JP2010276676A - Compound wiring member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compound wiring member, preventing connection failure of an element. <P>SOLUTION: The compound wiring member includes: a copper layer 3 for mounting the element, which is formed on one side surface of a flexible base plate 2; a resin layer 4 formed on the other side surface of the flexible base plate 2; and an elongation preventive layer 5, stuck to the resin layer 4, for preventing elongation of the resin layer 4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a composite wiring member in which a flexible resin layer is combined with a flexible substrate, and relates to a composite wiring member that prevents connection failure of elements.

  The flexible substrate is a flexible substrate made of a polymer sheet or the like. On one side of the flexible substrate, a copper layer for transmitting an electric signal and a copper layer for mounting an element such as an electric element or an electro-optical element are formed. The flexible substrate is laid in a narrow space or a bent space, taking advantage of its flexibility (ease of bending), or provided as a transmission line that connects a movable part to a machine or information device.

  As an optoelectric wiring member in which an optical wiring member is combined with a flexible substrate, Patent Document 1 discloses an optoelectric device in which an optical element or an electronic component is mounted on one surface of a flexible substrate and an optical wiring member is formed on the other surface. In the wiring member, by providing a metal plate from one end of the optical wiring member to a portion located below the optical element or electronic component on the lower surface side of the optical wiring member, heat generated from the optical element or electronic component is efficiently radiated. An optoelectric wiring member that can be described is described.

JP 2008-151993 A

  When a resin layer is combined with a flexible substrate, the resin layer also needs to have flexibility so that flexibility, which is an advantage of the flexible substrate, is not lost.

  However, a flexible resin layer (specifically, a Young's modulus of 1 GPa or less in a range from room temperature to 150 ° C.) has a property of being easily stretched. This is because bending and elongation are essentially the same phenomenon.

  When a flexible resin layer is formed on the opposite side of the copper layer of the flexible substrate, pressure was applied to the element placed on the copper layer in order to mount an element such as an electric element or an electro-optical element on the copper layer. When the pressure is applied to the resin layer, the resin layer extends sideways, or the flexible substrate and the resin layer warp. In this way, since the pressure applied to mount the element is absorbed by the resin layer, the pressure with which the element is pressed against the copper layer is insufficient, and the element escapes, resulting in poor connection.

  Therefore, an object of the present invention is to provide a composite wiring member that solves the above-described problems and prevents poor connection of elements.

  To achieve the above object, the present invention provides an element mounting copper layer formed on one side of a flexible substrate, a resin layer formed on the opposite side of the flexible substrate, and the resin layer bonded to the resin layer. And an elongation preventing layer for preventing the layer from stretching.

  The copper layer may be a copper layer for mounting a flip chip.

  The resin layer may be a layer that forms an optical transmission line.

  The elongation preventing layer may be provided only within a predetermined range including an element mounting portion of the copper layer.

  The resin layer may have a Young's modulus of 1 GPa or less.

  The elongation preventing layer may have a Young's modulus of 10 GPa or more.

  According to the present invention, it is possible to prevent poor connection of elements.

It is sectional drawing of the composite wiring member which shows one Embodiment of this invention. It is sectional drawing of the composite wiring member which shows other embodiment of this invention. It is a top view of the composite wiring member which shows other embodiment of this invention. It is a bottom view of the resin layer used for other embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, a composite wiring member 1 according to the present invention is formed on a copper layer (copper wiring layer) 3 for element mounting formed on one side surface of a flexible substrate 2 and on the opposite side surface of the flexible substrate 2. The resin layer 4 is provided, and an elongation preventing layer 5 which is bonded to the resin layer 4 so as to face the element mounting copper layer 3 and prevents the resin layer 4 from stretching.

  For example, a light emitting element (VCSEL) 6 and a driver IC 7 that drives the light emitting element 6 are mounted on the copper layer 3. For the light emitting element 6 and the driver IC 7, for example, a flip chip mounting type element is preferably used. When the light emitting element 6 and the driver IC 7 are flip chip mounting type elements, a copper layer 3 for mounting a flip chip is used as the copper layer 3.

  The resin layer 4 is a flexible layer having flexibility to the extent that the flexibility of the flexible substrate 2 is not lost when combined with the flexible substrate 2. Specifically, the Young's modulus is preferably 1 GPa or less in the range from room temperature to 150 ° C.

  The elongation preventing layer 5 reinforces the mechanical strength of the resin layer 4 to prevent the resin layer 4 from stretching. The rate is preferably 10 GPa or more. Specific materials for the elongation preventing layer 5 include metals such as copper, nickel, and stainless steel, glass, hard resin, and the like.

  The elongation preventing layer 5 is integrally bonded to the resin layer 4 by adhesion or the like. This is to prevent the resin layer 4 from stretching when pressure is applied to the resin layer 4.

  In the embodiment of FIG. 1, the stretch preventing layer 5 is provided from the left end of the composite wiring member 1 to a position past the right end of the light emitting element 6.

  Next, the effect of the composite wiring member 1 will be described.

  In the composite wiring member 1 according to the present invention, since the flexible resin layer 4 is combined with the flexible substrate 2, the flexibility of the flexible substrate 2 is not lost, and a narrow space or It is installed in a bent space or as a transmission line that connects a movable part to a machine or information device.

  The composite wiring member 1 according to the present invention is in a state in which the copper layer 3, the flexible substrate 2, the resin layer 4, and the elongation preventing layer 5 are sequentially laminated, that is, the elongation preventing layer 5 that prevents the resin layer 4 from stretching. Is bonded to the resin layer 4, so that when the pressure is applied to the light emitting element 6 and the driver IC 7 mounted on the copper layer 3, the resin layer 4 is prevented from extending or warping sideways due to the pressure. Is done. The pressure that presses the element against the copper layer 3 is not absorbed by the resin layer 4, thereby preventing connection failure of the element.

  Next, another embodiment of the present invention will be described.

  The composite wiring member 21 of FIG. 2 is bonded to the resin layer 4 and the resin layer 4 formed on one side of the flexible substrate 2, the resin layer 4 formed on the opposite side of the flexible substrate 2, and the resin layer 4. An elongation preventing layer 5 for preventing the layer 4 from stretching.

  The flexible substrate 2 is made of a polymer sheet 22. The resin layer 4 is a polymer optical waveguide layer 23 that forms an optical transmission line with a clad and a core, and epoxy, acrylic, silicone, polyimide, or the like is used as a material. The resin layer 4 is formed with a mirror 24 for reflecting the light emitted from the light emitting element 6 and transmitted through the flexible substrate 2 in the transmission direction.

  The composite wiring member 31 of FIG. 3 is bonded to the resin layer 4 and the resin layer 4 formed on the opposite side of the flexible substrate 2, the copper layer 3 for element mounting formed on one side of the flexible substrate 2. An elongation preventing layer 5 for preventing the layer 4 from stretching.

  In this embodiment, the elongation preventing layer 5 is provided only within a predetermined range including the element mounting portion of the copper layer 3.

  The composite wiring member 31 is provided with a flexible resin layer 4 so as not to lose the flexibility of the flexible substrate 2. However, since the elongation preventing layer 5 is hard, the elongation preventing layer 5 is disposed on the entire surface of the resin layer 4. If it is expanded and provided, the flexibility of the entire composite wiring member 31 is lost. Therefore, the elongation preventing layer 5 is not spread over the entire surface of the resin layer 4 and is provided only around the element mounting portion.

  In the illustrated example, the light emitting element 6 and the driver IC 7 are mounted on the copper layer 3, and the stretch preventing layer 5 is located on the back side of the copper layer 3 and is formed in a rectangular shape including the light emitting element 6 and the driver IC 7. The elongation preventing layer 5 is preferably shaped and sized so that the resin layer 4 does not stretch when an element is mounted on the copper layer 3. As a result, the composite wiring member 31 is easy to bend because the resin layer 4 is prevented from stretching around the element mounting location, and the stretch prevention layer 5 is not provided at a location appropriately separated from the element mounting location.

  The width W of the flexible substrate 2 is 5 mm. The width a of the elongation preventing layer 5 is 3 to 4 mm, and the length b is 3 to 5 mm. The length direction dimension d1 of the light emitting element 6 is 0.5 mm, and the length direction dimension d2 of the driver IC 7 is 1 mm. These numerical values are merely examples, and the present invention is not limited thereto.

  The resin layer 41 in FIG. 4 includes an optical fiber 42 and a flexible layer 43 that fills both sides of the optical fiber 42 to the same thickness as the diameter of the optical fiber 42 in order to protect the optical fiber 42. In the embodiment of FIG. 2, the resin layer 4 is a polymer optical waveguide layer 23 that forms an optical transmission line with a clad and a core, but the optical transmission line may be an optical fiber 42 as in the embodiment of FIG. 4. .

DESCRIPTION OF SYMBOLS 1 Composite wiring member 2 Flexible board 3 Copper layer 4 Resin layer 5 Stretch prevention layer 6 Light emitting element 7 Driver IC

Claims (6)

  A copper layer for element mounting formed on one side of the flexible substrate, a resin layer formed on the opposite side of the flexible substrate, and an elongation preventing layer bonded to the resin layer to prevent the resin layer from stretching. A composite wiring member comprising:   2. The composite wiring member according to claim 1, wherein the copper layer is a copper layer for mounting a flip chip.   The composite wiring member according to claim 1, wherein the resin layer is a layer that forms an optical transmission line.   4. The composite wiring member according to claim 1, wherein the elongation preventing layer is provided only within a predetermined range including an element mounting portion of the copper layer.   The composite wiring member according to claim 1, wherein the resin layer has a Young's modulus of 1 GPa or less.   The composite wiring member according to claim 1, wherein the elongation preventing layer has a Young's modulus of 10 GPa or more.

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