JP2013231783A - Liquid crystal display module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display module which allows two flexible printed circuit boards to be easily integrated without using a double-sided tape and is capable of suppressing stress applied to an electrical connection part.SOLUTION: A liquid crystal display module comprising a liquid crystal display panel and a back light is provided with a flexible printed circuit board (FPC1) connected to the liquid crystal display panel and a flexible printed circuit board (FPC2) connected to the back light. A part of the flexible printed circuit board (FPC1) and a part of the flexible printed circuit board (FPC2) are electrically connected (S), and either one of the flexible printed circuit boards has an engagement part (H) formed in it, which engages with the other flexible printed circuit board.

Description

  The present invention relates to a liquid crystal display module, and more particularly to a liquid crystal display module including a liquid crystal display panel and a backlight.

  Liquid crystal display modules (LCM) are used in display devices of many portable information devices such as mobile phones, personal digital assistants (PDAs), digital cameras, and multimedia players.

  The liquid crystal display module includes a liquid crystal display panel and a backlight. In particular, in a portable liquid crystal display module, a drive wiring to the liquid crystal display panel and a power supply wiring to the light source (light emitting diode) of the backlight are used. A flexible printed circuit (FPC) is used for downsizing the entire apparatus and facilitating wiring work.

  In addition, the flexible printed circuit board (panel FPC) connected to the liquid crystal display panel and the flexible printed circuit board (backlight FPC) connected to the backlight are electrically connected, and the flexible print is derived from the liquid crystal display module. A single substrate is also used.

  FIG. 1 is a diagram schematically showing a liquid crystal display panel LCD and a backlight BL. A flexible printed circuit board FPC1 is connected to the liquid crystal display panel LCD of FIG. In the backlight of FIG. 1B, light emitting diodes LED as light sources are arranged in a frame FR, and these light emitting diodes are arranged on a flexible printed circuit board FPC2 and arranged at predetermined positions in the frame. .

  The two flexible printed boards (FPC1, FPC2) are electrically connected to each other at the respective terminal portions (TM1, TM2). As a connection method, solder or connector connection can be used.

  2A and 2B are diagrams in which the liquid crystal display panel LCD and the backlight BL in FIG. 1A are combined, FIG. 2A is a front view, and FIG. 2B is a side view. As shown in FIG. 2, when two flexible printed boards (FPC1, FPC2) are connected to terminal portions with solder S or the like, the two flexible printed boards are fixed in the vicinity of the solder S with double-sided tape DA. FIG. 3 is an enlarged view of the vicinity of the terminal portion of FIG.

  When the flexible printed circuit board FPC2 bends, the light emitting diodes LED arranged on the flexible printed circuit board rise from the frame FR, and light from the light emitting diodes leaks out of the frame. As a result, problems such as insufficient light quantity of the backlight occur. Further, when a load is applied to the flexible printed circuit board itself, such as bending the flexible printed circuit boards (FPC1, FPC2), stress is applied to the connection part such as solder, and there is a risk that the connection part is disconnected or disconnected. In order to solve such a problem, a double-sided tape DA is attached in the vicinity of the connection portion such as the solder S to suppress the floating of the flexible printed circuit board FPC2 and the generation of stress on the connection portion such as solder.

  However, the work of connecting the flexible printed circuit board using the double-sided tape DA is heavy, and when the distance between the connecting portion such as solder and the LED arrangement position becomes long, the double-sided tape is attached to a plurality of locations in the vicinity of each. The amount of work is further increased.

  Patent Document 1 discloses a technique for unifying a flexible printed circuit board derived from a liquid crystal display module. In order to electrically connect the two flexible printed circuit boards, the connector insertion portion of the backlight FPC is inserted into the connector portion provided in the panel FPC. In order to perform the operation of inserting the insertion portion into the connector portion, it is necessary to provide a margin in the length of the portion connected to the insertion portion of the backlight FPC. However, when a display panel or a backlight is attached, and when an insertion portion is attached to the connector portion, the portion connected to the insertion portion bends, and the light emitting diode disposed in the backlight FPC accommodates the backlight. Detrimental effects such as floating from

  In Patent Document 1, in order to solve such a problem, a hook-shaped portion is provided in a part of a frame that accommodates the backlight, and the lifting of the backlight FPC is suppressed by the hook-shaped portion. However, no consideration is given to the stress applied to the electrical connection portion of the flexible printed circuit board.

  Moreover, when connecting a flexible printed circuit board (FPC) to a printed circuit board (PCB board) which is a rigid board, a configuration in which a protruding portion is provided on the PCB substrate and the FPC is locked by the protruding portion is disclosed in Patent Document 2. Is disclosed. Thereby, even if a flexible printed circuit board is pulled, it is suppressing that stress is applied to a solder contact. However, when connecting two flexible printed boards with solder or the like, the configuration as in Patent Document 2 cannot be adopted because a rigid board is not used.

JP 2006-157487 A JP 2002-119004 A

  The problem to be solved by the present invention is a liquid crystal display module that solves the above-described problems, can easily integrate two flexible printed boards without using double-sided tape, and can suppress stress applied to an electrical connection portion. Is to provide.

The liquid crystal display module of the present invention has the following characteristic configuration in order to solve the above-described problems.
(1) In a liquid crystal display module including a liquid crystal display panel and a backlight, the liquid crystal display module includes a flexible printed circuit board A connected to the liquid crystal display panel and a flexible printed circuit board B connected to the backlight. A part of the printed circuit board A and a part of the flexible printed circuit board B are electrically connected, and one of the flexible printed circuit boards is formed with an engaging portion that engages with the other flexible printed circuit board. It is characterized by being.

(2) In the liquid crystal display module according to (1), the engagement portion is formed in the vicinity of the electrically connected connection portion.

(3) In the liquid crystal display module according to (1) or (2), a plurality of the engaging portions are arranged so as to sandwich the electrically connected connecting portions.

(4) In the liquid crystal display module according to any one of (1) to (3), the engaging portion is a cut, a through-hole, or a slit formed in the flexible printed board. .

(5) In the liquid crystal display module according to (4), the minimum clearance of the through hole or the slit is 1 mm or more.

(6) In the liquid crystal display module according to any one of (1) to (5), the engaging portion is formed where the electrode film of the flexible printed board is provided. .

(7) In the liquid crystal display module according to any one of (1) to (6), an interval between the electrically connected joint portion and the engaging portion, or an interval between the engaging portions. The minimum value is 5 mm or more.

  As in the present invention, since one of the two flexible printed boards to be electrically connected has an engaging portion that engages with the other flexible printed board, double-sided tape Even without using the liquid crystal display module, it is possible to provide a liquid crystal display module in which two flexible printed boards can be easily integrated and the stress applied to the electrical connection portion can be suppressed.

It is the schematic explaining the conventional liquid crystal display panel and a backlight. It is the (a) top view at the time of combining the liquid crystal display panel and backlight of FIG. 1, and (b) side view. It is an enlarged view in the junction part of the flexible printed circuit board of FIG. It is the schematic of two flexible printed circuit boards used for the 1st Example of the liquid crystal display module of this invention. It is a figure which shows a mode that two flexible printed circuit boards shown in FIG. 4 were combined. It is a figure which shows sectional drawing in the dashed-dotted line A of FIG. It is the schematic of the flexible printed circuit board (FPC1) used for the 2nd Example by the liquid crystal display module of this invention. It is a figure explaining the use condition of the flexible printed circuit board shown in FIG. It is sectional drawing explaining the 3rd Example of the liquid crystal display module of this invention. It is sectional drawing explaining the 4th Example of the liquid crystal display module of this invention. It is the schematic of two flexible printed circuit boards used for the 5th Example of the station display module of this invention. It is a figure which shows a mode that the two flexible printed circuit boards shown in FIG. 11 were combined.

  The liquid crystal display module according to the present invention will be described in detail below. FIGS. 4 to 12 are diagrams for explaining the embodiments of the present invention. In order to explain mainly the structure of the flexible printed circuit board which is a feature of the present invention, a liquid crystal display panel and a backlight connected to the flexible printed circuit board are described. Since (light emitting diode) is the same as that in FIGS. 1 and 2, it is omitted here.

  The present invention provides a liquid crystal display module including a liquid crystal display panel and a backlight, and a flexible printed circuit board A (FPC1) connected to the liquid crystal display panel and a flexible printed circuit board B (FPC2) connected to the backlight. And electrically connecting a part of the flexible printed circuit board A and a part of the flexible printed circuit board B (see S), and one flexible printed circuit board is connected to the other flexible printed circuit board. An engaging portion (see symbols H and SL) that engages with the substrate is formed.

  FIG. 4A is a plan view showing a flexible printed circuit board FPC1 connected to a liquid crystal display panel (not shown). FIG. 4B is a plan view showing the flexible printed circuit board FPC2 in which the light emitting diodes LED incorporated in the backlight are arranged.

  A feature of the liquid crystal display module of the present invention is that an engagement portion that engages with the other flexible printed board is formed on one of the flexible printed boards. In FIG. 4, two through holes H are formed as engaging portions on the flexible printed circuit board FPC1.

  As shown in FIG. 5, a part of the flexible printed circuit board FPC2 is passed through the through hole H, and the terminal TM1 of the flexible printed circuit board FPC1 and the terminal TM2 of the flexible printed circuit board FPC2 shown in FIG. ) Etc. for electrical connection.

  6 shows a cross-sectional view taken along the alternate long and short dash line A in FIG. By engaging the two flexible printed boards so as to be knitted, the flexible printed boards can be temporarily fixed without a double-sided tape. As a result, it is possible to suppress lifting due to bending of the flexible printed circuit board. In addition, by forming such an engaging portion in the vicinity of the electrical connection portion such as solder, the stress applied to the electrical connection portion can be relaxed, and the reliability related to the connection portion can be improved.

  The distance a from the electrical connection part to the through-hole (engagement part), the distance b between the through-holes, the distance c from the through-hole to the substrate end, etc. are secured by 5 mm or more, respectively. This is preferable for maintaining the mechanical strength of the engaging portion.

  Furthermore, by setting the widths (d, e) of the through holes to 1 mm or more, it becomes possible to easily insert another flexible printed board into the through holes. The same applies to the case where the engaging portion is formed by a slit described later.

  Further, as shown in FIG. 4A, it is possible to provide slightly larger holes at both ends of the through hole. This plays a role of escape or play that suppresses breakage of the through-hole even when the through-hole is greatly opened when the flexible printed circuit board is combined.

  Further, in order to increase the mechanical strength of the engaging portion, particularly the portion where the through hole is formed, the portion of the flexible printed circuit board where the electrode film for wiring (particularly a ground electrode is preferable) is penetrated. It is preferable to provide a hole.

  As another example of the engaging portion, a slit SL can be used as shown in FIG. In the case of such a slit, another flexible printed board can be easily inserted from the side of the flexible printed board FPC1 (the right end portion in the figure). FIG. 8 is a view showing a state in which two flexible printed boards are combined using the engaging portion shown in FIG. The cross-sectional view taken along the alternate long and short dash line A has the same configuration as FIG.

  In FIG. 4 or FIG. 7, the through holes H and the slits SL have a constant opening width, but it goes without saying that it can function as an engaging portion only by inserting a notch penetrating with a knife or the like into the flexible printed circuit board. Yes.

  Furthermore, as shown in FIG. 9, an electrical connection portion S such as solder can be disposed in the middle of the through-hole H that constitutes the engagement portion, and the floating of the substrate in the vicinity of the electrical connection portion can be suppressed. is there. Furthermore, as shown in FIG. 10, it is possible to increase the number of through holes and further strengthen the integration of the two flexible printed boards.

  In FIG. 11, the engaging portion SL is provided on the flexible printed circuit board FPC2 of the backlight. FIG. 11A shows a flexible printed circuit board FPC1 connected to the liquid crystal display panel, and FIG. 11B shows a flexible printed circuit board FPC2 on the backlight side. FIG. 12 is a diagram illustrating a state in which both are combined.

  As described above, according to the present invention, it is possible to provide a liquid crystal display module in which two flexible printed boards can be easily integrated without using double-sided tape and the stress applied to the electrical connection portion can be suppressed. It becomes.

BL Backlight DA Double sided tape FPC1 Flexible printed circuit board FPC2 for liquid crystal display panel Flexible printed circuit board FR for backlight Frame H Through hole LCD Liquid crystal display panel LED Light emitting diode S Electrical connection (solder etc.)
SL slit TM1, TM2 terminals

Claims (7)

In a liquid crystal display module having a liquid crystal display panel and a backlight,
A flexible printed circuit board A connected to the liquid crystal display panel;
A flexible printed circuit board B connected to the backlight;
A part of the flexible printed circuit board A and a part of the flexible printed circuit board B are electrically connected, and one flexible printed circuit board is formed with an engaging portion that engages with the other flexible printed circuit board. A liquid crystal display module characterized by being made.   2. The liquid crystal display module according to claim 1, wherein the engaging portion is formed in the vicinity of the electrically connected connection portion.   3. The liquid crystal display module according to claim 1, wherein a plurality of the engaging portions are arranged so as to sandwich the electrically connected connecting portions.   4. The liquid crystal display module according to claim 1, wherein the engaging portion is a cut, a through hole, or a slit formed in the flexible printed circuit board. 5.   5. The liquid crystal display module according to claim 4, wherein a minimum gap between the through hole or the slit is 1 mm or more.   6. The liquid crystal display module according to claim 1, wherein the engaging portion is formed at a place where an electrode film of a flexible printed board is provided.   7. The liquid crystal display module according to claim 1, wherein a minimum value of a distance between the electrically connected joint portion and the engagement portion or a distance between the engagement portions is 5 mm or more. A liquid crystal display module characterized by the above.

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