Packaging substrate with infiltrated side wings and method of fabrication
By using an etch barrier layer as a protective layer on the semiconductor packaging substrate, the limitations of wire bonding are overcome, enabling high-quality side-mounted vertical assembly and multi-directional functionality, while reducing packaging costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHUHAI YUEXIN SEMICON LLC
- Filing Date
- 2024-12-17
- Publication Date
- 2026-07-31
AI Technical Summary
In existing semiconductor packaging technologies, wire bonding cannot meet the requirements for high I/O numbers, leading to increased packaging costs and reduced product yield. At the same time, it makes heat dissipation difficult and makes it hard to achieve side vertical assembly and multi-directional transceiver functions.
An etch barrier layer is used as a protective layer for the etch sacrificial copper pillars of the carrier board. By stacking the etch barrier layer and the metal seed layer, a packaging substrate that can wet the side wings is formed, avoiding problems such as incomplete plating, dents and etch perforations, and simplifying the process flow.
It achieves a smooth and regular cavity structure at the bottom, improves the quality of the packaging substrate, reduces costs, and supports side vertical assembly and multi-directional functional requirements.
Smart Images
Figure CN119812004B_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of packaging technology, and in particular to a packaging substrate with wettable side wings and a method for manufacturing it. Background Technology
[0002] In semiconductor packaging technology, whether it is bump flip-chip packaging technology based on metal bumps (also known as bumps), or packaging technologies based on pin mounting, through-hole mounting, wire bonding, etc., metal bumps or leads are arranged on the chip as electrical connection points to the lead frame or IC substrate (Integrated Circuit, abbreviated as IC).
[0003] As the number of I / Os increases, wire bonding packaging can no longer meet packaging requirements. The limited area of the packaging structure also restricts the increase in the number of solder balls on the substrate. Related technologies address this issue by arranging redistribution layers on the wafer to increase the spacing and create new electrical contacts, thus forming Ball Grid Array (BGA) or Land Grid Array (LGA) packages. However, this approach leads to reduced product yield and increased packaging costs. Furthermore, because the solder pads are located at the bottom of the package, devices can only be vertically mounted on the printed circuit board using surface mounting. Device heat dissipation needs to be conducted downwards through the circuitry or actively cooled from the back of the device, making it unsuitable for side-mounted vertical assembly scenarios and failing to meet the multi-directional transceiver requirements of specific semiconductor devices. Summary of the Invention
[0004] In view of this, the purpose of this disclosure is to provide a packaging substrate with wettable side wings and a method for manufacturing it.
[0005] To achieve the above objectives, this disclosure provides a method for fabricating a packaging substrate with wettable side wings, comprising:
[0006] (a) Prepare a carrier plate; wherein the carrier plate includes an etch barrier layer and a first metal seed layer on the etch barrier layer, which are stacked together;
[0007] (b) Forming sacrificial copper pillars on the first metal seed layer;
[0008] (c) A laminated dielectric material covers the sacrificial copper pillar to form a first dielectric layer, and exposes the end face of the sacrificial copper pillar so that the end face of the sacrificial copper pillar is flush with the first surface of the first dielectric layer.
[0009] (d) Etching the sacrificial copper pillar to form a cavity structure with the etching barrier layer at the bottom;
[0010] (e) A first circuit layer is formed on the first surface and the inner wall of the cavity structure;
[0011] (f) Remove the carrier plate to expose the second surface of the first dielectric layer;
[0012] (g) A second circuit layer is formed on the second surface of the first dielectric layer;
[0013] The cavity structure is longitudinally cut to obtain a packaging substrate with wettable winglets formed by the first circuit layer.
[0014] In some embodiments, it also includes:
[0015] (h) A surface treatment layer is formed on the first circuit layer and the second circuit layer.
[0016] In some embodiments, the thickness of the first metal seed layer is 1–3 μm; and / or
[0017] The material of the first metal seed layer is copper.
[0018] In some embodiments, step (b) forms the sacrificial copper pillar by pattern electroplating.
[0019] In some embodiments, step (d) includes:
[0020] A first photoresist layer is formed by attaching a film to the first surface of the first dielectric layer, exposing it, and developing it.
[0021] Etch the sacrificial copper pillars until the etch barrier layer is exposed;
[0022] Remove the first photoresist layer.
[0023] In some embodiments, the carrier plate further includes a first metal layer and a second metal layer physically bonded together; the etch barrier layer is located on the side of the second metal layer away from the first metal layer;
[0024] Step (f) specifically includes:
[0025] Separate the first metal layer and the second metal layer;
[0026] The second metal layer and the etch barrier layer are etched.
[0027] In some embodiments, before etching the second metal layer and the etch barrier layer, the method further includes forming a second photoresist layer covering the first surface on a first surface of the first dielectric layer.
[0028] In some embodiments, the material of the etch barrier layer includes at least one of nickel, titanium, and tin.
[0029] In some embodiments, step (g) includes:
[0030] A second metal seed layer is formed on the second surface of the first dielectric layer;
[0031] A second pattern layer is formed by attaching a film to the surface of the second metal seed layer, exposing it, and developing it.
[0032] A second circuit layer is electroplated in the second pattern layer;
[0033] Remove the second pattern layer;
[0034] The second metal seed layer is etched.
[0035] Based on the same inventive concept, embodiments of this disclosure also provide a packaging substrate manufactured by any of the aforementioned manufacturing methods.
[0036] In some embodiments, the packaging substrate includes a first dielectric layer, a first circuit layer, and a second circuit layer; wherein the first circuit layer and the second circuit layer are located on two surfaces of the first dielectric layer, and the first circuit layer extends to cover the sidewalls of the first dielectric layer to form wettable wing.
[0037] As can be seen from the above description, this disclosure provides a packaging substrate with wettable side wings and a method for manufacturing it. Specifically, the manufacturing method uses the etch barrier layer of the carrier plate as a protective layer for etching the sacrificial copper pillars, eliminating the need for an electroplated protective layer. This fundamentally prevents quality problems such as incomplete plating, dents, and etch perforations, resulting in a smooth and regular cavity structure at the bottom, which helps improve the quality of the packaging substrate with wettable side wings. Furthermore, the manufacturing method provided in this disclosure reduces the number of process steps, helping to lower costs. Attached Figure Description
[0038] 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.
[0039] Figure 1 A schematic flowchart illustrating a method for fabricating a packaging substrate with wettable side wings, provided for related technologies;
[0040] Figures 2(a) to 2(i) This is a cross-sectional schematic diagram of the intermediate structure of each step in a method for manufacturing a packaging substrate with wettable side wings provided in an embodiment of this disclosure. Detailed Implementation
[0041] 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.
[0042] 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 words 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.
[0043] In related technologies, to meet the requirements of vertical side assembly, the copper block is directly cut. However, this method is difficult to eliminate cracks and burrs, easily leading to product quality issues. Other technical solutions, such as... Figure 1 As shown, the method of first fabricating a cavity sacrificial copper pillar and then electroplating a metal layer as an etching barrier layer is complex and costly. Furthermore, the etching barrier layer is prone to incomplete plating, which can lead to quality problems such as dents and etching perforations at the bottom of the cavity.
[0044] In view of this, the present disclosure provides a wettable wing-type packaging substrate and a method for manufacturing it. Specifically, the method includes (a) preparing a carrier board; wherein the carrier board includes an etch barrier layer and a first metal seed layer stacked on the etch barrier layer; (b) forming sacrificial copper pillars on the first metal seed layer; (c) laminating a dielectric material to form a first dielectric layer exposing the end faces of the sacrificial copper pillars; (d) etching the sacrificial copper pillars to form a cavity structure with the etch barrier layer as the bottom; (e) forming a first circuit layer on a first surface of the first dielectric layer and the inner wall of the cavity structure; (f) removing the carrier board to expose a second surface of the first dielectric layer; (g) forming a second circuit layer on the second surface of the first dielectric layer; wherein the first circuit layer is capable of forming a wettable wing structure after the cavity structure is cut. This technical solution uses the etch barrier layer of the carrier board as a protective layer for the etched sacrificial copper pillars, eliminating the need for an electroplated protective layer and fundamentally preventing quality issues such as incomplete plating, dents, and etch perforations. It results in a smooth, regular cavity structure at the bottom, which helps improve the quality of the wetting-compatible packaging substrate. Furthermore, the manufacturing method provided in this disclosure reduces the number of process steps, contributing to cost reduction.
[0045] Figures 2(a) to 2(i) This is a cross-sectional schematic diagram of the intermediate structure of each step in a method for manufacturing a packaging substrate with wettable side wings provided in an embodiment of this disclosure.
[0046] like Figures 2(a) to 2(i) As shown, the manufacturing method includes:
[0047] First, prepare a support plate 100—step (a), as shown in Figure 2(a).
[0048] In some embodiments, the carrier plate 100 sequentially includes a core layer 101, a first metal layer 102, a second metal layer 103, an etch barrier layer 104, and a first metal seed layer 105.
[0049] Optionally, the first metal layer 102 and the second metal layer 103 can be copper layers, which are physically bonded together and can be physically separated, such as by tearing.
[0050] Alternatively, the material of the etch barrier layer 104 may include at least one of nickel, titanium, and tin.
[0051] Optionally, the first metal seed layer 105 is typically made of copper, which can serve as a conductive base for subsequent electroplating. Optionally, the thickness of the first metal seed layer 105 is 1–3 μm, for example, 1 μm, 2 μm, or 3 μm.
[0052] Next, a sacrificial copper pillar 201 is formed on the first metal seed layer 105—step (b), as shown in Figure 2(b).
[0053] For example, step (b) may include: first, attaching a film to the first metal seed layer 105, exposing and developing it to form a first pattern layer, then performing pattern electroplating, and finally removing the film and etching the first metal seed layer 105 to obtain the sacrificial copper pillar 201.
[0054] As can be seen from Figure 2(b), the sacrificial copper pillar 201 is located on the etch barrier layer 104, and its bottom is in direct contact with the etch barrier layer 104.
[0055] Then, a first dielectric layer 301 is formed by laminating dielectric material, and the first surface A of the first dielectric layer 301 is exposed and flush with the end face of the sacrificial copper pillar 201—step (c), as shown in Figure 2(c). Here, the end face of the sacrificial copper pillar 201 can be exposed by mechanical grinding.
[0056] In some embodiments, the material of the first dielectric layer 301 may be a glass fiber-free resin material, such as selected from the group consisting of liquid crystal polymers, BT (bismaleimide triazine) resin, prepreg, ABF (Ajinomoto build-up) film, epoxy resin and polyimide resin, but this disclosure is not limited thereto.
[0057] Next, the sacrificial copper pillar 201 is etched to form a cavity structure 501 with the etch barrier layer 104 as its bottom—step (d), as shown in FIG2(d). Here, the opening of the cavity structure 501 is located on the first surface A of the first dielectric layer 301, and the bottom of the cavity structure 501 is relative to the opening of the cavity structure 501. The bottom and the opening are located at the two ends of the cavity structure 501, respectively.
[0058] For example, step (d) may include: first, attaching a film to the first surface A of the first dielectric layer 301, exposing it, and developing it to form a first photoresist layer; next, etching the sacrificial copper pillar 201 until the etch barrier layer 104 is exposed to obtain the cavity structure 501, and finally removing the first photoresist layer.
[0059] In some embodiments, the step of forming the first photoresist layer may be omitted, and etching may be performed directly; this disclosure does not limit this.
[0060] It should be noted that the etching barrier layer 104 can precisely control the etching progress of the sacrificial copper pillar 201, ensuring that the sacrificial copper pillar 201 is completely etched and effectively protecting the second metal layer 103. The bottom of the cavity structure 501 is the etching barrier layer 104, whose surface is smooth and regular, without dents or perforations, which helps in the subsequent fabrication of the first circuit layer.
[0061] The etch barrier layer 104 is a layer structure derived from the carrier plate 100. It not only reduces the process steps of conventional electroplating etch barrier layers, but also fundamentally solves the technical problems caused by electroplating etch barrier layers, such as incomplete plating and the presence of dents. Furthermore, since there is no problem of incomplete plating, the problem of etch perforation caused by the lack of protection due to incomplete plating is avoided.
[0062] Then, a first circuit layer 302 is formed in the first surface of the first dielectric layer 301 and the cavity structure 501—step (e), as shown in FIG2(e).
[0063] In some embodiments, step (e) includes: first, fabricating a third metal seed layer; next, applying a film, exposing, and developing to form a third pattern layer; and then electroplating a first circuit layer 302 on the third pattern layer.
[0064] Optionally, the fabrication of the third metal seed layer includes sputtering and plated through-hole (PTH) processes. Using such processes, a third metal seed layer can be formed on the surface of the cavity structure 501, thereby ensuring that a plating layer can be formed in the cavity structure 501 during subsequent electroplating processes, which helps the first circuit layer 302 extend to the sidewalls and bottom of the cavity structure 501.
[0065] The first circuit layer 302 extends from the surface of the first dielectric layer 301 to the sidewalls and bottom of the cavity structure 501. The first circuit layer 302 is not only located on the surface of the first dielectric layer 301, but also extends to the thickness direction of the first dielectric layer 301. This structure facilitates the vertical mounting of the packaging substrate on the side.
[0066] Next, the carrier plate 100 is removed, exposing the second surface B of the first dielectric layer 301—step (f), as shown in Figure 2(f).
[0067] In some embodiments, step (f) specifically includes:
[0068] Separate the first metal layer 102 and the second metal layer 103;
[0069] The second metal layer 103 and the etching barrier layer 104 are etched.
[0070] It should be noted that when etching the second metal layer 103, the etching barrier layer 104 can protect the first circuit layer 302 of the substrate and prevent over-etching.
[0071] Optionally, before etching the second metal layer 103 and the etching barrier layer 104, the method further includes: forming a second photoresist layer 303 covering the entire surface of the first dielectric layer 301 to protect the second circuit layer 302. After etching the barrier layer 104, the second photoresist layer 303 is removed.
[0072] Then, a second circuit layer 402 is formed on the second surface B of the first dielectric layer 301; wherein, referring to FIG2(i), the second circuit layer 402 can be together with the first circuit layer 302 to form a wettable wing structure after cutting the cavity structure 501—step (g), as shown in FIG2(g).
[0073] In some embodiments, step (g) includes:
[0074] A second metal seed layer is formed on the second surface B of the first dielectric layer 301; here, compared with the fabrication of a third metal seed layer, the fabrication of the second metal seed layer can omit the chemical copper plating process.
[0075] A second pattern layer is formed by attaching a film to the surface of the second metal seed layer, exposing it, and developing it.
[0076] The second circuit layer 402 is electroplated in the second pattern layer;
[0077] Remove the second pattern layer; etch the second metal seed layer.
[0078] Alternatively, the second line layer 402 can be inspected using Automatic Optical Inspection (AOI).
[0079] Next, the solder resist layer 403 and the surface treatment layer 401 are fabricated—step (h), as shown in FIG2(h). Optionally, the surface treatment layer 401 is formed on the first circuit layer 302 and the second circuit layer 402. The solder resist layer 403 is formed on the first dielectric layer 301. It should be noted that the solder resist layer 403 may cover part of the first circuit layer 302 and the second circuit layer 402, and this disclosure does not limit this.
[0080] In some embodiments, the surface treatment layer 401 can be formed by a nickel-palladium-gold (ENEPIG) process. Other surface treatment processes can also be used by those skilled in the art, and this disclosure does not limit them.
[0081] Finally, the cavity structure 501 is cut at a predetermined position to form a packaging substrate capable of wetting the side wings—step (i), as shown in Figure 2(i). The predetermined position can be referred to as the position indicated by the dotted line in Figure 2(i), but this disclosure does not limit it.
[0082] After cutting the cavity structure 501, the first circuit layer 302 on the sidewall and bottom of the cavity structure 501, or together with the second circuit layer 402, is exposed to the side of the packaging substrate to form a wettable side wing structure, which facilitates vertical side assembly.
[0083] Based on the same inventive concept, embodiments of this disclosure also provide a packaging substrate with wettable sidewalls prepared by any of the above-described manufacturing methods. As shown in FIG2(i), the packaging substrate includes a first dielectric layer 301, a first circuit layer 402, and a second circuit layer 302; wherein the first circuit layer 402 and the second circuit layer 302 are located on two surfaces of the first dielectric layer 301, and the first circuit layer 302 extends to the sidewall of the first dielectric layer 301 to form a wettable sidewall. This structure facilitates the vertical assembly of components on the side.
[0084] Optionally, the first circuit layer 302 is electrically connected to the second circuit layer 402 on the sidewall of the first dielectric layer 301.
[0085] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this disclosure (including the claims) is limited to these examples; within the framework of this disclosure, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this disclosure as described above, which are not provided in detail for the sake of brevity.
[0086] 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 method for manufacturing a packaging substrate with wettable side wings, characterized in that, include: (a) Prepare a carrier plate; wherein the carrier plate includes an etch barrier layer and a first metal seed layer on the etch barrier layer, which are stacked together; (b) Forming sacrificial copper pillars on the first metal seed layer; (c) A laminated dielectric material covers the sacrificial copper pillar to form a first dielectric layer, and exposes the end face of the sacrificial copper pillar so that the end face of the sacrificial copper pillar is flush with the first surface of the first dielectric layer; (d) Etching the sacrificial copper pillar to form a cavity structure with the etch barrier layer at the bottom; (e) A first circuit layer is formed on the first surface and the inner wall of the cavity structure; (f) Remove the carrier plate to expose the second surface of the first dielectric layer; (g) A second circuit layer is formed on the second surface of the first dielectric layer; The cavity structure is longitudinally cut to obtain a packaging substrate with wettable side wings formed from the first circuit layer; wherein... The carrier plate further includes a first metal layer and a second metal layer that are physically bonded together; the etching barrier layer is located on the side of the second metal layer away from the first metal layer. Step (f) specifically includes: Separate the first metal layer and the second metal layer; The second metal layer and the etch barrier layer are etched.
2. The manufacturing method according to claim 1, characterized in that, Also includes: (h) A surface treatment layer is formed on the first circuit layer and the second circuit layer.
3. The manufacturing method according to claim 1, characterized in that, The thickness of the first metal seed layer is 1~3 μm; and / or The material of the first metal seed layer is copper.
4. The manufacturing method according to claim 1, characterized in that, Step (b) involves forming the sacrificial copper pillar by pattern electroplating.
5. The manufacturing method according to claim 1, characterized in that, Step (d) includes: A first photoresist layer is formed by attaching a film to the first surface of the first dielectric layer, exposing it, and developing it. Etch the sacrificial copper pillars until the etch barrier layer is exposed; Remove the first photoresist layer.
6. The manufacturing method according to claim 1, characterized in that, Before etching the second metal layer and the etching barrier layer, the method further includes forming a second photoresist layer covering the first surface on the first surface of the first dielectric layer.
7. The manufacturing method according to claim 1, characterized in that, The material of the etch barrier layer includes at least one of nickel, titanium, and tin.
8. The manufacturing method according to claim 1, characterized in that, Step (g) includes: A second metal seed layer is formed on the second surface of the first dielectric layer; A second pattern layer is formed by attaching a film to the surface of the second metal seed layer, exposing it, and developing it. A second circuit layer is electroplated in the second pattern layer; Remove the second pattern layer; The second metal seed layer is etched.
9. A packaging substrate with wettable side wings obtained by the manufacturing method according to any one of claims 1 to 8.
10. The packaging substrate with wettable side wings according to claim 9, characterized in that, The packaging substrate includes a first dielectric layer, a first circuit layer, and a second circuit layer; wherein the first circuit layer and the second circuit layer are located on two surfaces of the first dielectric layer, and the first circuit layer extends to cover the sidewall of the first dielectric layer to form a wettable wing.