Method for manufacturing printed circuit board, and aggregate sheet

Abstract

This method for manufacturing a printed circuit board comprises: an etching step for etching a metal base material (M) by spraying an etching solution onto the metal base material (M), thereby forming a metal portion comprising only a metal. In the etching step, the size of the metal portion is adjusted by adjusting the jet impact force calculated on the basis of the following calculation formula. (In the above calculation formula, F represents the injection impact force, Q represents the injection amount of each injection nozzle, rho represents the density of the etching liquid, and P represents the injection pressure).

Description

Manufacturing method of wiring circuit board and assembly sheet Technical Field

[0001] This invention relates to a method for manufacturing a wiring circuit board and an assembly sheet. Background Technology

[0002] Previously, as an example of a wiring circuit board, there is a known suspended board with circuitry, which includes: a mounting portion on which a skid with a magnetic head is mounted; and an extended support portion disposed around the mounting portion (for example, see Patent Document 1 below).

[0003] Prior art literature, patent literature, patent literature 1: Japanese Patent Application Publication No. 2020-061202 Summary of the Invention

[0004] The problem to be solved by the invention is that in a suspended substrate with circuitry as described in Patent Document 1, there is a need for further improvement in dimensional accuracy.

[0005] This invention provides a method for manufacturing a wiring circuit board and an assembly sheet, which can improve the dimensional accuracy of the metal parts.

[0006] The present invention [1] is a method for manufacturing a wiring circuit board, which is a method for manufacturing a wiring circuit board having a conductor pattern and a metal part, wherein the conductor pattern has terminals and the metal part is made of only metal. The method for manufacturing the wiring circuit board includes: an etching process, wherein the metal part is formed by etching the substrate by spraying an etching solution onto the metal substrate. In the etching process, the size of the metal part is adjusted by adjusting the spray impact force calculated based on the following formula.

[0007] Calculation formula:

[0008] [Formula 1]

[0009] (In the above calculation formula, F represents the jet impact force, Q represents the jet volume of each jet nozzle, ρ represents the density of the etching solution, and P represents the jet pressure).

[0010] According to this method, the dimensions of the metal part can be adjusted by adjusting the jet impact force.

[0011] Therefore, for example, compared to methods that adjust the injection pressure, it is possible to improve the dimensional accuracy of the metal parts.

[0012] The present invention [2] includes a method for manufacturing a wiring circuit board as described in [1] above, wherein the etching apparatus used in the etching process has a plurality of jet lines arranged in a width direction orthogonal to the travel direction of the substrate, the jet lines having at least one jet nozzle, and in the etching process, the jet impact force of each of the plurality of jet lines is adjusted to be fixed.

[0013] Using this method, the jet impact force of each of the multiple jet lines arranged along the width direction is adjusted to a fixed value.

[0014] This allows for the uniformity of the dimensions of the metal portion in the width direction.

[0015] The present invention [3] includes a method for manufacturing the wiring circuit board described in [2] above, wherein, in the etching process, the difference between the maximum and minimum values ​​of the jet impact force of each of the plurality of jet lines is adjusted to be less than 0.15N.

[0016] This method enables further homogenization of the dimensions of the metal portion in the width direction.

[0017] The present invention [4] includes a method for manufacturing a wiring circuit board as described in [2] or [3] above, wherein the jetting pipeline has a plurality of jetting nozzles arranged along the travel direction.

[0018] The present invention [5] includes a method for manufacturing a wiring circuit board according to any one of [1] to [4] above, wherein the wiring circuit board further comprises: a metal support layer for supporting the conductor pattern; and an insulating layer disposed between the metal support layer and the conductor pattern, the method for manufacturing the wiring circuit board further comprising: an insulating layer forming step for forming the insulating layer on the substrate; and a conductor pattern forming step for forming the conductor pattern on the insulating layer, wherein in the etching step, the substrate is etched to form the metal support layer and the metal portion.

[0019] The present invention [6] includes a method for manufacturing a wiring circuit board according to any one of [1] to [5] above, wherein the wiring circuit board is a suspended board with circuitry, the suspended board with circuitry having: a mounting portion on which a skid with a magnetic head is mounted; and an extension bracket portion disposed around the mounting portion, the metal portion being the extension bracket portion, the size of the metal portion being the width of the extension bracket portion.

[0020] The permissible dimensional tolerance in the width of the extended support section is the smallest among suspended substrates with circuitry.

[0021] Therefore, as long as the dimensional accuracy of the width of the extended support portion can be improved, it can be inferred that the dimensional accuracy of other parts of the circuit-connected suspension substrate (the parts other than the extended support portion) has also been improved.

[0022] In this respect, according to the present invention, the width of the extended support portion is adjusted by adjusting the jet impact force.

[0023] Therefore, for example, compared with the method of adjusting the injection pressure, it is possible to improve the dimensional accuracy of the width of the extended support portion.

[0024] The present invention [7] includes a method for manufacturing a wiring circuit board according to any one of [1] to [6] above, wherein the substrate is made of stainless steel and the etching solution is a ferric chloride solution.

[0025] The present invention [8] includes an assembly sheet extending along a travel direction and a width direction orthogonal to the travel direction, wherein the assembly sheet has a plurality of columns arranged along the width direction, the columns including a plurality of wiring circuit boards arranged along the travel direction, the wiring circuit boards having: a conductor pattern having terminals; a metal support layer supporting the conductor pattern; an insulating layer disposed between the metal support layer and the conductor pattern; and a metal portion consisting only of metal, wherein the difference between the maximum and minimum values ​​of the average values ​​of the metal portions of each of the plurality of columns is less than 6% relative to the average values ​​of the metal portions of all the wiring circuit boards.

[0026] Based on this structure, the difference between the maximum and minimum values ​​of the average values ​​of the metal portions of multiple columns is adjusted to less than 6% relative to the average value of the metal portions of all wiring circuit boards.

[0027] Therefore, it is possible to achieve uniformity in the dimensions of the metal portion in the width direction, and to improve the dimensional accuracy of the metal portion of the wiring circuit board.

[0028] The present invention [9] includes the composite sheet of [8] above, wherein the composite sheet has three or more of the columns described above.

[0029] The present invention

[10] includes the assembly sheet of [8] or [9] above, wherein the assembly sheet has more than 100 of the wiring circuit boards.

[0030] Effects of the Invention: According to the manufacturing method of the wiring circuit board and the assembly sheet of the present invention, the dimensional accuracy of the metal parts can be improved. Attached Figure Description

[0031] Figure 1 is a top view of an assembly sheet as an embodiment of the wiring circuit board of the present invention.

[0032] Figure 2 is an enlarged view of the suspended substrate with circuitry shown in Figure 1.

[0033] Figure 3 is an AA cross-sectional view of the suspended substrate with circuitry shown in Figure 2.

[0034] Figure 4 is a rear view of the suspended substrate with circuitry shown in Figure 2.

[0035] Figures 5A to 5C are process diagrams illustrating the manufacturing method of the suspended substrate with circuitry shown in Figure 3. Figure 5A represents the first insulating layer formation process, Figure 5B represents the conductor pattern formation process, and Figure 5C represents the second insulating layer formation process.

[0036] Figure 6 follows Figure 5C, showing the etching process.

[0037] Figure 7 is a block diagram showing the manufacturing system of a suspended substrate with circuitry.

[0038] Figure 8 is a piping diagram of the etching apparatus shown in Figure 7.

[0039] Figure 9 is a block diagram used to illustrate the control device shown in Figure 7. Detailed Implementation

[0040] 1. As shown in Figure 1, the assembly sheet 1 extends along the travel direction and the width direction. The width direction is orthogonal to the travel direction. The assembly sheet 1 has a frame 2 and a plurality of circuit-carrying suspension substrates 3 (an example of wiring circuit substrates). The frame 2 supports the plurality of circuit-carrying suspension substrates 3.

[0041] The assembly sheet 1 may have, for example, more than 100 circuit-connected suspension substrates 3. It should be noted that the number of circuit-connected suspension substrates 3 is not limited. The assembly sheet 1 may have more than 300 circuit-connected suspension substrates 3, or more than 500 circuit-connected suspension substrates 3.

[0042] Multiple circuit-bearing suspension substrates 3 form multiple columns L1, L2, L3 arranged along the width direction. That is, the assembly sheet 1 has multiple columns L1, L2, L3 arranged along the width direction. Each column L1, L2, L3 includes multiple circuit-bearing suspension substrates 3. The multiple circuit-bearing suspension substrates 3 are arranged along the travel direction.

[0043] The sheet assembly 1 may have, for example, three or more columns. It should be noted that there is no limit to the number of columns. The sheet assembly 1 may also have five or more columns.

[0044] The circuit-connected suspension substrate 3 is a component of the head suspension assembly of a hard disk drive.

[0045] As shown in Figure 2, the suspended substrate 3 with circuitry has a mounting portion 3A, an extended support portion 3B (an example of a metal part), and a wiring portion 3C.

[0046] A skid S with a read / write head is mounted on the mounting section 3A. The read / write head is capable of reading data from the recording surface of the hard disk and writing data to the recording surface of the hard disk. The mounting section 3A is located at one end of the suspension board 3 with circuitry. In this embodiment, the mounting section 3A has a generally rectangular shape. It should be noted that the shape of the mounting section 3A is not limited. A plurality of terminals 131A, 131B, 131C, and 131D are arranged on the mounting section 3A. The terminals 131A, 131B, 131C, and 131D will be described later.

[0047] The extended support portion 3B is disposed around the mounting portion 3A. The extended support portion 3B surrounds the mounting portion 3A. In this embodiment, the extended support portion 3B has a frame shape that is generally rectangular when viewed from above. It should be noted that the shape of the extended support portion 3B is not limited.

[0048] The wiring section 3C extends in the width direction. An extended support section 3B is connected to one end of the wiring section 3C in the width direction. The wiring section 3C has a strip shape. Multiple wirings 133A, 133B, 133C, and 133D, and multiple terminals 132A, 132B, 132C, and 132D are arranged in the wiring section 3C. The wiring and terminals will be explained later.

[0049] As shown in Figure 3, the suspended substrate 3 with circuitry has a metal support layer 11, a first insulating layer 12 as an example of an insulating layer, a conductor pattern 13, and a second insulating layer 14.

[0050] (1) As shown in FIG4, the metal support layer 11 is disposed in the mounting portion 3A and the wiring portion 3C. That is, the mounting portion 3A has the metal support layer 11. The metal support layer 11 supports the first insulating layer 12, the conductor pattern 13 and the second insulating layer 14 in the mounting portion 3A and the wiring portion 3C. For example, stainless steel and copper alloy can be used as materials for the metal support layer 11.

[0051] It should be noted that the extended support portion 3B is made entirely of metal. The extended support portion 3B does not have the first insulating layer 12, the conductor pattern 13, or the second insulating layer 14. The extended support portion 3B is made entirely of the same metal as the metal support layer 11 of the mounting portion 3A and the wiring portion 3C.

[0052] The thickness of the extended support portion 3B and the metal support layer 11 is, for example, less than 30 μm, or more than 10 μm.

[0053] In this embodiment, the metal support layer 11 of the mounting portion 3A is not connected to the extended bracket portion 3B. Alternatively, the metal support layer 11 of the mounting portion 3A may be connected to the extended bracket portion 3B.

[0054] (2) As shown in FIG2, the first insulating layer 12 is disposed on the metal support layer 11 in the mounting portion 3A and the wiring portion 3C. The first insulating layer 12 is disposed on the metal support layer 11 in the thickness direction of the suspended substrate 3 with circuitry. The first insulating layer 12 is disposed between the metal support layer 11 and the conductor pattern 13 in the thickness direction. The first insulating layer 12 insulates the conductor pattern 13 relative to the metal support layer 11. The first insulating layer 12 is made of resin. Examples of resins include polyimide, maleimide, epoxy resin, polybenzoxazole, and polyester.

[0055] The first insulating layer 12 has a first portion 121, a second portion 122, and a plurality of connecting portions 123.

[0056] The first part 121 is disposed on the mounting part 3A. That is, the mounting part 3A has a first insulating layer 12.

[0057] The second part 122 extends from the first part 121 in the width direction. The second part 122 is disposed in the wiring section 3C.

[0058] Each connecting portion 123 connects the first portion 121 to the extended support portion 3B. Each connecting portion 123 extends from the first portion 121. The front end of each connecting portion 123 is disposed on the extended support portion 3B. Each connecting portion 123 has a strip shape. It should be noted that the arrangement and shape of each connecting portion 123 are not limited.

[0059] (3) As shown in FIG3, the conductor pattern 13 is disposed on the first insulating layer 12 in the thickness direction. The conductor pattern 13 is made of metal. Examples of metals include copper, silver, gold, iron, aluminum, chromium, and their alloys. From the viewpoint of obtaining good electrical properties, copper is preferred.

[0060] As shown in Figure 2, the conductor pattern 13 has multiple terminals 131A, 131B, 131C, 131D, multiple terminals 132A, 132B, 132C, 132D, and multiple wirings 133A, 133B, 133C, 133D.

[0061] Terminals 131A, 131B, 131C, and 131D are disposed on the mounting portion 3A. That is, the mounting portion 3A has a conductor pattern 13. With the skid S mounted on the mounting portion 3A, terminals 131A, 131B, 131C, and 131D are electrically connected to the magnetic head. Terminals 131A, 131B, 131C, and 131D are arranged along the travel direction. Each of terminals 131A, 131B, 131C, and 131D has a square pad shape.

[0062] Terminals 132A, 132B, 132C, and 132D are disposed at the other end of the wiring section 3C in the width direction. Terminals 132A, 132B, 132C, and 132D are electrically connected, for example, to the control board of a hard disk drive. Terminals 132A, 132B, 132C, and 132D are arranged in the traveling direction. It should be noted that the arrangement direction of terminals 132A, 132B, 132C, and 132D may differ from the arrangement direction of terminals 131A, 131B, 131C, and 131D. Each of terminals 132A, 132B, 132C, and 132D has a square pad shape.

[0063] Wiring 133A electrically connects terminals 131A and 132A. One end of wiring 133A is connected to terminal 131A. The other end of wiring 133A is connected to terminal 132A. Wiring 133B electrically connects terminals 131B and 132B. One end of wiring 133B is connected to terminal 131B. The other end of wiring 133B is connected to terminal 132B. Wiring 133C electrically connects terminals 131C and 132C. One end of wiring 133C is connected to terminal 131C. The other end of wiring 133C is connected to terminal 132C. Wiring 133D electrically connects terminals 131D and 132D. One end of wiring 133D is connected to terminal 131D. The other end of wiring 133D is connected to terminal 132D.

[0064] (4) As shown in FIG3, the second insulating layer 14 covers wirings 133A, 133B, 133C, and 133D. The second insulating layer 14 is disposed on the first insulating layer 12 in the thickness direction. The second insulating layer 14 does not cover terminals 131A, 131B, 131C, 131D, and terminals 132A, 132B, 132C, and 132D. The second insulating layer 14 is made of resin. Examples of resins include polyimide, maleimide, epoxy resin, polybenzoxazole, and polyester.

[0065] 2. Manufacturing method of suspension substrate with circuitry Next, the manufacturing method of suspension substrate 3 with circuitry will be described.

[0066] The manufacturing method of the suspended substrate 3 with circuitry includes a first insulating layer formation process (see Figure 5A), a conductor pattern formation process (see Figure 5B), a second insulating layer formation process (see Figure 5C), and an etching process (see Figure 6).

[0067] (1) The first insulating layer forming process is shown in FIG5A. In the first insulating layer forming process, a first insulating layer 12 is formed on a substrate M. The substrate M is made of metal. For example, stainless steel and copper alloy can be used as materials for the substrate M. The thickness of the substrate M is, for example, less than 30 μm, and for example, more than 10 μm.

[0068] To form the first insulating layer 12, firstly, a solution of photosensitive resin (varnish) is coated onto the substrate M and allowed to dry, forming a photosensitive resin coating. Next, the photosensitive resin coating is exposed to light, and then the exposed coating is developed. Thus, the first insulating layer 12 is formed.

[0069] (2) The conductor pattern forming process is shown in Figure 5B. In the conductor pattern forming process, a conductor pattern 13 is formed on the first insulating layer 12. The conductor pattern forming process includes a seed layer forming process, an anti-plating agent forming process, a plating process, an anti-plating agent stripping process, and a seed layer removal process.

[0070] To form the conductor pattern 13, a seed layer is first formed on the surface of the first insulating layer 12 (seed layer formation process). The seed layer is formed, for example, by sputtering. Examples of materials for the seed layer include chromium, copper, nickel, titanium, and alloys thereof.

[0071] Next, an anti-plating agent is applied to the first insulating layer 12 on which the seed layer is formed, so that the portion forming the conductor pattern 13 is in a light-shielding state, and the anti-plating agent is exposed.

[0072] Next, the exposed resist is developed. Thus, the resist in the shaded areas is removed, and the seed layer is exposed in the areas where the conductor pattern 13 is formed. It should be noted that resist residue remains in the exposed areas, i.e., the areas where the conductor pattern 13 is not formed (resist formation process).

[0073] Next, a conductor pattern 13 is formed on the exposed seed layer by electroplating (plating process). After electroplating is completed, the resist is stripped (resist stripping process).

[0074] Next, the seed layer exposed due to the stripping of the resist is removed, for example by wet etching or dry etching (seed layer removal process).

[0075] (3) The second insulating layer forming process is shown in Figure 5C. In the second insulating layer forming process, the second insulating layer 14 is formed on the first insulating layer 12 and the conductor pattern 13 in the same manner as the first insulating layer 12 is formed.

[0076] (4) The etching process is shown in Figure 6. In the etching process, the substrate M is etched by spraying an etching solution onto it. It should be noted that in the etching process, the portions forming the metal support layer 11 and the extended support portion 3B are covered by the etching resist R. When the substrate M is made of stainless steel, the etching solution is, for example, a ferric chloride solution.

[0077] In the etching process, the substrate M is etched, as shown in Figures 2 and 3, to form a metal support layer 11 and an extended support portion 3B.

[0078] It should be noted that during the etching process, the etching solution sprayed onto the substrate M can be recovered and sprayed back onto the substrate M.

[0079] Through an etching process, an assembly sheet 1 with multiple suspended substrates 3 containing circuits is obtained (see Figure 1).

[0080] 3. Manufacturing System for Suspended Substrate with Circuit Next, the manufacturing system 100 used to implement the above-described manufacturing method for suspended substrate 3 with circuit will be described.

[0081] As shown in FIG7, it includes a first insulating layer forming line 101, a conductor pattern forming line 102, a second insulating layer forming line 103, and an etching line 104.

[0082] (1) First Insulating Layer Forming Line: The first insulating layer forming process described above is performed in the first insulating layer forming line 101. That is, the first insulating layer forming line 101 forms a first insulating layer 12 on the substrate M. The first insulating layer forming line 101 includes, for example, a coating apparatus, a drying apparatus, an exposure apparatus, and a developing apparatus. The coating apparatus coats a solution of photosensitive resin (varnish) onto the substrate M. The drying apparatus dries the solution of photosensitive resin coated on the substrate M, forming a photosensitive resin coating film on the substrate M. The exposure apparatus exposes the photosensitive resin coating film. The developing apparatus develops the exposed coating film.

[0083] (2) Conductor Pattern Forming Line The conductor pattern forming process described above is performed on the conductor pattern forming line 102. That is, the conductor pattern forming line 102 forms a conductor pattern 13 on the first insulating layer 12. The conductor pattern forming line 102 includes, for example, a sputtering apparatus, a resist bonding apparatus, an exposure apparatus, a developing apparatus, an electroplating apparatus, a resist stripping apparatus, and a seed layer removal apparatus. The sputtering apparatus forms a seed layer on the surface of the first insulating layer 12. The resist bonding apparatus bonds a resist to the first insulating layer 12 on which the seed layer is formed. The exposure apparatus exposes the resist. The developing apparatus develops the exposed resist. The electroplating apparatus forms the conductor pattern 13 on the seed layer exposed from the resist. The resist stripping apparatus strips the resist. The seed layer removal apparatus removes the seed layer exposed due to the removal of the resist.

[0084] (3) The second insulating layer forming line performs the above-described second insulating layer forming process in the second insulating layer forming line 103. That is, in the second insulating layer forming line 103, the second insulating layer 14 is formed on the first insulating layer 12 and the conductor pattern 13. The second insulating layer forming line 103 is similar to the first insulating layer forming line 101, for example, having a coating apparatus, a drying apparatus, an exposure apparatus and a developing apparatus.

[0085] (4) The etching process described above is performed in the etching line 104. The etching line 104 includes, for example, an etching apparatus 104A, a measuring device 104B, and a control device 104C. That is, the etching apparatus 104A is used in the etching process.

[0086] (4-1) As shown in FIG6, the etching apparatus 104A etches the substrate M by spraying etching solution onto the substrate M. The etching apparatus 104A etches the substrate M to form a metal support layer 11 (see FIG3) and an extended support portion 3B (see FIG3).

[0087] The etching apparatus 104A has a tank 1041, multiple spray lines 1042A, 1042B, 1042C (see Figure 8), and a recovery line 1043.

[0088] Can 1041 contains etching solution.

[0089] As shown in Figure 8, multiple injection lines 1042A, 1042B, and 1042C are arranged along the width direction. Each injection line 1042A, 1042B, and 1042C has multiple injection nozzles 10421, piping 10422, pump 10423, valve 10424, pressure sensor 10425, and flow meter 10426.

[0090] Multiple spray nozzles 10421 are arranged along the direction of travel. Each of the multiple spray nozzles 10421 sprays the etching solution supplied from the tank 1041 toward the substrate M.

[0091] Pipe 10422 is used to supply the etching solution in tank 1041 to a plurality of spray nozzles 10421. One end of pipe 10422 is connected to tank 1041. Each spray nozzle 10421 is connected to pipe 10422. Etching solution from tank 1041 toward each spray nozzle 10421 passes through pipe 10422.

[0092] Pump 10423 delivers etching solution from tank 1041 to each spray nozzle 10421. Pump 10423 can be a known liquid delivery pump. For example, a gear pump can be used as pump 10423.

[0093] Valve 10424 is positioned midway through piping 10422. Valve 10424 is positioned between pump 10423 and injection nozzle 10421. Valve 10424 controls the flow rate of etching solution through piping 10422. Examples of valves 10424 include solenoid valves, diaphragm valves, and butterfly valves.

[0094] Pressure sensor 10425 detects the pressure (jet pressure) of the etching solution supplied to jet nozzle 10421. Pressure sensor 10425 is mounted on piping 10422. Examples of pressure sensors 10425 include elastomeric pressure gauges such as burden tubes and diaphragms.

[0095] Flow meter 10426 detects the flow rate of etching solution passing through piping 10422. Flow meter 10426 is installed in piping 10422. Examples of flow meters 10426 include ultrasonic flow meters, electromagnetic flow meters, Coriolis flow meters, and differential pressure flow meters.

[0096] The recovery line 1043 is a piping system used to return the etching solution sprayed onto the substrate M to the tank 1041. In the case where the substrate M is stainless steel foil, metals in the stainless steel that are difficult to dissolve in the etching solution may become fine particles (sludge) and mix into the recovered etching solution. Therefore, when the substrate M is stainless steel foil, a filter for collecting sludge can be installed midway through the recovery line 1043.

[0097] (4-2) As shown in Figure 7, the measuring device 104B measures the width W of the extended support portion 3B. Examples of measuring methods for the measuring device 104B include laser, LED, ultrasonic, contact, and TOF (Time of Flight) types. For example, an LED-type online projection image measuring machine can be used as the measuring device 104B.

[0098] It should be noted that the etching line 104 may also be without the measuring device 104B. In this case, an offline measuring device independent of the etching line 104 can be used to measure the width W of the extended support portion 3B. As an offline measuring device, a three-dimensional measuring instrument (QVH4 HYPER 404Pro, manufactured by Mitutoyo) can be cited as an example.

[0099] (4-3) Control device The control device 104C controls the etching device 104A. The control device 104C is electrically connected to the measuring device 104B and the etching device 104A.

[0100] In detail, as shown in Figure 9, the control device 104C is electrically connected to the measuring device 104B, the pressure sensor 10425, the flow meter 10426, the pump 10423, and the valve 10424. The control device 104C can acquire the width W of the extended support portion 3B measured by the measuring device 104B, the injection pressure P detected by the pressure sensor 10425, and the flow rate detected by the flow meter 10426. The control device 104C can control the pump 10423 and the valve 10424.

[0101] In the etching process of the above-described manufacturing method, the control device 104C adjusts the jet impact force F of each jet pipeline 1042A, 1042B, and 1042C to a fixed value.

[0102] In detail, the control device 104C first acquires the injection pressure P detected by the pressure sensor 10425 and the flow rate detected by the flow meter 10426, and calculates the injection impact force F of each injection line 1042A, 1042B, and 1042C.

[0103] The jet impact force F is expressed by the following formula.

[0104] Calculation formula:

[0105] [Formula 1]

[0106] In the above formula, F represents the jet impact force, Q represents the jet volume of each jet nozzle, ρ represents the density of the etching solution, and P represents the jet pressure. The jet volume of each jet nozzle is calculated by dividing the flow rate measured by the flow meter 10426 by the number of jet nozzles.

[0107] Next, the control device 104C controls at least one of the pump 10423 and the valve 10424 to adjust the jet impact force F of each jet line 1042A, 1042B, 1042C to a fixed value.

[0108] "Fixed" means that the difference between the maximum and minimum values ​​of the jet impact force F of each jet line 1042A, 1042B, and 1042C converges within a given range. During the etching process, the control device 104C adjusts the difference between the maximum and minimum values ​​of the jet impact force F of each jet line 1042A, 1042B, and 1042C to, for example, 0.15N or less, preferably 0.09N or less. When the difference between the maximum and minimum values ​​of the jet impact force F of each jet line 1042A, 1042B, and 1042C is below the aforementioned upper limit, the width W of the extended support portion 3B can be further homogenized in the width direction.

[0109] Specifically, when the difference between the maximum and minimum values ​​of the jet impact force F of each jet line 1042A, 1042B, and 1042C is below the aforementioned upper limit value, the difference between the maximum and minimum values ​​of the average width W of the extended support portion 3B of the circuit-connected suspension substrate 3 of each column L1, L2, and L3 is, for example, 3.0 μm or less, preferably 2.5 μm or less, and more preferably 2.0 μm or less.

[0110] Furthermore, when the difference between the maximum and minimum values ​​of the jet impact force F of each jet line 1042A, 1042B, and 1042C is less than or equal to the aforementioned upper limit, the difference between the maximum and minimum values ​​of the average width W of the extended support portion 3B of the circuit-connected suspension substrate 3 in each column L1, L2, and L3 is, for example, less than 6%, preferably less than 4%, relative to the average width W of the extended support portion 3B of all circuit-connected suspension substrates 3.

[0111] That is, in the etching process, by adjusting the jet impact force F of each jet line 1042A, 1042B, 1042C to a fixed value, the width W (an example of the size of the metal component) of the extended support portion 3B of the circuit-connected suspension substrate 3 of each column L1, L2, L3 is adjusted to a fixed value.

[0112] It should be noted that the jet impact force F can also be controlled by feedback based on the width W of the extended support portion 3B measured by the measuring device 104B.

[0113] Alternatively, at least one of pump 10423 and valve 10424 may not be controlled by control device 104C. At least one of pump 10423 and valve 10424 may also be operable by an operator. In this case, the jet impact force F can also be adjusted by the operator operating at least one of pump 10423 and valve 10424. For example, control device 104C displays the jet impact force F of each jet line 1042A, 1042B, 1042C on a given monitor. The operator may also operate at least one of pump 10423 and valve 10424 to fix the jet impact force F displayed on the monitor.

[0114] 4. Effects (1) According to the manufacturing method of the circuit-connected suspension substrate 3, the width W of the extended support part 3B is adjusted by adjusting the jet impact force.

[0115] Therefore, for example, compared with the method of adjusting the injection pressure, it is possible to improve the dimensional accuracy of the extended support portion 3B.

[0116] (2) According to the manufacturing method of the suspended substrate 3 with circuit, as shown in FIG8, the etching apparatus 104A has a plurality of jet lines 1042A, 1042B, and 1042C arranged in the width direction. Furthermore, in the etching process, the jet impact force of each of the plurality of jet lines 1042A, 1042B, and 1042C is adjusted to be fixed.

[0117] Therefore, it is possible to achieve uniformity of the width W of the extended support portion 3B in the width direction.

[0118] (3) According to the manufacturing method of the circuit-connected suspension substrate 3, by adjusting the jet impact force, the dimensional accuracy of the width W of the extended support part 3B can be improved.

[0119] The allowable dimensional tolerance of the width W of the extended support portion 3B is the smallest among the suspended substrate 3 with circuitry.

[0120] Therefore, as long as the dimensional accuracy of the width W of the extended support portion 3B can be improved, it can be inferred that the dimensional accuracy of other parts of the circuit-connected suspension substrate 3 (parts other than the extended support portion 3B) has also been improved.

[0121] (4) As shown in Figure 1, the composite sheet 1 manufactured by the above manufacturing method has multiple columns L1, L2, L3 arranged along the width direction, and each column L1, L2, L3 includes multiple circuit-carrying suspension substrates 3 arranged along the travel direction.

[0122] Furthermore, by adjusting the jet impact force in the above etching process, the difference between the maximum and minimum values ​​of the average width W of the extended support portion 3B of each column L1, L2, and L3 is adjusted to less than 6% relative to the average width W of the extended support portion 3B of all circuit-connected suspension substrates 3.

[0123] Therefore, it is possible to achieve uniformity of the width W of the extended support portion 3B in the width direction, and to improve the dimensional accuracy of the extended support portion 3B.

[0124] 5. Variation (1) The wiring circuit board is not limited to the suspended board 3 with circuitry. The wiring circuit board may also be a flexible printed circuit board or a lead frame that carries semiconductor components.

[0125] (2) The metal part is not limited to the extended support part 3B. When the mounting part 3A is made only of the metal support layer 11, the metal part may also be the mounting part 3A.

[0126] Alternatively, the metal portion can also be part of the conductor pattern. For example, in the case where the conductor pattern has a fly wire and the fly wire is made by etching the metal support layer 11, the metal portion can also be the fly wire.

[0127] (3) The number of jet lines 1042A to 1042C in the etching apparatus 104A may also be different from the number of columns L1 to L3 in the aggregate sheet 1. For example, the number of jet lines 1042A to 1042C may be more than the number of columns L1 to L3.

[0128] Examples and comparative examples are shown below to further illustrate the present invention. It should be noted that the present invention is not limited to any of the examples and comparative examples. In addition, the specific numerical values ​​of proportions (including proportions), physical property values, parameters, etc. used in the following description can replace the corresponding upper limits (defined as "less than" or "less than") or lower limits (defined as "more than" or "exceeding") of the proportions (including proportions), physical property values, parameters, etc., recorded in the "Specific Embodiments" above.

[0129] 1. Manufacturing of a suspended substrate with circuitry (1) Example 1 First, a solution of photosensitive resin (varnish) is coated on a stainless steel substrate and dried to form a photosensitive resin coating.

[0130] Next, the photosensitive resin coating is exposed to light, and then the exposed coating is developed. As a result, a first insulating layer is formed on the substrate (first insulating layer formation process).

[0131] Next, a seed layer composed of chromium was formed on the surface of the first insulating layer by sputtering.

[0132] Next, an anti-plating agent is applied over the first insulating layer on which the seed layer is formed, so that the part forming the conductor pattern is exposed to the anti-plating agent.

[0133] Next, the exposed resist was developed. As a result, the resist in the shaded areas was removed, and the seed layer was exposed in the areas where the conductor pattern was formed.

[0134] Next, a conductor pattern is formed on the exposed seed layer by electrolytic copper plating. After the electrolytic plating is completed, the resist is stripped, and the seed layer exposed due to the stripping of the resist is removed by wet etching (conductor pattern formation process).

[0135] Next, a second insulating layer is formed on top of the first insulating layer and the conductor pattern in the same manner as the formation of the first insulating layer (second insulating layer formation process).

[0136] Next, using an etching apparatus equipped with nine spray lines, an etching solution (ferric chloride solution) is sprayed onto the substrate, which is covered with an etching resist to form the metal support layer and the extended support portion, and the substrate M is etched. This forms the metal support layer and the extended support portion (etching process).

[0137] Through the above steps, an assembly sheet with multiple suspended substrates containing circuits was obtained.

[0138] The difference between the maximum and minimum injection pressure of each injection line (pressure difference) and the difference between the maximum and minimum injection impact force of each injection line (impact force difference) are shown in Table 1.

[0139] (2) Examples 2 to 3, except that they were etched using the pressure difference and impact difference described in Table 1, obtained aggregate sheets in the same manner as in Example 1.

[0140] 2. Measurement of the width of the extended support portion: In the assembly sheets obtained in each embodiment and each comparative example, the width of the extended support portion of each circuit-connected suspension substrate was measured using a three-dimensional dimension measuring instrument (QVH4HYPER 404Pro, manufactured by Mitutoyo).

[0141] The average width of the extended support portion for each column was calculated, and then the difference between the maximum and minimum values ​​of the average value for each column (the dimensional difference between columns) was calculated. Table 1 shows the "dimensional difference between columns" and the "ratio of the dimensional difference between columns to the average width of the extended support portions of all circuit-connected suspension substrates" (the ratio of the dimensional difference). The smaller the dimensional difference between columns, the higher the dimensional accuracy.

[0142] [Table 1]

[0143] 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.

[0144] Industrial Applicability: The method for manufacturing the wiring circuit board and the assembly sheet of the present invention can be used in the manufacture of wiring circuit boards.

[0145] Symbol Explanation 1: Assembly sheet 3: Suspended substrate with circuit (an example of a wiring circuit substrate) 3A: Mounting part 3B: Extended support part (an example of a metal part) 11: Metal support layer 12: First insulating layer (an example of an insulating layer) 13: Conductor pattern 131A: Terminal 104A: Etching device 1042A: Spray line 1042B: Spray line 1042C: Spray line 10421: Spray nozzle L1~L3: Column M: Substrate S: Skid W: Width of the extended support part.

Claims

1. A method for manufacturing a wiring circuit board, comprising manufacturing a wiring circuit board having a conductor pattern and a metal portion, wherein the conductor pattern has terminals, and the metal portion is composed solely of metal, wherein... The method for manufacturing the wiring circuit board includes an etching step, in which the substrate is etched by spraying an etching solution onto it to form the metal portion. In the etching step, the dimensions of the metal portion are adjusted by adjusting a spray impact force calculated based on the following formula: In the calculation formula, F represents the jet impact force, Q represents the jet volume of each jet nozzle, ρ represents the density of the etching solution, and P represents the jet pressure.

2. The method for manufacturing a wiring circuit board according to claim 1, wherein, The etching apparatus used in the etching process has a plurality of jet lines arranged in a width direction orthogonal to the travel direction of the substrate, each jet line having at least one jet nozzle, and the jet impact force of each of the plurality of jet lines is adjusted to be fixed in the etching process.

3. The method for manufacturing a wiring circuit board according to claim 2, wherein, In the etching process, the difference between the maximum and minimum values ​​of the jet impact force of each of the plurality of jet lines is adjusted to be below 0.15N.

4. The method for manufacturing a wiring circuit board according to claim 2, wherein, The injection pipeline has a plurality of injection nozzles arranged along the direction of travel.

5. The method for manufacturing a wiring circuit board according to claim 1, wherein, The wiring circuit board further includes: a metal support layer that supports the conductor pattern; The method for manufacturing the wiring circuit board further includes an insulating layer disposed between the metal support layer and the conductor pattern, and an insulating layer forming step, wherein the insulating layer is formed on the substrate. The process includes a conductor pattern forming process, in which the conductor pattern is formed on the insulating layer, and an etching process, in which the substrate is etched to form the metal support layer and the metal portion.

6. The method for manufacturing a wiring circuit board according to claim 1, wherein, The wiring circuit board is a suspended board with circuitry, the suspended board with circuitry having: a mounting portion capable of mounting a skid with a magnetic head; and an extension bracket portion disposed around the mounting portion, the metal portion being the extension bracket portion, the size of the metal portion being the width of the extension bracket portion.

7. The method for manufacturing a wiring circuit board according to claim 1, wherein, The substrate is made of stainless steel, and the etching solution is a ferric chloride solution.

8. A composite sheet extending along a direction of travel and a width direction orthogonal to the direction of travel, wherein, The assembly sheet has a plurality of columns arranged along the width direction, the columns including a plurality of wiring circuit boards arranged along the travel direction, the wiring circuit boards having: conductor patterns having terminals; A metal support layer that supports the conductor pattern; An insulating layer disposed between the metal support layer and the conductor pattern; and a metal portion consisting solely of metal, wherein the difference between the maximum and minimum values ​​of the average size of the metal portions of each of the plurality of columns is less than 6% relative to the average size of the metal portions of all the wiring circuit boards.

9. The composite sheet according to claim 8, wherein, The composite sheet has three or more of the columns.

10. The composite sheet according to claim 8, wherein, The assembly sheet has more than 100 of the aforementioned wiring circuit boards.

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