JP4779826B2 - Flexible printed circuit board - Google Patents

Description

  The present invention relates to a flexible printed circuit board and an electronic device including the same.

  In recent years, with the downsizing and weight reduction of electronic devices, the circuit configuration mounted inside the electronic devices has also been increased in the degree of integration of semiconductor chips and downsized on circuit boards. Along with this miniaturization, a flexible printed board is used to connect circuit boards by taking advantage of advantages such as flexibility and bendability.

  However, the flexible printed circuit board has the advantage of bendability, but when stress such as bending is applied in the area of electronic components mounted on the flexible printed circuit board, the solder that connects the electronic components mounted on the flexible printed circuit board Stress may be generated on the soldered parts and the legs of highly integrated semiconductor chips, causing breaks in the soldered connection parts and bending of the electronic parts, and the electronic parts themselves may be broken internally. .

  Therefore, in order to improve the disconnection of the connection portion and the deterioration of the components, there has been a configuration in which a through hole is provided in the flexible printed board to absorb the bending stress and to eliminate the disconnection of the connection portion and the deterioration of the electronic components. For example (Patent Document 1).

  FIG. 10 is a cross-sectional view of a conventional flexible printed circuit board.

  In FIG. 10, 801 is a flexible printed circuit board, 802 is a film base, 803 is a wiring pattern, 804 is a relaxation hole, 805 is a semiconductor chip, and 806 is a soldering portion.

An electronic component including a semiconductor chip 805 is mounted on the flexible printed circuit board 801, and a plurality of relaxation holes 804 are disposed through the base film 802 around the electronic component. The relaxation holes 804 are arranged avoiding the circuit pattern.
JP 2000-82868 A

  However, in the conventional configuration, a plurality of relaxation holes provided in the flexible printed circuit board are provided so as to avoid a circuit pattern and each side of the four circumferences of the electronic component, and it is necessary to avoid the wiring pattern around the electronic component. There is a problem that cannot be applied to an electronic component having a short foot pitch such as an IC (integrated circuit).

  In addition, in the configuration of (Patent Document 1), a plurality of through holes are provided on each side of the four circumferences of the semiconductor chip. However, in the case of a rectangular semiconductor chip having a high degree of integration, a pitch is formed around the four circumferences of the semiconductor chip. A plurality of narrow connection legs are provided, and stress is distributed to the plurality of semiconductor legs with respect to bending perpendicular to the legs on each side, so that disconnection of the connection portion and deterioration of the parts do not occur. On the other hand, in the diagonal direction of the rectangular semiconductor chip, there is a problem that stress is not dispersed and disconnection of the connection portion or deterioration of the components occurs.

Therefore, an object of the present invention is to provide a flexible printed circuit board that can reduce the shape of the flexible printed circuit board, and that does not cause disconnection of connection parts of electronic components such as semiconductors or deterioration of the components.

To solve such a problem, a flexible printed circuit board of the present invention is formed with the wiring pattern so as to hold in the first off i Rumubesu and second off Lee Rumubesu, polygonal first off the semiconductor chip shape Lee Rumubesu a base substrate to be mounted on the side, said the wiring pattern of the second off Lee Rumubesu anda reinforcing plate provided on the opposite side, the reinforcing plate, the outer region of at least one of the vertices of the semiconductor chip A long hole-shaped hole portion is provided at a predetermined distance from each other, the long side of the long hole-shaped hole portion is disposed to face the apex, and the wiring pattern side region of the long hole-shaped hole portion is characterized in that it faces the second full b Rumubesu.

According to the present invention, when the flexible printed circuit board is attached to other components, the bending of the flexible printed circuit board is affected by the bending of the flexible printed circuit board even if the flexible printed circuit board is bent. In addition, it is possible to prevent contact failure caused by connection portion cracks between the semiconductor chip and the base substrate and disconnection of the internal wiring portions of the components, which are generated when mounting to other components.

  In particular, the mounting of the semiconductor chip on the base substrate is weaker to the influence from the oblique side on the apex side of the semiconductor chip than the influence from the side where the pins of the semiconductor chip are arranged. In this respect, by arranging the long side of the long hole shape facing the apex of the semiconductor chip, the long hole shape bends even if the flexible printed circuit board is bent from the apex direction of the semiconductor chip. The influence of the bending of the flexible printed circuit board does not reach the semiconductor chip, and the contact failure caused by the crack of the connection between the semiconductor chip and the base substrate or the disconnection of the internal wiring part of the component that occurs during mounting Can be prevented.

The invention of claim 1, wherein is formed a wiring pattern so as to hold in the first off i Rumubesu and second off Lee Rumubesu, a base substrate for mounting a semiconductor chip of polygonal shape in the first off i Rumubesu side, the wiring pattern of the second off Lee Rumubesu anda reinforcing plate provided on the opposite side, the reinforcing plate is a predetermined distance apart from the long hole shape from at least one apex to the outer region of the semiconductor chip hole is provided, a long side of the hole portion of the long hole shape is disposed opposite to the vertex, wiring pattern side region of the hole portion of the long hole shape is characterized by facing the second off Lee Rumubesu It is a flexible printed circuit board.

Thereby, when the flexible printed circuit board is attached to other components, even if the flexible printed circuit board is bent, the bending of the flexible printed circuit board does not affect the semiconductor chip because the bent hole is bent as a valley. It is possible to prevent contact failure caused by connection portion cracks between the semiconductor chip and the base substrate and disconnection of the internal wiring portions of the components, which are generated during attachment to other components.

  In particular, the mounting of the semiconductor chip on the base substrate is weaker to the influence from the oblique side on the apex side of the semiconductor chip than the influence from the side where the pins of the semiconductor chip are arranged. In this respect, by arranging the long side of the long hole shape facing the apex of the semiconductor chip, the long hole shape bends even if the flexible printed circuit board is bent from the apex direction of the semiconductor chip. The influence of the bending of the flexible printed circuit board does not reach the semiconductor chip, and the contact failure caused by the crack of the connection between the semiconductor chip and the base substrate or the disconnection of the internal wiring part of the component that occurs during mounting Can be prevented.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(Embodiment)
In the present invention, a flexible printed circuit board (hereinafter also referred to as FPC) and an electronic apparatus including the flexible printed circuit board will be described based on an optical disk device.

  FIG. 1 is a schematic diagram of an optical disc apparatus according to an embodiment of the present invention.

  In FIG. 1, reference numeral 2 denotes a housing, and the housing 2 is configured by combining an upper housing portion 2a and a lower housing portion 2b. The upper casing 2a and the lower casing 2b are fixed to each other using a spiral or the like. As the constituent material of the housing 2, a conductive material such as a metal material such as iron, iron alloy, aluminum, aluminum alloy, and magnesium alloy is preferably used. In addition, a structure in which each casing is made of a resin material and a highly conductive metal film is formed thereon using a technique such as electrodeposition may be used. Furthermore, each of the upper housing portion 2a and the lower housing portion 2b may be made of the same material or different materials. Moreover, the average thickness of the main plane part of each of the upper casing part 2a and the lower casing part 2b is between 0.3 mm and 1.6 mm. If this average thickness is relatively thin, the upper casing part 2a and the lower housing | casing part 2b are comprised with a metal material, for example, are formed by press work etc. of a metal plate. When the average thickness is relatively large, the upper casing 2a and the lower casing 2b are made of die casting (aluminum, magnesium alloy, etc.).

  Reference numeral 3 denotes a tray provided in the housing 2 so as to be able to move freely, 5 denotes a spindle motor provided in the tray 3, 4 denotes an optical pickup module, 6 denotes a cover, and 7 denotes an optical pickup. The optical pickup 7 performs at least one of an operation of writing information to the optical disc or reading information. The optical pickup 7 is mounted on a carriage 43 that is held so as to be movable in the radial direction of the optical disk. Reference numeral 8 denotes a bezel provided on the front end surface of the tray 3, and the bezel 8 is configured to close the entrance and exit of the tray 3 when the tray 3 is stored in the housing 2.

  Reference numerals 3a and 3b denote rails that are slidably attached to both the tray 3 and the casing 2, respectively. The rails 3a and 3b are provided on both sides of the tray 3, and the rails 3a and 3b are used for the casing. The tray 3 is attached so that it can be raised and lowered freely.

  FIG. 2 is a schematic view of the optical pickup module 4 according to the embodiment of the present invention. The optical pickup module 4 includes a cover 6, a spindle motor 5, an optical pickup 7, and the like. The optical pickup 7 approaches the spindle motor 5 in the direction of the arrow in the drawing or from the spindle motor. It has a structure that can be moved away and moved.

  FIG. 3 is a diagram of an optical pickup according to the embodiment of the present invention.

  As shown in FIG. 3, the upper portion of the optical pickup 7 is covered with an FPC cover 31 and an actuator cover 32, and the actuator cover 32 includes an opening 34 through which the actuator 33 is exposed. The optical pickup 7 and a circuit that controls the optical pickup 7 are connected by the FPC 40. Accordingly, the FPC 40 is bent or stretched each time the optical pickup 7 approaches or moves away from the spindle motor 5.

  In order to eliminate the influence of the bending or stretching stress of the FPC 40, the optical pickup 7 is provided with an FPC cover 31 so as to press the connection portion of the optical pickup 7 of the FPC 40.

  FIG. 4 is an assembly diagram showing the FPC of the optical pickup according to the embodiment of the present invention.

  FIG. 4 shows a schematic view with the FPC cover 31 in FIG. 3 removed.

  In FIG. 4, 31 is an FPC cover, 61 is a reinforcing plate, 62 is a long hole, and 64a is a semiconductor chip. The FPC 40 is assembled so that an electronic component including a semiconductor chip 64a mounted on the front surface of the FPC 40 is disposed and stored inside the optical pickup 7 with the back surface facing the FPC cover 31. A reinforcing plate 61 is provided on the FPC 40 in a region where the back surface of the FPC 40 is disposed inside the optical pickup 7 by the FPC cover 31.

  Further, when the FPC cover 31 is pressed from the top of the reinforcing plate 61, the portion of the FPC 40 positioned inside the pickup 7 of the electronic component including the mounted semiconductor chip 64a is connected to the connecting portion by the stress with which the FPC cover 31 is pressed. The reinforcing plate 61 is provided with a long hole 62 at a position facing the at least one apex of the semiconductor chip 64a outside the electronic component so as not to cause disconnection or deterioration of the component. Details of the long hole 62 will be described later. The long holes 62 are provided in the reinforcing plate 61, and the long holes 62 are not provided in the base substrate on which the pattern wiring of the FPC 40 is provided.

  FIG. 5 is a schematic diagram of the FPC 40 according to the embodiment of the present invention.

  FIG. 5A is a plan view of the front surface, and FIG. 5B is a plan view of the back surface.

  In FIG. 5, 40 is an FPC, 60 is a base substrate, and 61 is a reinforcing plate. Electronic components including a semiconductor chip 64a and resistors 64b are mounted on the base substrate 60.

  As shown in FIG. 5B, a reinforcing plate 61 is provided on the back surface of the base substrate 60 outside the mounting region 65 where the semiconductor chip 64a and the resistors 64b are mounted. Therefore, when the FPC 40 is handled, the reinforcing plate 61 bends around the reinforcing plate 61 with respect to the bending of the electronic component including the semiconductor chip 64a, so that stress is generated in the electronic component including the semiconductor chip 64a. Therefore, it is possible to protect against breakage of the component without applying stress to the disconnection of the connection part of the electronic component including the semiconductor chip 64a or the electronic component itself.

  In order to cope with a strong stress applied to the FPC 40 such that the reinforcing plate 61 is bent, a long hole 62 is provided outside the semiconductor chip 64 a of the reinforcing plate 61.

  The configuration of the long hole 62 will be described with reference to FIG.

  FIG. 6 is a mounting diagram of the semiconductor chip according to the embodiment of the present invention.

As shown in FIG. 6, the FPC 40 includes a base substrate 60 and a reinforcing plate 61. The base substrate 60 includes film bases 66a and 66b and a wiring pattern 63, and includes a film base 66a (second film base) and a film. The wiring pattern 63 is protected and insulated by the base 66b (first film base) .

  The film base 66b is eliminated from the connection portion with the wiring pattern such as the semiconductor chip 64a and the resistors 64b, so that the wiring pattern can be soldered to the semiconductor chip 64a and the resistors 64b.

  6 (a) is a plan view of the FPC 40, and FIG. 6 (b) is a diagram showing a schematic cross section of the arrow D in FIG. 6 (a).

  In FIG. 6A, an arrow 67 indicates one of the diagonal directions of the semiconductor chip 64a, and an arrow 68 indicates the direction of the long hole. The direction of the long hole 62 is substantially parallel to the diagonal direction 67 of the semiconductor chip 64a as indicated by an arrow 68, and stress against bending in the diagonal direction of the semiconductor chip 64a can be relaxed. If the length of the long hole 62 is longer than the foot width Y in the diagonal direction of the semiconductor chip 64a, the stress applied to the connecting portion of the foot of the semiconductor chip 64a can be reduced. The shape of the long hole 62 will be described later with reference to FIGS.

  Further, as shown in FIG. 6A, the position of the long hole 62 is provided in the outer region of the semiconductor chip 64a at a predetermined interval X from the position of the legs of the semiconductor chip 64a. If the distance X is longer than the leg width Y in the diagonal direction of the semiconductor chip 64a, the distance X is concentrated on one leg of the stress applied to the connecting portion of the leg of the semiconductor chip 64a. Since the long hole-shaped hole absorbs the influence of bending at a distance X of the distance X, the connection part crack between the semiconductor chip 64a and the base substrate 60 generated during the attachment or the disconnection of the internal wiring part of the component Can prevent contact failure.

  In FIG. 6, the long holes 62 are represented by a configuration in which all four locations of the semiconductor chip 64 a are provided. However, some of the four locations are defined depending on the mounting position of the electronic device to be mounted and the location where bending is applied to the FPC 40. You may choose and provide.

  FIG. 7 is a cross-sectional view of the FPC when stress is generated according to the embodiment of the present invention.

  In FIG. 7, the long hole 62 provided outside the reinforcing plate 61 is located at the position (lower part) where the semiconductor chip 64 a is mounted when the reinforcing plate 61 of the FPC 40 mounted on the surface of the FPC 40 is bent. Since it is protected by the external package of the chip 64a, no bending occurs. Further, outside the semiconductor chip 64a, even if a bending stress is generated in the entire reinforcing plate 61, the bending stress is absorbed by the long holes 62 to relieve the stress on the legs of the semiconductor chip 64a, and the electronic component including the semiconductor chip 64a No stress is applied to the connector, and disconnection of the connecting portion and deterioration of the components can be prevented.

  FIG. 8 is an explanatory diagram of a long hole according to the embodiment of the present invention.

  As shown in FIG. 8A, a long hole 62a is disposed to face the apex 71a of the semiconductor chip 64a. The long hole 62a is substantially parallel to the diagonal line 82a of the triangle 85 (hatched portion) formed by the sides 81a and 81b forming the apex 71a of the semiconductor chip 64a and the diagonal line 82a. is doing.

  All of the long holes 62a, 62b, 62c and 62d may be disposed, or may be provided so as to face the apex of at least one semiconductor chip 64a which generates stress when incorporated in an electronic device.

  FIG.8 (b) is explanatory drawing of the long hole of another structure concerning embodiment of this invention. As shown in FIG. 8B, the elongated hole portion 63a includes shapes 91a and 91b along two polygonal sides 81a and 81b that form the apex 71a of the semiconductor chip 64a. Similarly, long holes 63b, 63c and 63d are provided.

  These long hole-shaped holes 63a, 63b, 63c, and 63d may be all disposed, or may be provided to face the apex of at least one semiconductor chip 64a that generates stress when incorporated in an electronic device.

  FIG.8 (c) is explanatory drawing of the long hole of another structure concerning embodiment of this invention.

  As shown in FIG. 8C, a long hole 69a is arranged to face the apex 71a of the semiconductor chip 64a. The long hole-shaped hole 69a is substantially parallel to the diagonal line 82a of the triangle 85 (hatched part) formed by the sides 81a, 81b forming the apex 71a of the semiconductor chip 64a and the diagonal line 82a, and the long hole-shaped hole 69a. Has the widest hole width 41 in the region facing the apex 71a. By doing so, it becomes easy to absorb the influence of the bending of the apex side of the semiconductor chip 64a from the oblique direction, so the influence of the bending of the flexible printed circuit board does not reach the semiconductor chip 64a, and the semiconductor chip 64a generated at the time of mounting. It is possible to prevent a contact failure due to a crack in the connection portion between the base substrate 60 and the internal wiring portion of the component.

  In FIG. 8, FIGS. 8A, 8 </ b> B, and 8 </ b> C have been described with different long hole configurations, but there are several different long hole shapes for each apex of the semiconductor chip 64 a. It is good also as a structure which combined.

  In FIG. 8, the semiconductor chip 64a is described as having a square shape, but the semiconductor chip may have a polygonal configuration.

  FIG. 9 is an explanatory diagram of long holes in the polygonal semiconductor chip according to the embodiment of the present invention.

  FIG. 9A shows the shape of a long hole in which the polygonal semiconductor chip 64a is a pentagonal shape. In FIG. 9A, the long hole-shaped hole 43a facing the vertex 71a is substantially parallel to the polygonal diagonal line 82a, and the long-hole-shaped hole 43b is the vertex 71b of the semiconductor chip 64a. The shape 45a, 45b along the polygonal two sides 44a, 44b which form is provided.

  FIG. 9B shows a configuration in which the polygonal semiconductor chip 64a has a hexagonal shape of a long hole.

  As shown in FIG. 9, a plurality of elongated holes 43a, 43b, 43c, 43d, 43e and 44a, 44b, 44c, 44d, 44e, 44f may all be arranged, but are incorporated in an electronic device. It may be provided to face the apex of at least one semiconductor chip 64a that sometimes generates stress.

  Further, the shape of the long hole can be changed as appropriate regardless of the embodiment of the present invention as long as it is arranged to face the apex of the semiconductor chip 64a.

  A flexible printed circuit board and an electronic apparatus including the flexible printed circuit board according to the present invention include a flexible printed circuit board in which the shape of the flexible printed circuit board is miniaturized, and disconnection of a connection part of an electronic component such as a semiconductor or deterioration of the component does not occur. Since an electronic device equipped with the electronic device can be provided, the present invention is useful for a flexible printed circuit board and an electronic device including the flexible printed circuit board.

Schematic diagram of an optical disc apparatus according to an embodiment of the present invention Schematic of an optical pickup module according to an embodiment of the present invention 1 is a diagram of an optical pickup according to an embodiment of the present invention. 1 is an assembly diagram showing an FPC of an optical pickup according to an embodiment of the present invention. Schematic diagram of FPC according to an embodiment of the present invention Semiconductor chip mounting diagram according to an embodiment of the present invention Sectional drawing of FPC at the time of the stress generation concerning embodiment of this invention Explanatory drawing of the long hole concerning embodiment of this invention Explanatory drawing of the long hole in the polygonal semiconductor chip concerning embodiment of this invention Sectional view of a conventional flexible printed circuit board

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical disk device 2 Housing | casing 3 Tray 4 Optical pick-up module 5 Spindle motor 6 Cover 7 Optical pick-up 8 Bezel 31 FPC cover 32 Actuator cover 33 Actuator 34 Opening 40 FPC
60 base substrate 61 reinforcing plate 62 long hole 63 wiring pattern 64a semiconductor chip 65 mounting area 66a, 66b film base 67 semiconductor chip diagonal direction 68 long hole direction 71a apex 81a, 81b side 82a diagonal

Claims (1)

Is formed a wiring pattern so as to hold in the first off i Rumubesu and second off Lee Rumubesu, a base substrate for mounting a semiconductor chip of polygonal shape on the first full Lee Rumubesu side,
Anda reinforcing plate provided on the opposite side to the wiring pattern of the second full Lee Rumubesu,
The reinforcing plate is provided with a long hole-shaped hole portion spaced from the at least one vertex of the semiconductor chip by a predetermined distance to an outer region thereof, and a long side of the long hole-shaped hole portion faces the vertex. Arranged,
The flexible printed circuit board the wiring pattern side region of the hole portion of the long hole shape, characterized in that facing the second full b Rumubesu.

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