JP2001215899A - Luminous display device and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a luminous display device which is formed as a luminous display device of a surface packaging type by using an insulating substrate but is formed of a structure to make resins or the like hardly adherable to electrode terminals for soldering to circuit boards and others and a method for manufacturing the same. SOLUTION: The surface of a substrate 1 formed with wiring patterns 11 in such a manner that multiple light emitting parts respectively constituting part of display images, such as respective segments of, for example, numerals may be formed are respectively segmented with the multiple light emitting parts. Light shielding wall parts 3 are adhered and disposed to the substrate 2 in such a manner that these multiple light emitting parts are formed as light guide parts 32 and are shielded of light from each other between the adjacent light emitting parts. LED chips 2 are bonded onto the respective wiring patterns 11 within these light guide parts 32. The liquid resin is injected into the respective light guide parts 32 or the light shielding wall parts 3 are inserted into the liquid resin put into a translucent case, by which a small amount of the translucent resin 4 is filled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device for displaying characters such as numbers and characters having a seven-segment or dot matrix structure by using a light emitting element such as an LED chip, which is used, for example, for displaying the amount of money in a vending machine. The present invention relates to a display device and a manufacturing method thereof. More specifically, while forming the light-emitting part on the substrate on which the electrode terminals are formed so that it can be surface-mounted, the electrode terminals soldered to the circuit board etc. have a structure that is easy to mount without resin etc. adhering to the electrode terminals. The present invention relates to a light emitting display device and a manufacturing method thereof.

[0002]

2. Description of the Related Art A conventional light-emitting display device having a seven-segment structure has a structure as shown in FIG.
That is, a light guide portion that forms seven segments is formed in the case 3, and a light emitting element (hereinafter, referred to as an LED chip) (not shown) is die-bonded and wire-bonded to a lead for each segment, and a light-transmitting portion is formed in the light guide portion. It is formed by filling the resin 4. LED
The chip has an anode and a cathode, two for each segment.
Although one lead is required, one lead of the anode or the cathode can be common to each segment, and 8 to 10 leads are formed for a single digit number (for displaying a decimal point). ), For example, from the side of the number.

[0003] A light-emitting display device for displaying such numbers and the like includes:
A number of the same items are displayed side by side and displayed with a large number of digits.
Therefore, it is necessary to arrange the leads laterally without any gap, and it is not possible to form the so-called gull-wing shape by bending the leading ends of the leads led out in the lateral direction outward, and to perform surface mounting. Therefore, in this type of light emitting display device, as shown in FIG. 5, each lead is extended straight and inserted into a through hole provided on a circuit board or the like and soldered, so that electrical connection and fixation are achieved. It has a lead dip shape to be made. At this time, the legs 31 are provided at the four corners of the case 3 to determine the height. Therefore, automatic mounting by an automatic machine and mounting by reflow soldering cannot be performed, and assembling man-hours are required.

On the other hand, as a type capable of surface mounting, for example, as shown in Japanese Patent Application Laid-Open No. 11-135839, a structure in which an LED chip is mounted on an insulating substrate without using a lead frame has been disclosed. I have.
That is, as shown in a perspective view and a sectional view of FIG. 6, an insulating substrate 6 on which a plurality of LED chips 62 are mounted
1 and a display plate 63 having a display pattern (a part constituting a part of a display image such as a segment) on the surface thereof are formed by bonding using a translucent thermosetting filler resin 64. I have. In FIG. 6, reference numeral 65 denotes an electrode terminal portion, and a conductor pattern 66 such as gold plating is formed on the inner surface of the through hole. Reference numeral 67 denotes a cover formed by covering the outer surface of the display panel 63 with the above-described light-transmitting resin. Reference numeral 68 denotes a through-hole provided in the insulating substrate 61, and a part of the through-hole is provided with a light-transmitting resin. Of the filling resin 64 is flowing.

[0005]

In the surface mount type light-emitting display device using the insulating substrate as described above, the electrode terminal portion 65 is used.
If the resin is not cleaned without adhering to the resin, the reliability of soldering by reflow to a circuit board or the like cannot be obtained. However, in the structure as shown in FIG.
The insulating substrate 61 and the display panel 63 are bonded to each other by using a liquid translucent resin 64. The resin flows out through the gaps between the conductor patterns, and also flows to and adheres to the electrode terminal portions 65. There is a problem that it is easy. In such a structure in which the cover 67 is formed while filling the liquid crystal resin and bonding the display panel 63, the resin easily leaks out, and it is an issue how to prevent the resin from adhering to the electrode terminal portions. I have.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem. A surface mount type light-emitting display device using an insulating substrate and a resin terminal portion for soldering to a circuit board or the like are provided. It is an object of the present invention to provide a light-emitting display device having a structure to which it is difficult to adhere, and a method for manufacturing the same.

[0007]

According to the present invention, there is provided a light emitting display device, comprising: a substrate on which a wiring pattern is formed so as to form a plurality of light emitting portions each constituting a part of a display image;
A light-shielding wall provided on the substrate so as to partition the plurality of light-emitting portions and to provide a light-guiding portion on the plurality of light-emitting portions and to mutually shield light between adjacent light-emitting portions; A light emitting element is bonded to each of the wiring patterns in the light portion, and a light transmitting resin is filled in at least a part of each of the light guide portions.

[0008] Here, the display image means an image that can change the display state of numbers, characters, characters, and the like. A part of the display image is, for example, one segment when a number is displayed in seven segments. means.

According to this structure, the light-shielding wall which makes each light-emitting portion on the insulating substrate on which the pattern is formed an independent light guide is provided by being bonded to the insulating substrate by, for example, injection molding. There is no need to integrate the light-shielding wall (reflection case) and the substrate with a resin, and only the light-guiding portion needs to be filled with the translucent resin. Moreover, the filling of the resin does not need to be completely filled in the light guide portion to every corner, and it is sufficient that the resin is filled to the extent that light can be diffused.
It may be in a semi-hollow state. As a result, it is not necessary to fill as much as the resin overflows, and it is possible to reduce the amount, so that the overflowed resin does not seep into the electrode terminal portions.

The filling of the resin may be performed, for example, by dropping the resin into each light guide part by a dispenser, or by placing a small amount of liquid resin in a light-transmitting case and placing a light shielding wall part therein. May be inverted and inserted and cured to fill the gap between the translucent case and the light-shielding wall with the translucent resin. In this case, if a resin escape portion is formed between the translucent case and the light shielding wall, even if the translucent resin overflows, the resin does not flow to the electrode terminal side.

Here, the resin escape portion is, for example, as shown in FIG. 4, a gap 3 between the light-transmitting case and the light-shielding wall.
6 or a concave portion 35 is formed in the light-shielding wall, or a thick portion 7a is formed in the side wall of the light-transmitting case so as to form a gap between the resin and the substrate. The light-transmitting case has a shallow side wall so that a resin pool can be easily formed between the light-shielding wall and the outer wall of the light-transmitting case. This means that the resin is less likely to flow toward the electrode terminal portion by making it easy to form a resin puddle on a wall.

A method for manufacturing a light emitting display device according to the present invention is as follows.
(A) a step of forming a substrate provided with a wiring pattern so as to form a plurality of light-emitting portions each forming a part of a display image; and (b) a light-guiding portion capable of including each of the plurality of light-emitting portions. (C) forming a light-shielding wall for shielding light between adjacent light-emitting portions on the substrate; (c) die-bonding and wire-bonding a light-emitting element on a wiring pattern in the light-guiding portion; And a step of filling at least a part of the light guide portion with a translucent resin.

The step (d) of filling the light-transmitting resin can be performed by sequentially injecting the light-transmitting resin into each of the light guide portions, or the light-transmitting resin filled with the light-transmitting resin can be used. It can also be performed by inserting and fixing the light-shielding wall in the light case.

[0014]

Next, a light emitting display device of the present invention and a method of manufacturing the same will be described with reference to the drawings. The light-emitting display device according to the present invention is formed with a plurality of light-emitting portions each forming a part of a display image such as each segment of a number as shown in FIG. The wiring pattern 11 is formed on the substrate 1 so that the wiring pattern can be formed. The plurality of light emitting portions are partitioned on the substrate 1, and the light emitting portions 32 are formed on the plurality of light emitting portions, and the light shielding wall 3 is bonded to the substrate 1 so that adjacent light emitting portions mutually shield light. It is provided.
Then, each wiring pattern 1 in the light guide portion 32
A light emitting element (LED chip) 2 is bonded on 1. At least a part of each of the light guide portions 32 is filled with the light transmitting resin 4. In other words, it may not be completely filled and may be in a semi-hollow state.

As the substrate 1, for example, a printed substrate made of glass epoxy or the like is used. Any material may be used as long as it has heat resistance and insulation properties and can form a wiring pattern on its surface. It is not necessary to have a three-dimensional shape. However, if an MID (Molded Interconect Device) in which a wiring pattern is formed on an insulating plastic molded product is used, the shape of the substrate can be three-dimensionally controlled while having the wiring pattern. It can also be shaped.

The wiring pattern 11 is formed into a pattern similar to the shape of a lead frame when it is manufactured using a lead frame, for example, by a printing method or a method of vapor deposition and patterning, and is a part of a display image.
For example, patterning is performed so that a light emitting portion is formed at the position of each of the seven segments. The ends of the wiring pattern 11 are led out to the back surface of the substrate 1 through the side surfaces of the substrate 1 or through holes, respectively, and electrically connected electrode terminals 12 are formed. That is, when mounted on a circuit board or the like, the structure is such that surface mounting can be performed by soldering at the electrode terminals 12. The formation of the conductor film on the side surface of the substrate 1
When forming in the state of a large substrate,
It can also be formed by forming a through hole at the boundary of each display device, attaching a conductor to the inner surface thereof, and cutting at the boundary.

The light-shielding walls 3 are formed directly on the substrate 1 by injection molding in which a resin is injected, for example, by sandwiching them with a mold so that the light-shielding walls 3 are formed around each light-emitting portion constituting each segment. Have been. By being formed by injection molding in this way, it is provided directly adhered on the substrate 1. However, a method may be used in which the light-shielding wall 3 is formed in advance so as to surround the light-emitting portions and the light-guiding portion is provided, and the light-shielding wall 3 is adhered to the substrate 1 with an adhesive or the like. In short, the light-shielding wall 3 may be directly bonded on the substrate 1 in advance so that the light-transmitting resin 4 does not need to be bonded to the substrate 1. The light-shielding wall 3 is formed of a heat-resistant thermoplastic resin such as a liquid crystal polymer, polycarbonate, and ABS. The display surface is painted with black to improve the appearance.

The LED chip 2 is die-bonded on the wiring pattern 11 in the light guide 32 surrounded by the light-shielding wall 3, and the other electrode is connected by wire bonding such as a gold wire 21. Thus, a light emitting section is formed for each segment. The formation of the light emitting section is performed in the same manner as in the related art.

Each light guide 32 to which the LED chip is bonded is filled with a translucent resin 4 such as a silicone resin or an epoxy resin. The translucent resin 4 does not need to be transparent, and may transmit light emitted from the LED chip 2.
In the case of the chip 2, even if the resin mixed with the red dye does not block the red light, it can be easily understood that the display device is a red display device when viewed from the outside when no display is performed.

The light-transmitting resin 4 is filled by, for example, injecting (potting) each light guide portion 32 with a dispenser, but the amount of potting is made small so as not to overflow. If the translucent resin 4 is too much and overflows, it is transmitted to the outer periphery of the light-shielding wall 3 and the electrode terminal 1
It is not preferable because it flows into two parts. On the other hand, even if the amount is too small, the light from the light emitting unit is diffused by the light transmitting resin 4 and is partially diffused by the light transmitting unit 3 if it is partially filled in the light guiding unit 32.
The whole of 2 appears to emit light, and one segment can emit light. Therefore, the filling of the resin is less potted. When injecting with a dispenser, one light emitting portion (light guiding portion) has a depth of, for example, about 2 mm and a length of about 4 mm, which is very small, and even a single drop is too large. By filling the wall of the dispenser with a tip of a dispenser and dropping about half a drop, it is possible to fill well.

To manufacture this light emitting display, FIG.
As shown in (a), first, the wiring pattern 11 and its end are led out to the back surface of the substrate 1 so that a plurality of light-emitting portions constituting each of the seven segments can be formed on the printed circuit board 1 or the like. By forming the electrode terminals 12, the substrate 1 on which the wiring patterns 11 are formed is prepared. Next, as shown in FIG. 2B, light-shielding walls 3 are formed by, for example, injection molding so as to shield between the light-emitting portions and form a light-guiding portion on each light-emitting portion. The display surface side of the light shielding wall 3 is painted black. Then, as shown in FIG. 2C, the LED chip 2 is die-bonded on the wiring pattern 11 in each light guide portion 32, and further wire-bonded with the gold wire 21 or the like. Then, the light-emitting display device shown in FIG. 1 is obtained by injecting the light-transmitting resin 4 into each light guide portion 32.

According to the light-emitting display device of the present invention, a light-emitting portion such as each segment has a structure in which an insulating substrate is used and the electrode terminals provided on the substrate can be surface-mounted on a circuit board or the like. Since the light-shielding wall for partitioning is previously bonded to the substrate, it is not necessary to bond the light-shielding resin with the light-transmitting resin, and the light-transmitting resin to be filled in the light emitting unit is small. Therefore, the resin filling the light emitting portion does not overflow and flow toward the electrode terminal portion, and the electrode terminal portion to be soldered is not contaminated by the resin or the like.
As a result, while the soldering can be performed very easily by surface mounting, the reliability of the soldering can be improved, and the mounting becomes very simple.

In the above-described example, the light-transmitting resin is injected into the light guide. However, the point is that the light-transmitting resin in such an amount that it does not overflow is applied to at least a part of each light guide. What is necessary is just to fill, and the filling method does not need to be an injection method. Another example of this filling method is shown in FIG. 3 by the same manufacturing process diagram as FIG.

First, as in the examples shown in FIGS. 2A to 2C, a wiring pattern 11 and electrode terminals 12 are formed on a printed circuit board 1 and the like, and a light-shielding wall 3 is formed by injection molding or the like. Then, L is printed on the wiring pattern 11 in each light guide portion 32.
The ED chip 2 is die-bonded, and further wire-bonded with a gold wire 21 or the like.

After that, the liquid translucent resin 4 is put into a translucent case 7 made of a liquid crystal polymer or the like in which the inner circumference is larger than the outer circumference of the light shielding wall 3 and the inner height is lower than the height of the light shielding wall 3. In addition, as shown in FIG.
The substrate 1 to which the D chip 2 is bonded is turned upside down,
The light shielding wall 3 is put in the translucent case 7. as a result,
The liquid light transmitting resin 4 in the light transmitting case 7 is
By entering the inside and curing the translucent resin 4, FIG.
As shown in (b), the translucent case 7 is adhered to the light shielding wall 3, and the translucent resin 4 is cured in the light guide 32. At this time, if the amount of the light transmitting resin 4 is set to be small, the light transmitting portion 32 may not be completely filled with the light transmitting resin 4 as shown in FIG. As in the above-described example, it is not necessary to completely fill the inside of the light guide portion 32 with the resin, and it is preferable that the resin does not overflow to the electrode terminal 12 side.

As shown in FIG. 3, when a liquid resin is put in the translucent case 7 and the light-shielding wall of the substrate 1 to which the LED chip 2 is bonded is inserted and manufactured, If the amount of the translucent resin 4 is too large, the translucent case 7
There is a risk of overflowing from the electrode terminal and flowing toward the electrode terminal 12.
A structure for avoiding such a danger is shown in FIG. That is, in the example shown in FIG. 4A, the concave portion 35 is formed in a part of the light shielding wall 3, and the overflowing resin is absorbed by the concave portion 35, and the inner periphery of the translucent case 7 is covered with the light shielding wall. 3 is made larger than the outer periphery of the gap 3 so that the resin overflowing in the gap 36 can be absorbed.

In the example shown in FIG. 4B, a thick portion 7a is formed on the side wall of the translucent case 7 so that a gap is formed between the transparent case 7 and the substrate 1. With such a structure, even if the amount of the translucent resin 4 is too large and overflows to the outside of the translucent case 7, the thick portion 7 of the translucent case 7 can be formed.
The translucent resin 4 is held in the gap between the a and the substrate 1 and does not flow toward the electrode terminal portion 12.

In the example shown in FIG. 4 (c), the depth of the translucent case 7 is reduced. By making the depth so small, even if the translucent resin 4 overflows, The translucent resin 4 is held between the side wall of the light shielding wall 3 and the end of the side wall of the translucent case 7, and does not transmit on the substrate 1.
Further, in the example shown in FIG. 4D, the depth of the translucent case 7 is reduced and the outer peripheral side wall is formed as a double wall 7b, so that a large amount of resin overflows. Even if the light cannot be absorbed only between the side wall of the light-shielding wall 3 and the end of the translucent case 7 shown in FIG. 3C, the resin flows into the gap between the double walls 7b by capillary action, so that the resin flows toward the substrate 1 side. The resin will not drip.

In each of the above-described examples, a printed circuit board is used as the substrate. However, an MID which is a plastic molded product capable of forming a wiring pattern may be used. Further, the light shielding wall is formed directly on the substrate by injection molding, but a light shielding wall formed in advance may be adhered to the substrate 1. Also,
In the case of the structure shown in FIG. 4, the effect is further enhanced by adopting each example in combination.

[0030]

According to the present invention, even when a surface mount type light emitting display device is formed using an insulating substrate, a light shielding wall in which light emitting portions forming a part of a display image are shielded from each other is adhered to the substrate. Since it is used, there is no need to adhere with a translucent resin, and the amount of the translucent resin can be extremely reduced. As a result, the translucent resin does not overflow and does not flow out to the electrode terminal portion provided for soldering on the substrate, so that a very reliable light emitting display device can be obtained at low cost.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating one embodiment of a light emitting display device according to the present invention.

FIG. 2 is an explanatory diagram showing a manufacturing process of the display device shown in FIG.

FIG. 3 is a view showing a manufacturing process of another embodiment of the light emitting display device of the present invention.

FIG. 4 is an explanatory sectional view showing a modified example of the example shown in FIG. 3;

FIG. 5 is a perspective view illustrating an example using a lead frame of a conventional light emitting display device.

FIG. 6 is a diagram illustrating an example of a conventional light emitting display device using an insulating substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 LED chip 3 Shield wall 4 Translucent resin 12 Electrode terminal 32 Light guide part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 33/00 H01L 33/00 N

Claims (6)

[Claims] 1. A substrate on which a wiring pattern is formed so as to form a plurality of light-emitting portions each constituting a part of a display image, and the plurality of light-emitting portions are partitioned, and the plurality of light-emitting portions are separated from each other. A light-shielding wall provided on the substrate so as to be a light-guiding portion and mutually shield light between adjacent light-emitting portions, and a light-emitting element bonded to each of the wiring patterns in the light-guiding portion; A light-emitting display device comprising a light-transmitting resin that fills at least a part of each of the light guides. 2. A light-transmitting case is provided at least on a display surface side of the light-shielding wall, and a gap between the light-transmitting case and the light-shielding wall is filled with the light-transmitting resin. Light-emitting display device. 3. The light-emitting display device according to claim 2, wherein a resin escape portion is formed between the translucent case and the light-shielding wall. 4. A step of forming a substrate on which a wiring pattern is provided so as to form a plurality of light emitting portions each forming a part of a display image, and (b) including each of the plurality of light emitting portions. Forming a light-shielding wall for shielding light between adjacent light-emitting portions on the substrate,
(C) a step of die-bonding and wire-bonding a light-emitting element on a wiring pattern in the light guide section;
(D) a step of filling at least a part of the light guide portion with a translucent resin. 5. The step (d) of filling a translucent resin,
5. The method according to claim 4, wherein the step is performed by sequentially injecting a translucent resin into each of the light guides. 6. The step (d) of filling a translucent resin,
5. The method according to claim 4, wherein the light shielding wall is inserted and fixed in a light transmitting case containing a light transmitting resin.