Method for manufacturing substrate and system for manufacturing substrate

Abstract

This method for manufacturing a printed circuit board (1) is provided with: an etching step for etching a part of a stainless steel base material (M) using a first etching solution; and a post-treatment step for treating the end surface (S) formed by the etching step with a second etching solution. The first etching liquid can dissolve iron in the stainless steel. The second etching liquid is capable of dissolving the metal which is not dissolved in the etching step and remains on the end surface (S).

Description

Technical Field

[0001] This invention relates to a method for manufacturing a substrate and a system for manufacturing a substrate. Background Technology

[0002] Previously, it was known that a method was used to sequentially form a base insulating layer, a conductor layer and a cover insulating layer on a suspension substrate containing a metal such as stainless steel, and then etch the suspension substrate into a given shape to obtain a suspension substrate with circuitry (for example, see Patent Document 1 below).

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2005-217250 Summary of the Invention

[0004] The problem that the invention aims to solve In the method described in Patent Document 1, there is a situation where a metal in the stainless steel that is difficult to dissolve in the etching solution remains on the end face obtained by etching. In this case, the smoothness of the end face may be reduced due to the metal remaining on the end face.

[0005] The present invention provides a method for manufacturing a substrate and a system for manufacturing a substrate, which can improve the smoothness of the end face formed by etching.

[0006] Technical solutions for solving the problem The present invention [1] includes a method for manufacturing a substrate, comprising: an etching step in which a portion of a stainless steel substrate is etched using a first etching solution, thereby forming an end face in the etched portion; and a post-processing step in which the end face formed by the etching step is processed using a second etching solution, wherein in the etching step the first etching solution is capable of dissolving iron in the stainless steel, and in the post-processing step the second etching solution is capable of dissolving metal other than the iron that was not dissolved in the etching step and remains on the end face.

[0007] According to this method, in the post-processing step, the metal that was not dissolved in the etching step and remained on the end face can be dissolved using a second etching solution.

[0008] Therefore, it is possible to remove the metal residue on the end face formed by etching, thereby improving the smoothness of the end face.

[0009] The present invention [2] includes a method for manufacturing the substrate of [1] above, wherein the metal is chromium.

[0010] This method can remove chromium residue on the end face formed by etching, thereby improving the smoothness of the end face.

[0011] The present invention [3] includes a method for manufacturing a substrate according to [1] or [2] above, wherein the substrate is a wiring circuit substrate, the wiring circuit substrate comprising: a metal support layer comprising the stainless steel substrate; a circuit pattern; and an insulating layer disposed between the metal support layer and the circuit pattern.

[0012] The present invention [4] includes a substrate manufacturing system that can be used in any of the substrate manufacturing methods described in [1] to [3] above, comprising: an etching apparatus that performs the etching process; and a post-processing apparatus that performs the post-processing process.

[0013] Based on this structure, a post-processing device is provided for carrying out post-processing procedures.

[0014] Therefore, the smoothness of the end face can be improved by using a post-processing device to remove the metal remaining on the end face formed by etching.

[0015] The present invention [5] includes a substrate manufacturing system of the above [4], wherein the post-processing device is disposed downstream of the etching device in the traveling direction of a continuous manufacturing line.

[0016] Invention Effects According to the substrate manufacturing method and substrate manufacturing system of the present invention, it is possible to improve the smoothness of the etched end face. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of the wiring circuit board.

[0018] Figures 2A to 2C It means Figure 1 The diagram shows a method for manufacturing a wiring circuit board. Figure 2A This indicates the first insulating layer formation process. Figure 2B This indicates the process of forming the circuit pattern. Figure 2C This indicates the process of forming the second insulating layer.

[0019] Figure 3A and Figure 3B It continues Figure 2C A diagram illustrating the manufacturing method of a wiring circuit board. Figure 3A Indicates the etching process. Figure 3B This indicates a post-processing step.

[0020] Figure 4 This is a block diagram representing the manufacturing system of a wiring circuit board.

[0021] Figure 5A This is a SEM (scanning electron microscope) image showing a cross-section of the substrate obtained in the embodiment. Figure 5BThis is an SEM image showing a cross-section of the substrate obtained in the comparative example. Detailed Implementation

[0022] 1. Wiring circuit board Reference Figure 1 The wiring circuit board 1, which is an example of a substrate, will be described. It should be noted that the wiring circuit board 1 can be a flexible wiring circuit board or a suspended board with circuitry.

[0023] The wiring circuit board 1 has a metal support layer 2, a first insulating layer 3 as an example of an insulating layer, a circuit pattern 4, and a second insulating layer 5.

[0024] (1) Metal support layer The metal support layer 2 supports the first insulating layer 3, the circuit pattern 4, and the second insulating layer 5. The metal support layer 2 comprises a stainless steel substrate. It should be noted that the metal support layer 2 may also comprise only a stainless steel substrate. The metal support layer 2 may also comprise a stainless steel substrate and a metal layer laminated on one side of the substrate in the thickness direction. The metal layer may be laminated entirely on one side of the substrate in the thickness direction, or it may be laminated on a portion of one side of the substrate in the thickness direction. The material of the metal layer is different from the material of the substrate (i.e., stainless steel). Examples of materials for the metal layer include gold, silver, copper, nickel, chromium, titanium, and their alloys.

[0025] (2) First insulating layer The first insulating layer 3 is disposed on one side of the metal support layer 2 in the thickness direction. The first insulating layer 3 is also disposed on one surface of the metal support layer 2 in the thickness direction. The first insulating layer 3 is disposed between the metal support layer 2 and the circuit pattern 4 in the thickness direction. The first insulating layer 3 insulates the metal support layer 2 from the circuit pattern 4. The first insulating layer 3 comprises a resin. Examples of resins include polyimide, maleimide, epoxy resin, polybenzoxazole, and polyester.

[0026] (3) Circuit diagram The circuit pattern 4 is disposed on one side of the first insulating layer 3 in the thickness direction. The circuit pattern 4 is disposed on one surface of the first insulating layer 3 in the thickness direction. The circuit pattern 4 is disposed on the opposite side of the metal support layer 2 in the thickness direction relative to the first insulating layer 3. The circuit pattern 4 contains metal. Examples of metals include copper, silver, gold, iron, aluminum, chromium, and their alloys. The circuit pattern 4 preferably contains copper. The shape of the circuit pattern 4 is not limited. The circuit pattern 4, for example, has a plurality of wirings 41 and a plurality of terminals (not shown). The wirings 41 can be signal wirings for transmitting electrical signals or power wirings for transmitting current from a power source.

[0027] (4) Second insulating layer The second insulating layer 5 covers all the wiring 41. The second insulating layer 5 is disposed above the first insulating layer 3 in the thickness direction. It should be noted that the second insulating layer 5 does not cover the terminals. The second insulating layer 5 comprises a resin. Examples of resins include polyimide, maleimide, epoxy resin, polybenzoxazole, and polyester.

[0028] 2. Manufacturing method of wiring circuit board Next, the manufacturing method of the wiring circuit board 1 will be described.

[0029] The manufacturing method of the wiring circuit board 1 includes a first insulating layer formation process (see reference). Figure 2A ), Circuit pattern formation process (refer to Figure 2B ), the second insulating layer formation process (refer to) Figure 2C Etching process (refer to) Figure 3A ), and post-processing procedures (refer to Figure 3B ).

[0030] (1) First insulating layer formation process like Figure 2A As shown, in the first insulating layer forming process, a first insulating layer 3 is formed on one side surface of a stainless steel substrate M.

[0031] In detail, in the first insulating layer formation process, firstly, a solution of photosensitive resin (varnish) is coated onto one side surface of the substrate M in the thickness direction and allowed to dry, forming a photosensitive resin coating. Next, the photosensitive resin coating is exposed and developed. Thus, the first insulating layer 3 is obtained.

[0032] (2) Circuit pattern formation process Next, as Figure 2B As shown, in the circuit pattern forming process, a circuit pattern 4 is formed on the first insulating layer 3.

[0033] In detail, firstly, a seed layer is formed on one side surface of the first insulating layer 3 and one side surface of the substrate M in the thickness direction. The seed layer is formed, for example, by sputtering. Examples of materials for the seed layer include chromium, copper, nickel, titanium, and alloys thereof.

[0034] Next, the seed layer is coated with an anti-plating agent.

[0035] Next, the resist is exposed and developed. As a result, the resist in the area forming circuit pattern 4 is removed, and the seed layer is exposed in the area forming circuit pattern 4.

[0036] On the other hand, there is residual anti-plating agent in the part where the circuit pattern 4 was not formed.

[0037] Next, circuit pattern 4 is formed on the exposed seed layer by electroplating. After electroplating is completed, the resist is stripped, and the seed layer exposed due to the stripping of the resist is removed by etching.

[0038] Thus, a circuit pattern 4 is formed on the first insulating layer 3.

[0039] (3) Second insulating layer formation process Next, as Figure 2C As shown, in the second insulating layer forming process, a second insulating layer 5 is formed on the first insulating layer 3.

[0040] In detail, in the second insulating layer forming process, firstly, a solution of photosensitive resin (varnish) is applied to the substrate M, the first insulating layer 3 and the circuit pattern 4 and then dried to form a photosensitive resin coating.

[0041] Next, the photosensitive resin coating is exposed and developed. As a result, a second insulating layer 5 is formed on the first insulating layer 3.

[0042] (4) Etching process Next, as Figure 3A As shown, in the etching process, a portion of the substrate M is etched using a first etching solution.

[0043] In detail, during the etching process, firstly, a photoresist R1 is formed on one side of the substrate M in the thickness direction, and a photoresist R2 is formed on the other side of the substrate M in the thickness direction. Photoresist R1 covers the first insulating layer 3, the circuit pattern 4, and the second insulating layer 5. Photoresist R2 covers the non-etchable portions of the substrate M and exposes the portions of the substrate M to be etched.

[0044] It should be noted that in order to form resists R1 and R2, dry film photoresist is pasted on one side and the other side of the substrate M in the thickness direction, and the dry film photoresist is exposed and developed.

[0045] Next, the portion of substrate M exposed from resist R2 (a part of substrate M) is etched using the first etching solution.

[0046] In the etching process, the first etching solution can dissolve the iron in the stainless steel. Examples of first etching solutions include aqueous solutions of ferric chloride, aqueous solutions of copper chloride, and aqueous solutions of sulfuric acid / hydrogen peroxide.

[0047] The portion etched by the first etching solution forms an end face S. In other words, the substrate M after the etching process has an end face S. The end face S extends along the thickness direction.

[0048] Here, there is a situation where particles G, composed of metals other than iron, remain on the end face S without dissolving. Metals other than iron refer to metals that are less soluble in the first etching solution than iron, such as chromium.

[0049] After the etching process, the substrate M is washed, for example, with water to remove the first etching solution adhering to the substrate M. After washing and before the post-processing process, the resists R1 and R2 are stripped. It should be noted that the post-processing process can also be performed without stripping the resists R1 and R2.

[0050] (5) Post-processing steps Next, as Figure 3B As shown, in the post-processing step, the end face S formed by the etching step is treated using a second etchant. More specifically, in the post-processing step, the metal particles G that remained on the end face S due to undissolved metal during the etching step are etched using the second etchant.

[0051] In the post-processing step, the second etching solution can dissolve the metal that remained on the end face S without dissolving during the etching step. The metal particles G remaining on the end face S are more readily soluble in the second etching solution than iron. Preferably, the second etching solution does not dissolve iron.

[0052] Examples of second etching solutions include cerium ammonium nitrate solution, aqueous sodium hydroxide solution, potassium permanganate solution, and sodium metasilicate solution.

[0053] After the etching process, for example, the substrate M is washed with water to remove the second etching solution adhering to the substrate M.

[0054] Afterwards, the substrate M is dried to obtain the wiring circuit board 1 described above.

[0055] 3. Manufacturing system for wiring circuit boards Next, the manufacturing system 10 for the wiring circuit board 1 that can be used in the above-described manufacturing method of the wiring circuit board 1 will be described.

[0056] like Figure 4 As shown, the manufacturing system 10 may include a continuous manufacturing line L. The manufacturing system 10 may also include multiple manufacturing lines L. The manufacturing line L includes an etching device 11, a cleaning device 12, and a post-processing device 13. That is, the manufacturing system 10 includes an etching device 11, a cleaning device 12, and a post-processing device 13.

[0057] It should be noted that the manufacturing line L can perform the above-mentioned etching process and post-processing process in a roll-to-roll manner, or it can perform the above-mentioned etching process and post-processing process on multiple sheet-shaped substrates conveyed along the travel direction.

[0058] Alternatively, the manufacturing line L may also have, on the upstream side of the etching apparatus 11 in the traveling direction of the manufacturing line L, an apparatus capable of being used for the first insulating layer formation process (e.g., coating apparatus, drying apparatus, exposure apparatus, developing apparatus), an apparatus capable of being used for the circuit pattern formation process (e.g., plating tank), and an apparatus capable of being used for the second insulating layer formation process (e.g., coating apparatus, drying apparatus, exposure apparatus, developing apparatus).

[0059] The etching apparatus 11 performs the etching process described above. The etching apparatus 11 is capable of spraying a first etching solution onto the substrate M. The etching apparatus 11 includes, for example, a tank and multiple spray nozzles. The tank contains the first etching solution. The multiple spray nozzles respectively spray the first etching solution supplied from the tank toward the substrate M. The etching apparatus 11, for example, sprays from the other side in the thickness direction (see reference...). Figure 3A The etching apparatus 11 can also spray the first etching solution onto the substrate M from both sides in the thickness direction.

[0060] The cleaning apparatus 12 cleans the substrate M after the etching process and before the post-processing process. The cleaning apparatus 12 is positioned downstream of the etching apparatus 11 and upstream of the post-processing apparatus 13 in the travel direction of the manufacturing line L. The cleaning apparatus 12 includes, for example, a tank and multiple spray nozzles. The tank contains a cleaning solution. Examples of cleaning solutions include water and acid. Each of the multiple spray nozzles sprays the cleaning solution supplied from the tank toward the substrate M.

[0061] It should be noted that the manufacturing line L may also have multiple cleaning devices 12 using different cleaning solutions, located downstream of the etching device 11 and upstream of the post-processing device 13 in the direction of travel of the manufacturing line L. For example, the manufacturing line L may also have a first cleaning device 12 using acid as a cleaning solution and a second cleaning device 12 using water as a cleaning solution, located downstream of the etching device 11 and upstream of the post-processing device 13 in the direction of travel of the manufacturing line L. Examples of acids used in the first cleaning device 12 include sulfuric acid, hydrochloric acid, and nitric acid. The second cleaning device 12 is disposed downstream of the first cleaning device 12 in the direction of travel of the manufacturing line L.

[0062] Alternatively, the manufacturing line L may also be equipped with a stripping agent for resists R1 and R2 (see reference) downstream of the cleaning device 12 and upstream of the post-processing device 13 in the direction of travel of the manufacturing line L. Figure 3A ( ) The resist stripping device.

[0063] The post-processing apparatus 13 performs the post-processing steps described above. The post-processing apparatus 13 is disposed downstream of the etching apparatus 11 in the travel direction of the manufacturing line L. The post-processing apparatus 13 is also disposed downstream of the cleaning apparatus 12 in the travel direction of the manufacturing line L. The post-processing apparatus 13 is capable of spraying a second etching solution onto the substrate M. The post-processing apparatus 13 includes, for example, a tank and multiple spray nozzles. The tank contains the second etching solution. The multiple spray nozzles spray the second etching solution supplied from the tank toward the substrate M. The post-processing apparatus 13 can spray the second etching solution supplied from the tank toward the substrate M, for example, from the other side in the thickness direction (see reference). Figure 3B The post-processing apparatus 13 sprays the second etchant onto the substrate M. Alternatively, the post-processing apparatus 13 may spray the second etchant onto the substrate M from both sides in the thickness direction. Alternatively, the post-processing apparatus 13 may not be able to spray the second etchant. The post-processing apparatus 13 may also have a solution tank for storing the second etchant and be able to immerse the substrate M in the second etchant within the solution tank.

[0064] It should be noted that the manufacturing line L may also be equipped with a cleaning device that uses water as a cleaning fluid and a drying device on the downstream side of the post-processing device 13 in the direction of travel of the manufacturing line L.

[0065] 4. Effects (1) According to the manufacturing method of wiring circuit board 1, such as Figure 3A and Figure 3B As shown, the etching process includes etching a stainless steel substrate M using a first etching solution (see reference). Figure 3A ), and a post-processing step that uses a second etching solution to treat the end face S formed by the etching process (see reference). Figure 3B The first etching solution can dissolve the iron in the stainless steel. The second etching solution can dissolve the metal particles G that remain on the end face S after the etching process.

[0066] Therefore, in the post-processing step, the metal particles G that were not dissolved in the etching step and remained on the end face S can be dissolved using the second etching solution.

[0067] Therefore, it is possible to remove the metal particles G remaining on the end face S formed by etching, thereby improving the smoothness of the end face S.

[0068] (2) According to the manufacturing method of the wiring circuit board 1, the metal that remains on the end face S without dissolving during the etching process is chromium.

[0069] Therefore, it is possible to remove chromium particles G remaining on the end face S formed by etching, thereby improving the smoothness of the end face S.

[0070] (3) According to the manufacturing system 10 of the wiring circuit board 1, such as Figure 4 As shown, the device includes an etching apparatus 11 for performing the etching process and a post-processing apparatus 13 for performing the post-processing process.

[0071] Therefore, the post-processing device 13 can be used to remove the metal particles G remaining on the end face S formed by etching, thereby improving the smoothness of the end face S.

[0072] Example The following examples and comparative examples further illustrate the present invention. It should be noted that the present invention is not limited to any particular example or comparative example. Furthermore, the specific numerical values ​​of proportions (including proportions), property values, parameters, etc., used in the following description can replace the corresponding upper limits (defined as "below" or "less than") or lower limits (defined as "above" or "exceeding") of the proportions (including proportions), property values, parameters, etc., recorded in the "Specific Embodiments" above.

[0073] <Example> The substrate, made of stainless steel and used as a metal support layer for wiring circuit board, is etched by spraying a first etching solution (iron chloride aqueous solution, liquid temperature: 50°C) for 120 seconds. Then, the substrate is cleaned with water.

[0074] Next, a second etching solution (cerium ammonium nitrate solution, liquid temperature: 40℃) is sprayed onto the substrate after the etching process for 40 seconds (post-processing process).

[0075] Thus, a substrate was obtained. The end face S (the end face obtained by etching) of the obtained substrate is shown below. Figure 5A .

[0076] <Comparative Example> The substrate was obtained in the same manner as in the embodiment, except that no post-processing steps were performed. The end face of the obtained substrate (the end face formed by etching) is shown below. Figure 5B .

[0077] In the comparative example, undissolved metal particles G protrude from the end face S during the etching process. On the other hand, in the embodiment (see...) Figure 5A In this case, there are fewer protrusions, resulting in a smoother end face S compared to the comparative example.

[0078] It should be noted that the above-described invention is provided as an illustrative embodiment of the present invention, but this is merely illustrative and should not be interpreted as limiting. Modifications of the invention that are obvious to those skilled in the art are included within the scope of protection of the technical solutions described below.

[0079] Industrial availability The substrate manufacturing method and substrate manufacturing system of the present invention can be used for the manufacture of wiring circuit boards.

[0080] Symbol Explanation 1: Wiring circuit board (an example of a board) 2: Metal support layer 3: First insulating layer 4: Circuit diagram 10: Manufacturing System L: Manufacturing line 11: Etching device 13: Post-processing unit M: Substrate S: End face formed by etching process G: Metal particles remaining on end face S.

Claims

1. A method of manufacturing a substrate, comprising: an etching step of etching a part of a base material made of stainless steel using a first etching liquid, thereby forming an end face in the part etched; and a post-treatment step of treating the end face formed by the etching step with a second etching liquid, in the etching step, the first etching liquid is capable of dissolving iron in the stainless steel, in the post-treatment step, the second etching liquid is capable of dissolving a metal other than the iron, which is not dissolved in the etching step and remains in the end face.

2. The method for manufacturing a substrate according to claim 1, wherein The metal is chromium.

3. The method of manufacturing a substrate according to claim 1, wherein The substrate is a wiring circuit substrate, The wiring circuit substrate includes: a metal support layer including the base material made of stainless steel; a circuit pattern; and an insulating layer disposed between the metal support layer and the circuit pattern.

4. A manufacturing system of a substrate, capable of being used in the method of manufacturing a substrate according to any one of claims 1 to 3, comprising: an etching device that implements the etching step; and a post-treatment device that implements the post-treatment step. The post-treatment device is disposed on a downstream side in a traveling direction of the etching device in a continuous manufacturing line.

5. The manufacturing system of a substrate according to claim 4, wherein, ​

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