JPH0815717A - Liquid crystal display - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a liquid crystal display device capable of easily determining by visual inspection that the electrode terminals to be soldered are securely connected to each other. A liquid crystal display device comprising: a liquid crystal display panel; and a circuit board on which an electronic component for driving the liquid crystal display panel is mounted, wherein a plurality of electrode terminals of the electronic component are provided on a plurality of circuit boards. In the liquid crystal display device soldered to the electrode terminals, the electrode terminal pitch dimension of the circuit board is made larger than the electrode terminal pitch dimension of the electronic component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a technique effective when applied to soldering of electronic parts used in the liquid crystal display device.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional liquid crystal display module (L
It is a disassembled perspective view of (CM).

As shown in FIG. 3, a liquid crystal display module (LCM) includes a frame-shaped frame made of a metal plate, a liquid crystal display panel (LCD), and drive circuit boards (PCB1 to PCB).
3), a fluorescent tube (CFL), a rubber bush, a lamp cover, a light guide, and a mold made of synthetic resin are stacked and assembled in a vertical arrangement relationship shown in FIG.

The TCP shown in FIG. 3 is a tape carrier package in which a driving IC chip is mounted by a tape automated bonding method.

Further, drive circuit boards (PCB1 to PCB
In 3), the tape carrier package (TCP), the capacitor and the like are mounted.

At this time, the tape carrier package (TC
P) and the electrode terminals such as capacitors are connected to the drive circuit board (PC
B1 to PCB3) are soldered to the electrode terminals.

FIG. 4 shows a tape carrier package (TC
P) electrode terminals to drive circuit boards (PCB1 to PCB
It is a figure which expands and shows the electrode terminal part at the time of soldering to the electrode terminal of 3).

In FIG. 4, 1 is an electrode terminal of a tape carrier package (TCP), 2 is a drive circuit board, 3 is an electrode terminal of the drive circuit board 2, and 4 is a solder fillet.

As shown in FIG. 4, when the electrode terminal 1 of the tape carrier package (TCP) is soldered to the electrode terminal 3 of the drive circuit board 2, the drive circuit board is mounted in order to ensure the soldering. The width of the second electrode terminal 3 is larger than the width of the opposite electrode terminal 1 of the tape carrier package (TCP).

As a result, the solder fillet 4 is formed at the soldering portion, and the tape carrier package (TCP) is formed.
However, it can be easily determined by visual inspection that the drive circuit board 2 is reliably soldered.

[0011]

However, in recent years,
The high-density mounting of liquid crystal display modules (LCM) has advanced,
The pitch of the electrode terminals 1 of the tape carrier package (TCP) is as small as 0.3 to 0.4 mm, and the width of the electrode terminal pattern is as small as 0.15 to 0.2 mm.

With such a size, it is difficult to make the width of the electrode terminal 3 of the drive circuit board 2 larger than the width of the electrode terminal 1 of the tape carrier package (TCP) due to restrictions on the electrode processing system. The width of the electrode terminals 1 of the tape carrier package (TCP) must be the same.

FIG. 5 shows an electrode terminal 1 of a tape carrier package (TCP) in which the electrode terminals have the same width.
FIG. 6 is an enlarged view showing an electrode terminal portion when the is soldered to the electrode terminal 3 of the drive circuit board 2.

As is apparent from FIG. 5, the tape carrier package (TC) in which the electrode terminals have the same width.
When the electrode terminal 1 of P) is soldered to the electrode terminal 3 of the drive circuit board 2, the solder fillet 4 is not formed in the soldering portion.

Therefore, in soldering as shown in FIG. 5, it is difficult to find a soldering defect by visual inspection.

Further, in the soldering as shown in FIG. 5, the soldering failure judged to be good by the electrical inspection is
It is difficult to find it easily, and for example, a soldering defect may be found after the product is delivered to the user.

Therefore, in the soldering as shown in FIG. 5, it has been demanded that the electrode terminals 1 and 3 are reliably soldered and that there is no soldering defect by the visual inspection. .

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to reliably connect electrode terminals to be soldered in a liquid crystal display device. It is an object of the present invention to provide a technology capable of easily determining the appearance by visual inspection.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0020]

Of the inventions disclosed in the present application, a representative one will be briefly described below.
It is as follows.

(1) A liquid crystal display device comprising a liquid crystal display panel and a circuit board on which an electronic component for driving the liquid crystal display panel is mounted, wherein a plurality of electrode terminals of the electronic component are circuits. In a liquid crystal display device soldered to a plurality of electrode terminals of a board, the electrode terminal pitch dimension of the circuit board is larger than the electrode terminal pitch dimension of the electronic component.

[0022]

In the liquid crystal display device, the electrode terminal pitch dimension of the circuit board is made larger than the electrode terminal pitch dimension of the electronic component so that the plurality of electrode terminals of the electronic component are connected to the circuit. Since the electrodes are soldered to a plurality of electrode terminals on the board, solder fillets are formed on the electrode terminals on the outer side of the electronic component, and it is possible to visually inspect that the electronic component is securely connected to the circuit board. It becomes possible to easily determine.

[0023]

Embodiments of the present invention applied to a liquid crystal module (LCM) will be described below in detail with reference to the drawings.

In all the drawings for explaining the embodiments, parts having the same function are designated by the same reference numerals, and the repeated description thereof will be omitted.

The structure of the liquid crystal display module (LCM) which is an embodiment of the present invention is the same as that of the liquid crystal display module (LCM) shown in FIG. 3, and therefore its explanation is omitted.

FIG. 1 is an enlarged view showing an electrode terminal portion of a liquid crystal display module (LCM) which is an embodiment of the present invention before a tape carrier package (TCP) is soldered to a drive circuit board. is there.

In FIG. 1, 1 is an electrode terminal of the tape carrier package (TCP), 2 is a drive circuit board, 3 is an electrode terminal of the drive circuit board 2, and P1 is an electrode terminal of the electrode terminal 1 of the tape carrier package (TCP). Pitch, P2 is the electrode terminal pitch of the electrode terminals 3 of the drive circuit board 2.

Liquid crystal display module (LCM) of this embodiment
In, the electrode terminal 1 of the tape carrier package (TCP) and the electrode terminal 3 of the drive circuit board 2 have almost the same electrode terminal width, and the electrode terminal pitch P2 of the drive circuit board 2 is It is set larger than the electrode terminal pick P1 of the tape carrier package (TCP) 1.

In this embodiment, the electrode terminal 1 of the tape carrier package (TCP) and the electrode terminal 3 of the drive circuit board 2 are aligned at the center electrode terminal, and each tape carrier package (TCP) is aligned. Solder by pressing with a heated heater chip.

FIG. 2 is an enlarged view showing the electrode terminal portion when the tape carrier package (TCP) is soldered to the drive circuit board 2 in the liquid crystal display module (LCM) which is an embodiment of the present invention. Is.

As is apparent from FIG. 2, in the electrode terminal 3 of the drive circuit board 2 of this embodiment, the position of the outer electrode terminal 3 increases with respect to the electrode terminal 1 of the tape carrier package (TCP). At that portion, the solder fillet 4 is formed on the electrode terminal outside the tape carrier package (TCP) 1.

Further, the solder fillet 4 becomes larger toward the outer electrode terminal.

The larger the positional deviation of the outermost electrode terminal 3 of the drive circuit board 2 with respect to the outermost electrode terminal 1 of the tape carrier package (TCP), the larger the solder fillet 4 becomes.

However, when the displacement becomes large, the outer electrode terminals 1 of the tape carrier package (TCP) are replaced by the outer electrode terminals 3 of the corresponding drive circuit board 2.
Instead, soldering will occur with the immediately preceding electrode terminal, and in consideration of this, the electrode terminal pitch P2 of the drive circuit board 2 with respect to the electrode terminal pick P1 of the tape carrier package (TCP) 1 is set. There is a need.

In this case, the electrode terminal pitch P2 of the drive circuit board 2 with respect to the most optimal electrode terminal pick P1 of the tape carrier package (TCP) 1 is the end portion of the outermost electrode terminal 1 of the tape carrier package (TCP). 5
This is a case where the drive circuit board 2 is positioned between the outermost electrode terminal 3 and the electrode terminal 3 immediately before the outermost electrode terminal 3.

Generally, a tape carrier package (TC
The electrode terminal 1 of P) and the electrode terminal 3 of the drive circuit board 2 are
When soldering is performed by pressing with a heated heater chip for each tape carrier package (TCP), defective soldering is likely to occur at the electrode terminals at both outer ends.

In the soldering as shown in FIG. 5, the solder fillet 4 is not formed, and a soldering defect, for example, a soldering defect which is judged as a non-defective product by an electrical inspection is to be found by visual inspection. However, according to the present embodiment, the solder fillet 4 is formed on the outer electrode terminal of the tape carrier package (TCP) 1, and the solder fillet 4 is larger than the outer electrode terminal. It becomes possible to find defective soldering by visual inspection.

A specific example of this embodiment will be described below.

For a tape carrier package (TCP) having an electrode terminal pitch of 0.46 mm, an electrode terminal width of 0.23 mm and an electrode terminal 1 of 32 terminals, an electrode terminal pitch of 0.466 mm and an electrode terminal width of 0.24 mm The drive circuit board 2 having the electrode terminals 3 of 1 was prepared.

The outermost electrode spacing of the tape carrier package (TCP) is 13.8 mm, the outermost electrode spacing of the drive circuit board 2 is 13.98 mm, and the tape carrier package (TCP) is located at the center electrode terminal. )
When the drive circuit board 2 and the drive circuit board 2 are aligned, the outermost electrode terminal 3 of the drive circuit board 2 is 0.00 relative to the outermost electrode terminal 1 of the tape carrier package (TCP).
The position is offset by 9 mm.

The electrode base material of the electrode terminal 1 of the tape carrier package (TCP) is copper (Cu), tin (Sn) of 2-3 μm is plated, and the electrode base material of the electrode terminal 3 of the drive circuit board 2 is copper. (Cu), 30μm solder (Pb / S
n) is plated.

As described above, after the alignment, the rosin-based flux is applied to the terminals, and the electrode terminals of the 32 tape carrier packages (TCP) are simultaneously pressed in parallel and heated for soldering. .

Regarding the connection state after soldering, in particular, solder fillets were formed on the outer few electrode terminals, and it was confirmed by electrical inspection that all of the electrode terminals were stably connected.

As a result, the soldering of the outer electrode terminal, which has conventionally been lacking in connection stability, becomes stable, and the solder fillet can be easily confirmed by visual inspection, which is effective in simplifying the inspection.

In this embodiment, the case where the tape carrier package (TCP) is soldered to the drive circuit board has been described, but it goes without saying that it can be applied to general electronic parts.

Further, the present invention can be applied not only to the liquid crystal display module (LCM) but also to all liquid crystal display devices.

Although the present invention has been specifically described based on the embodiments, it is needless to say that the present invention is not limited to the above embodiments and various modifications can be made without departing from the scope of the invention.

[0048]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1) In the liquid crystal display device, the electrode terminal pitch dimension of the circuit board is made larger than the electrode terminal pitch dimension of the electronic component so that the plurality of electrode terminals of the electronic component are soldered to the plurality of electrode terminals of the circuit substrate. Since the solder fillets are formed on the outer electrode terminals of the electronic component, the outer electrode terminals, which are conventionally lacking in connection stability, are more stable in soldering.

This makes it possible to easily determine by visual inspection that the electronic component is securely connected to the circuit board, and the inspection can be simplified.

[Brief description of drawings]

FIG. 1 shows a tape carrier package (TC) in a liquid crystal display module (LCM) which is an embodiment of the present invention.
FIG. 6B is an enlarged view showing the electrode terminal portion before P) is soldered to the drive circuit board.

FIG. 2 shows a tape carrier package (TC) in a liquid crystal display module (LCM) which is an embodiment of the present invention.
FIG. 8 is an enlarged view showing an electrode terminal portion when P) is soldered to a drive circuit board.

FIG. 3 is an exploded perspective view of a conventional liquid crystal display module (LCM).

FIG. 4 is an enlarged view showing an electrode terminal portion when the electrode terminal of the tape carrier package (TCP) is soldered to the electrode terminal of the drive circuit board.

FIG. 5 is an enlarged view showing an electrode terminal portion when the electrode terminal of the tape carrier package (TCP) having the same width of the electrode terminal is soldered to the electrode terminal of the drive circuit board.

[Explanation of symbols]

LCM ... Liquid crystal display module, LCD ... Liquid crystal display panel, PCB1 to PCB3 ... Drive circuit board, CFL ... Fluorescent tube, TCP ... Tape carrier package, 1 ... Tape carrier package (TCP) electrode terminal, 2 ... Drive circuit board, 3 ... electrode terminals of drive circuit boards (PCB1 to PCB3), 4 ... solder fillets, 5 ... end portions of electrode terminals 1 of tape carrier package (TCP).

Claims (1)

[Claims] 1. A liquid crystal display device comprising a liquid crystal display panel and a circuit board on which an electronic component for driving the liquid crystal display panel is mounted, wherein a plurality of electrode terminals of the electronic component are circuit boards. In the liquid crystal display device soldered to the plurality of electrode terminals, the electrode terminal pitch dimension of the circuit board is made larger than the electrode terminal pitch dimension of the electronic component.