JP2016012386A - Wiring circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiring circuit board capable of achieving a fine-pitched terminal as well as preventing short circuit of terminals adjacent to each other.SOLUTION: A suspension substrate 1 with a circuit includes a magnetic head connection terminal 16 having: a main body part 16A continuous to corresponding wiring 18, and a connection part 16B having a shorter dimension in width dimension than that of the main body part 16A and projecting from the main body part 16A. At least the connection part 16B of the magnetic head connection terminal 16 is configured to project from a base insulating layer 3.

Description

  The present invention relates to a printed circuit board.

  Conventionally, a printed circuit board including a base insulating layer and a conductor pattern formed on the base insulating layer is known.

  As such a wired circuit board, for example, a suspension board with circuit including a conductor pattern having a connection terminal portion connected to an external wiring circuit substrate and a magnetic head side terminal portion connected to a magnetic head is known.

  In the suspension board with circuit, the connection terminal portion is connected to the external wiring circuit board by solder (for example, see Patent Document 1).

JP 2007-250662 A

  In a printed circuit board such as the suspension board with circuit described in Patent Document 1, when the fine pitch of the terminal portions is studied, the interval between the adjacent terminal portions becomes narrow.

  Then, when connecting the suspension board with circuit to the external wiring circuit board, excess solder out of the melted solder may spread to adjacent terminal portions, and the adjacent terminal portions may be easily short-circuited. is there.

  An object of the present invention is to provide a printed circuit board capable of achieving a fine pitch between terminals and preventing a short circuit between adjacent terminals.

  The wired circuit board according to the present invention includes a base insulating layer and a conductor pattern provided on the base insulating layer, wherein the conductor pattern includes a plurality of terminals arranged in parallel at intervals, and the plurality of the plurality of terminals. A plurality of wirings continuous to each of the terminals, each of the plurality of terminals including a main body portion continuous to the corresponding wiring, and a connection portion protruding from the main body portion, and at least one of the terminals The connection portion protrudes from the base insulating layer, and the dimension of the connection portion in the parallel direction of each of the plurality of terminals is shorter than the dimension of the main body portion in the parallel direction.

  According to such a structure, the connection part protrudes from the base insulating layer.

  For this reason, when the solder is melted on the terminal, the excess solder flows so as to wrap around under the connection portion between the connection portions, and adheres to the side surface and the lower surface of the connection portion in the parallel direction.

  Thereby, it can suppress that the excess solder wets and spreads on the base insulating layer toward the adjacent terminal, and adheres to the adjacent terminal.

  And since the space | interval between connection parts is ensured wider than the space | interval between main-body parts, it can further suppress that excess solder adheres to the adjacent terminal.

  As a result, the interval between the main body portions can be narrowed to achieve a fine pitch, and a short circuit between adjacent terminals can be prevented at the connection portion.

  In the wired circuit board of the present invention, it is preferable that the main body portion is disposed on the insulating base layer, and the connecting portion protrudes from the insulating base layer.

  According to such a configuration, while the main body can be reliably supported by the base insulating layer, a short circuit between adjacent terminals can be prevented in the connection portion.

  In the wired circuit board according to the present invention, it is preferable that the connection portion is used for electrical connection with an external electronic element, and the main body portion is used when inspecting the continuity of the conductor pattern.

  According to such a configuration, when inspecting the continuity of the conductor pattern when manufacturing the printed circuit board, the probe can be brought into contact with the main body portion wider than the connection portion.

  Therefore, the probe can be reliably received in the main body portion wider than the connection portion.

  As a result, the conduction of the conductor pattern can be reliably inspected.

  According to the wired circuit board of the present invention, it is possible to reduce the pitch of terminals and prevent short-circuiting between adjacent terminals.

FIG. 1 is a plan view showing a suspension board with circuit as a first embodiment of a wired circuit board according to the present invention. 2A is an enlarged view of a main part of the suspension board with circuit shown in FIG. 1, and FIG. 2B is a cross-sectional view taken along line AA of the suspension board with circuit shown in FIG. FIG. 3 is a plan view showing a state in which the slider is mounted on the suspension board with circuit shown in FIG. 4A is an enlarged view of a main part of the suspension board with circuit shown in FIG. 3, and FIG. 4B is a cross-sectional view taken along line BB of the suspension board with circuit shown in FIG. FIG. 5A is a plan view showing a flexible printed circuit board as a second embodiment of the wired circuit board of the present invention. 5B is a CC cross-sectional view of the flexible printed circuit board shown in FIG. 5A. FIG. 6 is an explanatory view for explaining another modified example of the wired circuit board of the present invention.

  As shown in FIG. 1, the suspension board with circuit 1 is formed in a flat band shape extending in the vertical direction on the paper surface.

  In the following description, when referring to the direction of the suspension board with circuit 1, the vertical direction in FIG. 1 is the front-rear direction, and the horizontal direction in FIG. 1 is the width direction as an example of the parallel direction. The upper side of the drawing in FIG. 1 is the front side, and the lower side of the drawing in FIG. 1 is the rear side. Further, the vertical direction in FIG. 2 is defined as the vertical direction (thickness direction). The upper side in FIG. 2 is the upper side (one side in the thickness direction), and the lower side in FIG. 2 is the lower side (the other side in the thickness direction). In FIGS. 1 and 3, the insulating cover layer 5 is omitted in order to more clearly show the configuration of the conductor pattern 4.

  As shown in FIGS. 1 and 2B, the suspension board with circuit 1 includes a metal supporting board 2, a base insulating layer 3, a conductor pattern 4, and a cover insulating layer 5.

  The metal supporting board 2 is formed in a flat band shape extending in the front-rear direction so as to constitute the outer shape of the suspension board with circuit 1. The metal support board 2 is integrally provided with a support frame portion 6, a tongue portion 7, an opening 9, and a wiring support portion 8 as an example of a support portion.

  The support frame portion 6 is disposed at the distal end portion of the metal support substrate 2. The support frame part 6 is formed in a substantially rectangular frame shape in plan view. Specifically, the support frame portion 6 includes a plurality (two) of outrigger portions 6A and a bridging portion 6B.

  Each of the plurality (two) of outrigger portions 6 </ b> A is disposed at each of both end portions in the width direction of the support frame portion 6. Each of the plurality (two) of outrigger portions 6A is formed in a substantially flat plate shape extending in the front-rear direction. The rear end portions of the plurality (two) of outrigger portions 6 </ b> A are continuous with both end portions in the width direction of the front end portion of the wiring support portion 8.

  The bridging portion 6 </ b> B is disposed at the distal end portion of the support frame portion 6. The bridging portion 6B is formed in a substantially flat plate shape extending in the width direction. Each of both ends in the width direction of the bridging portion 6B is continuous with the respective leading end portions of a plurality (two) of outrigger portions 6A.

  The tongue part 7 is arranged inside the support frame part 6 so that the width direction both end edges and the rear end edge are spaced from the inner peripheral edge of the support frame part 6. The tongue portion 7 is formed in a flat plate shape having a substantially rectangular shape in plan view so as to continuously extend rearward from the rear end edge of the bridging portion 6B. Thereby, between the tongue part 7 and the support frame part 6, the penetration part 10 of the planar view substantially U shape open | released toward the front side is divided.

  The opening 9 is disposed at a boundary portion between the bridging portion 6 </ b> B and the tongue portion 7. The opening 9 has a substantially rectangular shape in plan view extending in the left-right direction. The opening 9 penetrates the metal support substrate 2 in the thickness direction. The front half of the opening 9 is disposed at the rear end of the bridging portion 6B. The rear half of the opening 9 is disposed at the tip of the tongue 7.

  The wiring support portion 8 is formed in a flat band shape that continuously extends rearward from the rear end portion of the support frame portion 6.

  The insulating base layer 3 is provided on the upper surface of the metal support substrate 2 so as to expose the tongue portion 7 and cover the support frame portion 6 and the wiring support portion 8.

  The conductor pattern 4 is formed on the upper surface of the base insulating layer 3. The conductor pattern 4 includes a magnetic head connection terminal 16 as an example of a plurality (eight) terminals, a plurality (eight) external connection terminals 17, and a plurality (eight) wirings 18.

  As shown in FIG. 2A, each of the plurality of magnetic head connection terminals 16 is arranged on the upper surface of the base insulating layer 3 so as to overlap the opening 9 in plan view. Each of the plurality of magnetic head connection terminals 16 is arranged in parallel at intervals in the width direction. Each of the plurality of magnetic head connection terminals 16 includes a main body portion 16A and a connection portion 16B.

  The main body portion 16 </ b> A is formed on the upper surface of the base insulating layer 3 overlapping the opening 9. The main body portion 16A is formed in a substantially rectangular shape in plan view extending in the front-rear direction.

  The connection portion 16 </ b> B is disposed at the rear end portion of the magnetic head connection terminal 16. The connection portion 16B continuously extends rearward from the center in the width direction of the rear end portion of the main body portion 16A. The connection portion 16B protrudes rearward from the rear edge of the base insulating layer 3 above the opening 9. The connecting portion 16B is formed in a substantially rectangular shape in plan view. As a result, the body portion 16 </ b> A is covered with the base insulating layer 3 while the connection portion 16 </ b> B is exposed from the base insulating layer 3 in the bottom view.

  As shown in FIG. 1, each of the plurality of external connection terminals 17 is connected to an external control board (not shown) or the like, and has a shape depending on the configuration of the external control board (not shown). The arrangement and joining method can be arbitrarily selected. Specifically, in this embodiment, each of the plurality of external connection terminals 17 is disposed at the rear end portion of the wiring support portion 8. The plurality of external connection terminals 17 are formed in a substantially rectangular shape in plan view. The plurality of external connection terminals 17 are arranged in parallel at intervals in the width direction.

  Each of the plurality of wirings 18 is formed at a distance from each other so as to continue from the front end portion of the corresponding magnetic head connection terminal 16 over the support frame portion 6 and the wiring support portion 8 to the external connection terminal 17. Has been.

  As shown in FIGS. 1 and 2B, the insulating cover layer 5 is formed on the upper surface of the insulating base layer 3 so as to expose the magnetic head connecting terminals 16 and the external connecting terminals 17 and cover the wirings 18.

  In order to manufacture the suspension board with circuit 1, first, the metal support board 2 is prepared.

  Examples of the material for forming the metal supporting substrate 2 include metal materials such as stainless steel, 42 alloy, aluminum, copper-beryllium, and phosphor bronze, and preferably stainless steel.

  The thickness of the metal supporting substrate 2 is, for example, 15 μm or more, for example, 50 μm or less, preferably 30 μm or less.

  Next, a varnish of a photosensitive insulating material is applied to the upper surface of the metal support substrate 2 and dried, then exposed and developed, and then heat-cured to form the base insulating layer 3 in the above-described pattern.

  Examples of the insulating material forming the base insulating layer 3 include synthesis of polyimide resin, polyamideimide resin, acrylic resin, polyether nitrile resin, polyether sulfone resin, polyethylene terephthalate resin, polyethylene naphthalate resin, polyvinyl chloride resin, and the like. An insulating material such as a resin can be used. Preferably, a polyimide resin is used.

  The insulating base layer 3 has a thickness of, for example, 1 μm or more, preferably 3 μm or more, for example, 35 μm or less, preferably 15 μm or less.

  Next, the conductor pattern 4 is formed on the upper surface of the insulating base layer 3 by an additive method or a subtractive method.

  Examples of the material for forming the conductor pattern 4 include conductor materials such as copper, nickel, gold, solder, or alloys thereof, and preferably copper.

  The thickness of the conductor pattern 4 is, for example, 3 μm or more, preferably 5 μm or more, for example, 50 μm or less, preferably 20 μm or less.

  The width of the wiring 18 is, for example, 5 μm or more, preferably 8 μm or more, for example, 200 μm or less, preferably 100 μm or less.

  Moreover, the width direction space | interval between the wiring 18 is 5 micrometers or more, for example, Preferably, it is 8 micrometers or more, for example, 1000 micrometers or less, Preferably, it is 100 micrometers or less. Moreover, the width direction space | interval between the wiring 18 is 5 micrometers or more, for example, Preferably, it is 8 micrometers or more, for example, 1000 micrometers or less, Preferably, it is 100 micrometers or less.

  Further, the width of the main body portion 16A of the magnetic head connection terminal 16 is, for example, 15 μm or more, preferably 20 μm or more, for example, 1000 μm or less, preferably 800 μm or less.

  The interval between the main body portions 16A of the magnetic head connection terminals 16 is, for example, 15 μm or more, preferably 20 μm or more, for example, 1000 μm or less, preferably 800 μm or less.

  Further, the width of the connection portion 16B of the magnetic head connection terminal 16 is shorter than the width of the main body portion 16A, and is, for example, 7 μm or more, preferably 10 μm or more, for example, 500 μm or less, preferably 400 μm or less. The width of the connection portion 16B of the magnetic head connection terminal 16 is, for example, 95% or less, preferably 90% or less, for example, 20% or more when the width of the main body portion 16A is 100%.

  Further, the interval between the connection portions 16B of the magnetic head connection terminal 16 is wider than the interval between the main body portions 16A, and is, for example, 20 μm or more, preferably 30 μm or more, for example, 1200 μm or less, preferably 1000 μm or less. The interval between the connection portions 16B of the magnetic head connection terminal 16 is, for example, greater than 100%, preferably 105% or more, for example, 200% or less, when the interval between the main body portions 16A is 100%. is there.

  Also, the width of the external connection terminal 17 is, for example, 15 μm or more, preferably 20 μm or more, for example, 1000 μm or less, preferably 800 μm or less.

  The interval between the external connection terminals 17 is, for example, 15 μm or more, preferably 20 μm or more, for example, 1000 μm or less, preferably 800 μm or less.

  Next, a varnish of a photosensitive insulating material is applied to the upper surface of the insulating base layer 3 so as to cover the conductor pattern 4 and dried, then exposed and developed, and then heat-cured to cover the insulating cover layer 5. Are formed in the pattern described above.

  As a material for forming the insulating cover layer 5, an insulating material similar to the insulating material of the base insulating layer 3 described above can be used. The insulating cover layer 5 has a thickness of, for example, 1 μm or more, for example, 40 μm or less, preferably 10 μm or less.

  Next, the metal supporting board 2 is processed into the above-described outer shape. At this time, the opening 9 and the through portion 10 are formed.

  In order to process the metal support substrate 2, for example, an etching method such as dry etching (for example, plasma etching) or wet etching (for example, chemical etching), for example, a drilling method, for example, a laser processing or the like is used. Preferably, processing is performed by an etching method.

  Thereby, the suspension board with circuit 1 is completed.

  Next, the mounting of the slider 32 on the suspension board with circuit 1 will be described with reference to FIGS.

  The slider 32 has a substantially rectangular shape in plan view, and has a magnetic head 30 as an example of an electronic component at the tip.

  In order to mount the slider 32, first, the solder ball 31 is formed on the rear end portion of the magnetic head connection terminal 16, that is, on the upper surface of the connection portion 16B.

  Next, the slider 32 is affixed to the tongue portion 7 with an adhesive so that the terminals 30 </ b> A of the magnetic head 30 are in contact with the solder balls 31. At this time, the slider 32 is disposed so as to expose the tip of the magnetic head connection terminal 16 in plan view.

  Next, the solder ball 31 is melted.

  Then, the melted solder is crushed between the terminal 30A of the magnetic head 30 and the connection part 16B, and spreads over the upper surface of the connection part 16B.

  At this time, if the solder ball 31 is excessively large, excess solder may flow outward in the width direction from the upper surface of the connection portion 16B.

  Then, the surplus solder flows so as to wrap around the lower side of the connection portion 16B through between the connection portions 16B, and adheres to the outer surface in the width direction of each connection portion 16B and the lower surface of each connection portion 16B.

  Thereafter, the molten solder is cooled and solidified, whereby the terminal 30A of the magnetic head 30 and the magnetic head connection terminal 16 are joined via the solder.

  According to the suspension board with circuit 1, as shown in FIG. 2A, the connection portion 16 </ b> B of the magnetic head connection terminal 16 protrudes rearward from the edge of the base insulating layer 3 inside the opening 9.

  Therefore, as described above, when the solder is melted on the magnetic head connection terminal 16, the excess solder flows so as to wrap around under the connection portion 16B via the connection portion 16B. It adheres to the width direction side surface and the lower surface of 16B.

  Thereby, it is possible to suppress surplus solder from spreading on the base insulating layer 3 toward the adjacent magnetic head connection terminal 16 and adhering to the adjacent magnetic head connection terminal 16.

  In addition, since the interval between the connection portions 16B is secured wider than the interval between the main body portions 16A, it is possible to further suppress the excess solder from adhering to the adjacent magnetic head connection terminals 16.

  As a result, the interval between the main body portions 16A can be narrowed to achieve a fine pitch, and short-circuiting between adjacent terminals can be prevented in the connection portion 16B.

  In the suspension board with circuit 1, as shown in FIG. 2A, the main body portion 16 </ b> A is disposed on the upper surface of the base insulating layer 3, and the connection portion 16 </ b> B protrudes rearward from the base insulating layer 3.

  Therefore, while the main body portion 16A can be reliably supported by the base insulating layer 3, it is possible to prevent a short circuit between the magnetic head connection terminals 16 adjacent to each other in the connection portion 16B.

  Further, in the suspension board with circuit 1, when the conduction of the conductor pattern 4 is inspected when the suspension board with circuit 1 is manufactured, the probe can be brought into contact with the main body portion 16A wider than the connection portion 16B.

  Therefore, the probe can be reliably received in the main body portion 16A which is wider than the connection portion 16B.

As a result, the conduction of the conductor pattern 4 can be reliably inspected.
(Second Embodiment)
In the first embodiment described above, the suspension board with circuit 1 is cited as the wired circuit board. However, as the wired circuit board, as shown in FIGS. 5A and 5B, a flexible wired circuit board 40 can also be cited.

  The flexible printed circuit board 40 has a substantially flat strip shape extending in the front-rear direction. The flexible printed circuit board 40 includes a base insulating layer 41, a conductor pattern 42, and a cover insulating layer 43.

  The base insulating layer 41 is formed in a flat strip shape extending in the front-rear direction so as to constitute the outer shape of the flexible printed circuit board 40.

  The conductor pattern 42 is formed on the base insulating layer 41. The conductor pattern 42 includes a plurality (eight) terminals 44 and a plurality (eight) wirings 45. Although not shown, the conductor pattern 42 also includes a terminal at the end opposite to the end where the plurality of terminals 44 are provided.

  Each of the plurality of terminals 44 is disposed on the top surface of the distal end portion of the base insulating layer 41. Each of the plurality of terminals 44 is arranged in parallel at intervals in the width direction. Each of the plurality of terminals 44 includes a main body portion 44A and a connection portion 44B.

  The main body 44 </ b> A is formed on the upper surface of the base insulating layer 41. The main body 44A is formed in a substantially rectangular shape in plan view extending in the front-rear direction.

  The connecting portion 44 </ b> B is disposed at the distal end portion of the terminal 44. The connecting portion 44B continuously extends toward the front side from the center in the width direction of the distal end portion of the main body portion 44A. The connecting portion 44 </ b> B protrudes further forward than the front end edge of the base insulating layer 41. The connecting portion 44B is formed in a substantially rectangular shape in plan view. Thus, the main body 44 </ b> A is covered with the base insulating layer 3 while the connection portion 44 </ b> B is exposed from the base insulating layer 3 in the bottom view.

  Each of the plurality of wirings 45 extends rearward from the rear end portion of the corresponding terminal 44 and is spaced from each other so as to be continuous with a terminal (not shown) provided at an end portion opposite to the end portion where the plurality of terminals 44 are provided. Are formed with a gap.

  The insulating cover layer 43 is formed on the upper surface of the insulating base layer 3 so as to expose the terminals 44 and cover the wiring 45.

  Such a flexible printed circuit board 40 is used, for example, when relaying other rigid boards (not shown) as an example of electronic components.

Also in the second embodiment, the same operational effects as those of the first embodiment described above can be obtained.
(Other variations)
In the first embodiment described above, the main body portion 16A is disposed on the upper surface of the base insulating layer 3. However, if at least the connection portion 16B protrudes from the base insulating layer 3, the above-described effects can be obtained. .

  For example, as shown in FIG. 6, the rear end portion of the main body portion 16 </ b> A can be projected from the base insulating layer 3.

DESCRIPTION OF SYMBOLS 1 Suspension board with a circuit 3 Base insulating layer 4 Conductor pattern 16 Magnetic head connection terminal 16A Main body part 16B Connection part 18 Wiring 30 Magnetic head 40 Flexible wiring circuit board 41 Base insulating layer 42 Conductive pattern 44 Terminal 44A Main body part 44B Connection part 45 Wiring

Claims (3)

A base insulating layer, and a conductor pattern provided on the base insulating layer,
The conductor pattern is
A plurality of terminals arranged in parallel and spaced apart from each other;
A plurality of wirings continuous to each of the plurality of terminals,
Each of the plurality of terminals is
A main body continuous to the corresponding wiring;
A connecting portion protruding from the main body,
At least the connection portion of the terminals protrudes from the base insulating layer,
The printed circuit board according to claim 1, wherein a dimension of the connection portion in the parallel direction of each of the plurality of terminals is shorter than a dimension of the main body portion in the parallel direction. The main body is disposed on the base insulating layer,
The wired circuit board according to claim 1, wherein the connection portion protrudes from the base insulating layer. The connecting portion is used for electrical connection with an external electronic component,
The printed circuit board according to claim 1, wherein the main body is used when inspecting conduction of the conductor pattern.

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