SEMICONDUCTOR LIGHT EMITTING DEVICE AND METHOD FOR MANUFACTURING THE SAME

Disclosed is a semiconductor light emitting device comprising at least one semiconductor light emitting chip, with each chip including a plurality of electrodes; a plurality of pads arranged at a designated distance from the plurality of electrodes on a plane, respectively; electrical connections provided on the same plane as the plurality of pads for electrically connecting the electrodes and the pads, respectively; and an encapsulation member for covering the at least one semiconductor light emitting chip.

TECHNICAL FIELD

The present disclosure relates generally to a semiconductor light emitting device with a lower probability of open-circuited and a method for manufacturing the same.

Further, the present disclosure relates to a semiconductor light emitting device capable of emitting lights from six sides.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art. Directional terms, such as “upper”, “lower”, “above”, “below” or others used herein are defined with respect to the directions shown in the drawings.

FIG. 1shows an example of a semiconductor light emitting chip in the prior art.

The semiconductor light emitting device includes a growth substrate11(e.g., a sapphire substrate), and a stack of layers sequentially deposited on the growth substrate11, including a buffer layer12, a first semiconductor layer13having a first conductivity (e.g., an n-type GaN layer), an active layer14for generating light by electron-hole recombination (e.g., an InGaN/(In)/GaN multiple quantum well (MQW) structure), and a second semiconductor layer15having a second conductivity different from the first conductivity (e.g., a p-type GaN layer). The semiconductor light emitting device further includes a light transmitting conductive film16for current spreading on the second semiconductor layer15, an electrode17serving as a pad formed on the light transmitting conductive film16, and an electrode18serving as a pad formed on an etched exposed portion of the first semiconductor layer13(e.g., a stack of Cr/Ni/Au metallic pads). This particular type of the semiconductor light emitting device as shown inFIG. 1is called a lateral chip. Here, one side of the growth substrate11serves as a mounting face during electrical connections to an external substrate. In the context herein, the term “external substrate” to which a semiconductor light emitting chip or a semiconductor light emitting device is electrically connected refers to a PCB (Printed Circuit Board), a submount, a TFT (Thin Film Transistor) or the like.

FIG. 2shows another example of a semiconductor light emitting chip disclosed in U.S. Pat. No. 7,262,436. For convenience of description, similar components may be indicated by the same or different reference numerals and technical terms as appropriate.

The semiconductor light emitting chip includes a growth substrate21, and a stack of layers sequentially deposited on the growth substrate21, including a first semiconductor layer23having a first conductivity, an active layer24adapted to generate light by electron-hole recombination and a second semiconductor layer25having a second conductivity different from the first conductivity. Three-layered electrode films29,29-1and29-2adapted to reflect light towards the growth substrate21are then formed on the second semiconductor layer25. In particular, a first electrode film29can be a reflecting Ag film, a second electrode film29-1can be a Ni diffusion barrier, and a third electrode film29-2can be an Au bonding film. Further, an electrode28serving as a pad is formed on an etched exposed portion of the first semiconductor layer23. Here, one side of the electrode film29-2serves as a mounting face during electrical connections to an external substrate. This particular type of the semiconductor light emitting chip as shown inFIG. 2is called a flip chip. In this flip chip ofFIG. 2, the electrode28formed on the first semiconductor layer23is placed at a lower height level than the electrode films29,29-1, and29-2formed on the second semiconductor layer, but alternatively, it may be formed at the same height level as the electrode films. Here, height levels are given with respect to the growth substrate21.

FIG. 3shows another example of a semiconductor light emitting chip disclosed in U.S. Pat. No. 8,008,683. For convenience of description, similar components may be indicated by the same or different reference numerals and technical terms as appropriate.

The semiconductor light emitting chip includes a stack of semiconductor layers sequentially deposited on a growth substrate, including a first semiconductor layer33having a first conductivity, an active layer34for generating light by electron-hole recombination, and a second semiconductor layer35having a second conductivity different from the first conductivity; an upper electrode36formed on a side free of the growth substrate; a supporting substrate31for supporting the semiconductor layers33,34and35while supplying current to the second semiconductor layer35; and a lower electrode32formed on the supporting substrate31. The upper electrode36is electrically connected to an external substrate by wire bonding. One side of the lower electrode32serves as a mounting face during electrical connections to the external substrate. The semiconductor light emitting device as shown inFIG. 3corresponds to a vertical chip where the electrodes36and32are disposed above and below the active layer34, respectively.

FIG. 4shows another example of a semiconductor light emitting device in the prior art.

The semiconductor light emitting device40has lead frames41and42, a mold43, and a vertical-type light emitting chip45in a cavity44which is filled with an encapsulation member47containing a wavelength converting material46. The lower surface of the vertical-type light emitting chip45is directly electrically connected to the lead frame41, and the upper surface48thereof is electrically connected to the lead frame42by a wire180. A portion of the light coming out of the vertical-type light emitting chip45excites the wavelength converting material46such that lights of different colors are generated, and white light is produced by mixing two different lights. For instance, blue light is generated by the semiconductor light emitting chip45, and yellow light is generated by the wavelength converting material46when it is excited. Then these blue and yellow lights can be mixed to produce white light. Alternatively, while the semiconductor light emitting device shown inFIG. 4includes the vertical-type light emitting chip45as shown inFIG. 3, it may also be obtained utilizing the semiconductor light emitting chips as illustrated inFIG. 1andFIG. 2.

FIG. 5illustrates an LED display described in Japanese patent application laid-open No. 1995-288341. For convenience of description, similar components may be indicated by the same or different reference numerals and technical terms as appropriate.

FIG. 5is a top view showing a pixel structure of the LED display. In the pixel structure, semiconductor light emitting chips54,55and56are electrically connected to conductor layers51formed on the PCB. The semiconductor light emitting chip54that emits blue light is a lateral chip, which is electrically connected to the conductor layer51by wire bonding and is attached to the conductor layer51by the insulating adhesive53. Meanwhile, the semiconductor light emitting chips55and56that emit green and red lights, respectively, are vertical chips, which are electrically connected to the conductor layer51by wire bonding and by a conductive adhesive57. These semiconductor light emitting chips are enveloped by a cover member52, separating them from their neighboring chips. Although not shown, a sealing member may be employed to cover the semiconductor light emitting chips54,55and56for protection.

As a compact, light-weight design is a trend nowadays, semiconductor light emitting chips are also being produced in smaller sizes to keep abreast of current technical trends. However, for a semiconductor light emitting chip where mini- or micro-LED chips having a maximum side-length of 300 μm or less are used, for example, pads are also smaller and have a narrower space between them, resulting in the occurrence of shorts or cracks (poor bonding) during the SMT (Surface Mounted Technology) process.

Accordingly, there is a need to produce a semiconductor light emitting device using mini- or micro-LED chips that is adapted to resolve those problems during the SMT process and to be optimized for a transparent display.

The purpose of the disclosure will be described hereinafter.

SUMMARY

According to one aspect of the present disclosure, there is provided a semiconductor light emitting device, comprising: at least one semiconductor light emitting chip, with each chip including a plurality of electrodes; a plurality of pads arranged at a designated distance from the plurality of electrodes on a plane, respectively; electrical connections provided on the same plane as the plurality of pads for electrically connecting the electrodes and the pads, respectively; and an encapsulation member for covering the at least one semiconductor light emitting chip.

According to another aspect of the present disclosure, there is provided a method for manufacturing a semiconductor light emitting device including at least one semiconductor light emitting chip, the method comprising: preparing a substrate; providing the at least one semiconductor light emitting chip on the substrate; providing an encapsulation member over the substrate and the semiconductor light emitting chips; removing the substrate; and forming, on the encapsulation member, electrical connections between pads and the semiconductor light emitting chips, respectively, with each of the pads being arranged at a designated distance from each of the light emitting chips.

According to another aspect of the present disclosure, there is provided a method for manufacturing a semiconductor light emitting device including at least one semiconductor light emitting chip, the method comprising: preparing a substrate; forming, on the substrate, electrical connections for connecting a plurality of pads and the at least one semiconductor light emitting chip, respectively, with the plurality of pads being arranged at a designated distance from the semiconductor light emitting chips; providing the at least one semiconductor light emitting chip on the substrate; providing an encapsulation member over the substrate and the semiconductor light emitting chips; and removing the substrate.

According to another aspect of the present disclosure, there is provided a semiconductor light emitting device, comprising: a semiconductor light emitting chip including a first electrode and a second electrode; a substrate including a plate on which electrical connections are formed, with the electrical connections including a first electrical connection electrically connected to the first electrode and a second electrical connection electrically connected to the second electrode; and metal blocks provided on the substrate, with the metal blocks including a first metal block that includes an upper surface electrically connected to an external substrate and a lower surface electrically connected to the first electrical connection, and a second metal block that includes an upper surface electrically connected to an external substrate and a lower surface electrically connected to the second electrical connection, wherein the metal blocks have a height equal to or greater than that of the semiconductor light emitting chip.

Objectives, advantages, and a preferred mode of making and using the claimed subject matter may be understood best by reference to the accompanying drawings in conjunction with the following detailed description of illustrative embodiments.

DETAILED DESCRIPTION

FIG. 6shows an exemplary embodiment of a semiconductor light emitting device100according to the present disclosure.

FIG. 6Ais a top view of the semiconductor light emitting device100, andFIG. 6Bis a cross-sectional view taken along with AA′ inFIG. 6A.

The semiconductor light emitting device100includes at least one semiconductor light emitting chip110, a plurality of pads121, electrical connections123, and an encapsulation member150.

Each of the semiconductor light emitting chips110includes a plurality of electrodes111.

The pads121are arranged at a designated distance from the semiconductor light emitting chips110. The semiconductor light emitting device100is directly electrically connected to an external substrate through the pads121.

As mentioned above, the pads121are not located beneath the semiconductor light emitting chips110. Rather, there is a designated distance between the pads121and the semiconductor light emitting chips110. With such space created, bigger pads121may be used and the pads121may be spaced with a broader distance between them, preventing the occurrence of shorts and cracks (poor bonding) during the SMT process. When this is applied to a transparent display where some elements (e.g., pads121and semiconductor light emitting chips110) of the semiconductor light emitting device100are not clustered but are scattered, occupying a certain area, the semiconductor light emitting device100may become less visible. In addition, as the light can travel through the space between the pads121and the semiconductor light emitting chips110, six-sided light emission can be accomplished. Here, the pads121are arranged in a one-to-one correspondence with the electrodes111.

The electrical connections123are provided between the pads121and the electrodes111, such that the pads121and the electrodes111are electrically connected to each other. In particular, the electrical connections123may be formed on the same plane as the pads121.

In the example shown inFIG. 6A, the electrical connection123is formed of a single line. In this case, if the electrical connection123is cut off, the semiconductor light emitting chip110will stop working. A possible solution for this will be described later with reference toFIG. 7.

The encapsulation member150serves to cover the semiconductor light emitting chips110. Typically, it is made of a light-transmitting material. This encapsulation member150, being spaced from the semiconductor light emitting chips110and the pads121by a designated distance, may contribute to a semiconductor light emitting device featuring six-sided light emission. In an alternative example, the pads121and the electrical connections123may be projected out of the encapsulation member150.FIG. 7illustrates an example where the pads121and the electrical connections123are formed in the encapsulation member150.

Preferably, the size of the pad121is larger than the size of the semiconductor light emitting chip110, and the designated distance between the pad121and the semiconductor light emitting chip110is greater than the size of the semiconductor light emitting chip110. For example, if the semiconductor light emitting chip110is a mini- or micro-semiconductor light emitting chip having a maximum side length of 300 μm or less, and the pad121has a maximum side length of at least 100 μm, the distance between one pad121and one semiconductor light emitting chip110should be at least 150 μm. The resulting semiconductor light emitting device100will have a maximum side length of 300 μm or more.

FIG. 7shows another exemplary embodiment of a semiconductor light emitting device100according to the present disclosure.

FIG. 7Ais a top view of the semiconductor light emitting device100, andFIG. 7Bis a cross-sectional view of the semiconductor light emitting device100shown inFIG. 7A.

The electrical connections123form multiple paths between each of the pads121and each of the electrodes111. Since the pads121and the electrodes111are electrically connected through these multiple paths, even if one of the paths may be cut off, the pads121would remain electrically connected to the electrodes111with the help of the other paths. Meanwhile, if the pads and the semiconductor light emitting chips are electrically connected by one single line as inFIG. 6A, failure in the line would inevitably cause the semiconductor light emitting device to stop working, as discussed earlier. Thus, the presence of multiple paths ensures that the pads121and the electrodes111always stay electrically connected to each other through one of the paths, even if one line might have been cut off. Moreover, the electrical connections123are not clustered and but are spread out broadly and thinly, making the back side of the semiconductor light emitting device100more visible.

The encapsulation member150is adapted to cover the electrical connections123, with at least a portion of the electrical connections123being exposed. Similarly, the encapsulation member150is adapted to cover the pads121, with at least a portion of the pads121being exposed.

As shown, a Zener diode130is provided to prevent the application of a reverse voltage across the semiconductor light emitting chips110. The Zener diode130and the semiconductor light emitting chips110are connected in parallel, such that the Zener diode130ensures that a current keeps flowing through the chips110and the chips110are protected even if a reverse voltage is applied thereto.

The Zener diode130includes a plurality of Zener electrodes131; one Zener electrode131is in contact with a corresponding pad121, and another Zener electrode131is electrically connected in reverse parallel to the semiconductor light emitting chips110. In other words, one Zener electrode131out of the plurality of Zener electrodes131may be connected to one of the electrodes111of the semiconductor light emitting chip110, and to one of the pads121, or to the electrical connection123. The Zener diode130will be described in more details with reference toFIG. 14below.

FIG. 8shows other exemplary embodiments of a semiconductor light emitting device according to the present disclosure.

FIG. 8Aillustrates the electrical connections123in the form of multiple paths between the pads121and the electrodes111.

FIG. 8Billustrates the electrical connections in the form of a net of the hexagonal honeycomb pattern. The pattern has a uniform size. This net form makes the back side of the semiconductor light emitting device100more visible.

FIG. 9shows other exemplary embodiments of a semiconductor light emitting device according to the present disclosure.

In particular,FIG. 9Aillustrates a semiconductor light emitting device100including a plurality of semiconductor light emitting chips110, a plurality of pads121and electrical connections123according to the present disclosure.

The plurality of semiconductor light emitting chips110may be comprised of a first semiconductor light emitting chip110including a first electrode111-1and a second electrode111-2, a second semiconductor light emitting chip110including a third electrode111-3and a fourth electrode111-4, and a third semiconductor light emitting chip110including a fifth electrode111-5and a sixth electrode111-6. The first electrode111-1and the second electrode111-2of the first semiconductor light emitting chip110have different polarities. For example, in the first semiconductor light emitting chip110, the first electrode111-1may be a negative (−) electrode, while the second electrode111-1may be a positive (+) electrode. Similarly, in the second semiconductor light emitting chip110, the third electrode111-3may be a negative (−) electrode, while the fourth electrode111-4may be a positive (+) electrode. Also, in the third electrode110, the fifth electrode111-5may be a negative (−) electrode, while the sixth electrode111-6may be a positive (+) electrode.

The plurality of pads121may be comprised of a first pad121-1, a second pad121-2, a third pad121-3, and a fourth pad121-4. The first pad121-1is electrically connected to the first electrode111-1, the third electrode111-3, and the fifth electrode111-5. The second pad121-2is electrically connected to the second electrode111-2. The third pad121-3is connected to the fourth electrode111-4. The fourth pad121-4is connected to the sixth electrode111-6. In an alternative example, the first pad121-1, the second pad121-2, the third pad121-3, and the fourth pad121-4may have different polarities. In another alternative example, while the second pad121-2, the third pad121-3, and the fourth pad121-4may have the same polarity, they are arranged separately to control ON/OFF of the first semiconductor light emitting chip110, the second semiconductor light emitting chip110and the third semiconductor light emitting chip110, respectively.

The electrical connections123may be comprised of first electrical connections123-1, a second electrical connections123-2, a third electrical connection123-3, and a fourth electrical connection123-4. The first electrical connections123-1serve to electrically connect the first pad121-2and the first electrode111-1, third electrode111-3, and fifth electrode111-5. The second electrical connection123-2serves to electrically connect the second pad121-2and the second electrode111-2. The third electrical connection123-3serves to electrically connect the third pad121-3and the fourth electrode111-4. The fourth electrical connection123-4serves to electrically connect the fourth pad121-4and the sixth electrode111-6.

The plurality of semiconductor light emitting chips110may be turned ON/OFF in various combinations to emit lights, such as white light or lights of different colors. The semiconductor light emitting chips110are centered in the semiconductor light emitting device100, and each of the semiconductor light emitting chip110(110-1,110-2, and110-3) and each of the pads121(121-1,121-2, and121-3) are separated by a designated distance from each other.

As colors are mixed to form a color pixel, the semiconductor light emitting chips110are needed to be at the center of the semiconductor light emitting device100. However, if the pads121are arranged beneath or right under the chips110, any neighboring pads121may undergo a short during the SMT process. Therefore, providing electrical connections123between the pads121and the semiconductor light emitting chips111as in the present disclosure may benefit from these centrally arranged mini- or micro- semiconductor light emitting chips110.

FIG. 9Billustrates another semiconductor light emitting device100including a plurality of semiconductor light emitting chips110according to the present disclosure.

In this example, the electrical connections123are provided in the net structure, in order to prevent any possible disconnection when the electrical connections123are formed of one single line as mentioned inFIG. 6A. Here, the electrical connections123are thinner and are spread across a broader area. Also, the electrical connections123form multiple paths between the pads121and the electrodes111as inFIG. 7, such that even if a part of the thin electrical connection123may be cut off, it is highly possible that the pads121and the electrodes111would remain connected. In other words, it is very unlikely to cause the semiconductor light emitting chips110to be electrically disconnected.

The electrical connections123may have a certain pattern, e.g., a net structure. The electrical connections123in contact with the pads121or the electrodes111are smaller than the electrical connections123not in contact with the pads121or the electrodes111. This will be described in further details with reference toFIG. 10below.

The first through fourth electrical connection123-1-123-4are formed in a net structure by connecting a plurality of patterns together. The pattern may have a polygonal shape. Examples of such a polygonal shape will be provided later with reference toFIG. 11. The first through fourth electrical connections123-1-123-4in the net structure is advantageous especially when the semiconductor light emitting device100is used for a transparent display in that the electrical connections123in the form of thinner lines across a broader area than those inFIG. 9Amake the back side of the semiconductor light emitting device100ofFIG. 9Bmore visible than the back side of the semiconductor light emitting device100ofFIG. 9A.

FIG. 10is a detailed view of the A part inFIG. 9B.

The third electrical connection123-3is positioned between the third pad121-3and the fourth electrode111-4. As shown, the third electrical connection123-3has a smaller pattern portion closer towards or in contact with the third pad121-3and the fourth electrode111-4such that more paths may be formed. That is, because the third electrical connection123-3has a limited area that gets closer and comes in contact with the third pad121-3and the fourth electrode111-4, the size of the pattern (a) which actually comes in contact with the third pad121-3and the fourth electrode111-4is made larger than the size of the pattern (b) which is not in contact with the third pad121-3and the fourth electrode111-4. As compared with the electrical connection of a one-sized pattern, multiple paths can be created for the third electrical connection123-3between the third pad121-3and the fourth electrode111-4, with a substantially lower probability of disconnection (being cut off).

FIG. 11illustrates different patterns according to the present disclosure.

The pattern may have various polygonal shapes including, but are not limited thereto, tetragonal (seeFIG. 11A-B), hexagonal (seeFIG. 11C), circular (seeFIG. 11D), and triangular (seeFIG. 11E) shapes.

FIG. 12shows an exemplary embodiment of a method for manufacturing a semiconductor light emitting device according to the present disclosure.

In the method for manufacturing a semiconductor light emitting device including at least one semiconductor light emitting chip110, first of all, a substrate140is prepared as shown inFIG. 12A. The substrate140may be a silicone tape, for example, onto which the semiconductor light emitting chips110are temporarily attached later. The substrate140is not electrically connected to the semiconductor light emitting chips110.

Referring next toFIG. 12B, the at least one semiconductor light emitting chip110are provided on the substrate140. Although not shown, Zener diodes130(seeFIG. 7) may be provided on the substrate140. If present, the Zener diodes130are arranged corresponding to the semiconductor light emitting chips110, while keeping a designated distance between the Zener diodes130and the chips110.

After that, the encapsulation member150is provided over the substrate140and semiconductor light emitting chips110, as shown inFIG. 12C. The encapsulation member150covers the substrate140, and the semiconductor light emitting chips110are secured accordingly.

The substrate140is then removed as shown inFIG. 12D. The substrate140t may be removed because it was originally provided for temporary attachment of the semiconductor light emitting chips110.

Referring finally toFIG. 12E, a plurality of pads121and electrical connections123are formed under the encapsulation member150. In particular, the pads121are arranged at a designated distance from the at least one semiconductor light emitting chip110, and the electrical connections123are arranged between the pads121and the semiconductor light emitting chips110for electrically connecting them. As can be seen, the formation of the pads121and electrical connections123comes after the encapsulation member150is formed, such that the pads121and the electrical connections123may be projected out of the encapsulation member150. For example, the pads121and the electrical connections123are deposited on the same plane, i.e., one side of the encapsulation member150.

FIG. 13shows another exemplary embodiment of a method for manufacturing a semiconductor light emitting device according to the present disclosure.

In the method for manufacturing a semiconductor light emitting device including at least one semiconductor light emitting chip110, first of all, a substrate140is prepared as shown inFIG. 13A. The substrate140may be a silicone tape, for example, onto which the semiconductor light emitting chips110are temporarily attached later. The substrate140is not electrically connected to the semiconductor light emitting chips110.

Referring next toFIG. 13B, on the substrate140, there are formed a plurality of pads121at a designated distance from at least one semiconductor light emitting chip110(to be described later), and electrical connections123for electrically connecting the pads121and the semiconductor light emitting chips110. For example, the pads121and the electrical connections123are deposited on the same plane, i.e., one side of the encapsulation member150.

Following that, at least one semiconductor light emitting chip110is provided on the substrate140, as shown inFIG. 13C. In particular, these semiconductor light emitting chips110are positioned to be in contact with the electrical connections123. Although not shown, Zener diodes130may be provided on the pads121, in a one-to-one correspondence with the semiconductor light emitting chips110.

The encapsulation member150is then provided over the substrate140and the semiconductor light emitting chips110, as shown inFIG. 13D.

Finally, the substrate140is removed, as shown inFIG. 13E. As the pads121and the electrical connections123are formed and covered with the encapsulation member150afterwards, the pads121as well as the electrical connections123are positioned inside the encapsulation member150. Thus, when the substrate140is removed, only the sides of the pads121and electrical connections123that were in contact with the substrate140are exposed.

If the pads121and the electrical connections123are projected out of the encapsulation member150as shown inFIG. 12E, adhesion between the encapsulation member150and the pads121/electrical connections123gets weaker and separated from each other. Therefore, it is preferred that the pads121and the electrical connections123remain inside the encapsulation member150.

FIG. 14shows Zener diodes according to the present disclosure.

FIG. 14Aillustrates how a Zener diode is mounted in a semiconductor light emitting device in the art.

A hole (H) is formed in the PCB substrate240, a pad221is provided under the PCB substrate240, and an electrical connection is formed along the hole (H) until it sticks out from the upper surface of the PCB substrate240. In addition, a pad electrode223is formed on the PCB substrate240such that it is connected to the pad221. With the electrical connection being projected, the pad electrode223is also projected. Therefore, a gap is created when the Zener electrodes131of the Zener diode130are attached to the pad electrode223, which will likely cause the Zener diode130to easily come off. Therefore, in an alternative example, although not shown, the Zener diode130may be provided in an area other than the pad electrode223, avoiding the hole (H) and without being overlapped with the pad221.

As shown, one of the Zener electrodes131of the Zener diode130is in contact with a pad121. This structure is possible because the pad121is formed flat, without having the hole (H) (seeFIG. 14A) and the pad electrode223(seeFIG. 14A).

While the pad121and the Zener diode130are configured to be able to increase the optical loss, it can be overcome by using the flat pad121and placing the Zener diode130in the pad such that the area of the pad121overlaps with the area of the Zener diode130. For the application to a transparent display, if the pad121and the Zener diode130are overlapped to a great extent, the semiconductor light emitting device100would have a higher transparency.

FIG. 15shows another exemplary embodiment of a semiconductor light emitting device100according to the present disclosure.

In particular,FIG. 15Ais a bottom view showing the lower surface of the semiconductor light emitting device100including a semiconductor light emitting chip110, andFIG. 15Bis a cross-sectional view taken along line AA′ ofFIG. 15A.

The semiconductor light emitting device100may include an insulating layer160adapted to cover the electrical connections123and to expose the pads121. Because the electrical connections123are covered with the insulating layer, the occurrence of shorts during soldering can be greatly reduced. The insulating layer can be used regardless that the electrical connections123and the pads121are arranged inside or projected out of the encapsulation member150. In general, the insulating layer160may be formed by silk screen printing, following the stepFIG. 12EorFIG. 13E.

Preferably, the insulating layer160has a height (h) of 10 μm or less. As the insulating layer160is formed after the step inFIG. 12EorFIG. 13Eis completed, exposing the pads121are formed, it is disposed at a higher level than the pads121. Forming the insulating layer160at the height (h) of 10 μm or less allows a solder material to make better contact with the pads121during soldering for electrical connection to an external substrate. In an alternative example, after the insulating layer160is formed, the pads121may be subject to a plating process such that the height of the pad121may reach a dotted line122(FIG. 15B) until it is equal to or greater than the height (h) of the insulating layer160.

The insulating layer160may be made from at least one of transparent materials or opaque materials. For example, if the insulating layer160is made from a transparent material, the semiconductor light emitting device100thus manufactured will be able to emit lights from six sides. Meanwhile, if the insulating layer160is made from an opaque material, the semiconductor light emitting device100will be able to emit lights from five sides. If applied to a transparent display, the semiconductor light emitting device100often should not let the light escape through its back side. In this case, the insulating layer160is preferably made from an opaque material. On the other hands, if the semiconductor light emitting device has dimensions of 500 μm×500 μm or less, it is not much visible even if the insulating layer is made opaque. In the present disclosure, however, the semiconductor light emitting device100has larger dimensions (e.g., 1500 μm×1500 μm) than those in the art because of the spacing between the pads and the semiconductor light emitting chips, which makes the semiconductor light emitting device100still visible. This can be overcome by employing both transparent and opaque materials for the insulating layer160. That is, a portion170of the insulating layer160below the semiconductor light emitting chip110, indicated by dotted lines inFIG. 15A, is made from an opaque material, while the remaining portion is made from a transparent material. In this way, the light from the semiconductor light emitting chip110is prevented from escaping through under the semiconductor light emitting device100, which ensures that the semiconductor light emitting device100having larger dimensions according to the present disclosure may still be suitable for use in a transparent display where the escape of light through under the device is not allowed. The portion170indicated by dotted lines is preferably 300 μm or less.

FIG. 15Cis a bottom view showing the lower surface of the semiconductor light emitting device100including at least one semiconductor light emitting chip110, for example.FIG. 15Dis a cross-sectional view taken along line BB′ ofFIG. 15C.

The descriptions in relation toFIG. 15AandFIG. 15Bmay be applied equally toFIG. 15CandFIG. 15D.

FIG. 16shows another exemplary embodiment of a semiconductor light emitting device200according to the present disclosure.

The semiconductor light emitting device200includes a semiconductor light emitting chip210, a substrate230, metal blocks250, and an encapsulation member270.

The semiconductor light emitting chip210, which emits light, has dimensions of 300 μm or less (in case of mini-LEDs) or 100 μm or less (in case of micro-LEDs). Both mini-LEDs and micro-LEDs are suitable for the semiconductor light emitting chip210in the present disclosure. In an alternative example, the semiconductor light emitting chip210may be a flip chip in which the escape of light mainly occurs through the upper surface of the flip chip.

The substrate230includes a plate231and electrical connections232. The plate231may be made from a light-transmitting material. For example, the plate231may be made from glass, sapphire, or the like. The electrical connections232may be deposited on the plate231. The electrical connections232serve to electrically connect the semiconductor light emitting chip210and the metal blocks250.

In case of the semiconductor light emitting devices100described above beginning fromFIG. 6toFIG. 15, the encapsulation member150is in direct contact with the electrical connections123. When the semiconductor light emitting device100is soldered to an external substrate, the encapsulation member150and the electrical connections123can experience precision deterioration due to heat during the soldering process. The encapsulation member150and the electrical connections123have substantially different degrees of expansion and contraction, and the electrical connections123made thinner according to the present disclosure may even be cut off. This can be overcome by providing the electrical connections232on the plate231as the plate231is resistant to heat-induced deformation. This leads to a simplified manufacturing process and improved reliability overall.

The metal blocks250are provided on the substrate230. The metal blocks250are electrically connected to an external substrate. Each metal block250has an upper surface250-1in contact with an external substrate, and a lower surface250-2in contact with the electrical connections232. The metal blocks250may have a column shape, including, but are not limited to, a cylinder, a rectangular cylinder, or the like. In particular, the metal blocks250may take any shape, provided that a portion of each of the metal blocks250is exposed for electrical connection to an external substrate.

Each metal block250may have a height (h2) equal to or greater than the height (h1) of the semiconductor light emitting chip210. If the height (h2) of the metal blocks250is greater than the height (h1) of the semiconductor light emitting chip210, it enables the semiconductor light emitting device200to be electrically connected above the upper surface of the semiconductor light emitting chip210. Meanwhile, if the height (h2) of the metal blocks250is equal to the height (h1) of the semiconductor light emitting chip210, the upper surface (not shown) of the semiconductor light emitting chip210will be exposed, similar to the upper surfaces250-1of the metal blocks250being exposed. This impedes the complete protection of the semiconductor light emitting chip210from outside because the exposed upper surface of the chip210will be affected adversely by external physical impacts and electrostatic discharge (ESD) and even discolored due to moisture penetration. Therefore, it is desired that the height (h2) of the metal blocks250should be greater than the height (h1) of the semiconductor light emitting chip210.

The encapsulation member270covers the semiconductor light emitting chip210and the substrate230and encloses the metal blocks250in such a manner that the upper surfaces250-1of the metal blocks250are exposed. The encapsulation member270may shrink during curing. Thus, the plate231of the substrate230is preferably made from a material that is less susceptible to warpage than the silicone tape because if the substrate230is bent by the shrinkage force from the encapsulation member270, the semiconductor light emitting device200might as well be broken or bent.

The semiconductor light emitting chip210includes a first electrode211and a second electrode212.

The electrical connections232is comprised of a first electrical connection232-1and a second electrical connection232-2. The first electrical connection232-1is electrically connected to the first electrode211of the semiconductor light emitting chip210, and the second electrical connection232-2is electrically connected to the second electrode212of the semiconductor light emitting chip210.

The metal blocks250is comprised of a first metal block251and a second metal block252. The first metal block251is electrically connected to the first electrical connection232-1, and the second metal block252is electrically connected to the second electrical connection232-2. The first metal block251and the second metal block252may have the same height (h2).

The first electrical connection232-1includes a first contact portion233-1, a first pad234-1, and a first connection portion235-1.

The first contact portion233-1is in contact with the first electrode211of the semiconductor light emitting chip210, and the first pad234-1is in contact with the first metal block251.

The first connection portion235-1is provided between the first contact portion233-1and the first pad234-1to electrically connect the first contact portion233-1and the first pad234-1. Preferably, the first contact portion233-1and the first pad234-1are arranged at a designated distance from each other. This is particularly important to allow the light to travel towards the lower surface of the semiconductor light emitting chip210for six-sided light emission, as it will be difficult for the light to keep going towards the lower surface of the semiconductor light emitting chip210if there is no space between the first contact portion233-1and the first pad234-1. In relation with that, the first connection portion235-1may have diverse patterns as illustrated inFIG. 11.

The second electrical connection232-2includes a second contact portion233-2, a second pad234-2, and a second connection portion235-2.

The second contact portion233-2is in contact with the second electrode212of the semiconductor light emitting chip210, and the second pad234-2is in contact with the second metal block252.

The second connection portion235-2is provided between the second contact portion233-2and the second pad234-2to electrically connect the second contact portion233-2and the second pad234-2. Preferably, the second contact portion233-2and the second pad234-2are arranged at a designated distance from each other. This is particularly important to allow the light to travel towards the lower surface of the semiconductor light emitting chip210for six-sided light emission, as it will be difficult for the light to keep going towards the lower surface of the semiconductor light emitting chip210if there is no space between the second contact portion233-2and the second pad234-2. In relation with that, the second connection portion235-2may have diverse patterns as illustrated inFIG. 11.

The first electrical connection232-1may have multiple paths between the first electrode211and the first metal block251, and the second electrical connection232-2may have multiple paths between the second electrode212and the second metal block252. In other words, the first contact portion232-1and the first pad234-1are connected by multiple paths of the first connection portion232-1, and the second contact portion233-2and the second pad234-2are connected by multiple paths of the second connection portion232-2. In addition, the first connection portion232-1and the second connection portion232-2may create a space which the light can travel through.

Further, the first pad234-1and the second pad234-2may serve as passages electrically connected to an external substrate, while retaining the same features as the pads121illustrated inFIG. 6.

FIG. 17shows another exemplary embodiment of a method for manufacturing a semiconductor light emitting device according to the present disclosure

First of all, the substrate230is prepared as shown inFIG. 17A. The substrate230is obtained by preparing the plate231, followed by forming the electrical connections232on the plate231by deposition, for example. The electrical connections232may be comprised of the first electrical connection232-1and the second electrical connection232-2.

Referring next toFIG. 17B, the semiconductor light emitting chip210and the metal blocks250are provided on the substrate230. The semiconductor light emitting chip210includes a first electrode211and a second electrode212. The first electrode211is electrically connected to the first electrical connection232-1, and the second electrode212is electrically connected to the second electrical connection232-2.

The lower surfaces251-2and252-2of the first metal block251and the second metal block252may have areas in any dimensions, provided that the first pad234-1is electrically connected to the first metal block251, and that and the second pad234-2is electrically connected to the second metal block252.

Referring lastly toFIG. 17C, the encapsulation member270are provided to enclose the first metal block251and the second metal block252, except for the upper surfaces251-1and252-1of the first and second metal blocks251and252. In addition, the encapsulation member270covers the upper surfaces of the semiconductor light emitting chip210and substrate230.

FIG. 18shows another exemplary embodiment of a semiconductor light emitting device200according to the present disclosure.

The semiconductor light emitting device200includes a plurality of semiconductor light emitting chips210. The plurality of semiconductor light emitting chips210may emit red light, green light, and blue light, respectively. The plurality of semiconductor light emitting chips210may be comprised of a first semiconductor light emitting chip210-1, a second semiconductor light emitting chip210-2, and a third semiconductor light emitting chip210-3. The first semiconductor light emitting chip210-1includes a first electrode211and a second electrode212, the second semiconductor light emitting chip210-2includes a third electrode213and a fourth electrode214, and the third semiconductor light emitting chip210-3includes a fifth electrode215and a sixth electrode216.

The metal blocks250may be comprised of a first metal block251, a second metal block252, a third metal block253, and a fourth metal block254. These metal blocks may have different polarities: the first metal block251may have a polarity different from the second metal block252and from the third and fourth metal blocks253and254. Four metal blocks250are provided in order to control the first semiconductor light emitting chip210-1, the second semiconductor light emitting chip210-2, and the third semiconductor light emitting chip210-3, respectively. For instance, the second metal block252may be used as a common electrode.

The electrical connections232(FIG. 16) may be comprised of a first electrical connection232-1, a second electrical connection232-2, a third electrical connection232-3, and a fourth electrical connection232-4.

The first electrical connection232-1may include a first contact portion233-1, a first pad234-1, and a first connection portion235-1. The second electrical connection232-1may include a second contact portion233-2, a fourth contact portion233-4, a sixth contact portion233-6, a second pad234-2, and a second connection portion235-2. The third electrical connection232-3may include a third contact portion233-3, a third pad234-3, and a third connection portion235-3. The fourth electrical connection232-4may include a fourth contact portion233-4, a fourth pad234-4, and a fourth connection portion235-4.

The first contact portion233-1is in contact with the first electrode211and they are electrically connected to each other. The second contact portion233-2is in contact with the second electrode212and they are electrically connected to each other. The third contact portion233-3is in contact with the third electrode213and they are electrically connected to each other. The fourth contact portion233-4is in contact with the fourth electrode214and they are electrically connected to each other. The fifth contact portion233-5is in contact with the fifth electrode215and they are electrically connected to each other. The sixth contact portion233-6is in contact with the sixth electrode216and they are electrically connected to each other.

Likewise, the first pad234-1is in contact with the first metal block251and they are electrically connected to each other. The second pad234-2is in contact with the second metal block252and they are electrically connected to each other. The third pad234-3is in contact with the third metal block253and they are electrically connected to each other. The fourth pad234-4is in contact with the fourth metal block254and they are electrically connected to each other.

The first connection portion235-1is provided between the first pad234-1and the first contact portion233-1to electrically connect them. The second connection portion235-2is provided between the second pad234-2and the second, fourth and sixth contact portions233-2,234-4and233-6, respectively, to electrically connect them. The third connection portion235-3is provided between the third pad234-3and the third contact portion233-3to electrically connect them. The fourth connection portion235-4is provided between the fourth pad234-4and the fifth contact portion233-4to electrically connect them.

The semiconductor light emitting device200may further include a Zener diode z. The Zener diode z has been described in detail with reference toFIG. 7. The Zener diode z may be electrically connected to the first and second electrical connections232-1and232-2. In relation with this, the first electrical connection232-1and the second electrical connection232-2may have Zener pads z1and z2, respectively, that come in contact with the Zener diode z. Although not shown, other Zener diodes z may be provided between the third electrical connection232-3and the second electrical connection232-3, and between the fourth electrical connection232-4and the second electrical connection232-4.

Referring back to the configuration shown inFIG. 8, the Zener diodes130were in contact with the pads121, which was made possible because and the pads and the electrical connections123were provided on the same plane. In the present disclosure, however, the pads234include metal blocks250having a height (h2) (seeFIG. 16), meaning that the metal blocks250are not provided on the same plane. Accordingly, the first, third, and fourth electrical connections232-1,232-3, and232-4on the same plane can be electrically connected to the second electrical connection232-2.

FIG. 19illustrates applications of a semiconductor light emitting device of the present disclosure to a transparent substrate.

The semiconductor light emitting chips110and210ofFIGS. 19A and 19Bare formed of flip chips. As can be seen from the drawings, a majority portion of the light escapes through the upper surfaces of the semiconductor light emitting chips110and210.

In the semiconductor light emitting device100ofFIG. 19A, although a portion of the light may escape through the transparent substrate290, a majority portion of the light escapes through the upper surface of the semiconductor light emitting chip110, in the opposite direction to the transparent substrate290. Here, the transparent substrate may be a transparent PCB, for example.

On the other hand, the semiconductor light emitting device200inFIG. 19Bis electrically connected to the transparent substrate290through the upper surfaces250-1of the metal blocks250, and a majority portion of the light of the semiconductor light emitting device200will escape through the transparent substrate290.

Since the plate231semiconductor light emitting device200may be made from glass or sapphire, it can be difficult to connect the plate230directly electrically to the transparent substrate290. Especially when the plate231of the semiconductor light emitting device200needs to be attached to the transparent substrate290as shown inFIG. 19A, it may be necessary to form electrical connections on the upper and lower surfaces of the plate231and holes for interconnecting the electrical connections. Optionally, the holes can be formed by laser drill processing. Due to high setup costs and lengthy processing time of the laser drill processing, however, the present disclosure has adopted the metal electrodes250as shown inFIG. 19B, such that electrical connections to the transparent substrate290are made possible without holes, thereby saving the time and cost.

Set out below are a series of clauses that disclose features of further exemplary embodiments of the present disclosure, which may be claimed.

(1) A semiconductor light emitting device, comprising: at least one semiconductor light emitting chip, with each chip including a plurality of electrodes; a plurality of pads arranged at a designated distance from the plurality of electrodes on a plane, respectively; electrical connections provided on the same plane as the plurality of pads for electrically connecting the electrodes and the pads, respectively; and an encapsulation member for covering the at least one semiconductor light emitting chip.

(2) There is also provided, the semiconductor light emitting device of clause (1) wherein: the electrical connections form multiple paths between the plurality of pads and the plurality of electrodes, respectively.

(3) There is also provided, the semiconductor light emitting device of clause (2) wherein: the electrical connections are formed in a net structure.

(4) There is also provided, the semiconductor light emitting device of clause (3) wherein: the electrical connections are formed in a uniform pattern.

(5) There is also provided, the semiconductor light emitting device of clause (4) wherein: the pattern of the electrical connections in contact with the plurality of pads or with the plurality of electrodes has a smaller size than the pattern of the electrical connections not in contact with the plurality of pads or with the plurality of electrodes.

(6) There is also provided, the semiconductor light emitting device of clause (1) wherein: the encapsulation member covers the electrical connections in such a manner that at least a portion of the electrical connections is exposed.

(7) There is also provided, the semiconductor light emitting device of clause (6) wherein: the encapsulation member covers the pads in such a manner that at least a portion of the pads is exposed.

(8) There is also provided, the semiconductor light emitting device of clause (1) wherein: the plurality of pads and the at least one semiconductor light emitting chip are arranged at a designated distance from each other, with the distance being equal to or greater than the width of the semiconductor light emitting chip.

(9) There is also provided, the semiconductor light emitting device of clause (1) wherein: the pad has a width greater than a width of the semiconductor light emitting chip.

(10) There is also provided, the semiconductor light emitting device of clause (1) wherein: the pads are projected out of the encapsulation member.

(11) There is also provided, the semiconductor light emitting device of clause (1) further comprising: a Zener diode adapted to prevent the application of a reverse voltage across the at least one semiconductor light emitting chip.

(12) There is also provided, the semiconductor light emitting device of clause (11) wherein: the Zener diode is provided on the pad.

(13) There is also provided, the semiconductor light emitting device of clause (1) wherein the at least one semiconductor light emitting chip comprises a first semiconductor light emitting chip including a first electrode and a second electrode, a second semiconductor light emitting chip including a third electrode and a fourth electrode, and a third semiconductor light emitting chip including a fifth electrode and a sixth electrode; wherein the pads comprises a first pad electrically connected to the first, third and fifth electrodes, a second pad electrically connected to the second electrode, a third pad electrically connected to the fourth electrode, and a fourth pad electrically connected to the sixth electrode; and wherein the electrical connections comprise a first electrical connection for electrically connecting the first pad, the first electrode, the third electrode and the fifth electrode, a second electrical connection for electrically connecting the second pad and the second electrode, a third electrical connection for electrically connecting the third pad and the third electrode, and a fourth electrical connection for electrically connecting the fourth pad and the fourth electrode.

(14) There is also provided, the semiconductor light emitting device of clause (1) comprising: a plurality of Zener diodes adapted to prevent the application of a reverse voltage across the first, second, and third semiconductor light emitting devices, respectively.

(15) There is also provided, the semiconductor light emitting device of clause (14) wherein: the plurality of Zener diodes is provided on the second, third and fourth pads, respectively.

(16) A method for manufacturing a semiconductor light emitting device including at least one semiconductor light emitting chip, the method comprising: preparing a substrate; providing the at least one semiconductor light emitting chip on the substrate; providing an encapsulation member over the substrate and the semiconductor light emitting chips; removing the substrate; and forming, on the encapsulation member, electrical connections between pads and the semiconductor light emitting chips, respectively, with each of the pads being arranged at a designated distance from each of the light emitting chips.

(17) There is also provided, the method for manufacturing a semiconductor light emitting device of clause (16) wherein: providing the at least one semiconductor light emitting chip on the substrate includes providing Zener diodes corresponding to the at least one semiconductor light emitting chip, with each of the Zener diodes being arranged at a designated distance from each of the at least one semiconductor light emitting chip.

(18) A method for manufacturing a semiconductor light emitting device including at least one semiconductor light emitting chip, the method comprising: preparing a substrate; forming, on the substrate, electrical connections for connecting a plurality of pads and the at least one semiconductor light emitting chip, respectively, with the plurality of pads being arranged at a designated distance from the semiconductor light emitting chips; providing the at least one semiconductor light emitting chip on the substrate; providing an encapsulation member over the substrate and the semiconductor light emitting chips; and removing the substrate.

(19) There is also provided, the method for manufacturing a semiconductor light emitting device of clause (18) wherein: providing the at least one semiconductor light emitting chip on the substrate includes providing, on the plurality of pads, Zener diodes corresponding to the at least one semiconductor light emitting chip.

(20) A semiconductor light emitting device, comprising: a semiconductor light emitting chip including a first electrode and a second electrode; a substrate including a plate on which electrical connections are formed, with the electrical connections including a first electrical connection electrically connected to the first electrode and a second electrical connection electrically connected to the second electrode; and metal blocks provided on the substrate, with the metal blocks including a first metal block that includes an upper surface electrically connected to an external substrate and a lower surface electrically connected to the first electrical connection, and a second metal block that includes an upper surface electrically connected to an external substrate and a lower surface electrically connected to the second electrical connection, wherein the metal blocks have a height equal to or greater than that of the semiconductor light emitting chip.

(21) There is also provided, the semiconductor light emitting device of clause (20) wherein: the metal blocks are arranged at a designated distance from the semiconductor light emitting chip.

(22) There is also provided, the semiconductor light emitting device of clause (20) wherein: the substrate is transparent.

(23) There is also provided, the semiconductor light emitting device of clause (20) wherein: the plate is made from a transparent material, and the electrical connections have multiple paths.

(24) There is also provided, the semiconductor light emitting device of clause (20) further comprising: an encapsulation member for enclosing the first and second metal blocks in such a manner that upper surfaces of the first and second metal blocks are exposed, and for covering the semiconductor light emitting chip and the substrate.

(25) There is also provided, the semiconductor light emitting device of clause (20) wherein: the first electrical connection includes a first contact portion in contact with the first electrode, a first pad in contact with the first metal block, and a first connection portion for electrically connecting the first contact portion and the first pad; and the second electrical connection includes a second contact portion in contact with the second electrode, a second pad in contact with the second metal block, and a second connection portion for electrically connecting the second contact portion and the second pad, with the first pad being provided under the first metal block, and the second pad being provided under the second metal block.

(26) There is also provided, the semiconductor light emitting device of clause (25) wherein: the first connection portion and the second connection portion are formed in a net structure.

(27) There is also provided, the semiconductor light emitting device of clause (25) further comprising: a second semiconductor light emitting device including a third electrode and a fourth electrode, and a third semiconductor light emitting device including a fifth electrode and a sixth electrode, wherein the metal blocks further include a third metal block and a fourth metal block, with the first metal block being electrically connected to the first electrode, the second metal block being electrically connected to the second, fourth, and sixth electrodes, the third metal block being electrically connected to the third electrode, and the fourth metal block being electrically connected to the firth electrode; and wherein the electrical connections include a first electrical connection formed between the first metal block and the first electrode, a second electrical connection formed between the second block and the second, fourth and sixth electrodes, a third electrical connection formed between the third metal block and the third electrode, and a fourth electrical connection formed between the fourth metal block and the fifth electrode.

(28) There is also provided, the semiconductor light emitting device of clause (20) wherein: the electrical connections connect the semiconductor light emitting chip and the metal blocks through multiple paths therebetween.

A semiconductor light emitting device according to an exemplary embodiment of the present disclosure has thinner electrical connections in a net structure, making the semiconductor light emitting device more visible.

A semiconductor light emitting device according to another exemplary embodiment of the present disclosure has electrical connections forming multiple paths between the pads and the electrodes, such that the pads and the electrodes stay electrically connected even if one of the paths may be cut off or disconnected.

A semiconductor light emitting device according to another exemplary embodiment of the present disclosure is configured so that the electrical connections and the pads are arranged inside the encapsulation member, preventing separation between them.

With a method for manufacturing a semiconductor light emitting device according to an exemplary embodiment of the present disclosure, the semiconductor light emitting device is configured so that the electrical connections are projected out of the encapsulation member.

With a method for manufacturing a semiconductor light emitting device according to another exemplary embodiment of the present disclosure, the semiconductor light emitting device is configured so that the electrical connections and the pads are arranged inside the encapsulation member, exposing only a portion of each.

A semiconductor light emitting device according to another exemplary embodiment of the present disclosure is configured to emit lights from six sides.

A semiconductor light emitting device according to another exemplary embodiment of the present disclosure is configured so that metal blocks connected to an external substrate are provided along the direction of lights escaping from the semiconductor light emitting chip.

With a method for manufacturing a semiconductor light emitting device according to another exemplary embodiment of the present disclosure, the semiconductor light emitting device is protected against warpage.