Assembly sheet and method for manufacturing assembly sheet

Abstract

To provide an assembly sheet and a method for manufacturing the assembly sheet which can prevent burrs from remaining on the edges of the assembly sheet.SOLUTION: An assembly sheet 1 includes a wired circuit board 2, a frame 3 that supports the wired circuit board 2, and an outer peripheral edge 4 that is disposed outside the frame 3. The wired circuit board 2 includes a metal support layer 21, a first insulating layer 24, and a conductive pattern 26. The wired circuit board 2 has at least one of a first protective layer 23 that is disposed between the metal support layer 21 and the first insulating layer 24, and a second protective layer 25 that is disposed between the first insulating layer 24 and the conductive pattern 26. The outer peripheral edge 4 has an edge metal layer 41 that is made of the same material as the metal support layer 21.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an assembly sheet and a method for manufacturing the assembly sheet. [Background technology]

[0002] BACKGROUND ART Conventionally, an assembly sheet including a plurality of wired circuit boards and a frame that supports the wired circuit boards has been known (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-168735 Summary of the Invention [Problem to be solved by the invention]

[0004] In the final stage of manufacturing an assembly sheet as described in Patent Document 1, the outer peripheral edge of the assembly sheet (the portion outside the frame) may be removed by etching to process the outer shape of the assembly sheet.

[0005] In this case, if burrs remain on the edges of the assembly sheet after etching, the burrs may become an obstacle and make handling of the assembly sheet difficult.

[0006] The present invention provides an assembly sheet that can prevent burrs from remaining on the edges of the assembly sheet, and a method for manufacturing the assembly sheet. [Means for solving the problem]

[0007] The present invention [1] includes an assembly sheet comprising a wired circuit board, a frame supporting the wired circuit board, and an outer peripheral edge portion disposed outside the frame, wherein the wired circuit board has a metal support layer, an insulating layer disposed on one side of the metal support layer in the thickness direction of the metal support layer, a conductor pattern disposed on one side of the insulating layer in the thickness direction, and at least one of a first protective layer made of metal disposed between the metal support layer and the insulating layer in the thickness direction, and a second protective layer made of metal disposed between the insulating layer and the conductor pattern in the thickness direction, and the outer peripheral edge portion has an edge metal layer made of the same material as the metal support layer.

[0008] According to this configuration, the outer peripheral end portion disposed outside the frame has an end metal layer made of the same material as the metal support layer.

[0009] Therefore, by etching the end metal layer in the same manner as etching the metal support layer, the outer peripheral end can be reliably removed.

[0010] As a result, it is possible to prevent burrs from remaining on the edges of the assembly sheet.

[0011] The present invention [2] includes the assembly sheet of [1] above, wherein the outer peripheral edge has, on one side of the edge metal layer in the thickness direction, at least one of a first metal thin film made from the same metal as the first protective layer and a second metal thin film made from the same metal as the second protective layer, and the sum of the thicknesses of the first metal thin film and the second metal thin film is thinner than the sum of the thicknesses of the first protective layer and the second protective layer.

[0012] According to this configuration, the sum of the thickness of the first metal thin film and the thickness of the second metal thin film is smaller than the sum of the thickness of the first protective layer and the thickness of the second protective layer.

[0013] Therefore, even if at least one of the first metal thin film and the second metal thin film is formed at the outer peripheral edge when forming at least one of the first protective layer and the second protective layer, the outer peripheral edge can be reliably removed by etching the edge metal layer in the same manner as etching the metal support layer.

[0014] As a result, it is possible to prevent burrs from remaining on the edges of the assembly sheet.

[0015] The present invention [3] includes the assembly sheet of the above [2], wherein the outer peripheral edge has the first metal thin film, and the thickness of the first metal thin film is thinner than the thickness of the first protective layer.

[0016] The present invention [4] includes the assembly sheet of the above [2] or [3], wherein the outer peripheral edge has the second metal thin film, and the thickness of the second metal thin film is thinner than the thickness of the second protective layer.

[0017] The present invention [5] includes the assembly sheet of the above [2], wherein the outer peripheral edge has the first metal thin film or the second metal thin film.

[0018] The present invention [6] includes the assembly sheet of any one of the above [2] to [5], wherein the sum of the thickness of the first metal thin film and the thickness of the second metal thin film is 50 nm or less.

[0019] With this configuration, even if at least one of the first metal thin film and the second metal thin film is formed at the outer peripheral edge when forming at least one of the first protective layer and the second protective layer, the outer peripheral edge can be reliably removed by etching the edge metal layer in the same manner as etching the metal support layer.

[0020] As a result, it is possible to prevent burrs from remaining on the edges of the assembly sheet.

[0021] The present invention [7] includes the assembly sheet of any one of the above [1] to [6], wherein the outer peripheral edge does not have a first metal thin film made from the same metal as the first protective layer, and a second metal thin film made from the same metal as the second protective layer.

[0022] The present invention [8] includes an assembly sheet comprising a wired circuit board, a frame supporting the wired circuit board, and an outer peripheral edge portion disposed outside the frame, wherein the wired circuit board has a metal support layer, an insulating layer disposed on one side of the metal support layer in the thickness direction of the metal support layer, a conductive pattern disposed on one side of the insulating layer in the thickness direction, and at least one of a first protective layer made of metal disposed between the metal support layer and the insulating layer in the thickness direction and a second protective layer made of metal disposed between the insulating layer and the conductive pattern in the thickness direction, and the outer peripheral edge portion has an end metal layer made of the same material as the metal support layer, and at least one of a first metal thin film made of the same metal as the first protective layer and a second metal thin film made of the same metal as the second protective layer, on one side of the end metal layer in the thickness direction, and the sum of the thicknesses of the first metal thin film and the second metal thin film is 50 nm or less.

[0023] According to this configuration, the peripheral edge portion disposed outside the frame includes an edge metal layer and at least one of a first metal thin film and a second metal thin film. The edge metal layer is made of the same material as the metal support layer, the first metal thin film is made of the same material as the first protective layer, and the second metal thin film is made of the same material as the second protective layer. The sum of the thicknesses of the first metal thin film and the second metal thin film is 50 nm or less.

[0024] Therefore, even if at least one of the first metal thin film and the second metal thin film is formed at the outer peripheral edge when forming at least one of the first protective layer and the second protective layer, the outer peripheral edge can be reliably removed by etching the edge metal layer in the same manner as etching the metal support layer.

[0025] As a result, it is possible to prevent burrs from remaining on the edges of the assembly sheet.

[0026] The present invention [9] includes any one of the assembly sheets [1] to [8] above, wherein the wiring circuit board further has a conductor layer arranged on one side of the metal support layer in the thickness direction, and the outer peripheral end further has an end conductor layer arranged on one side of the end metal layer in the thickness direction and made of the same material as the conductor layer of the wiring circuit board.

[0027] The present invention

[10] is an assembly sheet according to any one of the above [1] to [9], wherein the outer peripheral edge portion further has an end second conductor layer arranged on one side of the end metal layer in the thickness direction and made of the same material as the conductor pattern of the wiring circuit board.

[0028] The present invention

[11] includes the assembly sheet of any one of the above [1] to

[10] , wherein the metal support layer contains copper, and the first protective layer and the second protective layer contain chromium.

[0029] With this configuration, if at least one of the first metal thin film and the second metal thin film is formed on the outer peripheral edge, chromium may inhibit etching of the outer peripheral edge under conditions similar to those for etching the metal support layer.

[0030] In this regard, in the present invention described above, the first metal thin film and the second metal thin film are not present at the outer peripheral edge, or even if at least one of the first metal thin film and the second metal thin film is present, the total thickness of the first metal thin film and the second metal thin film is thin.

[0031] Therefore, by etching the end metal layer in the same manner as etching the metal support layer, the outer peripheral end can be reliably removed.

[0032] As a result, it is possible to prevent burrs from remaining on the edges of the assembly sheet.

[0033] The present invention

[12] includes the assembly sheet of any one of the above [1] to

[11] , wherein the outer peripheral end is a portion 5 mm from the outer peripheral edge of the assembly sheet.

[0034] The present invention

[13] is a method for manufacturing an aggregate sheet according to any one of the above [1] to

[12] , comprising: an insulating layer forming step of forming the insulating layer; a conductor pattern forming step of forming the conductor pattern; and at least one of a first sputtering step of forming the first protective layer by sputtering before the insulating layer forming step; and a second sputtering step of forming the second protective layer by sputtering after the insulating layer forming step and before the conductor pattern forming step, wherein in the first sputtering step and the second sputtering step, sputtering is performed in a state where a portion of the target facing the outer circumferential edge is masked.

[0035] According to this method, in the first sputtering step and the second sputtering step, the portion of the target facing the outer circumferential edge is masked.

[0036] Therefore, in the first sputtering process and the second sputtering process, either the first metal thin film and the second metal thin film are not formed at the outer peripheral edge, or a metal thin film (at least one of the first metal thin film and the second metal thin film) that is thinner than the sum of the thicknesses of the first protective layer and the second protective layer is formed.

[0037] Therefore, in the obtained assembly sheet, the outer peripheral edge can be reliably removed by etching the edge metal layer in the same manner as etching the metal support layer.

[0038] As a result, it is possible to prevent burrs from remaining on the edges of the assembly sheet. [Effects of the Invention]

[0039] According to the assembly sheet and the method for manufacturing the assembly sheet of the present invention, it is possible to prevent burrs from remaining on the edges of the assembly sheet. [Brief explanation of the drawings]

[0040] [Figure 1] FIG. 1 shows a plan view of an assembly sheet as one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the printed circuit board shown in FIG. 1 taken along the line AA. [Figure 3] 3A to 3C are process diagrams showing a method for manufacturing the wired circuit board shown in FIG. 1, where FIG. 3A shows a conductor layer forming process, FIG. 3B shows a first sputtering process, and FIG. 3C shows a first insulating layer forming process. [Figure 4] Figures 4A to 4C are process diagrams showing a method for manufacturing a wired circuit board, following Figure 3C, in which Figure 4A shows a second sputtering process, Figure 4B shows a process for forming a conductor pattern by electrolytic plating in the conductor pattern formation process, and Figure 4C shows a process for removing the second sputtering layer and the first sputtering layer exposed by peeling off the plating resist in the conductor pattern formation process. [Figure 5] FIG. 5 shows a plan view of the assembly sheet shown in FIG. 1 after contour processing. [Figure 6] 6A and 6B are process diagrams for contour processing of an assembly sheet, where FIG. 6A shows the state in which etching resist has been formed on both sides of the assembly sheet, and FIG. 6B shows the assembly sheet after contour processing (cross-sectional view taken along line BB in FIG. 5). [Figure 7] FIG. 7 is an explanatory diagram for explaining the modified example (1). [Figure 8] FIG. 8 is an explanatory diagram for explaining the modified example (2). [Figure 9] FIG. 9 is an explanatory diagram for explaining the modified example (3). [Figure 10] FIG. 10 is an explanatory diagram for explaining the modified example (4). DETAILED DESCRIPTION OF THE INVENTION

[0041] 1. Assembly sheet The assembly sheet 1 will be described with reference to FIGS.

[0042] As shown in Figure 1, the assembly sheet 1 has a sheet shape extending in a first direction and a second direction. The second direction is perpendicular to the first direction. The assembly sheet 1 includes a plurality of wired circuit boards 2, a frame 3, and an outer peripheral edge 4.

[0043] (1) Wired circuit board The multiple wired circuit boards 2 are arranged at intervals from each other in the first direction and at intervals from each other in the second direction. Each of the multiple wired circuit boards 2 has the same structure. Therefore, only one of the multiple wired circuit boards 2 will be described, and descriptions of the other wired circuit boards 2 will be omitted.

[0044] The wired circuit board 2 extends in a first direction and a second direction. In this embodiment, the wired circuit board 2 has a substantially rectangular shape. However, the shape of the wired circuit board 2 is not limited.

[0045] As shown in FIG. 2, the wired circuit board 2 includes a metal support layer 21, a conductor layer 22, a first protective layer 23, a first insulating layer 24, a second protective layer 25, a conductor pattern 26, and a second insulating layer 27.

[0046] (1-1) Metal support layer The metal support layer 21 supports the conductor layer 22, the first protective layer 23, the first insulating layer 24, the second protective layer 25, the conductor pattern 26, and the second insulating layer 27. In this embodiment, examples of materials for the metal support layer 21 include stainless steel and copper alloys. The metal support layer 21 is preferably made of a copper alloy. In other words, the metal support layer 21 preferably contains copper.

[0047] The metal support layer 21 has a thickness of, for example, 10 μm to 300 μm, or preferably 15 μm to 250 μm.

[0048] (1-2) Conductor layer The conductor layer 22 is disposed on one surface S1 of the metal support layer 21 in the thickness direction of the metal support layer 21. The thickness direction is perpendicular to the first direction and the second direction. The conductor layer 22 is disposed between the metal support layer 21 and the first insulating layer 24 in the thickness direction. The conductor layer 22 is disposed between the metal support layer 21 and the first protective layer 23 in the thickness direction. The conductor layer 22 is made of, for example, copper. The conductor layer 22 is thinner than the metal support layer 21. The one surface S2 of the conductor layer 22 in the thickness direction is smoother than the one surface S1 of the metal support layer 21 in the thickness direction. The surface roughness of the one surface S2 of the conductor layer 22 in the thickness direction is lower than the surface roughness of the one surface S1 of the metal support layer 21 in the thickness direction.

[0049] (1-3) First protective layer The first protective layer 23 is disposed on one surface S2 of the conductor layer 22 in the thickness direction. The first protective layer 23 is disposed between the metal support layer 21 and the first insulating layer 24 in the thickness direction. The first protective layer 23 is disposed between the conductor layer 22 and the first insulating layer 24 in the thickness direction. The first protective layer 23 protects the conductor layer 22 and the metal support layer 21. The first protective layer 23 is made of a metal. Examples of metals include chromium, nickel, titanium, and alloys thereof. The first protective layer 23 preferably contains chromium.

[0050] The first protective layer 23 has a thickness of, for example, 5 nm to 100 nm, or preferably 10 nm to 75 nm.

[0051] (1-4) First insulating layer The first insulating layer 24 is disposed on one side of the metal support layer 21 in the thickness direction. The first insulating layer 24 is disposed on the first protective layer 23 in the thickness direction. The first insulating layer 24 is disposed between the conductor layer 22 and the conductor pattern 26 in the thickness direction. The first insulating layer 24 is disposed between the first protective layer 23 and the second protective layer 25 in the thickness direction. The first insulating layer 24 insulates the conductor layer 22 from the conductor pattern 26. The first insulating layer 24 is made of a resin. Examples of resins include polyimide, maleimide, epoxy resin, polybenzoxazole, and polyester.

[0052] (1-5)Second protective layer The second protective layer 25 is disposed between the first insulating layer 24 and the conductive pattern 26 in the thickness direction. The second protective layer 25 is disposed on the first insulating layer 24 in the thickness direction. The second protective layer 25 protects the conductive pattern 26. The second protective layer 25 is made of a metal. Examples of metals include chromium, nickel, titanium, and alloys thereof. The second protective layer 25 preferably contains chromium.

[0053] The second protective layer 25 has a thickness of, for example, 5 nm to 100 nm, or preferably 10 nm to 75 nm. The thickness of the second protective layer 25 may be the same as or different from the thickness of the first protective layer 23.

[0054] (1-6) Conductor pattern The conductive pattern 26 is disposed on one side of the first insulating layer 24 in the thickness direction. The conductive pattern 26 is disposed on the second protective layer 25. The conductive pattern 26 is made of a metal. An example of the metal is copper. The shape of the conductive pattern 26 is not limited.

[0055] 1, the conductor pattern 26 has a plurality of terminals 261A, 261B, 261C, and 261D, a plurality of terminals 262A, 262B, 262C, and 262D, and a plurality of wirings 263A, 263B, 263C, and 263D. Note that the number of terminals and the number of wirings are not limited.

[0056] The terminals 261A, 261B, 261C, and 261D are arranged at one end of the wired circuit board 2 in the second direction. In this embodiment, the terminals 261A, 261B, 261C, and 261D are aligned in the first direction at intervals from one another. Each of the terminals 261A, 261B, 261C, and 261D has a square land shape. One surface S3 (see FIG. 1) of each of the terminals 261A, 261B, 261C, and 261D in the thickness direction is smoother than one surface S1 of the metal support layer 21 in the thickness direction. In other words, one surface S3 of the conductive pattern 26 in the thickness direction is smoother than one surface S1 of the metal support layer 21 in the thickness direction. The surface roughness of one surface S3 of each of the terminals 261A, 261B, 261C, and 261D in the thickness direction is lower than the surface roughness of one surface S1 of the metal support layer 21 in the thickness direction. In other words, the surface roughness of one surface S3 of the conductive pattern 26 in the thickness direction is lower than the surface roughness of one surface S1 of the metal support layer 21 in the thickness direction.

[0057] The terminals 262A, 262B, 262C, and 262D are arranged at the other end of the wired circuit board 2 in the second direction. In this embodiment, the terminals 262A, 262B, 262C, and 262D are spaced apart from one another and lined up in the first direction. Each of the terminals 262A, 262B, 262C, and 262D has a square land shape.

[0058] One end of the wiring 263A is connected to the terminal 261 A. The other end of the wiring 263A is connected to the terminal 262 A. The wiring 263A electrically connects the terminal 261A and the terminal 262A.

[0059] One end of the wiring 263B is connected to the terminal 261 B. The other end of the wiring 263B is connected to the terminal 262 B. The wiring 263B electrically connects the terminal 261 B and the terminal 262B.

[0060] One end of the wiring 263C is connected to the terminal 261C, and the other end of the wiring 263C is connected to the terminal 262C. The wiring 263C electrically connects the terminal 261C and the terminal 262C.

[0061] One end of the wiring 263D is connected to the terminal 261D, and the other end of the wiring 263D is connected to the terminal 262D. The wiring 263D electrically connects the terminal 261D and the terminal 262D.

[0062] (1-7) Second insulating layer The second insulating layer 27 covers all of the wirings 263A to 263D. The second insulating layer 27 is disposed on the first insulating layer 24 (see FIG. 2) in the thickness direction. The second insulating layer 27 does not cover the terminals 261A to 261D and the terminals 262A to 262D. The second insulating layer 27 is made of a resin. Examples of resins include polyimide, maleimide, epoxy resin, polybenzoxazole, and polyester.

[0063] A third protective layer (not shown) may be disposed between second insulating layer 27 and each of wires 263A to 263D. The third protective layer is, for example, a plated layer made of metal, and protects each of wires 263A to 263D together with second protective layer 25. Examples of materials for the third protective layer include nickel and nickel-phosphorus alloys.

[0064] (2) Frame The frame 3 surrounds the plurality of wired circuit boards 2. The frame 3 supports the plurality of wired circuit boards 2. In this embodiment, the frame 3 has a frame shape. Specifically, the frame 3 has a first frame 3A, a second frame 3B, a third frame 3C, and a fourth frame 3D.

[0065] The first frame 3A is disposed at one end in the first direction of the assembly sheet 1. The first frame 3A extends in the second direction.

[0066] The second frame 3B is disposed at the other end of the assembly sheet 1 in the first direction. The second frame 3B is disposed apart from the first frame 3A in the first direction. The multiple wired circuit boards 2 are disposed between the first frame 3A and the second frame 3B in the first direction. The second frame 3B extends in the second direction.

[0067] The third frame 3C is disposed at one end of the assembly sheet 1 in the second direction. The third frame 3C extends in the first direction. One end of the third frame 3C in the first direction is connected to one end of the first frame 3A in the second direction. The other end of the third frame 3C in the first direction is connected to one end of the second frame 3B in the second direction.

[0068] The fourth frame 3D is disposed at the other end of the assembly sheet 1 in the second direction. The fourth frame 3D is disposed away from the third frame 3C in the second direction. The multiple wired circuit boards 2 are disposed between the third frame 3C and the fourth frame 3D in the second direction. The fourth frame 3D extends in the first direction. One end of the fourth frame 3D in the first direction is connected to the other end of the first frame 3A in the second direction. The other end of the fourth frame 3D in the first direction is connected to the other end of the second frame 3B in the second direction.

[0069] 2, in this embodiment, the frame 3 is made of the same metal layer as the metal support layer 21 and the same conductor layer as the conductor layer 22. The frame 3 may have at least one of an insulating layer made of the same material as the first insulating layer 24 and an insulating layer made of the same material as the second insulating layer 27. The frame 3 may have a dummy pattern (not shown) and an alignment mark (not shown).

[0070] (3) Outer edge As shown in FIG. 1 , the outer peripheral edge 4 is located outside the frame 3. The outer peripheral edge 4 is a portion 5 mm from the edge E of the periphery of the assembly sheet 1. In this embodiment, the outer peripheral edge 4 has a frame shape. The outer peripheral edge 4 surrounds the frame 3 and the multiple wired circuit boards 2. Unlike the frame 3, the outer peripheral edge 4 does not have an insulating layer. The outer peripheral edge is made of one or more metal layers.

[0071] In detail, as shown in FIG. 2, in this embodiment, the outer peripheral end portion 4 has an end metal layer 41, an end conductor layer 42, a first metal thin film 43, a second metal thin film 44, and an end second conductor layer 45.

[0072] (3-1) End metal layer The end metal layer 41 is made of the same material as the metal support layer 21 of the printed circuit board 2. The thickness of the end metal layer 41 is the same as the thickness of the metal support layer 21.

[0073] (3-2) Edge conductor layer The end conductor layer 42 is disposed on one surface S11 of the end metal layer 41 in the thickness direction. The end conductor layer 42 is disposed between the end metal layer 41 and the end second conductor layer 45 in the thickness direction. The end conductor layer 42 is disposed between the end metal layer 41 and the first metal thin film 43 in the thickness direction. The end conductor layer 42 is made of the same material as the conductor layer 22 of the printed circuit board 2. The thickness of the end conductor layer 42 is the same as the thickness of the conductor layer 22. The one surface S12 of the end conductor layer 42 in the thickness direction is smoother than the one surface S11 of the end metal layer 41 in the thickness direction. The surface roughness of the one surface S12 of the end conductor layer 42 in the thickness direction is lower than the surface roughness of the one surface S11 of the end metal layer 41 in the thickness direction.

[0074] (3-3) First metal thin film The first metal thin film 43 is disposed on one side of the end metal layer 41 in the thickness direction. The first metal thin film 43 is disposed on one surface S12 of the end conductor layer 42 in the thickness direction. The first metal thin film 43 is disposed between the end metal layer 41 and the end second conductor layer 45 in the thickness direction. The first metal thin film 43 is disposed between the end metal layer 41 and the second metal thin film 44 in the thickness direction. The first metal thin film 43 is made of the same metal as the first protective layer 23 of the wired circuit board 2.

[0075] The thickness of the first metal thin film 43 is thinner than the thickness of the first protective layer 23. The thickness of the first metal thin film 43 is, for example, less than 60 nm, preferably 50 nm or less, more preferably 30 nm or less, and more preferably 20 nm or less.

[0076] If the thickness of the first metal thin film 43 is equal to or less than the above upper limit, it is possible to prevent the first metal thin film 43 from impeding the etching of the end metal layer 41 and the end conductor layer 42 of the outer peripheral edge 4 when etching the end metal layer 41 and the end conductor layer 42 of the outer peripheral edge 4 together with the metal support layer 21 and the conductor layer 22 of the wiring circuit board 2 during the contour processing of the assembly sheet 1. As a result, if the thickness of the first metal thin film 43 is equal to or less than the above upper limit, the outer peripheral edge 4 can be reliably removed during the contour processing of the assembly sheet 1.

[0077] There is no lower limit to the thickness of the first metal thin film 43. The thickness of the first metal thin film 43 may be 0 nm. In other words, the outer peripheral edge 4 does not have to have the first metal thin film 43. The thickness of the first metal thin film 43 is, for example, 1 nm or more. The thickness of the first metal thin film 43 may be 5 nm or more, or 10 nm or more.

[0078] The thickness of the first metal thin film 43 may be equal to or greater than 0 nm and less than 60 nm, 1 nm to 50 nm, 5 nm to 30 nm, or 10 nm to 20 nm.

[0079] (3-4) Second metal thin film The second metal thin film 44 is disposed on one side of the end metal layer 41 in the thickness direction. The second metal thin film 44 is disposed on the first metal thin film 43 in the thickness direction. The second metal thin film 44 is disposed between the end metal layer 41 and the end second conductor layer 45 in the thickness direction. The second metal thin film 44 is disposed between the first metal thin film 43 and the end second conductor layer 45 in the thickness direction. The second metal thin film 44 is made of the same metal as the second protective layer 25 of the wired circuit board 2.

[0080] The thickness of the second metal thin film 44 is thinner than the thickness of the second protective layer 25. The thickness of the second metal thin film 44 is, for example, less than 60 nm, preferably 50 nm or less, more preferably 30 nm or less, and preferably 20 nm or less.

[0081] If the thickness of the second metal thin film 44 is equal to or less than the above upper limit, it is possible to prevent the second metal thin film 44 from impeding the etching of the end metal layer 41 and the end conductor layer 42 of the outer peripheral edge 4 when etching the end metal layer 41 and the end conductor layer 42 of the outer peripheral edge 4 together with the metal support layer 21 and the conductor layer 22 of the wiring circuit board 2 during the contour processing of the assembly sheet 1. As a result, if the thickness of the second metal thin film 44 is equal to or less than the above upper limit, the outer peripheral edge 4 can be reliably removed during the contour processing of the assembly sheet 1.

[0082] There is no lower limit to the thickness of the second metal thin film 44. The thickness of the second metal thin film 44 may be 0 nm. In other words, the outer peripheral edge 4 does not need to have the second metal thin film 44. The thickness of the second metal thin film 44 is, for example, 1 nm or more. The thickness of the second metal thin film 44 may be 5 nm or more, or 10 nm or more.

[0083] The thickness of the second metal thin film 44 may be equal to or greater than 0 nm and less than 60 nm, 1 nm to 50 nm, 5 nm to 30 nm, or 10 nm to 20 nm.

[0084] The sum of the thickness of the first metal thin film 43 and the thickness of the second metal thin film 44 is thinner than the sum of the thickness of the first protective layer 23 and the thickness of the second protective layer 25. The sum of the thickness of the first metal thin film 43 and the thickness of the second metal thin film 44 is, for example, less than 60 nm, preferably 50 nm or less, preferably 35 nm or less, and more preferably 30 nm or less.

[0085] If the sum of the thicknesses of the first metal thin film 43 and the second metal thin film 44 is not more than the above upper limit, it is possible to prevent the first metal thin film 43 and the second metal thin film 44 from impeding the etching of the edge metal layer 41 and the edge conductor layer 42 of the outer peripheral edge 4 when etching the edge metal layer 41 and the edge conductor layer 42 of the outer peripheral edge 4 together with the metal support layer 21 and the conductor layer 22 of the wiring circuit board 2 during the contour processing of the assembly sheet 1. As a result, if the sum of the thicknesses of the first metal thin film 43 and the second metal thin film 44 is not more than the above upper limit, the outer peripheral edge 4 can be reliably removed during the contour processing of the assembly sheet 1.

[0086] There is no lower limit to the sum of the thicknesses of the first metal thin film 43 and the second metal thin film 44. The sum of the thicknesses of the first metal thin film 43 and the second metal thin film 44 may be 0 nm. In other words, the outer peripheral edge 4 does not have to have the first metal thin film 43 and the second metal thin film 44. The sum of the thicknesses of the first metal thin film 43 and the second metal thin film 44 is, for example, 1 nm or more. The sum of the thicknesses of the first metal thin film 43 and the second metal thin film 44 may be 5 nm or more, or 10 nm or more.

[0087] The sum of the thickness of the first metal thin film 43 and the thickness of the second metal thin film 44 may be 0 nm or more and less than 60 nm, 1 nm to 50 nm, 5 nm to 35 nm, or 10 nm to 30 nm.

[0088] (3-5) End second conductor layer The end second conductor layer 45 is disposed on one side of the end metal layer 41 in the thickness direction. The end second conductor layer 45 is disposed on one side of the first metal thin film 43 in the thickness direction. The end second conductor layer 45 is disposed on one side of the second metal thin film 44 in the thickness direction. The end second conductor layer 45 is disposed on the second metal thin film 44 in the thickness direction. The end second conductor layer 45 is made of the same material as the conductor pattern 26 of the wired circuit board 2. The end second conductor layer 45 is made of the same material as the terminal 261A of the wired circuit board 2. The thickness of the end second conductor layer 45 may be the same as the thickness of the conductor pattern 26. The thickness of the end second conductor layer 45 may be the same as the thickness of the terminal 261A. The thickness of the end second conductor layer 45 may be different from the thickness of the conductor pattern 26. The thickness of the end second conductor layer 45 may be thinner than the thickness of the terminal 261A. One surface S13 of the end second conductor layer 45 in the thickness direction may be smoother than one surface S11 of the end metal layer 41 in the thickness direction. The surface roughness of one surface S13 of the end second conductor layer 45 in the thickness direction may be lower than the surface roughness of one surface S11 of the end metal layer 41 in the thickness direction.

[0089] 2. Manufacturing method of assembly sheet Next, a method for manufacturing the assembly sheet 1 will be described with reference to FIGS. 3A to 4C.

[0090] The manufacturing method of the assembly sheet 1 includes a conductor layer forming step (see FIG. 3A), a first sputtering step (see FIG. 3B), a first insulating layer forming step (see FIG. 3C), a second sputtering step (see FIG. 4A), a conductor pattern forming step (see FIGS. 4B and 4C), and a second insulating layer forming step (see FIG. 2).

[0091] (1) Conductor layer formation process As shown in FIG. 3A, in the conductor layer forming step, a plating layer P is formed on one surface of a metal substrate M by, for example, electrolytic plating.

[0092] The base material M has a product region A1 where the wired circuit board 2 is formed, a frame region A2 where the frame 3 is formed, and an edge region A3 where the outer peripheral edge 4 is formed.

[0093] The base material M in the product region A1 is the metal support layer 21, and the base material M in the edge region A3 is the edge metal layer 41. Furthermore, the plating layer P in the product region A1 is the conductor layer 22, and the plating layer P in the edge region A3 is the edge conductor layer 42. That is, in the conductor layer forming step, the conductor layer 22 is formed on the metal support layer 21.

[0094] (2) First sputtering process Next, as shown in Fig. 3B, in the first sputtering step, a first sputtering layer SL1 is formed by sputtering on one surface of the plating layer P. In the first sputtering step, sputtering is performed with the portion of the target T facing the end region A3 (i.e., the outer peripheral end 4) masked. As a result, the thickness of the first sputtering layer SL1 in the end region A3 is thinner than the thickness of the first sputtering layer SL1 in the product region A1.

[0095] The first sputtering layer SL1 in the product region A1 is the first protective layer 23, and the first sputtering layer SL1 in the edge region A3 is the first metal thin film 43. That is, in the first sputtering step, the first protective layer 23 is formed by sputtering before the first insulating layer forming step.

[0096] (3) First insulating layer formation process Next, as shown in FIG. 3C, in the first insulating layer forming step, a first insulating layer 24 is formed on the first protective layer 23.

[0097] Specifically, to form the first insulating layer 24, a photosensitive resin solution (varnish) is first applied onto the first sputtering layer SL1 and dried to form a photosensitive resin coating. Next, the photosensitive resin coating is exposed to light and developed. As a result, the first insulating layer 24 is formed on the first protective layer 23.

[0098] (4) Second sputtering process 4A, in the second sputtering step, a second sputtering layer SL2 is formed by sputtering on one surface of the first sputtering layer SL1 and the first insulating layer 24. In the second sputtering step, as in the first sputtering step, sputtering is performed with the portion of the target T facing the end region A3 (i.e., the outer peripheral end 4) masked. As a result, the thickness of the second sputtering layer SL2 in the end region A3 is thinner than the thickness of the second sputtering layer SL2 in the product region A1.

[0099] The second sputtering layer SL2 in the product region A1 is the second protective layer 25, and the second sputtering layer SL2 in the edge region A3 is the second metal thin film 44. That is, in the second sputtering step, the second protective layer 25 is formed by sputtering after the first insulating layer forming step and before the conductive pattern forming step.

[0100] Moreover, the second sputtering layer SL2 functions as a seed layer for electrolytic plating in the next conductive pattern forming step.

[0101] (5) Conductor pattern formation process Next, as shown in FIGS. 4B and 4C, in the conductive pattern forming step, conductive patterns 26 are formed on second protective layer 25.

[0102] Specifically, to form the conductive pattern 26, first, as shown in Fig. 4B, a plating resist R1 is attached to the product region A1 and the frame region A2 so as to cover the second sputtering layer SL2. However, the plating resist R1 is not attached to the edge region A3. In other words, the edge region A3 is exposed from the plating resist R1.

[0103] Next, the plating resist R1 is exposed to light while shielding the portion where the conductive pattern 26 is to be formed. Next, the exposed plating resist R1 is developed.

[0104] As a result, the plating resist R1 in the light-shielded portions is removed, and the second sputtering layer SL2 is exposed in the portions where the conductive pattern 26 will be formed. Note that the plating resist R1 in the exposed portions, i.e., the portions where the conductive pattern 26 will not be formed, remains.

[0105] Next, the conductive pattern 26 is formed on the exposed second sputtering layer SL2 by electrolytic plating.

[0106] At this time, power may be supplied from a part of the second sputtering layer SL2 (second metal thin film 44) in the edge region A3. In other words, the part of the second sputtering layer SL2 (second metal thin film 44) in the edge region A3 may be a power supply part for electrolytic plating.

[0107] After the electrolytic plating is completed, the plating resist R1 is stripped off, and then the second sputtering layer SL2 exposed by the stripping of the plating resist R1 and the first sputtering layer SL1 underneath are removed by etching.

[0108] As a result, the conductive pattern 26 is formed as shown in FIG. 4C.

[0109] (6) Second insulating layer formation process Next, as shown in FIG. 2, in the same manner as in the formation of the first insulating layer 24, the second insulating layer 27 is formed on the first insulating layer 24 and the wirings 263A to 263D.

[0110] With the above steps, the assembly sheet 1 is completed.

[0111] 3.External processing of the assembly sheet Next, the outer shape processing of the assembly sheet 1 will be described with reference to FIGS. 5 to 6B.

[0112] The above-described assembly sheet 1 of the present invention (see FIG. 1) is the assembly sheet 1 before being subjected to contour processing.

[0113] As shown in FIG. 5, the assembly sheet 1 is subjected to contour processing to remove the outer peripheral edge 4 and to form a notch 5 and connection portions 6A and 6B around the wired circuit board 2.

[0114] 6A, in the contour processing, etching resist R11 is attached to one surface of the assembly sheet 1, and etching resist R12 is attached to the other surface of the assembly sheet 1. At this time, etching resist R11 covers one surface of the wired circuit board 2 and one surface of the frame 3, but does not cover one surface of the outer peripheral edge 4. In addition, etching resist R12 covers the other surface of the wired circuit board 2 and the other surface of the frame 3, but does not cover the other surface of the outer peripheral edge 4.

[0115] Next, the etching resists R11 and R12 are exposed to light while the portion where the notch 5 is to be formed is shielded from light. Next, the exposed etching resists R11 and R12 are developed. As a result, an opening OP1 is formed in the portion of the etching resist R11 where the notch 5 is to be formed. Also, an opening OP2 is formed in the portion of the etching resist R12 where the notch 5 is to be formed.

[0116] Next, the substrate M exposed in the openings OP1 and OP2 and the outer peripheral edge 4 are etched by spraying an etching solution from both sides in the thickness direction.

[0117] At this time, when the substrate M is a copper alloy and the plating layer P is copper, the etching liquid is, for example, a ferric chloride solution.

[0118] Therefore, when the first metal thin film 43 and the second metal thin film 44 contain chromium, the first metal thin film 43 and the second metal thin film 44 may inhibit etching of the outer circumferential edge 4. If etching of the outer circumferential edge 4 is inhibited, part of the outer circumferential edge 4 may remain as a burr.

[0119] In this regard, in the assembly sheet 1, the outer peripheral edge 4 does not have the first metal thin film 43 or the second metal thin film 44 (the sum of the thickness of the first metal thin film 43 and the thickness of the second metal thin film 44 is 0 nm), or even if the outer peripheral edge 4 has the first metal thin film 43 and the second metal thin film 44, the sum of the thickness of the first metal thin film 43 and the thickness of the second metal thin film 44 is less than 60 nm (preferably 50 nm or less).

[0120] Therefore, it is possible to prevent the first metal thin film 43 and the second metal thin film 44 from hindering etching of the outer periphery edge 4.

[0121] As a result, it is possible to prevent a part of the outer peripheral edge 4 from remaining as a burr, and the outer peripheral edge 4 can be removed reliably.

[0122] As shown in FIG. 6B, the outer peripheral edge 4 is removed and a notch 5 is formed, thereby completing the outer shaping of the assembly sheet 1.

[0123] 4. Effects (1) According to the assembly sheet 1, as shown in FIG. 2, the outer peripheral end 4, which is positioned outside the frame 3, has an end metal layer 41 made from the same material as the metal support layer 21 and an end conductor layer 42 made from the same material as the conductor layer 22.

[0124] Therefore, by etching the metal support layer 21 and the conductor layer 22 as well as the end metal layer 41 and the end conductor layer 42, the outer circumferential end 4 can be removed reliably.

[0125] As a result, burrs remaining on the edges of the assembly sheet 1 can be suppressed.

[0126] (2) According to the assembly sheet 1, as shown in FIG. 2, the sum of the thickness of the first metal thin film 43 and the thickness of the second metal thin film 44 is thinner (less than 60 nm) than the sum of the thickness of the first protective layer 23 and the thickness of the second protective layer 25.

[0127] Therefore, even if the first metal thin film 43 and the second metal thin film 44 are formed at the outer peripheral end 4 when the first protective layer 23 and the second protective layer 25 are formed, the outer peripheral end 4 can be reliably removed by etching the end metal layer 41 and the end conductor layer 42 together with etching the metal support layer 21 and the conductor layer 22.

[0128] As a result, burrs remaining on the edges of the assembly sheet 1 can be suppressed.

[0129] (3) According to the assembly sheet 1, as shown in Figures 3B and 4A, in the first sputtering process (see Figure 3B) and the second sputtering process (see Figure 4A), the portion of the target T facing the end region A3 (i.e., the outer peripheral end 4) is masked.

[0130] Therefore, in the first sputtering process and the second sputtering process, the first metal thin film 43 and the second metal thin film 44 are not formed on the outer peripheral edge 4, or metal thin films (the first metal thin film 43 and the second metal thin film 44) that are thinner than the sum of the thicknesses of the first protective layer 23 and the second protective layer 25 are formed.

[0131] Therefore, in the obtained assembly sheet 1, by etching the metal support layer 21 and the end metal layer 41, the outer peripheral end 4 can be reliably removed.

[0132] As a result, burrs remaining on the edges of the assembly sheet 1 can be suppressed.

[0133] 4. Variations Next, a modified example will be described. In the modified example, the same components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0134] (1) As shown in FIG. 7 , the outer peripheral edge 4 may have a first metal thin film 43 and not have a second metal thin film 44. The outer peripheral edge 4 may be made of an edge metal layer 41, an edge conductor layer 42, a first metal thin film 43, and an edge second conductor layer 45. As in the above-described embodiment, the wired circuit board 2 has a first protective layer 23 and a second protective layer 25. When the thickness of the first protective layer 23 is less than 60 nm, the thickness of the first metal thin film 43 may be the same as the thickness of the first protective layer 23.

[0135] (2) As shown in Fig. 8, the outer peripheral edge 4 may have a second metal thin film 44 and not have a first metal thin film 43. The outer peripheral edge 4 may be composed of an edge metal layer 41, an edge conductor layer 42, a second metal thin film 44, and an edge second conductor layer 45. As in the above-described embodiment, the wired circuit board 2 has a first protective layer 23 and a second protective layer 25. When the thickness of the second protective layer 25 is less than 60 nm, the thickness of the second metal thin film 44 may be the same as the thickness of the second protective layer 25.

[0136] (3) As shown in FIG. 9 , the outer peripheral edge 4 may have a first metal thin film 43 but may not have a second metal thin film 44. The outer peripheral edge 4 may be composed of an edge metal layer 41, an edge conductor layer 42, a first metal thin film 43, and an edge second conductor layer 45. The wired circuit board 2 may not have the second protective layer 25. When the thickness of the first protective layer 23 is less than 60 nm, the thickness of the first metal thin film 43 may be the same as the thickness of the first protective layer 23.

[0137] (4) As shown in FIG. 10 , the outer peripheral edge 4 may have a second metal thin film 44 and may not have a first metal thin film 43. The outer peripheral edge 4 may be composed of an edge metal layer 41, an edge conductor layer 42, a second metal thin film 44, and an edge second conductor layer 45. The wired circuit board 2 may not have the first protective layer 23. When the thickness of the second protective layer 25 is less than 60 nm, the thickness of the second metal thin film 44 may be the same as the thickness of the second protective layer 25.

[0138] (5) The wired circuit board 2 may not have the conductor layer 22. The first protective layer 23 may be disposed on the metal support layer 21. In this case, the outer peripheral end 4 does not have the end conductor layer 42. The first metal thin film 43 is disposed on the end metal layer 41.

[0139] (6) The outer peripheral edge 4 does not have to have the first metal thin film 43 and the second metal thin film 44. The outer peripheral edge 4 may consist of only the end metal layer 41. The outer peripheral edge 4 may consist of the end metal layer 41 and the end second conductor layer 45.

[0140] (7) In the modified examples (1) to (6), the same effects as those of the above-described embodiment can be obtained. [Example]

[0141] The present invention will be described in more detail below with reference to examples and comparative examples. It should be noted that the present invention is not limited to these examples and comparative examples. The specific numerical values of the blending ratios (content ratios), physical property values, parameters, etc. used in the following description can be substituted with the upper limit (a numerical value defined as "equal to or less than") or lower limit (a numerical value defined as "equal to or more than" or "exceeding") of the corresponding blending ratios (content ratios), physical property values, parameters, etc. described in the "Description of the Invention" above.

[0142] 1. Manufacturing of assembly sheets (1) Example First, a plating layer (conductor layer and end conductor layer) made of copper was formed by electrolytic plating on one surface of a base material made of a copper alloy (conductor layer forming step, see FIG. 3A).

[0143] Next, a first sputtering layer made of chromium was formed on one side of the plating layer by sputtering (first sputtering step, see Figure 3B). In the first sputtering step, sputtering was performed while the portion of the target facing the edge region (a portion 5 mm from the outer periphery of the substrate) was masked. The thickness of the first sputtering layer (first metal thin film) in the edge region was 15 nm. The thickness of the first sputtering layer (first protective layer) in the product region was 30 nm.

[0144] Next, a first insulating layer was formed on the first protective layer (first insulating layer forming step, see FIG. 3C).

[0145] Next, a second sputtering layer made of chromium was formed by sputtering on one side of the first sputtering layer and the first insulating layer (second sputtering step, see Figure 4A). In the second sputtering step, as in the first sputtering step, sputtering was performed with the portion of the target facing the edge region masked. The thickness of the second sputtering layer (second metal thin film) in the edge region was 15 nm. The thickness of the second sputtering layer (second protective layer) in the product region was 30 nm.

[0146] Next, a conductive pattern made of copper was formed on the second protective layer by electrolytic plating using a power supply from a part of the second metal thin film (conductive pattern forming step, see FIGS. 4B and 4C). Note that a second end conductive layer made of copper was formed on the second metal thin film.

[0147] Next, in the same manner as in the formation of the first insulating layer, a second insulating layer was formed on the first insulating layer and the wiring (second insulating layer forming step).

[0148] In this way, an assembly sheet was produced.

[0149] (2) Comparative Example An assembly sheet was produced in the same manner as in Example, except that in the first sputtering step and the second sputtering step, the portion of the target facing the end region was not masked.

[0150] The thickness of the first sputtering layer (first metal thin film) in the edge region and the thickness of the second sputtering layer (second metal thin film) in the edge region were each 30 nm.

[0151] 2.External processing of the assembly sheet The edge regions of each of the assembly sheets obtained in the examples and comparative examples were etched (external shape processed) using a ferric chloride solution under the same etching conditions, and the processability was evaluated.

[0152] In the comparative example, burrs remained on the outer peripheral edge.

[0153] On the other hand, in the example, no burrs were generated and the outer peripheral edge was completely removed. [Explanation of symbols]

[0154] 1 Assembly sheet 2 Wiring circuit board 3 frames 4 Outer edge 21 Metal support layer 22 Conductor layer 23 1st protective layer 24 First insulating layer (an example of an insulating layer) 25 Second protective layer 26 Conductor Pattern 41 End metal layer 42 Edge conductor layer 43 First metal thin film 44 Second metal thin film 45 End second conductor layer

Claims

1. a wired circuit board; a frame supporting the wired circuit board; and an outer peripheral end portion disposed outside the frame, The printed circuit board is a metal support layer; an insulating layer disposed on one side of the metal support layer in a thickness direction of the metal support layer; a conductor pattern disposed on one side of the insulating layer in the thickness direction; at least one of a first protective layer made of metal and disposed between the metal support layer and the insulating layer in the thickness direction, and a second protective layer made of metal and disposed between the insulating layer and the conductor pattern in the thickness direction; and The assembly sheet has an outer peripheral edge having an edge metal layer made from the same material as the metal support layer.

2. The outer peripheral end portion is At least one of a first metal thin film made of the same metal as the first protective layer and a second metal thin film made of the same metal as the second protective layer, on one side of the end metal layer in the thickness direction. and The assembly sheet according to claim 1 , wherein a sum of a thickness of the first metal thin film and a thickness of the second metal thin film is smaller than a sum of a thickness of the first protective layer and a thickness of the second protective layer.

3. the outer peripheral edge portion has the first metal thin film, The assembly sheet according to claim 2 , wherein the thickness of the first metal thin film is smaller than the thickness of the first protective layer.

4. the outer peripheral edge has the second metal thin film, The assembly sheet according to claim 2 , wherein the second metal thin film has a thickness smaller than that of the second protective layer.

5. The assembly sheet according to claim 2 , wherein the outer peripheral edge portion has the first metal thin film or the second metal thin film.

6. The assembly sheet according to claim 2 , wherein the sum of the thickness of the first metal thin film and the thickness of the second metal thin film is 50 nm or less.

7. 2. The assembly sheet according to claim 1, wherein the outer peripheral edge does not have a first metal thin film made of the same metal as the first protective layer and a second metal thin film made of the same metal as the second protective layer.

8. a wired circuit board; a frame supporting the wired circuit board; and an outer peripheral end portion disposed outside the frame, The printed circuit board is a metal support layer; an insulating layer disposed on one side of the metal support layer in a thickness direction of the metal support layer; a conductor pattern disposed on one side of the insulating layer in the thickness direction; at least one of a first protective layer made of metal and disposed between the metal support layer and the insulating layer in the thickness direction, and a second protective layer made of metal and disposed between the insulating layer and the conductor pattern in the thickness direction; and The outer peripheral end portion is an edge metal layer made of the same material as the metal support layer; At least one of a first metal thin film made of the same metal as the first protective layer and a second metal thin film made of the same metal as the second protective layer is provided on one side of the end metal layer in the thickness direction. and The assembly sheet, wherein the sum of the thickness of the first metal thin film and the thickness of the second metal thin film is 50 nm or less.

9. The printed circuit board is a conductor layer disposed on one surface of the metal support layer in the thickness direction, The outer peripheral end portion is 9. The assembly sheet according to claim 2, further comprising an end conductor layer disposed on one side of the end metal layer in the thickness direction and made of the same material as the conductor layer of the wiring circuit board.

10. The outer peripheral end portion is 9. The assembly sheet according to claim 1, further comprising a second end conductor layer arranged on one side of the end metal layer in the thickness direction and made of the same material as the conductor pattern of the wiring circuit board.

11. the metal support layer contains copper; The assembly sheet according to claim 1 or 8, wherein the first protective layer and the second protective layer contain chromium.

12. The assembly sheet according to claim 1 or 8, wherein the outer peripheral end portion is a portion 5 mm from the outer peripheral edge of the assembly sheet.

13. A method for producing the assembly sheet according to claim 1 or 8, an insulating layer forming step of forming the insulating layer; a conductor pattern forming step of forming the conductor pattern; at least one of a first sputtering step of forming the first protective layer by sputtering before the insulating layer forming step, and a second sputtering step of forming the second protective layer by sputtering after the insulating layer forming step and before the conductive pattern forming step; Including, In the first sputtering step and the second sputtering step, sputtering is performed in a state where a portion of the target facing the outer peripheral end is masked.

Images