Patent Application
20130008377
The present invention relates to a resin coating device in an LED package manufacturing system that manufactures an LED package formed by covering an LED element mounted on a substrate with a phosphor-containing resin.
LEDs (light-emitting diode) exhibiting superior characteristics; namely, less power consumption and a longer life, have come into extensive use as light sources for various illuminating devices. The fundamental light emitted from an LED element is currently limited to the three primary lights; red light, green light, and blue light. For this reason, in order to generate white light suitable for general illumination purposes, there has been employed a technique of generating white light by mixing the three fundamental lights through additive color mixture or a technique of generating pseudo white light by combination of a blue LED with a phosphor that emits yellow fluorescent light which is complementary to a blue color. In recent years, the latter technique has come into wide use. An illuminating device using an LED package that is a combination of a blue LED and YAG phosphor has widely been used for a backlight of a liquid-crystal panel (see; for instance, Patent Document 1).
In this example Patent Document, an LED element is mounted on a bottom of a recessed mounting section having sidewalls over which a reflection surface is formed. Subsequently, a silicone resin, an epoxy resin, or the like, that includes dispersed YAG-based phosphor particles is poured into the mounting section, thereby forming a resin package section. An LED package is thus configured. There are also descriptions about example formation of a surplus resin storage section that is intended for providing a uniform height to the resin package section formed in the mounting section after pouring of a resin and preserving a surplus resin which has been poured in excess of a specified quantity and hence drained out of the resin mounting section. Even when variations exist in discharge rate of a dispenser during pouring of a resin, a resin package section having a given quantity of resin and a defined height is formed on an LED element.
However, a problem confronted by the related art example is that a change in emission characteristic of an LED package which is to become a product is caused by a variation in emission wavelength of an individual LED element change. Specifically, LED elements have passed through a manufacturing process in which a plurality of elements are collectively fabricated on a wafer. For reasons of various error factors in the manufacturing process; for instance, uneven composition occurred when a film is formed over a wafer, LED elements separated as pieces from the wafer are inevitably subject to variations in emission wavelength. In the foregoing example, the height of the resin package covering the LED element is uniformly set. Hence, variations in emission wavelength of respective individual LED elements are reflected as variations in emission characteristic of LED packages that are products. As a consequence, an increase inevitably arises in the number of defective products that are out of an acceptable quality range. As mentioned above, the related-art LED package manufacturing technique has hitherto encountered the following problem; specifically, because of variations in emission wavelength of respective LED elements, variations arise in emission characteristic of LED packages that are products, which in turn causes deterioration of product yield.
Accordingly, the present invention aims at providing a resin coating device in an LED package manufacturing system that, even when variations occur in emission wavelength of respective LED elements, can make emission characteristics of LED packages uniform, to thus enhance product yield.
A resin coating device in an LED package manufacturing system of the present invention corresponds to a resin coating device that coats a plurality of LED elements mounted on a substrate by a component mounting device in an LED package manufacturing system that manufactures LED packages by coating the LED elements mounted on the substrate with a phosphor-containing resin, the LED packaging manufacturing system comprising:
an element characteristic information providing unit that provides, as element characteristic information, information obtained by section of preliminarily, individually measuring emission characteristics including emission wavelengths of the plurality of LED elements;
a resin information providing unit that provides, as resin coating information, information which makes a coating quantity of resin appropriate for obtaining an LED package having a specified emission characteristic correlated with the element characteristic information;
a map data preparation unit that prepares, for each substrate, map data which correlate mounting position information showing positions of the LED elements mounted on the substrate by the component mounting device with the element characteristic information about the LED elements, and transmits the map data to the resin coating device;
an emission characteristic inspection device that inspects emission characteristics of the LED resin applied over the LED elements, to thus detect deviations from a specified emission characteristic, and that feeds back inspection results to the resin coating device;
a coating information updating unit that, when the detected deviations exceed an allowable value, performs processing for updating the resin coating information according to the fed-back inspection results; and
a resin coating control unit that includes a resin discharge mechanism for discharging the resin fed from a resin feed section from a discharge nozzle and a relative movement mechanism for relatively moving the discharge nozzle with respect to the substrate and that controls the resin discharge mechanism and the relative movement mechanism according to the transmitted map data and the transmitted resin coating information, thereby coating the respective LED elements with resin having coating quantities appropriate for exhibiting the specified emission characteristic.
Even when variations occur in emission wavelength of respective LED elements, the present invention can make emission characteristics of LED packages uniform, to thus enhance product yield.
By reference to the drawings, an embodiment of the present invention will now be described. First, a configuration of an LED package manufacturing system 1 is described by reference to
The component mounting device M1 bonds and mounts LED elements 5 on a substrate 4 (see
By reference to
Each of the LED packages 50 has a function of emitting white light used as light sources of various illuminating devices. The LED element 5 that is a blue LED is combined with the resin 8 that includes a phosphor which emits yellowish fluorescent light that is a complementary color of blue, whereby pseudo white light is produced. As shown in
As shown in
In order to prevent occurrence of a quality defect attributable to variations in emission characteristics, emission characteristics of the plurality of LED elements 5 manufactured through the same manufacturing processes are preliminarily measured in the embodiment. Element characteristic information that correlate the respective LED elements 5 with data representing emission characteristics of the respective LED elements 5 is preliminarily prepared. During application of the resin 8, each of the LED elements 5 is coated with an appropriate quantity of resin 8 commensurate with the emission characteristic of the LED element 5. Since an appropriate quantity of resin 8 is applied, resin coating information to be described later is previously prepared.
First, element characteristic information is described. As shown in
In the emission characteristic measurement device 11, electric power is fed to the respective LED elements 5 by way of a probe, thereby letting the LED elements actually emit light. The thus-emitted light is subjected to spectroscopic analysis and measured in connection with predetermined items; like, an emission wavelength and emission intensity. The LED element 5 that is an object of measurement has preliminarily been provided with, as reference data, a standard distribution of an emission wavelength. Further, a wavelength range corresponding to a standard range in the distribution is divided into a plurality of wavelength regions. The plurality of LED elements 5 that are objects of measurement are thereby classified according to an emission wavelength. Respective ranks, which are set as a result of a wavelength range being classified into three regions, are given, in sequence from a lower wavelength, Bin codes [1], [2], and [3]. There is prepared element characteristic information 12 including a data configuration in which element ID 12a is allocated to Bin code 12b.
Specifically, the element characteristic information 12 is information obtained by preliminarily, individually measuring emission characteristics including respective emission wavelengths of the plurality of LED elements 5. An LED element manufacturer preliminarily prepares the information, and the information is transmitted to the LED package manufacturing system 1. In relation to a form of transmission of the element characteristic information 12, the information may also be transmitted while solely recorded in a storage medium or to the supervisory computer 3 by way of the LAN system 2. In any event, the thus-transmitted element characteristic information 12 is stored in the supervisory computer 3 and provided to the component mounting device M1, as required.
The plurality of LED elements 5 having finished undergoing emission characteristic measurement are sorted into three types of characteristic ranks as shown in
Resin coating information preliminarily prepared in correspondence with the element characteristic information 12 is now described by reference to
As mentioned above, variations classified by the Bin codes [1], [2], and [3] concurrently exist in emission wavelengths of the plurality of LED elements 5 that are objects of work. For this reason, an appropriate quantity of phosphor particles in the resin 8 applied so as to cover the LED element 5 varies according to the Bin codes [1], [2], and [3]. As shown in
As provided in a phosphor concentration field 16, a phosphor concentration showing the concentration of phosphor particles in the resin 8 is set in numbers (three concentrations D1, D2, and D3 in the embodiment). A different numeral is also used for an appropriate coating quantity of resin 8 according to a concentration of phosphor in the resin 8 used. The reason why different appropriate application quantities are set according to the phosphor concentration is because applying the resin 8 having an optimum phosphor concentration according to a degree of variation in emission wavelength is more desirable from the viewpoint of securing quality. For instance, when the LED element 5 given Bin code [2] in connection with the Bin code category 17 is taken as a target, it is desirable to set an appropriate discharge rate in such a way that the resin 8 having a phosphor concentration D2 is squirted by only a quantity of v22 nl. As a matter of course, when the resin 8 having a single phosphor concentration is used for reasons, an appropriate discharge rate commensurate with the Bin code category 17 is selected according to the phosphor concentration.
By reference to
As shown in
The substrate 4 coated with the adhesive is transported downstream and positioned by the component mounting section B as shown in
During operation for mounting the LED element 5 onto the substrate 4 performed by the component mounting device M1, component mounting operation is carried out according to a preliminarily-prepared element mounting program. The element mounting program preliminarily sets a sequence in which the component mounting mechanism 26 picks up the LED elements 5 from which one of the LED sheets 13A, 13B, and 13C during individual mounting operation and mounts the thus-picked-up LED elements 5 respectively on the plurality of substrate pieces 4a of the substrate 4.
When component mounting operation is performed, mounting position information 71a (see
In
Specifically, the component mounting device M1 is equipped with the map preparation processing section 74 that serves as map data preparation unit for preparing for each substrate 4 the map data 18 which correlate the mounting position information showing the position of the LED element 5 mounted on the substrate 4 by the component mounting device with the element characteristic information 12 about the LED element 5. The thus-prepared map data 18 are transmitted as feedforward data to the resin coating device M4 to be described later, by way of the LAN system 2.
By reference to
As shown in
The nozzle transfer mechanism 35 and the resin feed section 38 are controlled by a coating control unit 36 and can thereby discharge the resin 8 by means of the discharge nozzle 33 to arbitrary LED mounting sections 4b formed respectively on the plurality of substrate pieces 4a of the substrate 4. During resin discharge operation, the coating control unit 36 controls the resin discharge mechanism 37, thereby controls the quantity of the resin 8 discharged from the discharge nozzle 33 to a desired quantity of resin according to an emission characteristic of the LED element 5 mounted on each of the LED mounting sections 4b.
Specifically, according to the preliminarily stored resin coating information 14 and the map data 18 transmitted from the component mounting device M1, the coating control unit 36 controls the resin discharge mechanism 37 and the nozzle transfer mechanism 35 that is a relative transferring mechanism. This control makes it possible to cause the discharge nozzle 33 to discharge the quantity of resin 8 appropriate for exhibiting a specified emission characteristic, thereby coating the respective LED elements 5. As will be described later, a coating information update section 84 (see
Specifically, the resin coating device M4 has a function of coating the respective LED elements 5 mounted on the substrate 4 with the quantity of resin 8 appropriate for exhibiting a specified emission characteristic, according to the map data 18 and the resin coating information 14. Further, the resin coating device M4 is additionally provided with the coating information update section 84 as coating information update section for updating the resin coating information 14. Although
By reference to
A spectroscope 43 is situated above the holding table 40 and receives the white light emitted from the LED package 50. A color hue measurement processing section 44 analyzes the thus-received white light. Emission characteristics of the white light, such as a color hue rank and a luminous flux, are inspected here, and deviation from specified emission characteristics is detected as inspection results. The thus-detected inspection results are fed back to the resin coating device M4. When the deviation has exceeded a preset acceptable range, the resin coating device M4 received the feedback performs processing for updating the resin coating information 14 according to the inspection result. Subsequently, coating the substrate 4 with a resin is thereafter performed according to the newly-updated resin coating information 14.
By reference to
In
The component mounting device M1 has a mounting control unit 70, a storage section 71, a communication section 72, a mechanism actuation section 73, and the map preparation processing section 74. In order to implement component mounting operation performed by the component mounting device M1, the mounting control unit 70 controls individual sections, which will be described below, according to various programs and data stored in the storage section 71. In addition to storing programs and data required for control processing of the mounting control unit 70, the storage section 71 stores the mounting position information 71a and the element characteristic information 12. The mounting position information 71a is prepared from data pertaining to a history of mounting operation control performed by the mounting control unit 70. The element characteristic information 12 is transmitted from the supervisory computer 3 by way of the LAN system 2. The communication section 72 is connected to other units by way of the LAN system 2 and thereby exchanges control signals and data.
Under control of the mounting control unit 70, the mechanism actuation section 73 actuates the component feed mechanism 25 and the component mounting mechanism 26. The LED elements 5 are thereby mounted on the respective substrate pieces 4a of the substrate 4. The map preparation processing section 74 (map data preparation unit) performs processing for generating, for each substrate 4, the map data 18 that correlate the mounting position information 71a, which is stored in the storage section 71 and which shows the position of the LED element 5 mounted on the substrate 4 by the component mounting device M1, with the element characteristic information 12 about the LED element 5. Specifically, the map data preparation unit is provided on the component mounting device M1, and the map data 18 are transmitted from the component mounting device M1 to the resin coating device M4. Alternatively, the map data 18 may also be transmitted from the component mounting device M1 to the resin coating device M4 by way of the supervisory computer 3. In this case, the map data 18 are stored in the storage section 61 of the supervisory computer 3, as well, as shown in
The resin coating device M4 has the coating control unit 36, the storage section 81, a communication section 82, a mechanism actuation section 83, and the coating information update section 84. In order to implement resin coating operation performed by the resin coating device M4, the coating control unit 36 controls individual sections to be described below, according to the various programs and data stored in the storage section 81. In addition to storing the programs and data required for control processing of the coating control unit 36, the storage section 81 stores the resin coating information 14 and the map data 18. The resin coating information 14 is transmitted from the supervisory computer 3 by way of the LAN system 2. Likewise, the map data 18 are transmitted from the component mounting device M1 by way of the LAN system 2. The communication section 82 is connected to other units by way of the LAN system 2 and exchanges a control signal and data.
Under control of the coating control unit 36, the mechanism actuation section 83 actuates the resin discharge mechanism 37, the resin feed section 38, and the nozzle transfer mechanism 35. The LED elements 5 mounted on the respective substrate pieces 4a of the substrate 4 are thereby coated with the resin 8. In accordance with an inspection result fed back from the emission characteristic inspection device M7, the coating information update section 84 performs processing for updating the resin coating information 14 stored in the storage section 81.
The emission characteristic inspection device M7 has an inspection control unit 90, a storage section 91, a communication section 92, a mechanism actuation section 93, and an inspection mechanism 94. In order to implement inspection operation performed by the emission characteristic inspection device M7, the inspection control unit 90 controls individual sections to be described below in accordance with inspection execution data 91a stored in the storage section 91. The communication section 92 is connected to other units by way of the LAN system 2 and exchanges a control signal and data. The mechanism actuation section 93 actuates an inspection mechanism 94 having a work transfer-hold function for handling the LED package 50 to inspect.
Under control of the inspection control unit 90, the color hue measurement processing section 44 performs emission characteristic inspection for measuring a color hue of the white light originating from the LED package 50 received by the spectroscope 43. An inspection result is fed back to the resin coating device M4 by way of the LAN system 2. Specifically, the emission characteristic inspection device M7 has a function of inspecting an emission characteristic of the LED package 50 fabricated by coating the LED element 5 with the resin 8, thereby detecting a deviation from the specified emission characteristic, and feeding back the inspection result to the resin coating device M4.
In the configuration shown in
In the configuration of the LED package manufacturing system 1, all of the component mounting device M1, the resin coating device M4, and the emission characteristic inspection device M7 are connected to the LAN system 2. The supervisory computer 3 having the element characteristic information 12 stored in the storage section 61 and the LAN system 2 serve as element characteristic information providing unit that provides information acquired by preliminary, individual measurement of emission characteristics including emission wavelengths of the plurality of LED elements 5, as the element characteristic information 12, to the component mounting device M1. Likewise, the supervisory computer 3 including the resin coating information 14 stored in the storage section 61 and the LAN system 2 serve as resin information providing unit that provides the resin coating device M4 with, as resin coating information, information that correlates the coating quantity of resin 8 appropriate for producing the LED package 50 having a specified emission characteristic with the element characteristic information.
Specifically, the element characteristic information providing unit for providing the element characteristic information 12 to the component mounting device M1 and the resin information providing unit for providing the resin coating information 14 to the resin contacting device M4 are configured so as to transmit to the component mounting device M1 and the resin coating device M4 the element characteristic information and the resin coating information read from the storage section 61 of the supervisory computer 63 that is external storage section, by way of the LAN system 2. Further, the emission characteristic inspection device M7 is configured so as to transmit the inspection result, as the characteristic inspection information 45 (see
Processing pertaining to LED package manufacturing processes performed by the LED package manufacturing system 1 is now described along a flowchart of
Subsequently, the substrate 4 that is an object of mounting operation is carried into the component mounting device M1 (ST2). As shown in
The substrate 4 having finished being mounted with components is then sent to the curing device M2, where the substrate 4 is heated. As shown in
The substrate 4 having undergone wire bonding operation is carried to the resin coating device M4 (ST6). As shown in
The thus-completed LED packages 50 are carried into the emission characteristic inspection device M7 (ST10), where each of the LED packages 50 undergoes emission characteristic inspection (ST11). Specifically, the emission characteristic inspection device M7 inspects each of the LED packages 50 in connection with its emission characteristic and detects a deviation between a specified emission characteristic and the thus-detected emission characteristic and feeds back the inspection result to the resin coating device M4. The resin coating device M4 received the feedback signal determines whether or not the detected deviation exceeds an acceptable value by means of the coating information update section 84 (ST12). When the deviation exceeds the acceptable value, the coating information update section 84 updates the resin coating information 14 according to the detected deviation (ST13). Operations, such as the component mounting operation and the resin coating operation, are continually carried out by use of the thus-updated resin coating information 14 (ST14). When the deviation is determined not to exceed the acceptable value in (ST12), processing proceeds to a process pertaining to (ST14) while the existing resin coating information 14 is maintained.
As mentioned above, the LED package manufacturing system 1 described in connection with the embodiment adopts a configuration made up of the followings: namely, the component mounting device M1 that mounts the plurality of LED elements 5 on the substrate 4; the element characteristic information providing unit that provides, as the element characteristic information 12, information acquired as a result of an emission wavelength of each of the plurality of LED elements 5 having been preliminarily measured; resin information providing unit that provides, as resin coating information 14, information which makes a coating quantity of resin 8 appropriate for producing the LED packages 50 having the specified emission characteristic correlated with the element characteristic information 12; the map data preparation unit for preparing, for each substrate 4, the map data 18 that correlate the mounting position information 71a showing a position of the LED element 5 mounted on the substrate 4 by the component mounting device M1 with the element characteristic information 12 about the LED element 5; the resin coating device M4 that applies the coating quantity of resin 8 appropriate for exhibiting a specified emission characteristic to each of the LED elements mounted on the substrate 4 according to the map data 18 and the resin coating information 14; the emission characteristic inspection device M7 that inspects emission characteristics of the LED elements 5 coated with the resin 8, to thus detect deviations from the specified emission characteristics, and that feeds back an inspection result to the resin coating device M4; and the coating information update section that performs operation for updating the resin coating information 14 according to the fed-back inspection result when the detected deviation exceeds an acceptable value.
The resin coating device M4 employed in the LED package manufacturing system 1 having the foregoing configuration includes the resin discharge mechanism 37 that discharges the resin 8 supplied by the resin feed section 38 from the discharge nozzle 33; the nozzle transfer mechanism 35 that relatively transfers the discharge nozzle 33 with respect to the substrate 4; and the coating control unit 36 that controls the resin discharge mechanism 37 and the nozzle transfer mechanism 35 according to the transmitted map data 18 and the resin coating information 14, thereby coating each of the LED elements 5 with the quantity of resin 8 appropriate for exhibiting a specified emission characteristic.
This makes it possible to apply the appropriate quantity of resin 8 at all times according to an emission characteristic of the LED element 5 to which the resin 8 is to be applied. Even when variations exist in emission wavelengths of the pieces of LED elements, emission characteristics of the LED packages can be made uniform, thereby enhancing a production yield. The resin coating information 14 can be fixedly applied to an LED package manufacturing system for practical production that is used after having sufficiently performed trial production in preparation for mass production. Therefore, the emission characteristic inspection device M7 and the coating information update section in the LED package manufacturing system 1 having the foregoing configuration can be omitted.
The LED package manufacturing system 1 having the foregoing configuration shows a configuration in which the supervisory computer 3 and the respective devices, from the component mounting device M1 to the emission characteristic inspection device M7, are connected by the LAN system 2. However, the LAN system 2 is not an indispensable configuration requirement. Specifically, the function of the LED package manufacturing system 1 exemplified in connection with the embodiment can be materialized, as long as the following section are provided; namely, storage section that stores, for each of the LED packages 50, the element characteristic information 12 and the resin coating information 14 which have been preliminarily prepared and transmitted from the outside; data providing unit capable of providing from the storage section, as required, the element characteristic information 12 to the component mounting device M1 and the resin coating information 14 and the map data 18 to the resin coating device M4, and data transmission section capable of feeding back an inspection result of the emission characteristic inspection device M7 to the resin coating device M4.
The present invention is also scheduled to be susceptible to various alterations and applications by skilled artisans without departing the gist and scope of the present invention according to the descriptions of the specification and well-known techniques, and the alterations and applications shall fall within a range where protection of the invention is sought. Moreover, the constituent elements described in connection with the embodiment can also be arbitrarily combined without departing the gist of the present invention.
The present patent application is based on Japanese Patent Application (JP-2010-201656) filed on Sep. 9, 2010, the entire subject matter of which is incorporated herein by reference.
The resin coating device in the LED package manufacturing system of the present invention yields an advantage of the ability to make emission characteristics of LED packages uniform even when variations exist in emission wavelengths of pieces of LED elements, thereby enhancing production yield. The system can be utilized in a field of manufacture of LED packages, each of which is configured by covering an LED element with a phosphor-containing resin.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2010-201656 | Sep 2010 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2011/002580 | 5/9/2011 | WO | 00 | 9/11/2012 |
