KR820000243B1 - Electro luminescent display device - Google Patents

Abstract

The title device includes two elongated, conductive contacts adjacent to and spaced from each other with two coextensive ends. A light emitting element is electrically coupled between the coextensive ends. An elongated insulating base is formed about and between the contacts with their elongated outer edges extending beyond the elongated sides of the base. The base extends the entire length of the outer edges of the contacts and is intergral between such contacts. The device is fabricated in a lead frame environment, where the light-emitting element is bonded to a lead frame. A lens is formed over the light-emitting element.

Description

Light emitting display

1 is an enlarged perspective view of an active base of a plug-in type light emitting diode device according to the present invention;

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1 showing the lead frame edge protruding above the active base surface of the FIG.

3, 4 and 5 show various stages of the assembly process of the device.

6 is an alternative embodiment of the present invention.

7, 8 and 9 show another embodiment of the present invention.

FIG. 10 is a schematic diagram illustrating how the device of FIG. 9 can be connected for protection of an electrical circuit. FIG.

The present invention relates to a light emitting device comprising a light emitting element that can be electrically operated.

Prior art light emitting diodes have been used to fabricate plug-in devices replacing switchboards, buttons, or similar lamps. This light emitting diode device has more advantages than the conventional switchboard lamps of carbon and tungsten filaments. These advantages include reduced power consumption, reduced risk of burns, extended life and reduced maintenance costs due to the use of suitable materials such as plastic.

However, these prior art devices are expensive due to the complexity and assembly techniques that require the time-consuming and expensive use of parts due to the processing of a single device.

Another drawback of the prior art devices is the lack of compactness and robustness. Such devices are, for example, liable to separate or break the adhesion between various metal-to-metal and plastic-to-metal.

Another disadvantage of the prior art devices is that they tend to rotate freely in the socket, thus losing proper electrical contact to the device.

The above-mentioned drawbacks of the prior art are solved by a light emitting display device which is characterized by including two contacts which are separated from each other and extended together, the light emitting elements being electrically coupled between adjacent ends of the contacts and between and around the contacts. An elongated insulating enclosure is formed, the elongated outer edge of the contact projecting over the side of the base and serving as a terminal for the device.

According to the present invention, the display device or light emitting die-yod 31 shown in FIGS. 1 and 2 overcomes many disadvantages of the prior art. The device 31 can be most easily implemented by describing its manufacturing method.

Many devices 31 are well assembled by batch processing techniques. For this purpose a number of lead frames connected side by side, shown at 32 in FIG. 3, are used. Each leadframe 32 includes a pair of isolated long parallel portions 33 and 34, the edges 36 and 37 (first, second and third degrees) of which form the terminals for the finished device 31 (first degree). do. Each leadframe 32 also includes a header portion 38 and a leading portion 39 whose header portion 38 is integrated with the contact portion 34.

Multiple frames 32 (only two are shown in FIG. 3) are interconnected by multiple supports 41, 42, and 43 and perforated support strips 44 and multiple props 45 for ease of extraction.

The lead frame 32 may be generally formed by press-fitting an electrically conductive thin plate such as an alloy of copper, nickel, and tin. Generally, the frame is plated with materials such as nickel, silver and gold. In addition, a frame strip which is sufficiently flexible and substantially planar is connected with the frame 32 so that it can be wound on the reel without damage.

In assembling the device 31, one terminal of a light emitting element or chip 46 (FIG. 3), which is usually formed of a suitably doped semiconductor wafer, is bonded to the header portion 38 of each leadframe 32. As shown in FIG. Although only one chip 46 is shown glued to each frame in FIG. 3, each frame may include multiple chips 46 bonded to one or several header portions 38. The better conductor 48, if gold, is glued to the other terminal of chip 46 and the leading part 39 of the leadframe 32, and the header part 38 and the leading part 39 of the frame 32 extend substantially the same length. After the wire 48 is bonded to the chip 46, a flexible transparent thin film insulation (not shown) such as silicone rubber or epoxy is applied to the chip 46.

Thus, the transparent insulating range cap 49 is formed on the head 46 and the head 38 and 39 of the chip 46, the lead 48, and the lead frame 32. Lens cap 49 is formed using a casting technique or an injection or moving mold technique from a suitable plastic, as used in the prior art apparatus. The shape of the range cap 49 includes a rounded top surface and a flat lower surface, and an independent solid cylinder projection 51 surrounding the frame header and leading portions 38 and 39.

The 53 and 54 portions of the support 43 are then removed, leaving each leadframe 32 by stamping as shown in FIG. Note that the 43 'portion of the support 43 is not removed at this time. The importance of this will be described later. Thus, the pair of terminals 56 of the voltage drop resistor 57 is welded to the flag portion 59 of the contact portion 33 of the lead frame 32 as shown in FIG. Since the terminal 56 of the resistor 57 has the same length, the orientation and welding of the resistor 57 are simplified. The optional resistor 57 allows the device 31 to be used over a wide range of operating voltages, typically in the region of about 6 to 48 volts. If resistor 57 is not installed in device 32, contact 33 of frame 32 may be made identical to contact 34.

If the resistor 57 is used in welding, the insulated solid enclosure 61 is bonded and formed to the frame part 32 and its portion, which encloses the protruding portion 51 of the lance cap 49 and the long active part 62 (first and fifth degrees). Including and having opposing flat surface 63 (FIG. 2). The active base 62 seals the contacts 33 and 34 of the leadframe 32 and the resistor 57 and the long edges 36 and 37 of the contact sections 33 and 34 protrude above the flat surface 63 of the active base 62. Typically, the edges 36 and 37 protrude approximately 15 mils above the flat surface 63 of the activity base 62.

Enclosure 61 also includes a cylindrical portion 64 that adheres to and encloses the cylindrical protrusion 51 of the stove cap 49, the enclosure 64 being completely connected to the active base 62. Thus, the enclosure 61 is equal to the total length of the frame part 32 and is completely glued thereto, resulting in a very robust device 31.

In addition, the activator portion 62 is pointed at the opposite end of the lens cap 49 for convenient insertion into a switchboard ramped or similar socket (not shown). The contact portions 33 and 34 are generally flat rectangular members placed in the plane passing through the longitudinal axis of the active part 62. The edges 36 and 37 of the contact members 33 and 34 can smoothly engage the contacts in the socket into which the device is inserted, and the leading edges of the contacts 33 and 34 are tapered inward. Flat surface 63 of active part 62 effectively reduces the rotation of device 31 in the socket.

Enclosure 61 is preferably formed by encapsulation, such as by injection technique or injection or transfer mold treatment. The stock used in enclosure 61 is insulating and wear resistant. Typically, this is a opaque plastic material of well known form.

A plurality of back notches 66 (FIG. 3) and a plurality of holes 67 are formed in the portions 33 and 34 to securely secure the contacts 33 and 34 of the leadframe 32 to the activity base 62. FIG.

The portions 41, 42 and 43 of support (FIG. 5) after the enclosure 61 is formed, and the struts 45 extending to the outside of the gripping strip 44 and the enclosure 61, are perforated and die (not shown) to separate the device 31 from each other. Not used). A number of indentations 69 are formed in active base 62 such that perforations and dies are provided with sufficient clearance to cut supports 41 and 42 flush with edges 36 and 37 of contacts 33 and 34. Another angle 70 provides the same clearance to cut the support 43 'from the leading portion 39 of the leadframe 32 (FIG. 3). Inside the shell 70, a piece of support 43 'remains. The indentation 70 and the stub portion 43 'are useful as display means for properly positioning the device, which means that the device becomes a permanent part of the device and is different from prior art devices using colored display means.

Shown in FIG. 6 is an alternative embodiment of the invention. In this embodiment, a plurality of cabinets 71 are formed in the contact portions 33 and 34. This cabinet 71 is used to engage multiple latches (not shown) so that the device remains more firmly in place when inserted into the socket (not shown).

In another embodiment, lens cap 49 and enclosure 61 are formed simultaneously as the same material to be a single piece.

In yet another embodiment, the enclosure 61 is formed of two or more preforms glued together to enclose a frame part 32 portion. In general, however, a suitable embodiment uses enclosure 61 which is molded directly to the device.

7, 8 and 9, other embodiments of the invention are shown. 7 and 8 show that, typically, a soluble wire is electrically coupled between the contact elements 33 and 34 of the device. In FIG. 7, the element 73 is bonded to the flag portion 59 and similar portion 74. In FIG. In FIG. 8, the element 73 is directly bonded to the contact portions 33 and 34.

In FIG. 9, the protection element 73 appears to be integrated with the contacts 33 and 34 of the leadframe 32. In FIG.

10 shows the apparatus of FIG. 9 connected to an electrical circuit comprising a load 75 and a battery 77. FIG. Under normal load conditions, the protective element 73, or the fuse, short-circuits the device 31, which remains undriven. However, when the circuit is overloaded, the protection element 73 is melted, evaporated or otherwise broken to open the circuit and at the same time the device 31 is driven by the battery 77. Thus, device 31 not only protects the circuit but also clearly and accurately indicates that an overload condition occurs in the circuit of FIG. This indication provides a method for quickly and conveniently determining the overload condition and the need for corrective action occurring in a number of circuits to which one of the devices 31 of FIGS. 7 to 10 is connected.

The apparatus 31 of FIGS. 7-10 is thus conveniently applied for the protection of telephone circuits.

Claims (1)

In a light emitting display device including a light emitting element 46 which can be electrically operated, two isolated contact members 33 and 34 are provided so that the light emitting element 46 is electrically connected between adjacent ends thereof. And an insulating encapsulation 61 formed between and around the two contact members so that the outer edges 36 and 37 of the two contact members protrude to be used as terminals for the device. .

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