JPH10150227A - Chip type light emitting device - Google Patents

Abstract

(57) [Problem] To provide a chip-type light-emitting element having a structure in which a package is not peeled off even in a very small chip-type light-emitting element. SOLUTION: A light emitting element chip (L) having an insulating substrate 1, terminal electrodes 2 and 3 provided at both ends of the insulating substrate, and two electrodes respectively connected to the terminal electrodes at both ends.
An ED chip) 4 and a package 5 made of a resin that covers the periphery of the light emitting element chip. A notch 1a is formed on the side of the substrate and extends to the back surface of the substrate. The package extends to the back surface of the substrate via the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to portable telephones and PHSs.
The present invention relates to a small chip-type light emitting element suitable for being used as a light source for illumination or display of portable electronic devices such as. More specifically, the present invention relates to a chip-type light-emitting element having a structure in which a light-emitting element chip is mounted on an insulating substrate, and a surface thereof is covered with a mold resin to form a package.

[0002]

2. Description of the Related Art As portable devices such as portable telephones and PHSs are downsized, light-emitting elements and the like used for them are also required to be light and thin.

As shown in FIG. 7, in this type of chip type light emitting element, terminal electrodes 2 and 3 are formed at both ends of a substrate 1, and a light emitting diode (LED) is formed on an electrode which is a part of one terminal electrode 2. A chip 4 (hereinafter referred to as an LED) is bonded and its lower electrode is directly connected to the terminal electrode 2, and its upper electrode is electrically connected to the other terminal electrode 3 by wire bonding with a gold wire 7. I have. The substrate 1 is made of a BT resin or the like in which a heat-resistant BT resin is impregnated in a glass cloth or the like, and the surface of the substrate 1 is molded with a resin made of a transparent or milky-colored epoxy resin to form an LED chip 4. A package 5 for covering and protecting the metal wire 7 and the like is formed. The substrate 1 made of BT resin or the like and the package 5 made of epoxy resin or the like have good adhesion and are fixed only by being coated on the surface of the substrate 1.

As described above, this type of light emitting element is required to be downsized, and its width (D) × length (E) × height (F) is reduced from the conventional size of about 2 mm × 1.25 mm × 0.8 mm. 1.6m
It is as small as about mx 0.8 mm x 0.8 mm, and further downsizing of about 1 mm x 0.5 mm x 0.5 mm is required.

[0005]

As described above, when miniaturization of a chip type light emitting element is required, characteristics such as the light emission luminance cannot be reduced, and the LED chip can hardly be reduced in size. . Therefore, the LED on the board
The size is reduced by reducing the portion without chips or the like. As described above, the epoxy resin of the package is well-adapted to the substrate and has high adhesive strength, but is poorly-adapted to metals such as electrodes on the surface of the terminal electrode and the surface of the LED chip, and has low adhesive strength. For this reason, as described above, when the size of the element is reduced and the number of substrate parts on which other components are not mounted is reduced, there is almost no contact between the package resin and the substrate, and the adhesive strength is reduced.

When such a chip type light emitting element is used in, for example, a switch section of a cellular phone, as shown in FIG. 8, it is provided side by side near the cut section 12 of the connection board 11 provided with the cut section 12. At the time of use on the user side, the board is cut off by the cut section 12 and incorporated into a mobile phone or the like together with the board.
When cutting off the package, force is applied to the package of the chip-type light emitting element 10, and the package may be peeled off. Further, even when the package is not attached to the substrate in advance, there is a problem that the package is peeled off due to collision between components or handling during assembly.

On the other hand, in a semiconductor device in which a chip of a semiconductor element is bonded on a lead frame and a package is formed by a mold resin, a locking hole is formed in the lead frame to prevent peeling of the package and removal of the lead from the package. It has been practiced to provide a mold resin and prevent peeling and lead omission by penetrating the mold resin. However, like a chip type light emitting element,
The board is different from the lead frame if the board is familiar with the resin of the package, and it is required to be miniaturized.Parts that have electrode terminals on the back of the chip component and require surface mounting directly on a printed board etc. The idea of a normal locking hole is that it is difficult to secure the space for the locking hole, the thickness of the back side of the board cannot be increased, and the formation of the back electrode terminal for surface mounting is necessary. Cannot be applied.

The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a chip type light emitting device having a structure in which a package is not peeled off even in a very small chip type light emitting device. And

Another object of the present invention is to provide a smaller and thinner chip-type light emitting device while preventing peeling of a package.

[0010]

According to the present invention, there is provided a chip-type light emitting device comprising a substrate, terminal electrodes provided at both ends of the substrate, and two electrodes respectively connected to the terminal electrodes at both ends. An element chip and a package made of a resin covering the periphery of the light emitting element chip, a cutout extending to the back surface of the substrate is formed on a side portion of the substrate, and the resin of the package passes through the cutout. The package extends around the back surface of the substrate.

According to this structure, not only a through-hole but a notch is formed in the substrate, and there is no need to increase the area of the substrate. Moreover, since the resin of the package extends from the front side of the substrate to the back side, the package does not peel off.

In a structure in which the terminal electrode is formed so as to extend to the back surface of the substrate, a resin formed to extend to the back surface of the substrate is a portion of the back surface of the substrate where no terminal electrode is provided, and By providing only the thickness, it is possible to firmly fix the package while keeping its thickness without increasing the size on the back surface side.

The light emitting element chip is formed in a rectangular parallelepiped shape such that the outer shape of a light emitting layer of the light emitting element chip is rectangular, and the long side surface of the rectangular shape is parallel to the substrate surface. By being provided on the substrate, the package can be firmly fixed while a thinner chip-type light-emitting element is obtained in a thinner thickness direction.

Here, the light-emitting layer means the recombination of electrons and holes in the vicinity of the pn junction where the p-type layer and the n-type layer are in direct contact, or in the active layer sandwiched between the p-type layer and the n-type layer. Means an area in which light is generated.

[0015]

Next, a chip type light emitting device of the present invention will be described with reference to the drawings.

FIG. 1A shows a chip type light emitting device of the present invention.
(B) is a structure as shown in a perspective view and (a) is a sectional view taken along the line II. That is, terminal electrodes 2 and 3 are provided at both ends of the substrate 1 over the back surface of the substrate 1, the lower electrode of the LED chip 4 is bonded to a part of the terminal electrode 2, and the upper electrode is a gold wire 7. Is wire-bonded to the other terminal electrode 3 to be electrically connected to each other. The periphery thereof is formed by being covered with a package 5 made of an epoxy resin or the like. The package 5 is provided so as to extend to the rear surface of the substrate 1 via a cutout 1 a provided on a side portion of the substrate 1.

The substrate 1 is made of an insulating substrate such as a BT resin in which a glass cloth is impregnated with a heat-resistant BT resin. It has a thickness of about 0.8 mm × 1.6 mm and a thickness of about 0.1 to 0.2 mm. This substrate is formed by forming a large number of elements in a matrix on a large substrate of about 10 cm × 5 cm at the manufacturing stage, and finally cutting the chips into chip elements. Therefore, in the state of the large substrate, the notch 1a is provided across the adjacent chips as shown in FIG. 2 showing a partial view of one row in which the terminal electrodes 2 and 3 are formed. After being molded, and cut by a dicing cut line G after molding, a cutout 1a as shown in FIG. 1 is filled with the resin of the mold. In addition, a slit is formed between the adjacent chip on the side of the terminal electrodes 2 and 3, and the end face is exposed.

The terminal electrodes 2 and 3 are coated with silver paste on the front and back surfaces thereof by screen printing or the like in the state of a large substrate, and by drying, the silver paste also flows on the end surfaces (side surfaces). As shown in a), the substrate 1 is provided from the front surface to the back surface.

The LED chip 4 comprises an n-type semiconductor layer 41 and a p-type semiconductor layer 42 made of a compound semiconductor such as GaAs or GaP, for example, as shown in a perspective view of FIG. A pn junction surface 43 serving as a layer is formed, and a semiconductor having a normal structure in which electrodes 44 and 45 are provided on respective semiconductor layers can be used. However, a structure in which the active layer is sandwiched between the n-type semiconductor layer and the p-type semiconductor layer may be used.

The package 5 is formed by molding a transparent or milky epoxy resin or the like that transmits light from the LED chip 4. This molding is performed by placing the substrate 1 on which the LED chip 4 is mounted on a lower mold, covering the upper mold having a cavity for the package 5 formed thereon, and injecting a molding resin. In the present invention, the back electrodes of the terminal electrodes 2 and 3 are also provided on the back surface of the substrate 1, and a gap is formed between the lower mold and the back surface of the substrate 1 in a portion having no back electrode. Since a notch (a through hole in a manufacturing stage) 1a is provided in a portion adjacent to the chip, the injected resin also flows into the back surface of the substrate 1 through the notch (a through hole) 1a. Therefore, the package 5 formed on the front surface of the substrate 1 is also formed so as to extend to the back surface side of the substrate 1. As described above, the package 5 provided on the back surface side of the substrate 1 is originally filled in the gap between the terminal electrodes on the back surface of the substrate 1 and has the same thickness as the thickness of the back surface of the terminal electrode. Therefore, the external dimensions are not large at all. Further, only the notch 1a is provided in the substrate 1, there is no change in the manufacturing process at the time of molding, and the number of steps is not increased as compared with the related art.

According to the chip-type light emitting device of the present invention, the resin for the package is formed on the substrate by utilizing the notch provided on the side of the substrate and the gap formed between the terminal electrodes on the back of the substrate. Since it is wrapped around the back surface side, there is no need to secure a space for a locking hole, and since it is provided with the same thickness as the back electrode of the terminal electrode, the outer shape of the element does not increase at all. In addition, since a part of the package resin is wrapped around the back surface of the substrate, it is possible to reliably prevent the package from peeling off, and it is not necessary to consider the adhesion between the substrate and the package. Can be achieved.

It is to be noted that, as shown in a side view in FIG. 4, a gap 5a is left partially in the gap between the terminal electrodes on the back surface of the substrate without allowing the resin for the package to flow around the gap. By providing a projection on the lower mold, the gap 5
The solder bridge due to a can be prevented. In FIG. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted.

Next, a method of manufacturing the chip type light emitting device of FIG. 1 will be described. In the manufacturing stage, a plurality of chips are formed in a matrix on a large substrate as described above, and cut and separated into chips in the last step.

First, as shown in FIG. 5, a plan view of the state where the LED chip is bonded is shown for one element.
Terminal electrodes 2 and 3 of elements formed by arranging elements of substrate 1 side by side
A notch 1a is formed in a boundary portion different from the side by a through hole, and a silver paste or the like is screen-printed on the front surface and the back surface and dried, so that the end surface (side surface) exposed by the slit at the boundary portion on the terminal electrode 2, 3 side. Electrodes are also formed
Terminal electrodes 2 and 3 are formed from the front surface to the rear surface of the substrate 1. Next, the LED chip 4 as shown in FIG. 3 is mounted by a suction collet (not shown) or the like, and the terminal electrode 2 and the lower electrode 44 of the LED chip 4 are electrically connected and fixed by a conductive adhesive. Thereafter, the gold wire 7 is wire-bonded between the electrode 45 and the terminal electrode 3.
The LED chip 4 is manufactured by a normal light emitting element wafer process and dicing.

Thereafter, the large substrate 1 on which a plurality of LED chips 4 are provided in a matrix is set in a lower mold of a mold, and the upper mold having a package cavity on the front side is covered with a transparent material. Or by injecting molding resin such as milky white epoxy resin,
The package 5 is formed. At this time, since the back surface electrode of the terminal electrode is provided on the back surface of the substrate 1, when the substrate 1 is set in the lower mold, the portion without the back electrode is located between the lower mold and the back surface of the substrate 1. A gap is formed by the thickness of the back electrode. A notch 1 a
Is provided, when the resin for molding is injected, the resin also flows into the gap between the substrate 1 and the lower mold via the notch 1a. Therefore, the package 5 is formed around the rear surface of the substrate 1 only by providing the notch 1a in the substrate 1 and without requiring a special process or a change in the manufacturing process.

Thereafter, the substrate 1 is cut along the dicing cut line G shown in FIG. 2 to obtain the chip-type light emitting device shown in FIG.

FIGS. 6A and 6B are views showing an example of a chip-type light emitting element which is further thinned, wherein FIG. 6A is a side sectional view, and FIG.
FIG. 3C is a perspective view illustrating a state in which the LED chip 4 is bonded thereon, and FIG. 3C is a perspective view illustrating the LED chip.

In this example, as shown in FIG.
The outer shape of the light emitting layer in which the LED chip 4 is formed by the pn junction surface 43 formed by the n-type semiconductor layer 41 and the p-type semiconductor layer 42 is formed in a rectangular parallelepiped shape. This LE
As shown in FIG. 6B, the D chip 4 is placed on its side so that its wide surface faces the surface of the substrate 1, and the electrodes 44 and 45 on both surfaces are directly connected to the substrate 1. Are fixed to the terminal electrodes 2 and 3 by soldering or a conductive adhesive 6 such as silver paste. A cutout portion 1a is formed in the other substrate 1, and as shown in FIG. 6A, the molding resin goes around the back surface side of the substrate 1 and a part of the package 5 is also formed on the back surface of the substrate 1. What is formed is the same as in the example of FIG. As a result, it is possible to obtain a chip-type light-emitting element in which the height of the LED chip 4 is low, the package is thin, and the package is not easily peeled.

When bonding the LED chip 4 by laying the LED chip 4 on its side, a solder paste or a silver paste is applied to the bonding portions of the two electrodes 44 and 45 and the terminal electrodes 2 and 3 or solder bumps are formed. It is preferable to make the connection easier.
The mounting of the LED chip 4 on the substrate 1 is performed, for example, by using a suction collet having a suction port larger than the narrow surface and smaller than the wide surface of the LED chip 4 while vibrating the cut and separated LED chip 4 with a parts feeder. When the LED chip is sucked, the LED chip whose direction is not correct is not sucked, and only the chip whose wide surface faces up and down is sucked and mounted correctly.

The rectangular parallelepiped LED chip 4 is formed by dicing from a wafer by changing the distance between the vertical and horizontal directions, and has a narrow width dimension H.
(See FIG. 6C), the width W is formed to be about 0.47 to 0.55 mm, the width W is formed to be about 0.4 to 0.55 mm, and the thickness T is set to 0.2 to 0.5 as in the conventional case. It is formed to about 0.3 mm.

According to this example, while the height from the surface of the substrate 1 is extremely low, the length of the substrate having a sufficient space in the width direction is increased, so that the area of the light emitting layer can be sufficiently increased. Can be secured. That is, even if one side of the rectangular shape, which is the outer shape of the light emitting layer, is made smaller, the area of the pn junction surface 43 can be made constant by making the other side larger. can do. Therefore, a sufficient light emission amount can be obtained without increasing the amount of input current, and a highly reliable and thin chip-type light-emitting element can be obtained while reducing the height of the chip-type light-emitting element to make it a thin light-emitting element. Furthermore, since the connection between the electrode of the LED chip 4 and the terminal electrodes 2 and 3 of the substrate 1 is directly connected by a conductive adhesive, there is no need for wire bonding for connection of the electrodes, and further thinning is achieved. It becomes possible.
Also in this case, the structure of the LED chip 4 is the same as that of the pn
The active layer is not limited to the one having the junction structure.
A structure sandwiched between a mold layer and an n-type layer may be used.

[0032]

According to the present invention, since a package for protecting a light emitting element chip or the like is provided not only on the front side of the substrate but also on the rear side of the substrate, a small external force is applied to the package. However, the package does not peel off. Therefore, for example, even when a connecting substrate having a chip-type light emitting element attached near a separation portion of the connecting substrate is cut and incorporated into a set, the package is not accidentally peeled off, handling is facilitated, and defective products are generated. And yield is high. Moreover, as the element, only a notch is formed on the side of the substrate, so that a small and inexpensive chip type light emitting element can be obtained.

Further, the light-emitting element chip is formed in a rectangular parallelepiped shape, turned down, and mounted so that the wide surface thereof is parallel to the substrate surface, so that a further reduction in thickness can be achieved, and Although the contact area with the package is reduced, the package is sufficiently fixed by the resin that has wrapped around the back side. At this time, since the light emitting element chip is directly connected to both terminal electrodes of the substrate by soldering or silver paste, a space for wire bonding becomes unnecessary, and the thickness of the chip type light emitting element to which the package is firmly fixed is reduced. It can be made as thin as about 0.5 mm or less.

As a result, the light source used for a switch button of a portable device such as a portable telephone or a PHS can be made extremely thin, which can contribute to further reduction in the size and size of the portable device.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of one embodiment of a chip-type light emitting device of the present invention.

FIG. 2 is an explanatory view of a state in which terminal electrodes are formed on a substrate at a stage of manufacturing the chip-type light emitting device of FIG. 1;

FIG. 3 is an enlarged explanatory view of the LED chip of FIG. 1;

FIG. 4 is a side view showing another example of the chip-type light emitting device of the present invention.

FIG. 5 is an explanatory plan view of one step in the manufacturing stage of the chip-type light-emitting device of FIG. 1;

FIG. 6 is an explanatory view showing still another example of the chip-type light emitting device of the present invention.

FIG. 7 is an explanatory diagram of a conventional chip type light emitting element.

FIG. 8 is a diagram showing an example of use of a conventional chip-type light emitting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 1a Notch 2, 3 Terminal electrode 4 LED chip 5 Package

Claims (3)

[Claims] 1. A substrate, terminal electrodes provided at both ends of the substrate, and terminal electrodes connected to the terminal electrodes at both ends.
A light emitting element chip having two electrodes, and a package made of a resin covering the periphery of the light emitting element chip,
A chip-type light emitting device, wherein a cutout from the front surface to the back surface is formed in a side portion of the substrate, and the resin is wrapped around the back surface of the substrate through the cutout portion to form the package. 2. The package according to claim 1, wherein the terminal electrode is formed so as to extend to the back surface of the substrate, and a package formed on the back surface of the substrate is provided on a portion of the back surface of the substrate where no terminal electrode is provided, the same thickness as the terminal electrode. The chip-type light-emitting device according to claim 1, which is formed. 3. The light emitting element chip is formed in a rectangular parallelepiped such that a light emitting layer of the light emitting element chip has a rectangular outer shape, and a surface on a long side of the rectangular shape is parallel to the substrate surface. 3. The chip type light emitting device according to claim 1, wherein said chip type light emitting device is provided on said substrate.