JP3152230B2 - Manufacturing method of liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure of a tape carrier, a mounting method thereof, and an electro-optical device and an electronic printing device using the same.

[0002]

2. Description of the Related Art FIG. 9 shows an example of a conventional mounting structure of a tape carrier.

[0003] A conventional tape carrier mounting method is a chip-on-flexible printed circuit (hereinafter referred to as C).
The outer lead 2 of the COF 1 is not coated with the solder coating 11 in advance on the outer lead 2 of the
And soldering land 4 of circuit board 3 by hand, or soldering outer lead 2 of COF 1 and circuit board 3 without prior solder coating 11 on outer lead 2 of COF 1. The land 4 was thermocompression-bonded with a heating tool 12 or the like and soldered. Therefore, the mounting structure of the conventional tape carrier is, as shown in FIG.
No recess was present.

[0004]

However, in the above-mentioned prior art, the soldering is performed manually, so that a considerable amount of processing time is required and the quality is not stable, or automatic soldering is performed using a heating tool or the like. However, it is difficult to control the quality of the connection between the outer leads of the tape carrier and the solder lands of the circuit board, and the connection strength is low and the reliability is very low.

In order to solve the above-mentioned drawbacks, the present invention is to coat the outer leads of the tape carrier with solder and then press the outer leads of the tape carrier and the soldering lands of the circuit board by thermocompression bonding using a heating tool or the like. The mounting method of the tape carrier is used.

It is an object of the present invention to provide an inexpensive and highly reliable mounting structure of a tape carrier, an electro-optical device using the same, and an electronic printing device using the same.

[0007]

A method of manufacturing a liquid crystal display device according to the present invention is a method of manufacturing a liquid crystal display device having a plurality of semiconductor devices, a circuit board, and a liquid crystal display element. A step of applying a solder coating to an outer lead of the device; and a step of connecting the outer lead and the circuit board. In the step of applying the solder coating, the semiconductor device is mounted on a terminal of the liquid crystal display element. In this state, the liquid crystal display element is lowered and the outer leads are immersed in solder in a solder bath.

[0008]

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

[Embodiment 1] FIGS. 1 and 2 show one embodiment of a method of mounting a tape carrier according to the present invention. In FIG. 1, terminals on three sides of the liquid crystal display element 6
1 is mounted with an anisotropic conductive film or the like. Where COF1
The term “single device” refers to a semiconductor device in which the semiconductor element 11 is mounted on a tape carrier, and the semiconductor element 11 is separated into single parts including a wiring pattern necessary for the function. In FIG. 1 (a), the liquid crystal display element 6 in which COF1 is mounted on each terminal (hereinafter referred to as an LCD unit) is held by a vacuum suction pad or the like attached to the tip of a manipulator or the like. Can change direction freely. Here, the LCD unit is first positioned so that the lower side thereof is substantially parallel to the flux 7 surface. Next, the LCD unit is lowered and its L
The outer lead 2 of the COF 1 on the lower side of the CD unit is dipped in the flux 7 to apply the flux, and the LCD unit is pulled up. By performing this operation for each side of the LCD unit, the liquid crystal display element 6
The flux 7 is applied to the outer leads 2 of all the COFs 1 mounted on the COF 1. Next, as shown in FIG.
The operation similar to that of FIG.
The outer leads 2 coated with the flux 7 are soldered 9
The outer lead 2 can be coated with the solder coating 11 by dipping in the inside. Also in this case, the same operation is performed for each side, so that the solder coating 1 is applied to all the outer leads 2 of the COF 1 of the LCD unit.
1 can be applied. The immersion time of the outer lead 2 of the COF 1 in the flux 7 and the solder 9 is set to 0.1. It is several seconds to ten and several seconds.

FIG. 2 is a sectional view showing an embodiment of a method for mounting a tape carrier according to the present invention, and shows a step following FIG. In FIG. 2A, the outer leads 2 of the COF 1 mounted on the liquid crystal display element 6 and coated with the solder coating 11 are aligned and arranged on the soldering lands 4 of the circuit board 3. A heating tool 12 for soldering is on standby on the lead 2. FIG.
In FIG. 2B, the heating tool 12 waiting in FIG.
Then, the outer leads 2 are pressed against the soldering lands 4 and simultaneously heated to melt the solder of the solder coating 11, and the outer leads 2 and the soldering lands 4 are soldered. At this time, the heating method of the heating tool 12 is an instantaneous heating method using a pulse current, but may be an instantaneous heating method using a laser beam, a heating wire, or the like, or another general constant heating method. In FIG. 2C, FIG.
The heating tool 12 that has completed the soldering of the outer leads 2 and the solder lands 4 in (b) is lifted upward away from the soldering portion. After the heating tool 2 is lifted, the solder coating 11 of the outer lead 2 has a concave portion 13 which is a mark of the heating tool 12 left. Examples of specifications of the COF 1, the circuit board 3, the flux 7, and the solder 9 used in the present embodiment are as follows.

<Specifications of COF1> Base film: 25-75 μm thick polyimide resin, polyester resin, etc.

Copper foil (outer lead material): Electrolytic copper foil having a thickness of several to 50 μm.

Plating of copper foil: Sn plating, Au plating, etc. of several μm.

<Specifications of the circuit board 3>-Board material: glass epoxy resin, epoxy composite material, paper phenol resin, bakelite, etc.

Copper foil (soldering land 4): Electrolytic copper foil having a thickness of several to 50 μm.

Plating of copper foil: solder plating of about several μm to several tens, Au plating or the like.

Surface: Insulating agent application and the like.

<Specifications of Flux 7> Standard: RF-35M RMA flux from Almit Japan.

<Solder 9>: Solder having a Pb / Sn ratio = 60/40 or the like.

Reference Example 1 FIG. 3 is a view showing one reference example of a method of mounting a tape carrier according to the present invention. In Example 1, application of flux 7 to outer leads 2 of COF 1 and solder coating were performed. 11 is performed not in the LCD unit state but in the tape carrier 5 state. From FIG. 3, it can be seen that when the tape carrier 5 is partially immersed in the flux 7 and the solder 9 and moved, the solder coating 11 is applied to the outer lead 2 of the COF 1 on the tape carrier.

Embodiment 2 FIG. 4 is a sectional view showing an embodiment of a mounting structure of a tape carrier according to the present invention, which is an example used for a liquid crystal display device as an example of an electro-optical device. This embodiment is formed by using the tape carrier mounting method of the first embodiment. As shown in FIG. 4, the outer lead 2 has a recess 13 at the center of the solder coating 11. By observing the appearance of the recess 13, it is possible to accurately and easily judge whether or not the outer leads 2 and the soldering lands 4 of the circuit board 3 are securely soldered.

Embodiment 3 FIG. 5 is a sectional view showing an embodiment of the mounting structure of the tape carrier of the present invention.

In this embodiment, the liquid crystal display element 6 is opposite to the front and back sides in the second embodiment, and accordingly, the direction of the COF 1 is also opposite.
The circuit board 3 is characterized in that the circuit board 3 is provided with a semiconductor element escape hole 15 for escaping the outer shape of the semiconductor element 14. There are many combinations of the electronic display element such as the liquid crystal display element 6, the electronic printing element, the COF 1 and the front and back directions of the circuit board 3, but it can be realized by slightly changing the mounting structure.

Embodiment 4 FIG. 6 is a sectional view showing an embodiment of the mounting structure of the tape carrier of the present invention.

This embodiment is characterized in that the COF 1 is bent by 90 ° with respect to the second embodiment. In FIG. 6, COF
Although the lead slit 16 is provided in the bent portion of 1,
The lead slit 16 may not be provided. COF1
May be bent up to 180 °.

[Embodiment 5] FIG. 7 is a sectional view showing an embodiment in which the mounting structure of the tape carrier of the present invention is used in a liquid crystal display device which is a kind of an electro-optical device. In FIG. 7, the backlight 18
There is a liquid crystal display element 6 on the top, COF 1 is mounted on the terminal of the liquid crystal display element 6, a solder coating 11 is applied to the outer lead 2 of the COF 1, and a thermocompression bonding is performed by a heating tool 12 to form a recess 13. ing.
The liquid crystal display element 6 is fixed to the backlight 18 by a frame 19, a pressing rubber 20, and the like, thereby forming a liquid crystal display device.

Reference Example 2 FIG. 8 is a cross-sectional view showing a reference example when the tape carrier mounting structure of the present invention is used in an electronic printing device such as a thermal head of a thermal printer. In this reference example, the mounting structure of Example 2 was used for an electronic printing device.

[0030]

According to the present invention, a plurality of semiconductor devices can be simultaneously coated with solder by immersing them in a solder bath with the plurality of semiconductor devices mounted on the terminals of the liquid crystal display element. Can be simplified. Further, a plurality of semiconductor devices can be simultaneously coated with solder without providing a large-scale device for solder coating. Also,
Variations in the solder coating for each semiconductor device can be suppressed to a small level, and a highly reliable liquid crystal display device can be provided. Further, since only the vicinity of the outer lead can be selectively coated with solder, the consumption of solder can be suppressed to a necessary minimum and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing one embodiment of the present invention.

FIG. 3 is a diagram showing a reference example of the present invention.

FIG. 4 is a diagram showing one embodiment of the present invention.

FIG. 5 is a diagram showing one embodiment of the present invention.

FIG. 6 is a diagram showing one embodiment of the present invention.

FIG. 7 is a diagram showing one embodiment of the present invention.

FIG. 8 is a diagram showing a reference example of the present invention.

FIG. 9 is a diagram showing a conventional technology example.

[Explanation of symbols]

 1. COF 2. Outer lead 3. Circuit board 4. Soldering land 5. Tape carrier 6. 6. Liquid crystal display device (LCD) Flux 8. Flux tank 9. Solder 10. Solder tank 11. Solder coating 12. Heating tool 13. Recess 14. Semiconductor device 15. Semiconductor element relief hole 16. Lead slit 17. Electronic printing element 18. Backlight 19. Frame 20. Presser rubber

Claims (1)

(57) [Claims] 1. A method of manufacturing a liquid crystal display device having a plurality of semiconductor devices, a circuit board, and a liquid crystal display element, wherein a step of applying a solder coating to outer leads of the plurality of semiconductor devices; And a step of connecting the circuit board with the circuit board. In the step of applying the solder coating, the liquid crystal display element is lowered while the semiconductor device is mounted on a terminal of the liquid crystal display element, and the outer is formed. A method for manufacturing a liquid crystal display device, wherein a lead is immersed in solder in a solder bath.