Wiring circuit board

Abstract

The wiring circuit substrate has a planar shape extending in a planar direction, and has a metal support layer, a first insulating layer disposed on one side of the metal support layer in a thickness direction, a wiring disposed on one side of the first insulating layer in the thickness direction, and a first metal layer disposed on one side of the first insulating layer in the thickness direction. An area of the first metal layer in a plan view is 50% or more relative to an area of the metal support layer in the plan view.

Description

Technical Field

[0001] This invention relates to a wiring circuit board. Background Technology

[0002] Wiring circuit boards have been used in various electrical or electronic devices in the past. For example, Patent Document 1 describes a wiring circuit board used in a hard disk drive device.

[0003] The wiring circuit board described in Patent Document 1 has a support substrate, a base insulating layer formed on the support substrate, a plurality of wiring patterns formed on the base insulating layer, and a cover insulating layer disposed on the plurality of wiring patterns.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-208443 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] Furthermore, when using a wiring circuit board, from the viewpoint of efficient space utilization, large external components are sometimes mounted on its upper surface. However, in the wiring circuit board of Patent Document 1, the upper surface of the area where wiring is arranged and the upper surface of the area where wiring is not arranged have different heights. That is, the planarity is low. Therefore, when it is desired to place external components on the upper surface of such a wiring circuit board, defects such as tilting of the external components and difficulty in placing the external components occur.

[0009] The present invention provides a wiring circuit board that allows external components to be easily disposed on one side of the thickness direction.

[0010] Solution for solving the problem

[0011] The present invention [1] includes a wiring circuit board having a planar shape extending in a surface direction, characterized in that it has: a metal support layer; a first insulating layer disposed on a surface of the metal support layer in the thickness direction; wiring disposed on a surface of the first insulating layer in the thickness direction; and a first metal layer disposed on a surface of the first insulating layer in the thickness direction, wherein the area of ​​the first metal layer in plan view is 50% or more relative to the area of ​​the metal support layer in plan view.

[0012] According to this wiring circuit board, a wiring and a first metal layer are provided on one side of the first insulating layer in the thickness direction, and the area of ​​the first metal layer is more than 50% of the area of ​​the metal support layer. That is, a large area of ​​the first metal layer 6 is disposed on one side of the first insulating layer in the thickness direction.

[0013] Therefore, by increasing the height of most of the area without wiring (non-wiring area) through the first metal layer, the height difference (distance in the thickness direction) between the area with wiring (wiring area) and the non-wiring area is reduced. That is, the planarity of the thickness direction side of the wiring circuit board is improved. Therefore, external components can be disposed on the thickness direction side of the wiring circuit board without tilting.

[0014] Furthermore, due to the presence of a large-area first metal layer, the rigidity of the wiring circuit board is improved. Therefore, even when mounting heavier external components, the wiring circuit board can be prevented from deflecting to the other side in the thickness direction, allowing external components to be mounted without tilting.

[0015] As a result, external components can be easily positioned on one side of the wiring circuit board in the thickness direction.

[0016] The present invention [2] includes the wiring circuit board described in [1], wherein a plurality of the wirings are arranged around the first metal layer.

[0017] According to this wiring circuit board, it has multiple wirings, and a first metal layer is disposed around them. That is, the first metal layer is disposed between the multiple wirings. Therefore, external components can be disposed between the multiple wirings without tilting.

[0018] The present invention [3] includes the wiring circuit board described in [1] or [2], wherein the wiring is formed along the outline of the first metal layer.

[0019] According to this wiring circuit board, the wiring is formed along the outline of the first metal layer. That is, the first metal layer is formed along the wiring. Therefore, external components can be arranged without tilting along the wiring.

[0020] The present invention [4] includes a wiring circuit board according to any one of [1] to [3], wherein the metal support layer has a first support portion and a second support portion arranged at intervals from each other, and the first metal layer is configured to span the first support portion and the second support portion when viewed from above.

[0021] According to this wiring circuit board, the first metal layer is configured to span the first support portion and the second support portion. Therefore, movement of the region where the first support portion is disposed and the region where the second support portion is disposed can be suppressed in the planar direction and the thickness direction. Thus, when an external component is disposed on the wiring circuit board, deviation and deflection of the wiring circuit board can be suppressed.

[0022] The present invention [5] includes the wiring circuit board described in [4], wherein the first support portion is configured to span the wiring and the first metal layer when viewed from above.

[0023] According to this wiring circuit board, the first support portion is configured to span the wiring and the first metal layer. Therefore, it is possible to suppress the independent movement of the wiring area and the area where the first metal layer is disposed (the first metal area) in the planar direction or the thickness direction. Thus, when external components are disposed, it is possible to suppress deviation and deflection between the wiring area and the first metal area.

[0024] The present invention [6] includes a wiring circuit board as described in any one of [1] to [5], wherein the first insulating layer has a first through hole at a position where it overlaps with the metal support layer and the first metal layer when projected along the thickness direction, and the first through hole is filled with a first metal connection portion that contacts the metal support layer and the first metal layer.

[0025] According to this wiring circuit board, the metal support layer and the first metal layer are connected by the first metal connection. Therefore, the first metal layer is reliably fixed by the metal support layer via the first metal connection. Consequently, when external components are mounted, the denting of the first metal layer can be suppressed, and the deflection of the wiring circuit board can be reliably suppressed.

[0026] The present invention [7] includes a wiring circuit board as described in any one of [1] to [6], wherein the wiring circuit board has: a second insulating layer disposed on a side of the wiring and the first metal layer in the thickness direction; and a second metal layer disposed on a side of the second insulating layer in the thickness direction, wherein the second insulating layer has a second through hole at a position where it overlaps with the first metal layer and the second metal layer when projected in the thickness direction, and the second through hole is filled with a second metal connection portion that contacts the first metal layer and the second metal layer.

[0027] According to this wiring circuit board, the rigidity of the wiring circuit board is further improved due to the presence of a second metal layer and a second insulating layer. Furthermore, since a second metal connection portion that contacts both the first and second metal layers is filled in the second through-hole, the second metal layer is fixed to the first metal layer by means of the second metal connection portion, and the denting of the second metal layer can be suppressed when external components are mounted. Therefore, the deflection of the wiring circuit board can be reliably suppressed.

[0028] The present invention [8] includes the wiring circuit board described in [7], wherein the second metal layer is configured to span the wiring and the first metal layer when viewed from above.

[0029] According to this wiring circuit board, the second metal layer is configured to span the wiring and the first metal layer. Therefore, it is possible to suppress independent movement between the wiring area and the first metal area along the planar or thickness direction. Consequently, when mounting external components, deviation and deflection between the wiring area and the first metal area can be suppressed more reliably.

[0030] The effects of the invention

[0031] According to the wiring circuit board of the present invention, external components can be easily disposed on one side of its thickness direction. Attached Figure Description

[0032] Figure 1 This is a side sectional view along the second direction showing a first embodiment of the wiring circuit board of the present invention.

[0033] Figure 2 A- Figure 2 C is Figure 1 The diagram shows a plan view of the wiring circuit board. Figure 2 A represents Figure 1 Plan view at AA, Figure 2 B indicates Figure 1 Plan view at BB, Figure 2 C indicates Figure 1 A plan view at CC.

[0034] Figure 3 A- Figure 3 B is Figure 1 The diagram shown is a schematic representation of the wiring circuit board on which external components are mounted. Figure 3 A represents a side sectional view along the first direction. Figure 3 B represents a side sectional view along the second direction.

[0035] Figure 4 A cross-sectional view showing the second embodiment of the wiring circuit board of the present invention (and) Figure 2 B is the corresponding plan view. Detailed Implementation

[0036] exist Figure 1In the diagram, the paper thickness direction is the first direction, the depth side of the paper is one side of the first direction, and the front side of the paper is the other side of the first direction. Furthermore, the left-right direction of the paper is the second direction (orthogonal to the first direction), the left side of the paper is one side of the second direction, and the right side of the paper is the other side of the second direction. Additionally, the up-down direction of the paper is the up-down direction (orthogonal to the first and second directions, the thickness direction), the upper part of the paper is the upper side (one side of the third direction, the thickness direction), and the lower part of the paper is the lower side (the other side of the third direction, the thickness direction). Refer to the directional arrows in each diagram for specific details.

[0037] <First Implementation>

[0038] Reference Figures 1-3 B, describes one embodiment of the wiring circuit board of the first embodiment of the present invention.

[0039] 1. Wiring circuit board

[0040] like Figure 1 and Figure 2 As shown, the wiring circuit board 1 has a planar shape extending along the surface direction (first direction and second direction). Specifically, the wiring circuit board 1 has a plate shape that is generally rectangular when viewed from above.

[0041] The wiring circuit board 1 has a metal support layer 2, a base insulating layer 3 (an example of a first insulating layer), a plurality of first metal connectors 4, wiring 5, a first metal layer 6, an intermediate insulating layer 7 (an example of a second insulating layer), a plurality of second metal connectors 8, a second metal layer 9, and a cover insulating layer 10.

[0042] The metal support layer 2 is disposed on the bottom layer of the wiring circuit board 1, forming the outer shape of the wiring circuit board 1. The metal support layer 2 has a planar shape extending in the surface direction, specifically, it has a plate shape that is approximately rectangular when viewed from above.

[0043] The metal support layer 2 has a first support portion 11 and a second support portion 12 disposed on the other side of the first support portion 11 in a second direction.

[0044] The first support portion 11 and the second support portion 12 each have a flat plate shape that is approximately rectangular when viewed from above.

[0045] The first support portion 11 and the second support portion 12 are independent of each other in the planar direction. That is, the first support portion 11 and the second support portion 12 are arranged at a distance from each other in the planar direction (second direction). As a result, a groove 13 extending in a straight line along the first direction is formed between the first support portion 11 and the second support portion 12.

[0046] Furthermore, when the wiring circuit board 1 is projected in the vertical direction, the area overlapping with the first support portion 11 is divided into the first support region 21, the area overlapping with the second support portion 12 is divided into the second support region 22, and the area overlapping with the groove portion 13 is divided into the groove region 23. That is, the wiring circuit board 1 (more specifically, each layer constituting these regions) has the first support region 21, the second support region 22, and the groove region 23.

[0047] The material of the metal support layer 2 can be appropriately selected and used from, for example, known or conventional metal materials. Specifically, examples of metal materials include metal elements classified into Groups 1 to 16 of the periodic table, alloys containing two or more of these metal elements (e.g., stainless steel). The metal material can also be any of transition metals or typical metals. More specifically, examples include, for instance, Group 2 main metal elements such as calcium, Group 4 subgroup metal elements such as titanium and zirconium, Group 5 subgroup metal elements such as vanadium, Group 6 subgroup metal elements such as chromium, molybdenum, and tungsten, Group 7 subgroup metal elements such as manganese, Group 8 (column 8) metal elements such as iron, Group 8 (column 9) metal elements such as cobalt, Group 8 (column 10) metal elements such as nickel and platinum, Group 1 subgroup metal elements such as copper, silver, and gold, Group 2 subgroup metal elements such as zinc, Group 3 main metal elements such as aluminum and gallium, and Group 4 main metal elements such as germanium and tin.

[0048] The thickness of the metal support layer 2 is, for example, 10 μm or more, preferably 30 μm or more, and furthermore, for example, 150 μm or less, preferably 100 μm or less.

[0049] The width of the groove 13 (distance in the second direction) is, for example, 30 μm or more, preferably 50 μm or more, and furthermore, for example, 500 μm or less, preferably 300 μm or less.

[0050] The base insulating layer 3 is disposed on the upper surface (the side in the thickness direction) of the metal support layer 2. Specifically, the base insulating layer 3 is disposed on the entire upper surface of the metal support layer 2 in such a way that it covers all the first support regions 21, the second support regions 22, and the groove region 23. That is, the base insulating layer 3 is disposed on the upper surface of the metal support layer 2 across (on) the first support portion 11 and the second support portion 12. The shape of the base insulating layer 3 is approximately the same as the shape of the metal support layer 2 when viewed from above.

[0051] The substrate insulating layer 3 has a plurality of (4) first through holes 14 in the second support region 22.

[0052] A plurality of first through holes 14 are formed at intervals along the surface direction. The plurality of first through holes 14 are arranged around the area that overlaps with the first metal layer 6 and the second metal layer 9 when viewed from above. The first through holes 14 are generally circular in shape when viewed from above. The first through holes 14 are filled with the first metal connecting portion 4, which will be described later.

[0053] The diameter of the first through hole 14 is, for example, 20 μm or more, preferably 30 μm or more, and furthermore, for example, 500 μm or less, preferably 300 μm or less.

[0054] The material of the base insulating layer 3 can be appropriately selected and used from, for example, known or conventional insulating materials. Specifically, examples of insulating materials include synthetic resins such as polyimide resin, polyamide-imide resin, acrylic resin, polyether nitrile resin, polyethersulfone resin, polyethylene terephthalate resin, polyethylene naphthalate resin, and polyvinyl chloride resin. Preferably, the base insulating layer 3 is formed of polyimide resin.

[0055] The thickness of the substrate insulating layer 3 is, for example, 1 μm or more, preferably 3 μm or more, and furthermore, for example, 30 μm or less, preferably 20 μm or less.

[0056] A plurality of first metal connecting portions 4 are disposed inside a plurality of first through holes 14. Specifically, the first metal connecting portions 4 are configured to completely fill the first through holes 14.

[0057] The first metal connector 4 has a generally cylindrical shape that extends in the vertical direction.

[0058] The lower surface of the first metal connection part 4 is in contact with the upper surface of the second support part 12, and the upper surface of the first metal connection part 4 is integrally continuous with the lower surface of the first metal layer 6.

[0059] The first metal connection portion 4 is formed of the same metal material as the first metal layer 6 described later. It is preferably formed of copper.

[0060] The thickness of the first metal connection part 4 is the same as the thickness of the base insulating layer 3.

[0061] Wiring 5 is disposed on the upper surface of the substrate insulating layer 3. Specifically, wiring 5 is disposed in the first support region 21 of the substrate insulating layer 3.

[0062] The wiring 5 is formed in a straight line extending along the first direction. Furthermore, the wiring 5 is formed along the outline (one edge in the second direction) of the first metal layer 6. Specifically, one edge of the wiring 5 in the first direction reaches one edge of the wiring circuit board 1 in the first direction, and the other edge of the wiring 5 in the first direction reaches the other edge of the wiring circuit board 1 in the first direction. For example... Figure 2As shown by the imaginary line B, one edge of the wiring 5 in the first direction is connected to a terminal 16 protruding in the first direction. Furthermore, the other edge of the wiring 5 in the first direction is connected to a terminal 17 protruding in the other direction.

[0063] The material for wiring 5 can be appropriately selected and used from, for example, known or commonly used metallic conductor materials. Specifically, examples of metallic conductor materials include, for example, copper, nickel, gold, solder, or alloys thereof. Preferably, wiring 5 is formed of copper.

[0064] The thickness of the wiring 5 is, for example, 1 μm or more, preferably 3 μm or more, and furthermore, for example, 30 μm or less, preferably 20 μm or less.

[0065] The first metal layer 6 is disposed on the upper surface of the substrate insulating layer 3. Specifically, the first metal layer 6 is disposed on the upper surface of the substrate insulating layer 3 such that it spans the first support portion 11 and the second support portion 12 when viewed from above. That is, the first metal layer 6 is disposed in the first support region 21, the groove region 23, and the second support region 22 of the substrate insulating layer 3. The first metal layer 6 is disposed at a distance from the wiring 5 on the other side in the second direction, and is disposed around the wiring 5 along the wiring 5.

[0066] The first metal layer 6 has a planar shape extending along the surface direction, specifically, it has a plate shape that is approximately rectangular when viewed from above.

[0067] The area of ​​the first metal layer 6 in plan view is 50% or more, preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more, of the area of ​​the metal support layer 2 in plan view (i.e., the total area enclosed by the outer shape of the metal support layer 2; in other words, the total area of ​​the first support region 21, the second support region 22, and the trench region 23). Furthermore, it is less than 100%, for example. If the area is above the aforementioned lower limit, a large portion of the height of the upper surface of the non-wiring region 25 can be increased, resulting in excellent planarity. In addition, the rigidity of the wiring circuit board 1 can be improved.

[0068] The material of the first metal layer 6 can be appropriately selected and used from, for example, known or conventional metal materials. Preferably, it is the same metal conductor material as the wiring 5. More preferably, the first metal layer 6 is formed of copper.

[0069] The thickness of the first metal layer 6 is the same as the thickness of the wiring 5, for example, 1 μm or more, preferably 3 μm or more, and also, for example, 30 μm or less, preferably 20 μm or less.

[0070] The shortest distance between the first metal layer 6 and the wiring 5 in the planar direction is, for example, 10 μm or more, preferably 20 μm or more, and furthermore, for example, 200 μm or less, preferably 100 μm or less. If the shortest distance is above or below the aforementioned lower limit, short circuits between the first metal layer 6 and the wiring 5 can be reliably suppressed. Furthermore, if the shortest distance is below or below the aforementioned upper limit, the depression on the upper surface between the first metal layer 6 and the wiring 5 can be reduced, and planarity can be maintained more reliably.

[0071] Furthermore, when the wiring circuit board 1 is projected in the vertical direction, the area overlapping with the wiring 5 is divided into wiring regions 24, and the area other than wiring regions 24 is divided into non-wiring regions 25. That is, the wiring circuit board 1 (more specifically, each layer constituting these regions) has wiring regions 24 and non-wiring regions 25.

[0072] In addition, in the non-wiring area 25, the area overlapping with the first metal layer 6 is divided into the first metal area 26.

[0073] An intermediate insulating layer 7 is disposed on the upper surface of the base insulating layer 3, the wiring 5, and the first metal layer 6. Specifically, the intermediate insulating layer 7 is disposed on the upper surface of the portion of the base insulating layer 3 exposed from the wiring 5 and the first metal layer 6, such that it covers the upper surface and side surfaces of the wiring 5 and the first metal layer 6. The shape of the intermediate insulating layer 7 is substantially the same as that of the base insulating layer 3 when viewed from above.

[0074] The intermediate insulating layer 7 has a plurality of second through holes 15 in the second support region 22.

[0075] A plurality of second through holes 15 are formed at intervals along the surface direction. The plurality of second through holes 15 are disposed around the area overlapping the first metal layer 6 and the second metal layer 9 when viewed from above. Specifically, the plurality of second through holes 15 overlap with a plurality of first through holes 14 when projected vertically. The second through holes 15 are generally circular in shape when viewed from above. The second through holes 15 are filled with the second metal connection portion 8, which will be described later.

[0076] The diameter of the second through hole 15 is the same as the diameter of the first through hole 14, for example, 20 μm or more, preferably 30 μm or more, and also, for example, 500 μm or less, preferably 300 μm or less.

[0077] The material of the intermediate insulating layer 7 can be appropriately selected and used from, for example, known or conventional insulating materials. Specifically, the same insulating material as the base insulating layer 3 can be used. Preferably, the intermediate insulating layer 7 is formed of polyimide resin.

[0078] The thickness of the intermediate insulating layer 7 is, for example, 1 μm or more, preferably 3 μm or more, and furthermore, for example, 30 μm or less, preferably 20 μm or less.

[0079] In the intermediate insulating layer 7, the upper surface of the wiring region 24 is at approximately the same height (vertical position) as the upper surface of the first metal region 26. Furthermore, the upper surfaces of the regions other than the wiring region 24 and the first metal region 26 are located below the upper surfaces of either the wiring region 24 or the first metal region 26.

[0080] Multiple second metal connectors 8 are disposed inside multiple second through holes 15. Specifically, the second metal connectors 8 are configured to completely fill the second through holes 15.

[0081] The second metal connector 8 has a generally cylindrical shape that extends in the vertical direction.

[0082] The lower surface of the second metal connector 8 is in contact with the upper surface of the first metal layer 6, and the upper surface of the second metal connector 8 and the lower surface of the second metal layer 9 are integrally continuous.

[0083] The second metal connection portion 8 is formed of the same metal material as the second metal layer 9, which will be described later. It is preferably formed of copper.

[0084] The thickness of the second metal connection part 8 is the same as the thickness of the intermediate insulating layer 7.

[0085] The second metal layer 9 is disposed on the upper surface of the intermediate insulating layer 7. Specifically, the second metal layer 9 is disposed on the upper surface of the intermediate insulating layer 7 such that it spans the wiring 5 and the first metal layer 6 when viewed from above. That is, the second metal layer 9 is disposed on the upper surface of the intermediate insulating layer 7 in the portion of the wiring region 24, the first metal region 26, and the portion of the non-wiring region 25 disposed between the wiring region 24 and the first metal region 26. Furthermore, the second metal layer 9 is disposed on the upper surface of the intermediate insulating layer 7 such that it spans the first support portion 11 and the second support portion 12 when viewed from above. That is, the second metal layer 9 is disposed on the upper surface of the intermediate insulating layer 7 in the first support region 21, the groove region 23, and the second support region 22.

[0086] The second metal layer 9 has a planar shape extending along the surface direction, specifically, it has a plate shape that is approximately rectangular when viewed from above.

[0087] In the second metal layer 9, the upper surface of the wiring region 24 and the upper surface of the first metal region 26 are approximately at the same height. In addition, the upper surface of the region other than the wiring region 24 and the first metal region 26 is located below the upper surface of the wiring region 24 or the first metal region 26.

[0088] The area of ​​the second metal layer 9 in top view is, for example, 50% or more, preferably 70% or more, more preferably 80% or more, and, for example, less than 100% of the area of ​​the metal support layer 2 in top view. If the area is above the lower limit, the rigidity of the wiring circuit board 1 can be improved. In addition, heat dissipation is excellent.

[0089] Furthermore, the area of ​​the second metal layer 9 in top view is, for example, 100% or more, preferably 110% or more, more preferably 120% or more, and for example, 200% or less, relative to the area of ​​the first metal layer 6 in top view. If the area is above the lower limit, the rigidity of the wiring circuit board 1 can be improved. In addition, heat dissipation is excellent.

[0090] The material of the second metal layer 9 can be appropriately selected and used from, for example, known or conventional metal materials. Preferably, it is the same metal conductor material as the first metal layer 6. More preferably, the second metal layer 9 is formed of copper.

[0091] The thickness of the second metal layer 9 is, for example, 1 μm or more, preferably 3 μm or more, and furthermore, for example, 30 μm or less, preferably 20 μm or less.

[0092] A cover insulating layer 10 is disposed on the upper surface of the intermediate insulating layer 7 and the second metal layer 9. Specifically, the cover insulating layer 10 is disposed on the upper surface of the portion of the intermediate insulating layer 7 exposed from the second metal layer 9, such that it covers the upper surface and sides of the second metal layer 9. The shape of the cover insulating layer 10 is substantially the same as that of the intermediate insulating layer 7 when viewed from above.

[0093] The material of the covering insulation layer 10 can be appropriately selected and used from, for example, known or conventional insulating materials. Specifically, the same insulating material as the base insulation layer 3 can be used. Preferably, the covering insulation layer 10 is formed of polyimide resin.

[0094] The thickness of the insulating layer 10 is, for example, 1 μm or more, preferably 3 μm or more, and furthermore, for example, 30 μm or less, preferably 20 μm or less.

[0095] In the covering insulating layer 10 (more specifically, the wiring circuit board 1), the upper surface of the wiring region 24 and the upper surface of the first metal region 26 are approximately at the same height. Furthermore, the upper surface of the region other than the wiring region 24 and the first metal region 26 is located below the upper surface of the wiring region 24 or the first metal region 26.

[0096] 2. Manufacturing method of wiring circuit board

[0097] Next, one embodiment of the manufacturing method of the wiring circuit board 1 will be described.

[0098] In this method, a metal support layer 2 is first prepared.

[0099] Specifically, a metal support plate made of metallic materials is prepared. Stainless steel plate is preferred.

[0100] Next, the substrate insulating layer 3 is formed on the upper surface of the metal support layer 2.

[0101] Specifically, as the material of the substrate insulating layer 3, a varnish of a photosensitive insulating material (e.g., photosensitive polyimide) is applied to the entire upper surface of the metal support layer 2 and dried to form a substrate coating. Then, the substrate coating is exposed using a photomask having a pattern corresponding to the first through-hole 14. The substrate coating is then developed and, if necessary, heated to cure it.

[0102] Next, wiring 5 and the first metal layer 6 are formed on the upper surface of the substrate insulating layer 3.

[0103] Specifically, wiring 5 and the first metal layer 6 are formed on the upper surface of the substrate insulating layer 3 using a patterning method such as an additive method. That is, wiring 5 and the first metal layer 6 are simultaneously disposed as a single layer on the upper surface of the substrate insulating layer 3. As a result, the thicknesses of wiring 5 and the first metal layer 6, i.e., the heights of wiring region 24 and the first metal region 26, can be set to be the same.

[0104] At this time, simultaneously with the formation of the first metal layer 6, the material of the first metal layer 6 is filled into the first through hole 14. That is, the first metal connection portion 4 is filled into the first through hole 14. Thus, the first metal layer 6 and the first metal connection portion 4 are integrally formed.

[0105] Next, an intermediate insulating layer 7 is formed on the upper surface of the wiring 5, the first metal layer 6, and the base insulating layer 3.

[0106] Specifically, an intermediate insulating layer 7 is formed on the upper side of the base insulating layer 3 in such a way that it covers the upper surface and side surface of the wiring 5 and the upper surface and side surface of the first metal layer 6. That is, an intermediate insulating layer 7 of the desired thickness is formed on the entire upper surface of the laminate having the base insulating layer 3, the wiring 5 and the first metal layer 6.

[0107] The intermediate insulating layer 7 is formed in the same way as the substrate insulating layer 3. Then, the substrate coating is exposed and developed in such a way that a plurality of second through-holes 15 are formed in the intermediate insulating layer 7.

[0108] Next, the second metal layer 9 is formed on the upper surface of the intermediate insulating layer 7.

[0109] The method for forming the second metal layer 9 is the same as the method for forming the first metal layer 6. At this time, simultaneously with the formation of the second metal layer 9, the material of the second metal layer 9 is filled into the second through-hole 15. That is, the second metal connector 8 is filled into the second through-hole 15. Thus, the second metal layer 9 and the second metal connector 8 are integrally formed.

[0110] Next, the covering insulating layer 10 is formed on the upper surface of the second metal layer 9 and the intermediate insulating layer 7.

[0111] Specifically, a covering insulating layer 10 is formed on the upper side of the intermediate insulating layer 7 in such a way that it covers the upper surface and sides of the second metal layer 9. That is, a covering insulating layer 10 of the desired thickness is formed on the entire upper surface of the laminate having the intermediate insulating layer 7 and the second metal layer 9.

[0112] The method for forming the covering insulating layer 10 is the same as the method for forming the base insulating layer 3.

[0113] Next, a groove 13 is provided in the metal support layer 2.

[0114] Specifically, a groove 13 is formed in the metal support layer 2 by etching or the like.

[0115] Therefore, as Figure 1 As shown, a wiring circuit board 1 was fabricated.

[0116] 3. Applications of wiring circuit boards

[0117] The wiring circuit board 1 is used in various applications, such as circuit boards for electronic devices and circuit boards for electrical equipment. Examples of such circuit boards for electronic components and electrical components include circuit boards used in various sensors such as position information sensors, obstacle detection sensors, and temperature sensors (sensor circuit boards); circuit boards used in various transport vehicles such as automobiles, trams, airplanes, and work vehicles (transport vehicle circuit boards); circuit boards used in various video devices such as flat panel displays, flexible displays, and projection video equipment (video equipment circuit boards); circuit boards used in various network devices, large-scale communication equipment, and other communication relay equipment (communication relay equipment circuit boards); circuit boards used in information processing terminals such as computers, tablet computers, smartphones, and home game consoles (information processing terminal circuit boards); circuit boards used in movable devices such as unmanned aerial vehicles and robots (movable device circuit boards); circuit boards used in various medical devices such as wearable medical devices and medical diagnostic devices (medical device circuit boards); circuit boards used in various electrical devices such as refrigerators, washing machines, vacuum cleaners, and air conditioning equipment (electrical equipment circuit boards); and circuit boards used in various video recording electronic devices such as digital cameras and DVD recording devices (video recording electronic device circuit boards).

[0118] Furthermore, the wiring circuit board 1 has a metal support layer 2, a base insulating layer 3 disposed on the upper surface of the metal support layer 2, wiring 5 disposed on the upper surface of the base insulating layer 3, and a first metal layer 6 disposed on the upper surface of the base insulating layer 3. The area of ​​the first metal layer 6 in top view is more than 50% of the area of ​​the metal support layer 2 in top view.

[0119] Therefore, a large area of ​​the first metal layer 6 is disposed on the upper surface of the substrate insulating layer 3. Consequently, most of the non-wiring area 25 is raised by the first metal layer 6, thus reducing the height difference (distance in the vertical direction) between the wiring area 24 and the non-wiring area 25. That is, the planarity of the upper surface of the wiring circuit board 1 is improved. Therefore, external components can be disposed on the upper surface of the wiring circuit board 1 without tilting.

[0120] Furthermore, due to the presence of a large-area first metal layer 6, the rigidity of the wiring circuit board 1 is improved. Therefore, even when heavy external components are mounted, downward bending of the wiring circuit board 1 can be suppressed, allowing external components to be mounted without tilting.

[0121] As a result, external components can be easily disposed on the upper surface of the wiring circuit board 1. Especially as Figure 3 A- Figure 3As shown in Figure B, sometimes a wiring circuit board 1 is arranged with mounting portions 31a and 31b spaced apart from each other along the first direction, and an external component 30 is mounted on the upper surface of the wiring circuit board 1. That is, sometimes one end of the wiring circuit board 1 in the first direction is placed on the mounting portion 31a, and the other end of the wiring circuit board 1 in the first direction is placed on the mounting portion 31b, with a larger and heavier external component 30 mounted on the upper surface of the center portion of the wiring circuit board 1 in the first direction. In this case, downward bending of the wiring circuit board 1 can be suppressed, and the external component 30 can be arranged in a manner that prevents it from tilting towards the other side of the second direction and downward. Therefore, it is possible to prevent the external component 30 from falling off the upper surface of the wiring circuit board 1.

[0122] Furthermore, in this wiring circuit substrate 1, wiring 5 is formed along the outline of the first metal layer 6.

[0123] Therefore, the first metal layer 6 is formed along the wiring 5. Thus, when the external component 30 is arranged along the wiring 5, that is, along the first direction, the external component 30 can be arranged in a manner that does not tilt towards the second direction or downward.

[0124] Furthermore, in this wiring circuit board 1, the metal support layer 2 has a first support portion 11 and a second support portion 12 arranged at intervals from each other. The first metal layer 6 is configured to span the first support portion 11 and the second support portion 12 when viewed from above.

[0125] Therefore, it is possible to suppress the deformation of the wiring circuit board 1 caused by the independent movement of the first support region 21 and the second support region 22 in the surface direction and vertical direction. Thus, when the external component 30 is disposed on the wiring circuit board 1, it is possible to suppress the deviation and deflection of the wiring circuit board 1.

[0126] Furthermore, in this wiring circuit board 1, the first support portion 11 is configured to span the wiring 5 and the first metal layer 6 when viewed from above.

[0127] Therefore, it is possible to suppress the deformation of the wiring circuit board 1 caused by the independent movement of the wiring area 24 and the first metal area 26 in the surface direction or vertical direction. Thus, when the external component 30 is arranged, it is possible to suppress the deviation and deflection between the wiring area 24 and the first metal area 26.

[0128] Furthermore, in this wiring circuit board 1, the substrate insulating layer 3 has a first through hole 14 at the position where it overlaps with the metal support layer 2 and the first metal layer 6 when projected in the vertical direction. The first through hole 14 is filled with a first metal connection portion 4 that contacts both the metal support layer 2 and the first metal layer 6.

[0129] Therefore, the first metal layer 6 is reliably fixed to the metal support layer 2 by means of the first metal connection portion 4. Thus, when the external component 30 is arranged, the dent of the first metal layer 6 can be suppressed, and the deflection of the wiring circuit board 1 can be reliably suppressed.

[0130] Furthermore, the heat stored inside the wiring circuit board 1 can be conducted to the second support portion 12 via the first metal layer 6 and the first metal connection portion 4. Therefore, heat dissipation is excellent.

[0131] Furthermore, the wiring circuit board 1 includes an intermediate insulating layer 7 disposed on the upper surface of the wiring 5 and the first metal layer 6, and a second metal layer 9 disposed on the upper surface of the intermediate insulating layer 7. The intermediate insulating layer 7 has a second through-hole 15 at a position where it overlaps with the first metal layer 6 and the second metal layer 9 when projected in the vertical direction. A second metal connection portion 8, which contacts the first metal layer 6 and the second metal layer 9, is filled in the second through-hole 15.

[0132] Therefore, due to the presence of the second metal layer 9 and the intermediate insulating layer 7, the rigidity of the wiring circuit board 1 is further improved. Furthermore, since the second through-hole 15 is filled with a second metal connection portion 8 that contacts the first metal layer 6 and the second metal layer 9, the second metal layer 9 is fixed to the first metal layer 6 by means of the second metal connection portion 8. As a result, when external components 30 are disposed, denting of the second metal layer 9 can be suppressed. With these structures, the deflection of the wiring circuit board 1 can be reliably suppressed.

[0133] Furthermore, when a through hole 32 is formed in the second support region 22 covering the insulating layer 10, Figure 3 When the second metal layer 9 and the external component 30 are electrically connected via the through hole 32 (the imaginary line of B), the second metal layer 9 can be used as a grounding layer. That is, the external component 30 can be grounded by means of the second metal layer 9, the second metal connection part 8, the first metal layer 6, the first metal connection part 4, and the second support part 12.

[0134] Furthermore, in this wiring circuit board 1, the second metal layer 9 is configured to span the wiring 5 and the first metal layer 6 when viewed from above.

[0135] Therefore, it is possible to suppress the deformation of the wiring circuit board 1 caused by the independent movement of the wiring area 24 and the first metal area 26 along the surface direction or vertical direction. As a result, when the external component 30 is arranged, it is possible to more reliably suppress the deviation and deflection between the wiring area 24 and the first metal area 26.

[0136] 4. Variations

[0137] exist Figures 1-2In the embodiment shown in C, the wiring circuit board 1 has a roughly rectangular shape when viewed from above, but its shape is not limited and may be, for example, roughly circular when viewed from above, etc., which is not shown in the figure.

[0138] exist Figures 1-2 In the embodiment shown in C, the two ends of the wiring 5 are connected to terminals (16, 17). However, for example, one end and the other end of the wiring circuit board 1 in the first direction may be continuous with another wiring circuit board (not shown) having a planar shape extending in a second surface direction that intersects the surface directions (the first and second directions). This is not shown.

[0139] <Second Implementation Method>

[0140] Reference Figure 4 This section describes one embodiment of the wiring circuit board according to the second embodiment of the present invention. Furthermore, in the second embodiment, the same reference numerals are used for components identical to those in the first embodiment described above, and their descriptions are omitted.

[0141] The wiring circuit board 1 of the first embodiment has one wiring 5, but the wiring circuit board 1 of the second embodiment has multiple (four) wirings 5 ​​(5a, 5b, 5c, 5d).

[0142] Multiple wirings 5 ​​are disposed on the upper surface of the substrate insulating layer 3, and also around the first metal layer 6.

[0143] The plurality of wirings 5 ​​have a first wiring 5a and a second wiring 5b extending along a first direction, and a third wiring 5c ​​and a fourth wiring 5d extending along a second direction.

[0144] The first wiring 5a extends along the first direction at one end in the second direction in a manner that follows the outline (one edge in the second direction) of the first metal layer 6.

[0145] The second wiring 5b and the first wiring 5a are arranged at a distance from each other in the second direction. The second wiring 5b extends along the first direction at its other end in the second direction in a manner that follows the outline of the first metal layer 6 (the other edge in the second direction). The first metal layer 6 is disposed between the second wiring 5b and the first wiring 5a.

[0146] The third wiring 5c ​​extends along the second direction at one end in the first direction in a manner that follows the outline (first direction edge) of the first metal layer 6. Specifically, the third wiring 5c ​​is formed in a U-shape from the first direction edge on one side of the second direction to the first direction edge on the other side of the second direction.

[0147] The fourth wiring 5d and the third wiring 5c ​​are arranged at a distance from each other in the first direction. The fourth wiring 5d extends along the second direction at its other end in the first direction, following the outline of the first metal layer 6 (the other edge in the first direction). Specifically, the fourth wiring 5d is formed in an inverted U-shape from the other edge in the first direction on one side of the second direction to the other edge in the first direction on the other side of the second direction. The first metal layer 6 is disposed between the fourth wiring 5d and the third wiring 5c.

[0148] The wiring circuit board 1 of the second embodiment has the same functional effect as the wiring circuit board 1 of the first embodiment. In addition, in the wiring circuit board 1 of the second embodiment, external components 30 can be arranged between the plurality of wirings 5 ​​without tilting.

[0149] Furthermore, the above-described invention is provided as an illustrative embodiment of the present invention, but it is merely illustrative and should not be interpreted as limiting. Modifications of the invention that will be apparent to those skilled in the art are included in the foregoing claims.

[0150] Industrial availability

[0151] Wiring circuit boards can be used in circuit boards for electronic devices, circuit boards for electrical equipment, etc.

[0152] Explanation of reference numerals in the attached figures

[0153] 1. Wiring circuit board; 2. Metal support layer; 3. Substrate insulating layer; 4. First metal connection portion; 5. Wiring; 6. First metal layer; 7. Intermediate insulating layer; 8. Second metal connection portion; 9. Second metal layer; 11. First support portion; 12. Second support portion; 14. First through hole; 15. Second through hole.

Claims

1. A wiring circuit board having a planar shape extending along a surface direction, The wiring circuit board is characterized in that it has: Metal support layer; The first insulating layer is disposed on one side of the metal support layer in the thickness direction; Wiring is disposed on one side of the first insulating layer in the thickness direction; The first metal layer is disposed on one side of the first insulating layer in the thickness direction. A second insulating layer is disposed on one side of the wiring and the first metal layer in the thickness direction, and The second metal layer is disposed on one side of the second insulating layer in the thickness direction. The area of ​​the first metal layer when viewed from above is more than 50% of the area of ​​the metal support layer when viewed from above. The second metal layer is configured to span the wiring and the first metal layer when viewed from above. The area of ​​the second metal layer when viewed from above is 100% and less than 200% of the area of ​​the first metal layer when viewed from above.

2. The wiring circuit board according to claim 1, characterized in that, A plurality of the wirings are arranged around the first metal layer.

3. The wiring circuit board according to claim 1, characterized in that, The wiring is formed along the outline of the first metal layer.

4. The wiring circuit board according to claim 1, characterized in that, The metal support layer has a first support portion and a second support portion arranged at intervals between each other. The first metal layer is configured to span the first support portion and the second support portion when viewed from above.

5. The wiring circuit board according to claim 4, characterized in that, The first support portion is configured to span the wiring and the first metal layer when viewed from above.

6. The wiring circuit board according to claim 1, characterized in that, The first insulating layer has a first through hole at the location where it overlaps with the metal support layer and the first metal layer when projected along the thickness direction. The first through hole is filled with a first metal connection portion that contacts the metal support layer and the first metal layer.

7. The wiring circuit board according to claim 1, characterized in that, The second insulating layer has a second through-hole at the location where it overlaps with the first and second metal layers when projected along the thickness direction. The second through hole is filled with a second metal connection portion that contacts the first metal layer and the second metal layer.

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