one embodiment of the invention, the metallic material filling the through holes 110 is one or a combination of copper, tungsten, aluminum, silver, and titanium.
[0049] In this embodiment, the isolation structure 200 is made of SiOx. SiOx has a sponge-like porous structure, which can disperse the local heat generated during the TGV process and prevent microcracks from forming on the substrate due to thermal stress concentration. When microcracks appear in the substrate body 100, the structure of the SiOx layer can block the force conduction path of the crack and prevent the crack from spreading across regions.
[0050] For example, SiOx can be SiO, SiO2, or Si2O3.
[0051] In a preferred embodiment, the isolation structure 200 is made of multiple layers of SiOx with different densities, and the SiOx density is lower along the direction away from the via. Compared to a single layer of SiOx, the multi-layered SiOx structure can more effectively disperse the thermal stress generated by the TGV process.
[0052] Specifically, the formation of SiOx in different layers mainly depends on the precise control of the proportion of reactant gases, temperature, and pressure during the deposition process.
[0053] In this embodiment, the thickness of the isolation structure 200 is 200-600 nm in the thickness direction of the substrate body 100.
[0054] Preferably, the thickness of the isolation structure 200 is 300-500 nm in the thickness direction of the substrate body 100. For example, the thickness of the isolation structure 200 is 300 nm, 350 nm, 400 nm, 450 nm, or 500 nm.
[0055] In one embodiment, the isolation structure 200 includes an isolation ring 210. The orthographic projection of the isolation ring 210 on the substrate body 100 surrounds the orthographic projection of the single through-hole 110 on the substrate body 100.
[0056] It should be noted that the isolation ring 210 is annular. Each isolation ring 210 surrounds a through hole 110, and each through hole 110 corresponds to at least one isolation ring 210. The isolation ring 210 can effectively disperse the heat generated during the TVG process, preventing microcracks from forming in the through hole due to heat concentration; if cracks have already appeared on the substrate body 100, the isolation ring 210 can also block the crack conduction path, preventing crack extension and propagation, thereby improving the single-hole yield and overall reliability of the packaging substrate.
[0057] For example, such as Figure 3 As shown, each through hole 110 corresponds to an isolation ring 210. That is, an isolation ring 210 surrounds the periphery of a through hole 110, forming a single-layer isolation ring 210 structure. The single-layer isolation ring 210 structure is relatively simple, but it can still achieve the effect of absorbing heat and reducing cracks.
[0058] It should be noted that, in this embodiment, as Figure 4 As shown, the number of isolation rings 210 can also be set to multiple.
[0059] Specifically, multiple isolation rings 210 are sequentially sleeved around the through hole 110, with the inner diameter of the multi-layer isolation rings gradually increasing from the inside to the outside. Compared with a single-layer isolation ring 210, the multi-layer isolation ring 210 has a better thermal stress dispersion effect, thus making it less likely for cracks to appear on the through hole 110.
[0060] In this embodiment, the orthographic projection of the isolation ring 210 onto the substrate body 100 and the orthographic projection of the corresponding through-hole 110 onto the substrate body 100 are concentrically arranged. Since the heat generated during the TGV process diffuses radially from the through-hole 110, the concentrically arranged isolation ring 210 can uniformly absorb thermal stress in all directions, preventing thermal stress concentration on one side of the through-hole due to local misalignment, thus preventing microcracks. This concentric arrangement allows for a larger and better protection range with a smaller isolation ring 210. In other words, the distance between the center of the orthographic projection of the isolation ring 210 onto the substrate body 100 and the center of the orthographic projection of the corresponding through-hole 110 onto the substrate body 100 is small.
[0061] In this embodiment, the spacing between the isolation structure 200 and the adjacent via 110 is 10-30 nm. For example... Figure 2 As shown, the spacing d1 between the isolation ring 210 and the adjacent via 110 is 10-30 nm. For example, the spacing d1 is 10 nm, 15 nm, 20 nm, 25 nm, or 30 nm. Alternatively, the distance between the isolation structure 200 and the adjacent via 110 is not less than 10 nm.
[0062] In another embodiment, the isolation structure 200 includes regional isolation pillars 220. For example... Figure 5 As shown, the orthographic projection of the zone isolation pillars 220 on the substrate body 100 surrounds the orthographic projection of the plurality of vias 110 on the substrate body 100. The zone isolation pillars 220 are used to solve the problem of microcracks extending and growing between different vias 110.
[0063] It should be noted that the area isolation pillars 220 are rectangular in shape. Each area isolation pillar 220 surrounds multiple vias 110; each via 110 corresponds to at least one area isolation pillar 220. The area isolation pillars 220 and the isolation rings 210 have the same technical effect: to disperse the heat generated by laser-induced etching, preventing large-area microcracks from forming on the substrate body 100 due to accumulated thermal stress. The area isolation pillars 220 can also prevent the deterioration and propagation of microcracks between different vias 110. Specifically, when microcracks extend between vias 110, the area isolation pillars 220 can block the crack path and prevent the crack from propagating across the vias 110.
[0064] It should be noted that the area isolation pillar 220 surrounds at least two through holes 110. For example, as shown... Figure 5 As shown, the zone isolation pillar 220 surrounds nine through holes 110. If a microcrack occurs in any of the nine through holes 110, the microcrack will be blocked by the zone isolation pillar 220 when it grows to the zone isolation pillar, effectively reducing the crack and preventing its further extension and growth.
[0065] In this embodiment, the thickness of the regional isolation pillars 220 is the same as the thickness of the substrate body 100. The regional isolation pillars 220 with the same thickness can enhance the mechanical strength of the via 110 region within the substrate body 100 and reduce the problem of excessive brittleness of the substrate body 100 due to excessively high hole density.
[0066] In this embodiment, the spacing between the isolation structure 200 and the adjacent via 110 is 10-30 nm. For example... Figure 5 As shown, the spacing d2 between the area isolation pillar and the adjacent via 110 is 10-30 nm. For example, the spacing d2 is 10 nm, 15 nm, 20 nm, 25 nm, or 30 nm.
[0067] In another embodiment, such as Figure 6 As shown, the isolation structure 200 includes an isolation ring 210 and regional isolation pillars 220. The isolation ring 210 is mainly designed for a single through-hole 110, surrounding the single through-hole to form point-to-point close-range protection; while the regional isolation pillars 220 surround multiple through-holes 110, which can not only disperse the heat accumulated between the through-holes 110 and prevent the microcracks around the holes from extending outward, but also prevent the deterioration and propagation of microcracks from affecting other normal areas. In this embodiment, the isolation ring 210 and regional isolation pillars 220 are simultaneously provided on the substrate body 100. The combination of the two can maximize the improvement of microcracks and greatly reduce the overall microcrack incidence rate of the packaging substrate.
[0068] For example, such as Figure 6 As shown, the orthographic projection of a regional isolation pillar 220 on the substrate body 100 surrounds the orthographic projections of nine arrayed through holes 110 on the substrate body 100. Simultaneously, an isolation ring 210 is provided around each through hole 110, meaning that the orthographic projection of each isolation ring 210 on the substrate body 100 surrounds the orthographic projection of a single through hole 110 on the substrate body 100. The isolation ring 210 can be a single isolation ring 210, or multiple isolation rings 210 arranged concentrically, a single multi-layered isolation ring 210, or multiple multi-layered isolation rings.
[0069] This application achieves the effect of blocking thermally-induced cracks in the packaging substrate and their continuous deterioration and growth by setting a pre-surrounding isolation ring and / or regional isolation pillars before fabricating the glass through-hole.
[0070] Based on the same inventive concept, such as Figure 7 As shown, this application also proposes a method for preparing a packaging substrate, which specifically includes the following steps:
[0071] S1: A substrate is provided, and at least one isolation film layer is stacked on one side of the substrate;
[0072] The substrate body 100 is the base of the encapsulation substrate and is used to support the redistribution layer. In this embodiment, the substrate body 100 is a glass substrate. In other embodiments, the substrate body 100 of the encapsulation substrate may also be other insulating substrates, such as ceramic substrates or silicon substrates, without specific limitations. Compared with silicon substrates, glass substrates have better mechanical strength and high-temperature resistance, reducing warpage of the encapsulation substrate body 100 during the encapsulation process; moreover, the glass material makes the fabrication of large-size ultra-thin encapsulation substrates easier than silicon-based adapters, eliminating the need for insulating layer deposition, resulting in lower manufacturing costs and difficulty.
[0073] In some embodiments, the substrate body 100 may adopt a rectangular plate-like structure. Of course, the substrate body 100 may also adopt a circular, irregular, or other shaped plate-like structure, without specific limitation.
[0074] In this embodiment, the isolation film is fabricated by chemical vapor deposition (CVD). Specifically, a SiOx film is deposited on the surface of the substrate 100.
[0075] S2: Coat the isolation film layer with photoresist to form a photoresist layer;
[0076] The photoresist layer can be made of either positive or negative photoresist. For positive photoresist, the exposed portions are soluble in the developer, while the unexposed portions are insoluble. For negative photoresist, the exposed portions are insoluble in the developer, while the unexposed portions are soluble. The photoresist layer is generally made of organic materials. For example, it can be applied using static or dynamic coating methods.
[0077] After applying the photoresist, the photoresist layer needs to be soft-baked to enhance the adhesion between the photoresist and the SiOx film, while also improving the thermal stability of the photoresist to prevent deformation during subsequent exposure.
[0078] S3: After sequentially exposing and developing the photoresist layer, a photoresist pattern is obtained, and the isolation film layer is dry-etched according to the pattern to form an isolation structure;
[0079] Photoresist patterns can be obtained by patterning a photoresist layer. The patterning process includes exposure and development of the photoresist layer. Specifically, a photoresist layer can be formed on the side of the isolation film layer facing away from the substrate 100, and then the photoresist layer is exposed and developed to form the desired photoresist pattern. This photoresist pattern includes an area exposing a portion of the surface of the isolation film layer facing away from the substrate 100. It should be noted that the photoresist pattern needs to be removed after the patterning process of the isolation film layer is completed.
[0080] It should be noted that the photoresist needs to be hard-baked before dry etching. This further enhances the adhesion and etching resistance of the photoresist, ensuring that it does not peel off or deform during the subsequent dry etching process.
[0081] Specifically, the isolation structure 200 includes an isolation ring 210 and / or a regional isolation pillar 220; the orthographic projection of the isolation ring 210 on the substrate body 100 surrounds the orthographic projection of the single through hole 110 on the substrate body 100 and / or the orthographic projection of the regional isolation pillar 220 on the substrate body 100 surrounds the orthographic projection of the plurality of through holes 110 on the substrate body 100.
[0082] In this embodiment, the isolation structure 200 is made of SiOx. SiOx has a sponge-like porous structure, which can disperse the local heat generated during the TGV process and prevent microcracks from forming on the substrate due to thermal stress concentration. When microcracks appear in the substrate body 100, the structure of the SiOx layer can block the force conduction path of the crack and prevent the crack from spreading across regions.
[0083] In one embodiment, the isolation structure 200 includes an isolation ring 210. The orthographic projection of the isolation ring 210 on the substrate body 100 surrounds the orthographic projection of the single through-hole 110 on the substrate body 100.
[0084] It should be noted that the isolation ring 210 is annular. Each isolation ring 210 surrounds a through hole 110, and each through hole 110 corresponds to at least one isolation ring 210. The isolation ring 210 can effectively disperse the heat generated during the TVG process, preventing microcracks from forming in the through hole due to heat concentration; if cracks have already appeared on the substrate body 100, the isolation ring 210 can also block the crack conduction path, preventing crack extension and propagation, thereby improving the single-hole yield and overall reliability of the packaging substrate.
[0085] For example, such as Figure 2 As shown, each through hole 110 corresponds to an isolation ring 210. That is, an isolation ring 210 surrounds the periphery of a through hole 110, forming a single-layer isolation ring 210 structure. The single-layer isolation ring 210 structure is relatively simple, but it can still achieve the effect of absorbing heat and reducing cracks.
[0086] It should be noted that, in this embodiment, as Figure 3 As shown, the number of isolation rings 210 can also be set to multiple.
[0087] Specifically, multiple isolation rings 210 are sequentially sleeved around the through hole 110, with the inner diameter of the multi-layer isolation rings gradually increasing from the inside to the outside. Compared with a single-layer isolation ring 210, the multi-layer isolation ring 210 has a better thermal stress dispersion effect, thus making it less likely for cracks to appear on the through hole 110.
[0088] In this embodiment, the orthographic projection of the isolation ring 210 onto the substrate body 100 and the orthographic projection of the corresponding through-hole 110 onto the substrate body 100 are concentrically arranged. Since the heat generated during the TGV process diffuses radially from the through-hole 110, the concentrically arranged isolation ring 210 can uniformly absorb thermal stress in all directions, preventing thermal stress concentration on one side of the through-hole due to local misalignment, thus preventing microcracks. This concentric arrangement allows for a larger and better protection range with a smaller isolation ring 210. In other words, the distance between the center of the orthographic projection of the isolation ring 210 onto the substrate body 100 and the center of the orthographic projection of the corresponding through-hole 110 onto the substrate body 100 is small.
[0089] In this embodiment, the spacing between the isolation structure 200 and the adjacent via 110 is 10-30 nm. For example... Figure 2 As shown, the spacing d1 between the isolation ring 210 and the adjacent via 110 is 10-30 nm. For example, the spacing d1 is 10 nm, 15 nm, 20 nm, 25 nm, or 30 nm.
[0090] In another embodiment, the isolation structure 200 includes regional isolation pillars 220. For example... Figure 5 As shown, the orthographic projection of the zone isolation pillars 220 on the substrate body 100 surrounds the orthographic projection of the plurality of vias 110 on the substrate body 100. The zone isolation pillars 220 are used to solve the problem of microcracks extending and growing between different vias 110.
[0091] It should be noted that the area isolation pillars 220 are rectangular in shape. Each area isolation pillar 220 surrounds multiple vias 110; each via 110 corresponds to at least one area isolation pillar 220. The area isolation pillars 220 and the isolation rings 210 have the same technical effect: to disperse the heat generated by laser-induced etching, preventing large-area microcracks from forming on the substrate body 100 due to accumulated thermal stress. The area isolation pillars 220 can also prevent the deterioration and propagation of microcracks between different vias 110. Specifically, when microcracks extend between vias 110, the area isolation pillars 220 can block the crack path and prevent the crack from propagating across the vias 110.
[0092] It should be noted that the area isolation pillar 220 surrounds at least two through holes 110. For example, as shown... Figure 5As shown, the area isolation pillar 220 surrounds nine through holes 110. If a microcrack occurs in any of the nine through holes 110, the microcrack will grow to the area isolation pillar 220 and be blocked by the area isolation pillar 210, effectively reducing the crack and preventing its further extension and growth.
[0093] In this embodiment, the thickness of the regional isolation pillars 220 is the same as the thickness of the substrate body 100. The regional isolation pillars 220 with the same thickness can enhance the mechanical strength of the via 110 region within the substrate body 100 and reduce the problem of excessive brittleness of the substrate body 100 due to excessively high hole density.
[0094] In this embodiment, the spacing between the isolation structure 200 and the adjacent via 110 is 10-30 nm. For example... Figure 5 As shown, the spacing d2 between the area isolation pillar and the adjacent via 110 is 10-30 nm. For example, the spacing d2 is 10 nm, 15 nm, 20 nm, 25 nm, or 30 nm.
[0095] In another embodiment, such as Figure 6 As shown, the isolation structure 200 includes an isolation ring 210 and regional isolation pillars 220. The isolation ring 210 is mainly designed for a single through-hole 110, surrounding the single through-hole to form point-to-point close-range protection; while the regional isolation pillars 220 surround multiple through-holes 110, which can not only disperse the heat accumulated between the through-holes 110 and prevent the microcracks around the holes from extending outward, but also prevent the deterioration and propagation of microcracks from affecting other normal areas. In this embodiment, the isolation ring 210 and regional isolation pillars 220 are simultaneously provided on the substrate body 100. The combination of the two can maximize the improvement of microcracks and greatly reduce the overall microcrack incidence rate of the packaging substrate.
[0096] For example, such as Figure 6 As shown, the orthographic projection of a regional isolation pillar 220 on the substrate body 100 surrounds the orthographic projections of nine arrayed through holes 110 on the substrate body 100. Simultaneously, an isolation ring 210 is provided around each through hole 110, meaning that the orthographic projection of each isolation ring 210 on the substrate body 100 surrounds the orthographic projection of a single through hole 110 on the substrate body 100. The isolation ring 210 can be a single isolation ring 210, or multiple isolation rings 210 arranged concentrically, a single multi-layered isolation ring 210, or multiple multi-layered isolation rings.
[0097] S4: Peel off the residual photoresist layer on the substrate, create through-holes, and complete the preparation of the packaging substrate.
[0098] Specifically, the residual photoresist after dry etching is removed to expose the complete isolation structure, providing a clean surface for the subsequent fabrication of vias and preventing residual photoresist from affecting the etching accuracy of via 110.
[0099] The through-hole 110 is a TGV via, which enables vertical electrical interconnection through the substrate body 100, allowing circuits or components on both sides of the substrate body 100 to be electrically connected through the through-hole 110. The through-hole 110 is filled with a metallic material to achieve electrical connection.
[0100] In one embodiment of the present invention, the metal material filling the through hole 110 is one or a combination of copper, tungsten, aluminum, silver, and titanium.
[0101] It should be noted that the packaging substrate fabrication process in this embodiment further includes:
[0102] An RDL layer is provided on the front side or the back side of the substrate body 100, and both the front RDL layer and the back RDL layer are electrically connected through through-holes 110.
[0103] The substrate surface is also provided with a plating layer, which covers the inner wall of the through hole, i.e., the surface of the isolation structure. The plating layer is made of nickel-gold alloy.
[0104] The front and back RDL layers also include dielectric layers and metal wiring. The dielectric layer is fabricated using silicon dioxide deposition via resist coating, photolithography and development, or chemical vapor deposition (CVD). Part of the dielectric layer on the chip surface is then partially opened using mechanical drilling, wet and dry etching, and photolithography to create space for subsequent metal wiring fabrication. The metal wiring layer is a film layer fabricated on the dielectric layer. It is fabricated using processes such as sputtering, resist coating, photolithography, development, electroplating, resist removal, and etching. The metals used can be copper, aluminum, nickel, gold, tin, tin-silver, etc. Solder balls are also placed on the metal wiring layer. Solder balls are fabricated in the opening areas using processes such as electroplating, printing, and ball placement. The solder balls are electrically connected to the circuitry on the side of the isolation structure 200 via via 110. The solder balls can be made of tin, tin-silver, a combination of copper and tin-silver, or a combination of copper and nickel and tin-silver.
[0105] It should be noted that the above description describes some embodiments of this disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.
[0106] This disclosure is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.
Claims
1. A packaging substrate, characterized in that, include: The substrate body has a plurality of through holes in a direction perpendicular to the substrate body. An isolation structure is disposed on one side of the substrate body; the isolation structure includes an isolation ring and / or a regional isolation pillar; the orthographic projection of the isolation ring on the substrate body surrounds the orthographic projection of a single through hole on the substrate body and / or the orthographic projection of the regional isolation pillar on the substrate body surrounds the orthographic projection of a plurality of through holes on the substrate body.
2. The packaging substrate according to claim 1, characterized in that, The isolation structure is made of SiOx; Preferably, the isolation structure is made of multiple layers of SiOx with different densities, and the SiOx density is smaller along the direction away from the through hole.
3. The packaging substrate according to claim 1, characterized in that, The substrate body is made of inorganic materials; Preferably, the substrate body is made of glass.
4. The packaging substrate according to claim 1, characterized in that, Each of the through holes corresponds to at least one of the isolation rings; The orthographic projection of the isolation ring on the substrate body is concentric with the orthographic projection of the corresponding through hole on the substrate body.
5. The packaging substrate according to claim 1, characterized in that, In the thickness direction of the substrate body, the thickness of the isolation structure is 200-600 nm; Preferably, the thickness of the isolation structure is 300-500 nm in the thickness direction of the substrate body.
6. The packaging substrate according to claim 1, characterized in that, The spacing between the isolation structure and the adjacent through-hole is 10-30 nm.
7. The packaging substrate according to claim 1, characterized in that, The isolation ring is ring-shaped.
8. The packaging substrate according to claim 1, characterized in that, The regional isolation pillars are rectangular in shape.
9. A method for preparing a packaging substrate, characterized in that, Includes the following steps: A substrate body is provided, and at least one isolation film layer is stacked on one side of the substrate body; Photoresist is coated on the isolation film layer to form a photoresist layer; After the photoresist layer is exposed and developed in sequence, an isolation structure pattern is obtained, and the isolation film layer is dry-etched according to the pattern to form an isolation structure; The residual photoresist layer on the substrate body is peeled off to create through-holes, thus completing the preparation of the packaging substrate.
10. The method for preparing a packaging substrate according to claim 9, characterized in that, Also includes: The material of the isolation membrane is SiOx.