JPH04298717A - Terminal coupling structure of electronic component - Google Patents

Abstract

PURPOSE:To obtain sufficient strength for thermal stress in the operation of the electronic component by forming the terminals of the electronic component and the terminals of a substrate in the same plane and providing conductive wires which connect the terminals. CONSTITUTION:The substrate is arranged at right angles to the electronic component 13, the terminals of the electronic component 13 and the terminals 7 of the substrate 6 are formed in the same plane, and those terminals are connected by the conductive wires 15. Further, terminals 7 of the substrate which are bent and connected to the terminals 14 of the electronic component 13 in the same plane are provided and those terminals are connected by conductive wires 15. Thus, the terminals are connected by the conductive wires 15, which have flexibility, so even when the thermal stress is generated owing to the thermal expansion difference between the electronic component 13 and substrate 6, the coupling parts are held safe.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal coupling structure for electronic components, which electrically couples terminals of an electronic component to terminals of a substrate disposed perpendicular thereto.

0002

2. Description of the Related Art FIG. 7 is a sectional view showing an example of a conventional terminal coupling structure of an electronic component. Electronic component terminals on the panel side; 2a is preliminary solder provided on the electronic component terminal 2; 3 is a copper pattern sandwiched between the base film 4 and the cover film 5 through which electronic signals flow; base film 4
and the cover film 5 constitute a flexible substrate 6. Further, this flexible substrate 6 is arranged in a direction perpendicular to the liquid crystal panel 1 provided vertically. Reference numeral 7 denotes a flexible board terminal for guiding electronic signals to the liquid crystal panel 1, and 7a indicates preliminary solder provided on the flexible board terminal 7.

FIG. 8 is a perspective view showing a display unit 8 having the above liquid crystal panel structure, and 9 is a flexible substrate 6.
The driver IC 10 mounted on the top is a frame that constitutes the base of the display unit 8. As shown in FIG. 9, a plurality of the display units 8 are stacked vertically and horizontally, and arranged with the liquid crystal panel 1 facing the front and the flexible substrates 6 placed above and below to form a large screen display device. . In this case, the gap 11 between each display unit 8
, 12 are desirably as small as possible, and the vertical dimension of the joint portion of each display unit 8 is extremely small.

[0004] Further, in order to control a large number of red, green, and blue pixels of the liquid crystal panel 1, a large number of electronic component terminals 2 are provided, each connected to a driver IC 9. A driver IC 9 for controlling this pixel is mounted on a flexible board 6, and a flexible board terminal 7 of this flexible board 6 is connected to the electronic component terminal 2 of the liquid crystal panel 1 and A in FIG.
In the portion between B, the number of pixels is soldered and connected at a high density. The liquid crystal panel 1 is fixed to the front surface of the frame 10, and the flexible substrate 6 is fixed to the upper and lower surfaces of the frame 10. Note that liquid crystal display devices with such a configuration are disclosed in Japanese Patent Publication No. 2-51196 and Japanese Patent Application Laid-Open No. 63-271.
This is shown in Publication No. 427, etc.

Next, the operation will be explained. First, in order to fix the liquid crystal panel 1 to the flexible substrate 6 at right angles,
The electronic component terminals 2 and the flexible board terminals 7 on the liquid crystal panel 1 side are brought close to each other, and the electronic component terminals 2 and the flexible board terminals 7 are positioned at right angles so that their positions do not deviate. Thereafter, the electronic component terminal 2 and the flexible board terminal 7 are heated using a soldering iron. As a result, the preliminary solders 2a and 7a are melted, and the electronic component terminal 2 and the flexible board terminal 7 are joined by fillet soldering. Note that the cover film 5 has been removed from the flexible board terminal near where soldering is to be performed.

[0006]

[Problems to be Solved by the Invention] Since the conventional terminal connection structure for electronic components is constructed as described above, the flexible board terminal 7 has the base film 4 bonded to one side, so that it can be connected to the liquid crystal display during use. Due to the difference in coefficient of thermal expansion between the panel 1 and the flexible substrate 6, large thermal stress acts on the soldered portion, and repeated application of this thermal stress causes the soldered portion to break. In other words, the arrangement of the terminals 2 and 7 in the soldered part is high density and the joint width is narrow, and there is not enough space to make a strong soldered joint, and the amount of solder is limited, making the joint safe. As a result of not being able to adopt a structure that allows for a high rate of reduction, there was a problem in that the soldered parts could break.

[0007] The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to obtain a terminal coupling structure for electronic components that has sufficient strength against thermal stress during operation of the electronic components. With the goal.

[0008]

[Means for Solving the Problems] A terminal coupling structure for an electronic component according to the invention of claim 1 has a substrate disposed at right angles to the electronic component, and a terminal of the electronic component and a terminal of the substrate. are formed on the same plane, and these terminals are connected with a conductive wire. Also, this claim 2
A terminal coupling structure for an electronic component according to the invention comprises a substrate disposed perpendicularly to the electronic component, and a terminal of the substrate bent so as to be coupled on the same plane to the terminal of the electronic component. In addition, these terminals are connected with conductive wires.

[0009]

[Operation] In the terminal coupling structure of electronic components according to the invention of claim 1, since the electrically conductive wires have flexibility by coupling the terminals using the electrically conductive wires, the difference in thermal expansion between the electronic components and the substrate The parts to be joined are held safely in the face of thermal stress.

In the electronic component terminal coupling structure according to the second aspect of the invention, the terminals of the board are bent and the bent portions are bonded to the terminals of the electronic component on the same plane. Facilitates automation of joining in the department,
At all times, electronic signals can be sent and received directly between each terminal,
Even if the bonding between the terminals becomes unstable due to the difference in thermal expansion, the electronic signal can be sent and received through the flexible wire that connects the terminals.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of the liquid crystal panel of the present invention, FIG. 2 is a perspective view of FIG. 1, FIG. 3 is a cross-sectional view showing an example of the terminal connection process using the electronic components shown in FIG. 1, and FIG. 1 is a sectional view showing an example of a terminal coupling structure of an electronic component according to the present invention, and in FIGS. 1 to 4, the same or equivalent components as in FIGS. 6 to 8 are denoted by the same reference numerals, and redundant explanation will be omitted. . In this embodiment, a bonding structure using micro spot solder will be explained using a liquid crystal display device as an example. In the figure, 13 is a liquid crystal panel as an electronic component constituting a liquid crystal display device, and this liquid crystal panel 13 is supported by a frame 10 made of synthetic resin such as reinforced plastic (FRP). Note that the flexible substrate 6 is also supported by the frame 10. Reference numeral 14 denotes an electronic component terminal provided at an end of the liquid crystal panel 13, and the electronic component terminal 14 is bent at right angles to the display surface of the liquid crystal panel 13. 14a is preliminary solder applied on the electronic component terminal 14. 15 is a conductive wire that connects the electronic component terminal 14 and the flexible board terminal 7; 16 is a spot soldering portion at both ends of the conductive wire 15 that is connected to the electronic component terminal 14 and the flexible board terminal 7.

Next, the operation will be explained. First, in order to connect the flexible substrate 6 to the liquid crystal panel 13 that is vertically erected by the frame 10, the positions of the electronic component terminals 14 of the liquid crystal panel 13 and the flexible substrate terminals 7 of the flexible substrate 6 must not shift. The flexible board terminal 7 is arranged on the same plane as the electronic component terminal 14, and the flexible board terminal 7 is accurately positioned at a distance of 2 mm or more from the electronic component terminal 14. Thereafter, as shown in FIG. 3, both terminals 7 and 14 are connected by micro spot soldering using a soldering iron 17 using a conductive wire 15.

Therefore, as shown in FIG.
The flexible board terminal 7 can be connected to the electronic component terminal 14 on the same plane, and the flexible board terminal can be placed at a distance of 2 mm or more from the electronic component terminal 14, compared to conventional fillet soldering. Thermal stress acting on the joint is significantly alleviated. Therefore, even if the liquid crystal panel 13 as an electronic component and the flexible substrate 7 are mutually deformed due to thermal stress due to the difference in thermal expansion coefficient during operation of the liquid crystal display device, the flexible conductive wire 1
5, both terminals 14 and 7 are coupled.

The reason why non-micro spot soldering is used to connect the electronic component terminals 14 and the flexible board terminals 7 is as follows. That is, ■ Since it can be bonded at a low melting point, it does not damage elements or parts that are susceptible to heat effects. ■ It is advantageous for dissimilar material joints because it does not involve a direct metallurgical reaction between the base materials that make up the joint. ■ Because joints are formed by their own surface tension and capillary action, advanced technology is not required for positioning parts. ■
Parts can be replaced by partially remelting the joint once joined.

FIG. 5 shows another embodiment of the invention. In this method, a flexible board terminal 7 bent at, for example, 90 degrees is connected to a terminal 14 of a liquid crystal panel as an electronic component so that it is connected on the same plane, and a connection is made between these two terminals 7 and 14. They are connected by conductive wires 15. According to this, since both terminals 7 and 14 are normally connected over a large area on the same plane, electronic signals can be sent and received with low resistance, and the connection between each terminal is prevented due to the difference in thermal expansion. Even when the terminal becomes stable, the conductive wire 15 enables transmission and reception of electronic signals, and a terminal structure with stable quality can be obtained. Furthermore, since the terminals 7 and 14 are directly joined on the same plane, the positions of these spot soldering parts 16 can be placed close to each other, facilitating automation of wire connections, and various joining methods can be employed.

In the above embodiment, connection by micro spot soldering has been described, but wire bonding as shown in FIG. 6 may be used instead of micro spot soldering, and the same effects as in the above embodiment can be obtained. In other words, wire bonding methods include thermocompression bonding and ultrasonic methods depending on the heat source, but these methods melt conductive wires with gold or aluminum wires, and are easier to automate than micro spot soldering methods. Stable quality can be obtained. Therefore, the working time can be shortened, and it can be said that this manufacturing method is optimal for devices such as large screen display devices that require a large number of terminal connections when manufacturing a large number of display units. In the figures, the same reference numerals indicate the same or equivalent parts.

Next, to explain the wire bonding method using thermocompression bonding, a gold wire 18 is used as a thin metal wire for wiring. This is primarily because the clean surface of this material, which has excellent oxidation resistance, is advantageous for stabilizing the bond. and,
By heating and melting the tip of the gold wire 18, the ball 1 can be stably held even in the atmosphere by its own surface tension.
9 can be formed, and the ball bonding method in which the ball portions are crimped and bonded can be used as a mass-produced bonding device with no restrictions on the subsequent connection direction.

FIG. 6 shows the operating sequence of thermocompression bonding. According to this, the gold wire 18 is supplied to its tip through a tool called a gapillary tip 20, and first a ball 19 with a diameter of 70 to 80 millimeters is formed at the tip by melting it using an electric arc.
Figure 6a). Thereafter, the capillary chip 20 descends to press the ball 19 onto the flexible board terminal 7 (ball bonding) (FIG. 6b). After ball bonding is performed in this manner, the capillary chip 20 is pulled up and moved directly above the electronic component terminal 14. The electronic component terminal 14 side is bonded by crimping the lying gold wire 18 with the capillary tip 20 (wedge bonding).
(Figure 6c). Subsequently, the gold wire 18 is clamped and pulled up together with the capillary chip 20, thereby automatically cutting the neck portion of the joint portion of the gold wire 18 with the electronic component terminal 14, thereby completing the joining between one terminal. Thereafter, this operation is repeated for the number of terminals to connect the terminals.

[0019] Also, to explain the ultrasonic wire bonding method, this ultrasonic wire bonding method uses aluminum wire instead of the gold wire used in the thermocompression bonding method. A sound wave method is adopted. According to this ultrasonic method, the material combination of the electronic component terminal and the flexible board terminal, which are the joint parts, is aluminum and aluminum, so unlike gold and aluminum, intermetallic compounds are not formed, so the diffusion layer becomes thicker. There is no need to worry about strength deterioration.

[0020]

As described above, according to the invention of claim 1, the terminal coupling structure of the electronic component is arranged so that the board is perpendicular to the electronic component, and the terminals of the electronic component and the terminals of the board are the same. Since these terminals are arranged on a plane and connected by conductive wire, the conductive wire has flexibility even when the electronic component is in operation, so the difference in thermal expansion between the electronic component and the board can be reduced. This has the effect that sufficient strength can be obtained against the thermal stress caused by this.

Further, according to the second aspect of the invention, the substrate is arranged perpendicularly to the electronic component, and the substrate is bent so as to be connected to the terminal of the electronic component on the same plane. The terminals are equipped with conductive wires to connect each of these terminals, making it easy to automate the joining of each terminal, while always ensuring sufficient electrical connection at each joint. When this bonding becomes unstable, the electrical connection can be maintained stably through the conductive wire, and a terminal structure with stable quality can be achieved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a liquid crystal panel which is an electronic component according to an embodiment of the present invention.

FIG. 2 is a perspective view of FIG. 1;

FIG. 3 is a sectional view illustrating a working state of connecting terminals of an electronic component according to an embodiment of the present invention.

FIG. 4 is a sectional view showing a terminal coupling structure of an electronic component according to an embodiment of the present invention.

FIG. 5 is a sectional view showing a terminal coupling structure of an electronic component according to another embodiment of the present invention.

FIG. 6 is a process chart showing the order of terminal connection work for electronic components according to the present invention.

FIG. 7 is a cross-sectional view showing an example of a conventional terminal coupling structure of an electronic component.

FIG. 8 is a perspective view showing a display unit having a conventional liquid crystal panel.

9 is a perspective view showing a large screen display device configured with the display unit of FIG. 8. FIG.

[Explanation of symbols]

6 Flexible board 7 Flexible board terminal 13 Electronic parts (liquid crystal panel) 14 Electronic component terminal 15 Conductive wire

Claims (2)

[Claims] 1. A device comprising: a substrate disposed perpendicularly to an electronic component; and a conductive wire that forms terminals of the electronic component and terminals of the substrate on the same plane and connects these two terminals. Terminal connection structure of electronic components. 2. A circuit board arranged perpendicularly to the electronic component, a terminal of the circuit board bent so as to be connected to the terminal of the electronic component on the same plane, and a connection between these two terminals. A terminal coupling structure for electronic components, which is equipped with a conductive wire.