Packaging substrate surface treatment manufacturing method and packaging substrate

Abstract

The invention discloses a packaging substrate surface treatment manufacturing method and a packaging substrate. The manufacturing method for surface treatment of the package substrate comprises the following steps: providing a substrate; the substrate is subjected to pretreatment; performing resistance welding on the pre-treated substrate so as to form a resistance welding layer on the substrate; performing first windowing processing on the solder mask layer to enable the substrate to form a first windowing area; performing first surface treatment on the first windowing area to form a first surface layer; performing second windowing processing on the solder mask layer to enable the substrate to form a second windowing area; and performing second surface treatment on the second windowing area to form a second surface layer. According to the method, the method that a dry film is used for selection in a traditional selection process is avoided, and the problem that the service life of surface treatment liquid medicine is shortened due to dry film dissolution substances can be fundamentally solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit board, in particular to a packaging substrate surface treatment manufacturing method and a packaging substrate. BACKGROUND

[0002] There are various surface treatment methods for the surface of the existing packaging substrate to meet different design and use requirements. When two or more surface treatment processes are designed on the same product, the traditional selective process flow will generally process all the windowed areas at one time in the solder resist process, then attach a dry film to the surface of the solder resist, and the dry film is exposed and developed to selectively open the window, so that the surface treatment is performed on the windowed area, such as nickel-palladium-gold plating. Before the next surface treatment, the selective dry film needs to be removed to expose another windowed area for surface treatment in the windowed area. Before the next surface treatment, a new dry film needs to be attached and developed to open the window for surface treatment in another windowed area. Since the dry film will be attacked by the nickel-palladium-gold solution during the first surface treatment (such as nickel-palladium-gold plating) to produce pre-soluble substances, which will affect the service life of the nickel-palladium-gold solution and the quality of the product. Moreover, in the traditional selective process, a dry film is attached to achieve windowing in the specified area, which is complicated to operate and wastes materials. Once the dry film is exposed and developed, the chemical structure of the dry film has changed, and its physical and chemical properties are no longer stable, which will affect the subsequent surface treatment effect. SUMMARY

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application provides a packaging substrate surface treatment manufacturing method, which avoids the method of using a dry film for selective treatment in the traditional selective process, and fundamentally solves the problem of reducing the service life of the surface treatment solution caused by the dry film solubles.

[0004] The present application further provides a packaging substrate.

[0005] According to the packaging substrate surface treatment manufacturing method of the first aspect of the present application, a substrate is provided, the substrate is pretreated, the solder resist layer is formed on the substrate by solder resist treatment, the first windowed area is formed on the solder resist layer by the first windowing treatment, the first surface layer is formed on the first windowed area by the first surface treatment, the second windowed area is formed on the solder resist layer by the second windowing treatment, and the second surface layer is formed on the second windowed area by the second surface treatment.

[0006] According to the packaging substrate surface treatment manufacturing method of the present application, the method of using a dry film for selective treatment in the traditional selective process is avoided, and the problem of reducing the service life of the surface treatment solution caused by the dry film solubles is fundamentally solved.

[0007] According to some embodiments of the present application, the first surface treatment is different from the second surface treatment.

[0008] According to some embodiments of the present application, the first surface treatment and the second surface treatment are respectively a pure metal material plating treatment and an alloy material plating treatment.

[0009] According to some embodiments of the present application, the first surface treatment is a chemical deposition of a layer of nickel-palladium-gold on the first opening area.

[0010] According to some embodiments of the present application, the first surface treatment is a pure metal material plating treatment or an alloy material plating treatment, and the second surface treatment is an organic material plating treatment.

[0011] According to some embodiments of the present application, the surface of the first surface layer of the first opening area is lower than the surface of the solder mask layer; and / or, the surface of the second surface layer of the second opening area is lower than the surface of the solder mask layer.

[0012] According to some embodiments of the present application, the first opening treatment of the solder mask layer includes: selectively exposing and developing the solder mask layer to form the first opening area, and the first opening area exposes the copper surface of the substrate.

[0013] According to some embodiments of the present application, the second opening treatment of the solder mask layer includes: using laser drilling to obtain the second opening area of the solder mask layer, and the second opening area exposes the copper surface of the substrate.

[0014] According to some embodiments of the present application, the solder mask layer is subjected to a third opening treatment, a fourth opening treatment,..., and an nth opening treatment, so as to form corresponding opening areas on the substrate, and different surface treatments are performed on the corresponding opening areas to form different surface layers.

[0015] The packaging substrate according to the second aspect of the embodiments of the present application is prepared by the manufacturing method of the surface treatment of the packaging substrate.

[0016] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings. Figure 1is a flowchart of a manufacturing method of a surface treatment of a packaging substrate according to an embodiment of the present application Figure One ; Figure 2 is a flowchart of a manufacturing method of a surface treatment of a packaging substrate according to an embodiment of the present application Figure Two ; Figure 3 is a flowchart of a manufacturing method of a surface treatment of a packaging substrate according to an embodiment of the present application Figure Three ; Figure 4 is a flowchart of a manufacturing method of a surface treatment of a packaging substrate according to an embodiment of the present application Figure Four .

[0018] Reference Signs: 1, substrate; 11, core board; 12, copper clad layer; 13, insulating board; 2, solder resist layer; 3, first windowing area; 4, first surface layer; 5, second windowing area; 6, second surface layer. DETAILED DESCRIPTION

[0019] Embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0020] The embodiments of the present application will be described below with reference to the accompanying drawings. Figures 1-4 A manufacturing method of a surface treatment of a packaging substrate according to an embodiment of the present application is described below.

[0021] As shown in Figures 1-4 , the manufacturing method of the surface treatment of the packaging substrate includes: providing a substrate 1; pre-treating the substrate 1; solder-resisting the pre-treated substrate 1 to form a solder resist layer on the substrate 1; first windowing the solder resist layer to form a first windowing area on the substrate 1; first surface-treating the first windowing area to form a first surface layer; second windowing the solder resist layer to form a second windowing area on the substrate 1; and second surface-treating the second windowing area to form a second surface layer.

[0022] Through the above scheme, first, the provided substrate 1 is pretreated to clean and roughen the board surface to enhance the bonding force between the board surface and the solder resist layer; then, the pretreated substrate 1 can be solder resist processed to tightly bond the solder resist layer made of ink with the substrate 1; then, the preset area of the solder resist layer is windowed to obtain a first windowed area; then, the first windowed area is subjected to a first surface treatment to obtain a first surface layer in the first windowed area; then, another preset area of the solder resist layer is windowed to obtain a second windowed area, and the second windowed area is subjected to a second surface treatment to obtain a second surface layer in the second windowed area. In this way, the windowing is performed in different preset areas of the solder resist layer before and after, and different surface treatments are performed after each windowing, so that the solder resist layer is directly windowed by exposure and development or laser ablation without attaching a selective dry film, which can fundamentally solve the problem of reduced service life of surface treatment chemicals caused by selective dry film solubles. Moreover, by directly depositing metal on the windowed area of the solder resist layer, good contact between the solder joint and the packaging substrate can be ensured, thereby improving the reliability and stability of the solder joint. This process can effectively prevent the "black plate" problem, i.e., the mutual migration between nickel and gold, thereby avoiding blackening or failure of the solder joint. Since the solder resist layer itself has a certain thermal resistance, the deposited metal layer can further improve the thermal management performance of the packaging substrate, helping to disperse and isolate heat and avoid component damage caused by local overheating. Moreover, by precisely controlling the windowing position of the solder resist layer, solder can be ensured to flow only to the predetermined solder joint, thereby improving the accuracy and quality of soldering and reducing defects such as cold soldering, cold soldering, or uneven solder joints. At the same time, the appearance quality and solderability can be improved: the deposited metal layer has high brightness, which can improve the appearance quality of the packaging substrate.

[0023] Therefore, the present application provides a packaging substrate surface treatment manufacturing method, which makes a first windowing on the solder resist layer and completes a first surface treatment, then makes a second windowing on the solder resist layer, and then performs a second surface treatment, finally achieving the purpose of realizing multiple surface treatments on the substrate 1, and effectively achieving the purpose of selective process. Compared with the manufacturing method of the traditional selective process, technicians generally believe that the selective film (including dry film) is attached to the surface, and a specific area is exposed by exposure and development to deposit metal, at this time, the selective film can prevent metal from being deposited in unwanted places, and plays the role of a mask, similar to the pattern transfer step in PCB manufacturing, which uses a selective film to define the pattern. The present application avoids the method of using a selective film for selective process in the traditional selective process, which can fundamentally solve the problem of reduced service life of surface treatment chemicals caused by selective dry film solubles, and improve the surface treatment effect of the substrate 1.

[0024] Further, the first surface treatment is different from the second surface treatment. In other words, the second surface treatment cannot use the same material as the first surface treatment. For example, if the first surface treatment uses a metal material of nickel-palladium-gold, the second surface treatment cannot be nickel-palladium-gold, so that different surface treatments of the substrate 1 can be achieved. Of course, since the process of attaching the film is avoided, for different surface treatments, there is no need to worry about the problem of reducing the service life of the surface treatment chemical solution caused by the dissolution of the film, and the same kind of material should be implemented in the same surface treatment, so as to improve the production efficiency.

[0025] Further, the first surface treatment and the second surface treatment are respectively plating of a pure metal material and plating of an alloy material. That is, the first surface treatment can use a pure metal material treatment, and the second surface treatment uses an alloy material treatment. Or, the first surface treatment can use an alloy material treatment, and the second surface treatment uses a metal material treatment. For example, the first surface treatment can use a nickel-palladium-gold material treatment, and the second surface treatment uses a tin material treatment, and the like.

[0026] Further, the first surface treatment uses a chemical deposition method to deposit a layer of nickel-palladium-gold on the first windowed area. In a specific embodiment, the following steps can be used: The process flow of chemical nickel-palladium-gold (ENEPIG) generally includes the following steps: using a special acidic degreaser to remove oil stains on the surface of the substrate 1; slightly etching the surface of the first windowed area by a chemical method to improve its activity; forming an active film on the surface of the first windowed area to prepare for subsequent chemical deposition; using a palladium activator to form catalytic seeds on the surface to promote subsequent chemical deposition; under the catalytic action of palladium, is reduced to metallic nickel and deposited on the surface of the first windowed area, so that the nickel layer plays a role in blocking copper diffusion and improving the adhesion of the plating layer; then, a layer of palladium is deposited on the nickel layer, which can serve as an activation layer for gold deposition, and also has good corrosion resistance; next, a layer of gold is deposited on the palladium layer, providing good electrical conductivity, solderability, and oxidation resistance; finally, drying treatment is performed to ensure the stability and adhesion of the plating layer.

[0027] Further, the first surface treatment is plating of a pure metal material or plating of an alloy material, and the second surface treatment is plating of an organic material. That is, the first surface treatment can use a pure metal material treatment or an alloy material treatment. For example, the first surface treatment can use a nickel-palladium-gold material or a tin material treatment, and the second surface treatment uses an OSP material treatment, and the like.

[0028] Further, the surface of the first surface layer of the first windowed region is lower than the surface of the solder resist layer; and / or, the surface of the second surface layer of the second windowed region is lower than the surface of the solder resist layer. Figure 1 As shown, the surface of the solder resist layer is first windowed, so that the surface of the solder resist layer forms a first windowed region in a groove structure. Since the metal layer is formed by chemical reduction reaction on the surface of the copper foil layer by layer during the chemical deposition in the windowed region of the solder resist layer. Since the deposition speed of nickel, palladium and gold is slow, and the thickness of the deposited layer is thin, the depth of the first windowed region cannot be too deep, and the depth needs to be greater than the thickness of the deposited layer. And the surface of the deposited layer is lower than the surface of the solder resist layer, a layer of solder resist layer can be covered on the metal deposition layer in the subsequent process, which can provide good conductivity and solderability, while ensuring the adhesion and stability of the metal deposition layer to protect the metal layer from environmental effects. Therefore, the surface of the first surface layer of the first windowed region is lower than the surface of the solder resist layer and the surface of the second surface layer of the second windowed region is lower than the surface of the solder resist layer, which can further improve the stability and reliability of the packaging substrate.

[0029] Further, the first windowing process of the solder resist layer includes: selectively exposing and developing the solder resist layer to form a first windowed region, and the first windowed region exposes the copper surface of the substrate 1.

[0030] In a specific embodiment, first, the substrate 1 is pretreated; more specifically, the surface of the substrate 1 is first cleaned and roughened by a specific physical and / or chemical method to enhance the adhesion between the surface and the solder resist layer in the subsequent process. Then, the solder resist layer is applied on the pretreated substrate 1, more specifically, the solder resist layer made of solder resist ink is vacuum hot-pressed onto the surface of the substrate 1 by a vacuum laminator, and tightly combined with the substrate 1. Then, according to the actual design requirements, the exposure negative can be used to expose the preset area of the solder resist layer under ultraviolet light, thereby obtaining a solder resist layer with solder resist patterns. In this step, the preset area irradiated by ultraviolet light (i.e. the area without light shielding) will be solidified and finally retained through subsequent processing steps, while the parts other than the preset area will be removed in the subsequent steps. Subsequently, the solder resist layer is developed using a developer to remove the parts other than the preset area which are not exposed to obtain a solder resist layer with a first windowed region, so that the first windowed region exposes the surface of the copper layer. Then, the solder resist layer is pre-baked before curing, so that the solder resist ink constituting the solder resist layer flows under heat. The flowing solder resist ink covers the developed side etching part from the outer edge of the developed side etching, gradually reducing the area of the developed side etching, while avoiding excessive coverage of the surface which has not undergone developed side etching, thereby avoiding the occurrence of insufficient development in the final step.

[0031] Further, the solder resist layer is subjected to a second time of windowing treatment, including: the solder resist layer is subjected to laser drilling to obtain a second windowing area, and the second windowing area exposes the copper surface of the substrate 1.

[0032] In a specific embodiment, after the first time of surface treatment, the preset area of the solder resist layer is subjected to laser ablation to perform windowing until the copper surface of the substrate 1 is exposed to stop, to obtain a second windowing area, and then the second windowing area is subjected to a second time of surface treatment to obtain a second surface layer. Compared with the traditional photoresist process, the present application avoids the method of using an attached film for photoresist in the traditional photoresist process, and uses laser ablation to perform windowing, which can directly perform patterning on the copper foil without using an attached film (dry film or wet film), thereby simplifying the production process, reducing the process and equipment investment. Moreover, laser ablation can achieve very fine line production, which is suitable for high-density interconnection (HDI) packaging substrates, and can produce finer lines and smaller pitches. Laser ablation does not need to use chemical agents for development or etching, thereby reducing the generation of waste water and waste residue, and eliminating the need for a mask plate or an exposure machine, which can reduce production costs, and is particularly suitable for photoresist process production.

[0033] Further, the solder resist layer is subjected to a second time of windowing treatment, including: the solder resist layer is subjected to laser drilling to obtain a second windowing area, and the second windowing area exposes the copper surface of the substrate 1.

[0034] According to the second aspect of the present application, the packaging substrate is prepared by the packaging substrate surface treatment manufacturing method described above.

[0035] Therefore, the present application provides a packaging substrate surface treatment manufacturing method, after the solder resist layer is subjected to a first time of windowing and a first time of surface treatment, laser ablation is used to manufacture a second windowing on the surface of the solder resist layer, and then a second time of surface treatment is performed, to finally achieve the purpose of photoresist. The present application avoids the method of using an attached film for photoresist in the traditional photoresist process, and can fundamentally solve the problem of reducing the service life of surface treatment chemicals caused by dry film elution.

[0036] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0037] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0038] Although embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A method for manufacturing a package substrate surface treatment, characterized by, The application relates to a surface treatment method of a packaging substrate. The application provides a substrate; The substrate is pretreated; The pretreated substrate is solder resist treated to form a solder resist layer on the substrate; The solder resist layer is first windowed to form a first windowed area on the substrate; The first windowed area is first surface treated to form a first surface layer; The solder resist layer is second windowed to form a second windowed area on the substrate; The second windowed area is second surface treated to form a second surface layer.

2. The method of claim 1, wherein The first surface treatment is different from the second surface treatment.

3. The method of claim 2, wherein The first surface treatment and the second surface treatment are respectively pure metal plating treatment and alloy plating treatment.

4. The method of claim 3, wherein The first surface treatment is chemical deposition of a layer of nickel-palladium-gold on the first windowed area.

5. The method of claim 2, wherein the surface treatment is performed by a method selected from the group consisting of a mechanical polishing method, a chemical polishing method, a plasma treatment method, and a combination thereof. The first surface treatment is pure metal plating treatment or alloy plating treatment, and the second surface treatment is organic material plating treatment.

6. The method of claim 1, wherein The first surface layer of the first windowed area is lower than the surface of the solder resist layer; and / or The second surface layer of the second windowed area is lower than the surface of the solder resist layer.

7. The method of claim 1, wherein The first windowing of the solder resist layer comprises: The solder resist layer is selectively exposed and developed to form the first windowed area, and the first windowed area exposes the copper surface of the substrate.

8. The method of claim 1, wherein The second windowing of the solder resist layer comprises: The solder resist layer is laser drilled to form the second windowed area, and the second windowed area exposes the copper surface of the substrate.

9. The method of claim 1, wherein The solder resist layer is third windowed, fourth windowed,..., n-th windowed to form corresponding windowed areas, and the corresponding windowed areas are different surface treated to form different surface layers.

10. A package substrate, characterized by, The packaging substrate surface treatment is prepared by the method of any one of claims 1-9.

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