Target material and laminate

Abstract

Provided is a target material suitable for forming a tightly bonded layer having excellent tight bonding properties with a substrate and excellent etching properties even when ferric chloride is used. The target material contains Ni and Cr as elements, and further contains Al and / or Zn, and when the total of the Ni, Cr, Al and Zn is 100 at%, the content of Cr is 4-14 at%, the total content of Al and / or Zn is 4-16 at%, and the remainder is Ni and unavoidable impurities.

Description

Technical Field

[0001] The present invention relates to a target material and a laminate having a tightly bonded layer for forming a film using the target material. Background Technology

[0002] Flexible wiring boards with wiring patterns formed on a resin film substrate are used in LCD panels, laptops, digital cameras, mobile phones, and the like. These flexible wiring boards are manufactured using a copper-clad laminate (laminate) having a resin film substrate (substrate) and a copper-clad film layer (conductive layer) laminated on at least one side of the resin film substrate.

[0003] In such a laminate, a specified tight adhesion force needs to be ensured between the resin film substrate and the copper coating layer. For example, in Patent Document 1 below, a base metal layer (tight adhesion layer) made of Ni-Ti-Cr alloy is formed between the resin film substrate and the copper coating layer.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2006-73766 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] However, the base metal layer (tight bonding layer) made of Ni-Ti-Cr alloy has poor etchability with ferric chloride, which is commonly used to remove excess conductive layer and form a specified wiring pattern on the substrate. It is difficult to simultaneously etch the tight bonding layer and the conductive layer thereon. As a result, etching must be performed in two stages, which poses a problem in terms of productivity.

[0009] Against the backdrop of the above circumstances, the present invention aims to provide a laminate having a tight-fitting layer with excellent adhesion to a substrate and excellent etchability when using ferric chloride, and a target suitable for forming the tight-fitting layer into a film.

[0010] Technical solutions for solving technical problems

[0011] To address the aforementioned issues, the inventors conducted repeated and in-depth research, discovering that replacing Ti in the Ni-Ti-Cr alloy with Al or Zn improves etchability. In this invention, by optimizing the Al and Zn content in the Ni-based alloy constituting the tight-fitting layer, both tight adhesion to the substrate and etchability when using ferric chloride are ensured.

[0012] Furthermore, the laminate of the present invention comprises a substrate, a close-fitting layer formed on the substrate, and a conductive layer formed on the close-fitting layer. As elements, it contains Ni, Cr, and at least one of Al and Zn. When the total of Ni, Cr, Al, and Zn is set to 100 at%, Cr: contains 4 to 14 at%, Al and at least one of Zn: contains 4 to 16 at%, and the remainder consists of Ni and unavoidable impurities.

[0013] According to the present invention, a laminate having a tight-fitting layer with excellent adhesion to the substrate and excellent etchability when using ferric chloride can be formed.

[0014] Furthermore, the target material of the present invention contains, as an element, Ni, Cr, and at least one of Al and Zn. When the total of these Ni, Cr, Al and Zn is set to 100 at%, Cr: contains 4 to 14 at%, at least one of Al and Zn: contains 4 to 16 at%, and the remainder consists of Ni and unavoidable impurities.

[0015] By using the target of the present invention as specified in this invention, a tightly bonded layer with excellent adhesion to the substrate and excellent etchability when using ferric chloride can be appropriately formed by sputtering. Attached Figure Description

[0016] Figure 1 This is a diagram showing a laminate having a tightly fitting layer according to an embodiment of the present invention.

[0017] Figure 2 It means Figure 1 Figures showing other examples of stacked structures. Detailed Implementation

[0018] Next, an example of an embodiment of the present invention will be specifically described.

[0019] <1. Layered Structures>

[0020] exist Figure 1 In the diagram, 10 represents an example of a laminate according to an embodiment of the present invention. The laminate 10 includes a substrate 12, a tight-fitting layer 14 formed on the substrate 12, and a conductive layer 16 formed on the tight-fitting layer 14.

[0021] The substrate 12 can be glass such as soda-lime glass, or resin materials such as polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polycarbonate (PC), polymethyl methacrylate (PMMA), and polyimide (PI).

[0022] The conductive layer 16 is preferably made of a highly conductive material with a resistivity of 8.0 μΩ·cm or less. Such materials include pure Cu, Cu alloys, pure Al, and Al alloys. In this embodiment, the conductive layer 16 is composed of a seed layer 17 formed by sputtering and an electroplated layer 18 with the seed layer 17 as the conductive path. The electroplated layer 18 is formed, for example, by electrolytic plating or chemical plating.

[0023] Next, the tight bonding layer 14 will be described. The tight bonding layer 14 is a Ni-based alloy layer between the substrate 12 and the conductive layer 16 to ensure tight adhesion between the substrate 12 and the conductive layer 16. The tight bonding layer 14 contains at least one of Ni, Cr, Al, and Zn. In addition, the tight bonding layer 14 may contain unavoidable impurities.

[0024] The following explains the reasons for limiting the chemical components in the tight-fitting layer 14.

[0025] Ni is the basic element of the tight bonding layer 14. Ni can also ensure a certain degree of tight adhesion to the substrate 12 and can be etched using ferric chloride. Therefore, in order to satisfy both tight adhesion and etching properties, it is most suitable to make the tight bonding layer 14 from a Ni-based alloy.

[0026] Cr: 4~14 at%

[0027] Cr is an effective element for improving the heat resistance of the tight-fitting layer 14. However, while increasing the Cr content improves heat resistance, it reduces etchability. Therefore, in this embodiment, the Cr content is specified as 4 to 14 at%. Preferably, it is 7 to 13 at%.

[0028] At least one of Al and Zn: 4–16 at% total

[0029] Al and Zn are both effective elements for improving the adhesion of the bonding layer 14. By diffusing Al or Zn in the substrate 12, the adhesion between the substrate 12 and the bonding layer 14 is improved. In this embodiment, either Al or Zn may be present, or both may be present. However, while increasing the content of Al and Zn improves adhesion, it reduces etchability. Therefore, in this embodiment, the total content of Al and Zn is specified to be 4 to 16 at%. Preferably, it is 7 to 13 at%.

[0030] When depositing the tightly bonded layer 14 thus configured onto one side of the substrate 12, sputtering is preferably used. Specifically, balanced magnetron sputtering, unbalanced magnetron sputtering, and ion plating are examples. Since the composition of the tightly bonded layer 14 formed by non-reactive sputtering is approximately the same as that of the sputtering target, using a sputtering target with the same composition as the tightly bonded layer 14 for film formation offers excellent manufacturability.

[0031] Then, after forming a tight bonding layer 14 on the substrate 12, a seed layer 17 based on sputtering and an electroplated layer 18 based on electrolytic plating or chemical plating are formed, thereby enabling the fabrication of... Figure 1 The layered body 10 shown.

[0032] Figure 1 The laminate 10 shown is actually further processed and used as an element of various components (e.g., flexible wiring board). Figure 2 The laminate 10B shown represents its processed laminate.

[0033] In the processed laminate 10B, the excess portions of the film-like conductive layer 16 and the adhering layer 14 in the unprocessed laminate 10 are removed, leaving only a plurality of fine lines S. Such fine lines S can be formed, for example, by using a wet etching method using an etchant such as an aqueous ferric chloride solution.

[0034] <2. Target Material>

[0035] The sputtering target of this embodiment is used to form the tightly bonded layer 14 of the laminate 10. As an element, it contains at least one of Ni, Cr, Al, and Zn. However, the target may contain unavoidable impurities.

[0036] Regarding the composition of the target material, with the total of Ni, Cr, Al, and Zn set at 100 at%, Cr: contains 4 to 14 at%, Al and Zn: contain at least one of them: contain 4 to 16 at%, and the remainder is Ni and unavoidable impurities.

[0037] The definition of the same range as the composition of the above-mentioned tight bonding layer 14 is based on the fact that the composition of the metal component of the tight bonding layer 14 formed by sputtering is approximately the same as the composition of the sputtering target.

[0038] This target material can be manufactured by melting and producing blocks with a specified composition, and then cutting them out.

[0039] Alternatively, depending on the circumstances, it can be manufactured by mixing powders containing the constituent elements and then pressing the mixture from a cold to a hot state. The raw material powder can be a pure metal or alloy containing the constituent elements. Forming methods include, for example, cold isostatic pressing (CIP), hot isostatic pressing (HIP), hot extrusion, and ultra-high pressure hot pressing.

[0040] [Example]

[0041] Next, embodiments of the present invention will be described in detail below. Here, a laminate having a tight-fitting layer having the composition shown in Table 1 below is fabricated, and its tightness and etchability are evaluated.

[0042] [Table 1]

[0043]

[0044] <Creating Layered Objects>

[0045] The target material is manufactured by melting in a manner that produces the composition shown in Table 1 above.

[0046] Next, using the fabricated target material, a tightly bonded layer 14 with a film thickness of 30 nm is formed on the surface of the evaluation substrate 12 (a polyimide material with dimensions of 75 mm square × 0.1 t (thickness of 0.1 mm)) by sputtering.

[0047] Furthermore, on the surface of the tight bonding layer 14, a seed Cu layer (seed layer 17) with a thickness of 300 nm is formed in a film by sputtering using a Cu target, thus creating an evaluation stack consisting of the seed Cu layer (thickness 300 nm), the tight bonding layer (thickness 30 nm), and the substrate.

[0048] The film formation conditions for the sputtered close-bonded layer 14 and the seeded Cu layer are as follows: • Vacuum degree: 1 × 10⁻⁶ -4 Below Pa; Film-forming gas: Ar gas; Sputtering pressure: 0.15 Pa; Sputtering power: 150 W

[0049] <Evaluation of fit>

[0050] After forming a 20 μm thick electroplated Cu layer (electroplated layer 18) on the surface of the seed Cu layer of the above-mentioned evaluation stack, the unwanted parts are etched away, and a 5 mm wide fine line S composed of a conductive layer 16 and a tight bonding layer 14 is formed on the substrate 12.

[0051] Then, according to JISC5016 1994, using a testing machine, a 5 mm wide thread S was gripped and stretched at a speed of 50 mm per minute in a direction at 90° relative to the plane of the laminate, thereby determining the peel strength of the thread S. The obtained value was taken as the tightness of the bond and evaluated according to the evaluation criteria below. The results are shown in Table 1.

[0052] ◎: The tightness of the fit is above 7N / mm

[0053] 〇: The tightness of the fit is above 5N / mm and less than 7N / mm.

[0054] △: The tightness of the fit is above 1N / mm and less than 5N / mm.

[0055] ×: Tight fit strength less than 1N / mm

[0056] <Etching performance evaluation>

[0057] A 20 mm square test piece was cut from the aforementioned evaluation laminate, and half of the test piece was immersed in a 20 wt% ferric chloride etching solution. Under this condition, the time until the seed Cu layer and the tightly bonded layer 14 immersed in the etching solution dissolved was measured, and the evaluation was performed according to the following evaluation criteria. The results are shown in Table 1.

[0058] ◎: Dissolves within 60 seconds

[0059] 〇: Dissolves within 60 to 120 seconds

[0060] ×: Dissolves after 120 seconds

[0061] The following can be seen from the evaluation results in Table 1.

[0062] First, Comparative Example 1 is an example of a tightly bonded layer composed of pure Ni. Etching performance is good, but the tightness of the bond is rated "×", failing to meet the target.

[0063] Next, Comparative Examples 5 to 8 are examples in which a tight bonding layer is composed of a Ni-Ti alloy or a Ni-Cr-Ti alloy. As also described in the aforementioned Patent Document 1, it is known that a tight bonding layer composed of a Ni-Cr-Ti alloy is a conventionally known configuration. However, in Comparative Examples 5 to 8 containing Ti, unlike Comparative Example 1, the evaluation of etchability does not meet the target.

[0064] Comparative Examples 2-4 are examples of tightly bonded layers constructed using an alloy of Ni and Cr, without the addition of Al or Zn. In Comparative Example 2 with low Cr (3 at%), the tightness of the bond was rated as "△", failing to meet the target. In Comparative Examples 3 and 4 with high Cr (15 at%) and 20 at%), the tightness of the bond was improved, but the etchability was rated as "×".

[0065] Comparative Examples 9 and 10 are examples of using an alloy composed of Ni and Al to form a tight bonding layer, but the amount of Al exceeds the range specified in this embodiment. In Comparative Example 9 with low Al (3 at%), the tight bonding performance was evaluated as "×", failing to meet the target. In Comparative Example 10 with high Al (20 at%), the etchability was evaluated as "×".

[0066] Comparative Examples 11 and 12 are examples of using an alloy composed of Ni, Cr, and Al to form a tightly bonded layer. However, Comparative Example 11 has high Al (20 at%) and Comparative Example 12 has high Cr (15 at%), which exceed the range specified in this embodiment, and the etchability evaluation of both is "×".

[0067] Comparative Examples 13 and 14 are examples of using an alloy composed of Ni and Zn to form a tight bonding layer, but the amount of Zn exceeds the range specified in this embodiment. In Comparative Example 13 with low Zn (3 at%), the tight bonding performance was evaluated as "×", failing to meet the target. In Comparative Example 14 with high Zn (20 at%), the etching performance was evaluated as "×".

[0068] Comparative Examples 15 and 16 are examples of using an alloy composed of Ni, Cr, and Zn to form a tightly bonded layer. However, Comparative Example 15 has high Zn (20 at%) and Comparative Example 16 has high Cr (15 at%), which exceed the range specified in this embodiment, and the etchability evaluation of both is "×".

[0069] As stated above, in each comparative example, the evaluation of at least one of the fit and etching properties did not meet the target.

[0070] In contrast, for Examples 1 to 18, where the tight bonding layer formed on the substrate is composed of Ni, Cr, and at least one of Al and Zn, and the content of the constituent elements meets the requirements of this embodiment, the tight bonding and etching properties were evaluated as “○” or “◎”, and good results were obtained.

[0071] A more detailed observation of the various embodiments reveals that, as shown in Examples 2-9 and Examples 11-18, by setting the Al or Zn content to 7 at% or more, the adhesion can be further improved. Furthermore, as shown in Examples 1-4, Examples 6-13, and Examples 15-18, by setting the Al or Zn content to 13 at% or less, the etchability can be further improved. Therefore, to further improve both adhesion and etchability, it is preferable to set the Al or Zn content to 7-13 at%.

[0072] The embodiments and examples of the present invention have been described in detail above, but these are only examples. For instance, in the above embodiments and examples, a target material with the same composition as the bonding layer is used to form a film of the bonding layer. However, a bonding layer with a specified alloy composition can also be formed on a substrate in a film form by using a sputtering method with various single metal targets. The present invention can be implemented in various modified ways without departing from its spirit.

[0073] This application is based on Japanese Patent Application No. 2024-192811, filed on November 1, 2024, the contents of which are incorporated herein by reference.

[0074] Explanation of reference numerals in the attached figures

[0075] 10, 10B: Laminated structures

[0076] 12: Substrate

[0077] 14: Tightly Adhesive Layer

[0078] 16: Conductive layer

[0079] 17: Seed layer

[0080] 18: Electroplating layer

[0081] S: Thin thread

Claims

1. A target material, characterized in that, As an element, it contains at least one of Ni, Cr, Al, and Zn, and the total amount of these Ni, Cr, Al, and Zn is set at 100 at%. Cr: contains 4~14 at%. At least one of Al and Zn: containing a total of 4–16 at%, The remainder consists of Ni and unavoidable impurities.

2. The target material according to claim 1, characterized in that, With the total of Ni, Cr, Al, and Zn set at 100 at%, the Cr content is 7-13 at%.

3. The target material according to claim 1 or 2, characterized in that, With the total content of Ni, Cr, Al, and Zn set at 100 at%, the total content of Al and Zn is 7–13 at%.

4. A laminated body, characterized in that, It includes a substrate, a bonding layer formed on the substrate, and a conductive layer formed on the bonding layer. The tightly bonded layer contains at least one of Ni, Cr, Al, and Zn, with the total amount of Ni, Cr, Al, and Zn set at 100 at%. Cr: contains 4~14 at%. At least one of Al and Zn: containing a total of 4–16 at%, The remainder consists of Ni and unavoidable impurities.

5. The laminated body according to claim 4, characterized in that, With the total of Ni, Cr, Al, and Zn set at 100 at%, the Cr content is 7–13 at%.

6. The laminate according to claim 4 or 5, characterized in that, With the total content of Ni, Cr, Al, and Zn set at 100 at%, the total content of Al and Zn is 7–13 at%.

7. The laminate according to claim 4 or 5, characterized in that, The conductive layer has a seed crystal layer formed on the tightly bonded layer and an electroplated layer formed on the seed crystal layer.

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