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Flex-rigid wiring board and manufacturing method thereof

A technology of flexible circuit boards and flexible substrates, applied in printed circuit manufacturing, multilayer circuit manufacturing, circuit substrate materials, etc., can solve problems such as constant curvature of unbendable parts, inability to ensure strength, deformation of flexible substrates, etc.

Inactive Publication Date: 2007-07-18
IBIDEN CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] However, the polyimide film used as an insulating base material for flexible substrates has strong water absorption and large dimensional changes, so it is necessary to form a large diameter of the pad in advance, which is subject to design constraints. , in order to improve the alignment accuracy, the workpiece size needs to be made smaller
Therefore, there is a problem that excellent connection reliability cannot be obtained, and the same problem also exists in reliability tests such as thermal cycles.
[0010] In addition, since the resin film such as polyimide used as the insulating base material of the flexible substrate is formed by a single film, it is not formed by impregnating the resin on the core material, so there are: (1) It is not possible to ensure sufficient (2) The curvature of the bent portion cannot be kept constant, (3) Due to the above (1) and (2), there is deformation of the flexible base material near the bent portion, or disconnection of the conductor circuit. The problem
In particular, when flexible substrates are repeatedly bent or conductor circuits are formed from fine wiring patterns, these problems are significant.
[0011] In addition, undulations (waves) may be formed near the bending portion of the flexible substrate or the region where the rigid portion is formed. When the undulations are formed, cracks may occur in the undulation-formed portion of the base material, or the conductor circuit may be disconnected. damage
[0012] Moreover, in the case where the cover layer for protecting the conductor circuit provided on the flexible substrate is formed by a polyimide film with an adhesive, since the connection reliability and insulation reliability of the through hole may be reduced, Therefore, there is also a problem that special control of opening, desmear, plating conditions, etc. is required, and it is restricted in forming a combined structure with other materials.

Method used

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  • Flex-rigid wiring board and manufacturing method thereof
  • Flex-rigid wiring board and manufacturing method thereof
  • Flex-rigid wiring board and manufacturing method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0239] (A) Manufacturing process of flexible substrate

[0240] (1) When manufacturing the flex-rigid circuit board of the present invention, a double-sided copper-clad laminate (Hitachi Chemical: product name "E-67") having a thickness of 50 μm is used as a starting material for manufacturing the flexible substrate 100A constituting it. (Figure 11(a)), the double-sided copper-clad laminate is impregnated with epoxy resin in a glass fiber cloth with a thickness of 20 μm (glass fiber cloth with a thickness of 30 μm or less can be used) (the average diameter of the glass fiber Copper foil 12 having a thickness of 18 μm was laminated on both surfaces of an insulating base material 11 obtained by drying the insulating base material 11 in the thickness of 4.0 μm.

[0241] (2) The copper foil 12 laminated on both sides of the above-mentioned insulating base material 11 is etched using an aqueous copper chloride solution to form a conductor circuit pattern 13 with a line width of 300...

Embodiment 2

[0268] Formed on the periphery of the bending part of the flexible substrate with each opening area of ​​40000μm 2 The grid-shaped dummy pattern 18 with rectangular openings such that the sum of the opening areas: the area of ​​the remainder of the pattern = 9:10 was made in the same manner as in Example 1 to manufacture the flex-rigid wiring board 300A.

Embodiment 3

[0270] Formed on the periphery of the bending part of the flexible substrate with each opening area of ​​90000μm 2 The grid-shaped dummy pattern 18 with rectangular openings such that the sum of the opening areas: pattern remaining area = 11:10 was the same as in Example 1 to manufacture the flex-rigid wiring board 300A.

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Abstract

A flex-rigid wiring board having excellent connection reliability and a manufacturing method thereof are provided. A flex-rigid wiring board is provided by connecting a hard rigid board wherein a conductor circuit is provided on an insulating board, and a bendable flexible board wherein a conductor circuit is provided on an insulating board and a coverlay is provided to cover the conductor circuit. As an insulating base material of the flexible board, a bendable base material provided by impregnating a glass cloth with a resin and drying it is employed. On one surface of the flexible board, the conductor circuit is formed, and on the other surface, a dummy pattern is formed close to a bending part. Thus, base material deformation easily generated close to the bending part, conductor circuit disconnection, wave formation and the like can be prevented. The equivalent effects can be obtained by increasing the width of a wiring pattern of the conductor circuit or by curving the wiring pattern in the width direction, at the bending part on the flexible board.

Description

technical field [0001] The present invention relates to a rigid-flex circuit board composed of a flexible flexible part that can be bent and a rigid part formed of a hard material and a manufacturing method thereof. Background technique [0002] In recent years, rigid-flex multilayer circuit boards have been used in portable electronic devices such as foldable mobile phones. Such a circuit board is generally shown in FIG. 22 , and the rigid parts 500 and 520 without flexibility and the flexible part 510 with flexibility are connected through a flexible substrate 544, and the conductor layer of the plated through hole 502 is used to conduct electricity in the rigid part 500. The laminated flexible substrate 544 is connected to the pattern layers 504 and 506 on the surfaces of the rigid substrates 500 and 520 (for example, refer to Japanese Patent Application Laid-Open No. 5-90756). [0003] The rigid-flexible multilayer circuit board of the above-mentioned prior art is forme...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H05K1/02H05K3/46H05K1/00H05K1/03H05K3/00
CPCH05K1/0366H05K2201/2009H05K2201/09681Y10T428/31663H05K3/4614H05K2201/09263H05K2201/09727H05K3/4691Y10T29/49165H05K2201/09781H05K1/0281Y10T29/49124H05K3/462H05K1/02H05K1/11
Inventor 三门幸信匂坂克巳川口克雄村木哲也
Owner IBIDEN CO LTD
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