Wired circuit board

Abstract

To provide a wiring circuit board capable of suppressing a short circuit between a terminal and a metal support layer while achieving miniaturization of the wiring circuit board.SOLUTION: A wired circuit substrate 1 includes a metallic support layer 2, terminals 41A, and a first insulating layer 3. The first insulating layer 3 has a first end edge E11 on one side in the first direction and a second end edge E12 on the other side in the first direction. Each of the terminals 41A includes a third edge E13 on one side in the first direction and a fourth edge E14 on the other side in the first direction. The metal-supporting layer 2 has a fifth end edge E15 at one side in the first direction and a sixth end edge E16 at the other side in the first direction. The third edge E13 and the fifth edge E15 are disposed between the first edge E11 and the second edge E12. The sum of the distances E11 and E15 between the first end edge D2 and the fifth end edge D1 is 15 μm or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a printed circuit board. [Background technology]

[0002] Conventionally, a wired circuit board has been known that includes a metal support layer, a conductor pattern arranged on one side of the metal support layer in the thickness direction, and a base insulating layer arranged between the metal support layer and the conductor pattern (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-171201 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to reduce the size of the wired circuit board as described in Patent Document 1, it has been considered to shorten the distance between the edge of the base insulating layer and the terminal.

[0005] In this regard, if the distance between the edge of the base insulating layer and the terminal becomes short, when the solder on the terminal melts and flows toward the edge of the base insulating layer, the flowed solder may pass over the edge of the base insulating layer and reach the metal support layer.

[0006] If the flowed solder reaches the metal support layer, there is a possibility that the terminal and the metal support layer may be short-circuited.

[0007] The present invention provides a wired circuit board that can be miniaturized and can suppress short circuits between terminals and a metal support layer. [Means for solving the problem]

[0008] The present invention [1] includes a wired circuit board comprising: a metal support layer; a terminal arranged on one side of the metal support layer in a thickness direction of the metal support layer; and a first insulating layer arranged between the metal support layer and the terminal in the thickness direction, wherein the first insulating layer extends in a first direction perpendicular to the thickness direction and has a first edge and a second edge arranged opposite the first edge in the first direction, the terminal has a third edge arranged between the first edge and the second edge in the first direction and a fourth edge arranged between the third edge and the second edge in the first direction, the metal support layer has a fifth edge arranged between the first edge and the second edge in the first direction and a sixth edge arranged on the opposite side of the first edge with respect to the fifth edge in the first direction, and the sum of the distance between the first edge and the third edge and the distance between the first edge and the fifth edge is 15 μm or more.

[0009] According to this configuration, the sum of the distance between the first edge and the third edge and the distance between the first edge and the fifth edge of the metal support layer is 15 μm or more.

[0010] Therefore, even when the first edge of the first insulating layer is disposed close to the terminal, the distance from the terminal to the metal support layer can be ensured.

[0011] Therefore, even if the solder on the terminal flows toward the first edge, it is possible to prevent the flowing solder from causing a short circuit between the terminal and the metal support layer.

[0012] As a result, it is possible to reduce the size of the printed circuit board and prevent short circuits between the terminals and the metal support layer.

[0013] The present invention [2] includes the wired circuit board according to the above [1], wherein the distance between the first edge and the third edge is 200 μm or less.

[0014] With this configuration, the printed circuit board can be made smaller.

[0015] The present invention [3] includes the wired circuit board of [1] or [2] above, wherein the distance between the first edge and the fifth edge is longer than the distance between the first edge and the third edge.

[0016] With this configuration, the first edge of the first insulating layer can be brought closer to the terminal, thereby further reducing the size of the wired circuit board.

[0017] The present invention [4] includes the wired circuit board of any one of [1] to [3] above, further comprising a second insulating layer arranged on one side of the first insulating layer in the thickness direction, and a portion of the second insulating layer being arranged between the first edge and the third edge in the first direction.

[0018] According to this configuration, the second insulating layer between the first edge and the third edge can prevent the solder on the terminal from flowing toward the first edge.

[0019] The present invention [5] includes the wired circuit board according to the above [4], wherein the second insulating layer covers the third edge.

[0020] With this configuration, the second insulating layer can further prevent the solder on the terminal from flowing toward the first edge.

[0021] The present invention [6] includes the wired circuit board of any one of [1] to [5] above, wherein the metal support layer has one end and the other end in the first direction, and a recess recessed from the one end toward the other end in the first direction, the recess overlapping the third edge in the thickness direction, and the fifth edge being the bottom of the recess.

[0022] The present invention [7] includes the wired circuit board of any one of the above [1] to [6], further comprising a wiring that is arranged between the second edge and the fourth edge and is connected to the terminal. [Effects of the Invention]

[0023] According to the wired circuit board of the present invention, it is possible to reduce the size of the wired circuit board and to prevent short circuits between the terminals and the metal support layer. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a plan view showing one embodiment of the wired circuit board 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] FIG. 3 is a plan view showing a printed circuit board of the modified example (1). [Figure 4] FIG. 4 is a plan view showing a printed circuit board according to a modified example (2). [Figure 5] 5A and 5B are plan views showing a printed circuit board according to a modified example (3). [Figure 6] 6A and 6B are plan views showing a printed circuit board according to a fourth modification. [Figure 7] Fig. 7A is a plan view showing a wired circuit board of a modified example (5), and Fig. 7B is a BB cross-sectional view of the wired circuit board shown in Fig. 7A. [Figure 8] FIG. 8 is a plan view showing a printed circuit board according to a sixth modification. DETAILED DESCRIPTION OF THE INVENTION

[0025] 1. Wiring circuit board As shown in FIG. 1, the wired circuit board 1 extends in a first direction and a second direction. The second direction is perpendicular to the first direction. The wired circuit board 1 has a predetermined width W0 in the first direction and extends longer than the width W0 in the second direction. The second direction is the direction in which multiple terminals 41A and 41B are arranged. The terminals 41A and 41B will be described later.

[0026] The width W0 of the wired circuit board 1 may be the same as or different from the width W11 of the first insulating layer 3 described below. The width W0 (length in the first direction) of the wired circuit board 1 is, for example, 200 μm to 1800 μm, or preferably 300 μm to 1600 μm. More specifically, the width W0 of the wired circuit board 1 is the width of a portion of the wired circuit board 1 where the terminals 41A and 41B are arranged.

[0027] As shown in FIG. 2, the wired circuit board 1 includes a metal support layer 2, a first insulating layer 3, a circuit pattern 4, and a second insulating layer 5.

[0028] (1) Metal support layer The metal support layer 2 supports the first insulating layer 3, the circuit pattern 4, and the second insulating layer 5. Examples of materials for the metal support layer 2 include stainless steel and copper alloys. The metal support layer 2 may have multiple layers made of different metals.

[0029] The metal support layer 2 has a thickness T1 in the range of, for example, 10 μm to 250 μm, or preferably 20 μm to 200 μm.

[0030] As shown in FIG. 1, the metal support layer 2 extends in a first direction and a second direction. The metal support layer 2 has a predetermined width W1 in the first direction and extends in the second direction. The metal support layer 2 has one end E1 and another end E2 in the first direction. The other end E2 is the end opposite the one end E1 in the first direction. The other end E2 is positioned away from the one end E1 in the first direction. The metal support layer 2 has a recess 20.

[0031] The recess 20 is disposed in the first direction at one end E1 of the metal support layer 2. The recess 20 is recessed in the first direction from the one end E1 toward the other end E2.

[0032] The width W1 of the metal support layer 2 (the distance between one end E1 and the other end E2 in the first direction) is in the range of, for example, 200 μm to 1600 μm, or preferably 300 μm to 1500 μm.

[0033] The width W2 (length in the first direction) of the metal support layer 2 in the portion where the recess 20 is formed is narrower than the width W1 and is in the range of, for example, 50 μm to 1450 μm, or preferably 100 μm to 1250 μm.

[0034] (2) First insulating layer As shown in FIG. 2, the first insulating layer 3 is disposed on one side of the metal support layer 2 in the thickness direction of the metal support layer 2. The thickness direction is perpendicular to the first and second directions. The first insulating layer 3 is disposed on one surface of the metal support layer 2 in the thickness direction. The first insulating layer 3 is disposed between the metal support layer 2 and the circuit pattern 4 in the thickness direction. In other words, the first insulating layer 3 is disposed between the metal support layer 2 and the terminal 41A in the thickness direction. The first insulating layer 3 can insulate the metal support layer 2 from the circuit pattern 4. The first insulating layer 3 is made of a resin. Examples of resins include polyimide, maleimide, epoxy resin, polybenzoxazole, and polyester.

[0035] The thickness T2 of the first insulating layer 3 is in the range of, for example, 1 μm to 30 μm, or preferably 3 μm to 25 μm.

[0036] 1, the first insulating layer 3 extends in a first direction and a second direction. The first insulating layer 3 has a predetermined width W11 in the first direction and extends in the second direction.

[0037] The width W11 (length in the first direction) of the first insulating layer 3 is in the range of, for example, 200 μm to 1600 μm, or preferably 300 μm to 1500 μm.

[0038] (3) Circuit pattern As shown in FIG. 2, the circuit pattern 4 is disposed on one side of the first insulating layer 3 in the thickness direction. In other words, the terminal 41A is disposed on one side of the metal support layer 2 in the thickness direction. The circuit pattern 4 is disposed on one surface of the first insulating layer 3 in the thickness direction. The circuit pattern 4 is disposed on the opposite side of the metal support layer 2 with respect to the first insulating layer 3 in the thickness direction. The circuit pattern 4 is made of a metal. Examples of metals include copper, silver, gold, iron, aluminum, chromium, and alloys thereof. From the viewpoint of obtaining good electrical properties, the circuit pattern 4 is preferably made of copper.

[0039] 1, the circuit pattern 4 has a plurality of terminals 41A, 41B and a plurality of wires 42A, 42B. In other words, the wired circuit board 1 includes a plurality of terminals 41A, 41B and a plurality of wires 42A, 42B.

[0040] Terminals 41A and 41B are aligned in the second direction. Terminal 41B is spaced apart from terminal 41A in the second direction. Terminals 41A and 41B each extend in the first direction and the second direction. Each of terminals 41A and 41B has a square land shape. One end of each of terminals 41A and 41B in the first direction overlaps recess 20 of metal support layer 2 in the thickness direction.

[0041] The width W21 (length in the first direction) of each of the terminals 41A and 41B is in the range of, for example, 100 μm to 1400 μm, or preferably 200 μm to 1300 μm.

[0042] When the width W11 of the first insulating layer 3 is taken as 100%, the width W21 of each of the terminals 41A and 41B is, for example, 50% to 95%, or preferably 65% ​​to 90%.

[0043] When the width W0 of the wired circuit board 1 is taken as 100%, the width W21 of each of the terminals 41A and 41B is in the range of, for example, 50% to 95%, or preferably 65% ​​to 90%.

[0044] The wiring 42A is connected to the other end of the terminal 41A in the first direction. The wiring 42B is connected to the other end of the terminal 41B in the first direction. The wiring 42B is arranged apart from the wiring 42B.

[0045] (4) Second insulating layer As shown in Fig. 2, the second insulating layer 5 is disposed on one side of the first insulating layer 3 in the thickness direction. The second insulating layer 5 is disposed on one surface of the first insulating layer 3 in the thickness direction. The second insulating layer 5 is made of a resin. Examples of resins include polyimide, maleimide, epoxy resin, polybenzoxazole, and polyester.

[0046] 1, the second insulating layer 5 covers the wirings 42A and 42B. The second insulating layer 5 may cover the peripheral edge portions of the terminals 41A and 41B. The second insulating layer 5 does not cover the central portions of the terminals 41A and 41B.

[0047] 2. Positional relationship between the metal support layer, first insulating layer, circuit pattern, and second insulating layer Next, the positional relationship between the metal support layer 2, the first insulating layer 3, the circuit pattern 4, and the second insulating layer 5 will be described in detail.

[0048] As shown in FIG. 1, the first insulating layer 3 has a first edge E11 and a second edge E12.

[0049] The first edge E11 is located at one end of the first insulating layer 3 in the first direction. The first edge E11 is an edge on one side of the first insulating layer 3 in the first direction. The first edge E11 extends in the second direction. In other words, the first edge E11 extends in the direction in which the multiple terminals 41A, 41B are arranged.

[0050] The second edge E12 is located on the opposite side to the first edge E11 in the first direction. The second edge E12 is located at the other end of the first insulating layer 3 in the first direction. The second edge E12 is the edge on the other side of the first insulating layer 3 in the first direction. The second edge E12 is located away from the first edge E11 in the first direction. The second edge E12 extends in the second direction.

[0051] The terminal 41A has a third edge E13 and a fourth edge E14.

[0052] The third edge E13 is located at one end of the terminal 41A in the first direction. The third edge E13 is an edge on one side of the terminal 41A in the first direction. The third edge E13 is located between the first edge E11 and the second edge E12 in the first direction. The third edge E13 is located between the first edge E11 and the fourth edge E14 in the first direction. The third edge E13 overlaps with the recess 20 in the thickness direction. In other words, the recess 20 overlaps with the third edge E13 in the thickness direction. The third edge E13 extends in the second direction. The third edge E13 is located away from the first edge E11 in the first direction.

[0053] The distance D1 between the first edge E11 and the third edge E13 is, for example, 200 μm or less, preferably 100 μm or less, more preferably 75 μm or less, and even more preferably 50 μm or less. The distance D1 between the first edge E11 and the third edge E13 may be 30 μm or less, or 15 μm or less. When the distance D1 between the first edge E11 and the third edge E13 is equal to or less than the above-mentioned upper limit, the first edge E11 of the first insulating layer 3 can be brought closer to the terminal 41A, thereby achieving miniaturization of the wired circuit board 1. The distance D1 between the first edge E11 and the third edge E13 may be shorter than the width W21 of each of the terminals 41A and 41B.

[0054] The distance D1 between the first edge E11 and the third edge E13 is, for example, 5 μm or more, or preferably 10 μm or more.

[0055] The fourth edge E14 is located at the other end of the terminal 41A in the first direction. The fourth edge E14 is the edge on the other side of the terminal 41A in the first direction. The fourth edge E14 is located away from the third edge E13 in the first direction. The fourth edge E14 is located between the third edge E13 and the second edge E12 in the first direction. The fourth edge E14 is located away from the second edge E12 in the first direction. The wirings 42A and 42B are located between the second edge E12 and the fourth edge E14 in the first direction. The wirings 42A and 42B extend in the second direction between the second edge E12 and the fourth edge E14. The fourth edge E14 extends in the second direction.

[0056] The distance D3 between the second edge E12 and the fourth edge E14 is, for example, 200 μm or less, preferably 150 μm or less. The distance D3 between the second edge E12 and the fourth edge E14 is, for example, 10 μm or more, preferably 25 μm or more. The distance D3 between the second edge E12 and the fourth edge E14 may be longer than the distance D1 between the first edge E11 and the third edge E13. The distance D3 between the second edge E12 and the fourth edge E14 may be shorter than the width W21 of each of the terminals 41A and 41B.

[0057] The metal support layer 2 has a fifth edge E15 and a sixth edge E16.

[0058] The fifth edge E15 is located at one end E1 of the metal support layer 2 in the first direction. In this embodiment, the fifth edge E15 is the bottom of the recess 20. In the portion where the recess 20 is formed, the fifth edge E15 is the edge on one side of the metal support layer 2 in the first direction. The fifth edge E15 overlaps the terminal 41A in the thickness direction. The fifth edge E15 is located between the first edge E11 and the second edge E12 in the first direction. The fifth edge E15 is located between the first edge E11 and the sixth edge E16 in the first direction. The fifth edge E15 is located between the third edge E13 and the sixth edge E16 in the first direction. The fifth edge E15 is located between the third edge E13 and the fourth edge E14 in the first direction. The fifth edge E15 extends in the second direction. The fifth edge E15 is disposed away from the first edge E11 in the first direction.

[0059] In this embodiment, the distance D2 between the first edge E11 and the fifth edge E15 is longer than the distance D1 between the first edge E11 and the third edge E13. The distance D2 between the first edge E11 and the fifth edge E15 is in the range of, for example, 10 μm to 300 μm, preferably 10 μm to 200 μm, or more preferably 20 μm to 100 μm.

[0060] The sum of the distance D1 between the first edge E11 and the third edge E13 and the distance D2 between the first edge E11 and the fifth edge E15 is 15 μm or more, preferably 30 μm or more. When the sum of the distances D1 and D2 is equal to or greater than the above-mentioned lower limit, the first edge E11 of the first insulating layer 3 can be brought closer to the terminal 41A while ensuring the distance from the terminal 41A to the metal support layer 2. Therefore, even if solder on the terminal 41A flows toward the first edge E11, it is possible to prevent the terminal 41A and the metal support layer 2 from short-circuiting due to the flowed solder.

[0061] The upper limit of the sum of the distances D1 and D2 is not limited as long as it does not excessively reduce the rigidity of the metal support layer 2. The sum of the distances D1 and D2 is, for example, 500 μm or less, preferably 300 μm or less, and more preferably 150 μm or less.

[0062] The sixth edge E16 is located at the other end of the metal support layer 2 in the first direction. The sixth edge E16 is the edge on the other side of the metal support layer 2 in the first direction. The sixth edge E16 is located on the opposite side of the first edge E11 with respect to the fifth edge E15 in the first direction. The sixth edge E16 is located away from the fifth edge E15 in the first direction. In this embodiment, the sixth edge E16 is located between the fifth edge E15 and the second edge E12 in the first direction. Note that the sixth edge E16 may be located on the other side of the second edge E12 in the first direction. In other words, the sixth edge E16 may be located on the opposite side of the fifth edge E15 with respect to the second edge E12 in the first direction. The sixth edge E16 extends in the second direction.

[0063] 2, a portion of the second insulating layer 5 is disposed between the first edge E11 and the third edge E13 in the first direction. This prevents the solder on the terminal 41A from flowing toward the first edge E11. In this embodiment, the second insulating layer 5 covers the third edge E13. This further prevents the solder on the terminal 41A from flowing toward the first edge E11.

[0064] 3. Effects (1) According to the wired circuit board 1, as shown in FIG. 1, the sum of the distance D1 between the first edge E11 and the third edge E13 and the distance D2 between the first edge E11 and the fifth edge E15 of the metal support layer 2 is 15 μm or more.

[0065] Therefore, even when the first end edge E11 of the first insulating layer 3 is disposed close to the terminal 41A, the distance from the terminal 41A to the metal support layer 2 can be ensured.

[0066] Therefore, even if the solder on the terminal 41A flows toward the first edge E11, it is possible to prevent the terminal 41A and the metal support layer 2 from being short-circuited by the flowing solder.

[0067] As a result, the wired circuit board 1 can be made smaller, and short circuits between the terminals 41A and the metal support layer 2 can be suppressed.

[0068] (2) According to the wired circuit board 1, the distance D1 (see FIG. 1) between the first edge E11 and the third edge E13 is 200 μm or less.

[0069] Therefore, the printed circuit board can be made smaller.

[0070] (3) According to the wired circuit board 1, as shown in FIG. 1, the distance D2 between the first edge E11 and the fifth edge E15 is longer than the distance D1 between the first edge E11 and the third edge E13.

[0071] Therefore, the first edge E11 of the first insulating layer 3 can be brought closer to the terminal 41A.

[0072] As a result, the wired circuit board 1 can be further reduced in size.

[0073] (4) According to the wired circuit board 1, as shown in FIG. 2, a portion of the second insulating layer 5 is disposed between the first edge E11 and the third edge E13 in the first direction.

[0074] Therefore, the second insulating layer 5 between the first edge E11 and the third edge E13 can prevent the solder on the terminal 41A from flowing toward the first edge E11.

[0075] (5) According to the wired circuit board 1, as shown in FIG. 2, the second insulating layer 5 covers the third edge E13.

[0076] Therefore, the second insulating layer 5 can further prevent the solder on the terminal 41A from flowing toward the first edge E11.

[0077] 4. Variations 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.

[0078] (1) As shown in Fig. 3, the wired circuit board 1 may include a ground terminal 100 that is not connected to a wire. The ground terminal 100 has a via 101 that penetrates the first insulating layer 3. The ground terminal 100 is electrically connected to the metal support layer 2 at the via 101.

[0079] (2) As shown in FIG. 4, the metal support layer 2 does not have to have the recess 20.

[0080] (3) As shown in Figures 5A and 5B, metal support layer 2 may have recess 20A overlapping terminal 41A and recess 20B overlapping terminal 41B. As shown in Figure 5A, the length of recess 20A in the second direction may be shorter than the length of terminal 41A. As shown in Figure 5B, the length of recess 20A in the second direction may be longer than the length of terminal 41A.

[0081] (4) As shown in Figures 6A and 6B, the distance D2 between the first edge E11 and the fifth edge E15 does not have to be longer than the distance D1 between the first edge E11 and the third edge E13. As shown in Figure 6A, the distance D2 may be shorter than the distance D1. As shown in Figure 6B, the distance D2 may be the same as the distance D1.

[0082] (5) As shown in FIGS. 7A and 7B, the second insulating layer 5 does not have to cover the periphery of the terminal 41A.

[0083] (6) As shown in Fig. 8, each of the wiring 42A and the wiring 42B may be a signal line for transmitting an electrical signal. The wiring 42A and the wiring 42B may form a differential pair. The wiring 42B extends parallel to the wiring 42A at a fixed interval from the wiring 42A. The length of the wiring 42B is preferably the same as the length of the wiring 42A.

[0084] (7) In the modified examples (1) to (6), the same effects as those of the above-described embodiment can be obtained. [Explanation of symbols]

[0085] 1 Wiring circuit board 2 Metal support layer 3 First insulating layer 41A terminal 42A wiring 5 Second insulating layer 20 recess E1 One end of the metal support layer E2 Other end of metal support layer E11 1st edge E12 Second edge E13 Third edge E14 Fourth edge E15 5th edge E16 6th edge D1 Distance D2 distance 20A recess 20B Recess

Claims

1. a metal support layer; a terminal disposed on one side of the metal support layer in a thickness direction of the metal support layer; a first insulating layer disposed between the metal support layer and the terminal in the thickness direction; Equipped with The first insulating layer extends in a first direction perpendicular to the thickness direction, and has a first edge and a second edge disposed on the opposite side of the first edge in the first direction. and the terminal has a third edge disposed between the first edge and the second edge in the first direction, and a fourth edge disposed between the third edge and the second edge in the first direction, the metal support layer has a fifth edge disposed between the first edge and the second edge in the first direction, and a sixth edge disposed on the opposite side of the first edge relative to the fifth edge in the first direction; A wired circuit board, wherein the sum of the distance between the first edge and the third edge and the distance between the first edge and the fifth edge is 15 μm or more.

2. The printed circuit board according to claim 1 , wherein the distance between the first edge and the third edge is 200 μm or less.

3. The printed circuit board according to claim 1 , wherein a distance between the first edge and the fifth edge is longer than a distance between the first edge and the third edge.

4. a second insulating layer disposed on one side of the first insulating layer in the thickness direction, The printed circuit board according to claim 1 , wherein a portion of the second insulating layer is disposed between the first edge and the third edge in the first direction.

5. The printed circuit board according to claim 4 , wherein the second insulating layer covers the third edge.

6. the metal support layer has one end and the other end in the first direction, and a recess recessed from the one end toward the other end in the first direction, the recess overlaps with the third edge in the thickness direction, The printed circuit board according to claim 1 , wherein the fifth edge is a bottom edge of the recess.

7. The printed circuit board according to claim 1 , further comprising a wiring disposed between the second edge and the fourth edge and connected to the terminal.

Images