KR20200054869A - Inspection apparatus and inspection method - Google Patents

Abstract

According to the present invention, a plurality of separated semiconductor light emitting elements are inspected in a lump right before mounting to sort out semiconductor light emitting elements having a defect in light emission. An inspection apparatus, which optically inspects a plurality of semiconductor light emitting elements separately arranged on an insulation film body, includes: a first plate including a first electrode; a second plate including a second electrode provided by inserting the semiconductor light emitting elements and the insulation film body between the first electrode and the second electrode; a driving power source electrically connected to the first and second electrodes; and an optical machine observing the light emission of the semiconductor light emitting elements from one of the first and second plates. Between the first and second electrodes, a plurality of individually separated light emission circuit parts, in which a capacitor made of an insulation film body is connected in series to each of the semiconductor light emitting elements, are placed. In the light emission circuit parts, the semiconductor light emitting elements emit light by generating an induced current when a current flows from the driving power source to the semiconductor light emitting elements in a forward direction.

Description

Inspection device and inspection method {INSPECTION APPARATUS AND INSPECTION METHOD}

The present invention relates to an inspection device used to functionally (optically) inspect a plurality of semiconductor light emitting devices made of a light emitting diode (LED) or the like, and an inspection method using the inspection device.

More specifically, the present invention relates to an inspection apparatus and an inspection method for inspecting light emission in a separated state of a plurality of light-emitting elements arrayed at a time before the plurality of semiconductor light-emitting elements are mounted.

Conventionally, as this type of inspection apparatus and inspection method, a field plate having an upper electrode to face a pn-bonded light emitting part of a plurality of LED devices formed on a support substrate plate) is disposed, the common electrode is electrically grounded as the lower electrode of the plurality of LED devices, and a plurality of LED devices emit light by applying the voltage from an external voltage source to the upper electrode, It is possible to measure the luminescence luminance by observation (for example, see Patent Document 1).

Although the plurality of LED devices are half cut in the trench, the trench does not penetrate the common contact layer serving as the lower electrode, and is in an unseparated state on the support substrate ([0048], Figure 3A, 3B, etc.).

That is, a plurality of LED devices are tested for light emission in an unseparated state from the supporting substrate, and their functions are evaluated by measuring light emission.

Patent Document 1: International Publication No. 2018/112267

By the way, among semiconductor light emitting elements, the LED chip is downsized for cost reduction, and a method for mounting the downsized LED chip with high speed and high precision has been performed. In particular, the LED used for the LED display is an LED chip having a size of 50 μm × 50 μm or less called a micro LED, and it is required to transfer and mount the LED chip in a divided state that reliably emits light with high precision of several μm.

However, in Patent Document 1, since a plurality of LED devices are tested for light emission in an unseparated state, in the die bonding process of mounting each LED device, it cannot be handled in an unseparated state, and a plurality of dicing may be performed before mounting. It was necessary to separate the LED devices of the individual.

In such a case, even if a plurality of LED devices are evaluated as "no problem in function" by a light emission test in a state where they are not separated from the supporting substrate, the possibility that new defects may occur due to subsequent separation processes or the like is undeniable, and mounting There was a problem in that reliability was poor because light emission could not be confirmed immediately before.

Under such a situation, an inspection apparatus or an inspection method capable of screening a plurality of separated LED devices prior to mounting to select LED devices having poor light emission is desired.

In addition, in order to prevent damage to the LED device by the light emission test, inspection in a low voltage environment avoiding electrical contact is required.

In order to solve this problem, the inspection device according to the present invention is an inspection device for optically inspecting a plurality of semiconductor light-emitting elements arranged separately on an insulating film, the first plate having a first electrode, and the first electrode. A second plate having a second electrode provided to sandwich the plurality of semiconductor light emitting elements and the insulating film between them, a driving power source electrically connected to the first electrode and the second electrode, and the first electrode And an optical machine for observing light emission of the plurality of semiconductor light emitting elements on either side of the plate or the second plate, and between the first electrode and the second electrode, each of the plurality of semiconductor light emitting elements A plurality of light-emitting circuit parts separated by a series of capacitors made of the insulating film are disposed in the plurality of light-emitting circuits. Is, by generating an induced current from the driving power source when a forward current flows to the plurality of semiconductor light-emitting device is characterized in that the plurality of the semiconductor light emitting element emits light.

In addition, in order to solve such a problem, the inspection method according to the present invention is an inspection method for optically inspecting a plurality of semiconductor light-emitting elements separately arranged in an insulating film, wherein the first electrode and the second plate are formed. Between two electrodes, a set process of forming a plurality of individually separated light-emitting circuit parts in which capacitors made of the insulating film are connected in series to each of the plurality of semiconductor light-emitting elements, and the voltage of the driving power supply to the first electrode and the A supply process applied from the second electrode to the plurality of light-emitting circuit units, and the plurality of semiconductor light-emitting elements that emit light by supplying voltage to the plurality of light-emitting circuit units, either of the first plate or the second plate. And an observation process for observing with an optical machine at the side, and in the observation process, from the driving power source It is characterized in that the plurality of semiconductor light emitting elements emit light by generating an induced current when a current in the forward direction flows through the plurality of semiconductor light emitting elements.

1 is an explanatory view showing the overall configuration of an inspection apparatus and an inspection method according to an embodiment of the present invention, (a) is a partially cut-away front view of an application process and an inspection process, and (b) is the same cross-sectional plan view.
2 is an explanatory view showing a modification of the inspection apparatus and inspection method according to the embodiment of the present invention, wherein (a) to (c) are partially cut front views of the application process and the inspection process.
3 is an explanatory view showing a modification of the inspection apparatus and inspection method according to the embodiment of the present invention, and is a partially cut-away front view of an application process and an inspection process.
4 is an explanatory view showing a modification of the inspection apparatus and inspection method according to the embodiment of the present invention, and is a partially cut-away front view of an application process and an inspection process.
5 is an explanatory view showing a modification of the inspection apparatus and inspection method according to the embodiment of the present invention, wherein (a) is a partial cut-away front view showing a specific example of an optical machine and a driving part, and (b) is the same reduced crossing It is a top view.
6 is an explanatory view showing a modification of the inspection apparatus and inspection method according to the embodiment of the present invention, and is a partially cut-away front view when a plurality of semiconductor light emitting elements are transportable.
7 is a circuit diagram, (a) is an equivalent circuit corresponding to FIGS. 1 to 5, and (b) is an equivalent circuit of a modified example.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail based on drawing.

As shown in FIGS. 1 to 7, the inspection device A according to the embodiment of the present invention, before mounting a plurality of arrayed semiconductor light emitting devices E, individually, the plurality of semiconductor light emitting devices E It is an optical property measurement device that is used to inspect functionally (optical) in a separated array state and to prevent the optically defective mounting of the light emitting element E.

In detail, the inspection device A according to the embodiment of the present invention includes a first plate 1 having a first electrode 1a and a second plate 2 having a second electrode 2a. , A plurality of semiconductor light-emitting from one side of the driving plate 3 and the first plate 1 or the second plate 2 provided to electrically connect to the first electrode 1a and the second electrode 2a The optical machine 4 provided for observing the light emission of the element E is provided as a main component.

Further, the dielectric layer 5 provided on either or both surfaces of the first electrode 1a or the second electrode 2a and the first plate 1 or the second plate 2 are relatively It is preferable to have a driving unit 6 provided for moving, and a control unit 7 provided for operating control of the driving power supply 3 and the driving unit 6.

In addition, the 1st plate 1 and the 2nd plate 2 are provided so that it may oppose normally up and down. In the example of illustration, the 1st plate 1 is arrange | positioned below, and the 2nd plate 2 is arrange | positioned above. Here, the direction in which the first plate 1 and the second plate 2 face each other is hereinafter referred to as "Z direction". The direction along the first plate 1 or the second plate 2 intersecting the Z direction is hereinafter referred to as "XY direction".

The plurality of semiconductor light emitting elements E are light-emitting diodes formed in a thin plate shape of approximately rectangular (rectangular quadrangles including squares and squares), each of which is smooth, as shown in Figs. 1 (a) and 1 (b). It is a semiconductor diode such as (LED) or laser diode (LD). Red, green, and blue chip LEDs are also included as the semiconductor diode.

Specific examples of the plurality of semiconductor light emitting devices E include 50 μm × 50 μm or less, referred to as micro LEDs, specifically 30 μm × 30 μm or less, and more specifically, LED chips or LD chips of several tens of square μm.

Further, as another example of the plurality of semiconductor light emitting devices E, for example, a LED chip having a size of around 100 μm square or so called a mini LED, a general LED chip such as 200 to 300 μm square, or a semiconductor diode of a general size such as an LD chip is included. It is also possible.

In general chip handling, a plurality of semiconductor light emitting elements E are arranged on a substrate or wafer for element formation made of a material such as silicon in a predetermined cycle in the XY direction, and the light emitting portion E1 is formed on the front side or the back side. ). The plurality of arrayed semiconductor light emitting elements E are each separated to maintain the arrangement state by a dividing process such as dicing, and transferred to the insulating film F described later while moving to the mounting process while maintaining the arrangement state. do.

In particular, as the plurality of semiconductor light-emitting elements E, the plurality of semiconductor light-emitting elements E individually arranged and used is a film-attached chip EF temporarily fixed to the insulating film F described later.

In addition, in the illustrated example, for the purpose of explanation, all of the rectangular semiconductor light emitting elements E are set to the same size as the arrangement of the plurality of semiconductor light emitting elements E. Moreover, although not shown as another example, it is also possible to change the arrangement | positioning of the some semiconductor light emitting element E other than an example of illustration.

The insulating film F is a transparent or opaque insulating material such as polyethylene terephthalate (PET), polypropylene (PP), polyvinyl chloride (PVC) (with a relative dielectric constant of about 3), and is formed in a film or sheet form. , It is also possible to use a dicing tape or the like made of an insulating material.

In addition, the insulating film F adheres to either the front side or the back side of the plurality of semiconductor light-emitting elements E where the light-emitting section E1 is disposed, or both to the surface side and the back side. By temporarily fixing by being detachable by this, the film-attached chip EF is constructed.

That is, as the insulating film F, the transparent light emitting side insulating film F1 temporarily fixed to the surface side where the light emitting portion E1 is disposed in the plurality of semiconductor light emitting devices E, or the plurality of semiconductor light emitting devices E In), there is a transparent or opaque double-side insulating film F2 temporarily fixed to the back side that is the opposite side of the light-emitting portion E1.

The plurality of individually separated semiconductor light emitting elements E is maintained without being separated by the light emitting side insulating film F1 or the back insulating film F2, and the light emitting side insulating film F1 or the double insulating film F2 is maintained. By peeling off, the light emitting portion E1 or the back surface of the plurality of semiconductor light emitting elements E is exposed and can be taken out, and mounting is also possible.

The first plate 1 and the second plate 2 are quartz, as shown in Figs. 1 (a), (b), 2 (a), (b), (c) and 3, etc. It consists of a platen formed on a plate with a rigid or transparent opaque material such as a hard synthetic resin. The first electrode 1a is formed on a surface of the first plate 1 that faces the second plate 2, and on a surface of the second plate 2 that faces the first plate 1, The second electrode 2a is formed.

The first electrode 1a and the second electrode 2a are also laminated with a transparent or opaque material in the same manner as the first plate 1 or the second plate 2.

The first electrode 1a of the first plate 1 and the second electrode 2a of the second plate 2 are between the first electrode 1a and the second electrode 2a. ) (A plurality of semiconductor light emitting elements E and an insulating film F) are arranged to face each other, and the driving power source 3 described later is electrically connected.

As a result, between the first electrode 1a and the second electrode 2a, a plurality of light-emitting circuit units, each of which is individually separated, in which a capacitor made of an insulating film F is connected in series to each of the plurality of semiconductor light-emitting elements E, (C) is placed.

In addition, as shown in FIGS. 4 and 5 (a) and (b) of the first plate 1 and the second plate 2, either the first plate 1 or the second plate 2 is It is also possible to form an area with a smaller area than the other side. In this case, the other side of the first plate 1 or the second plate 2, or both of the first plate 1 and the second plate 2, the first plate 1 and It is preferable to support the second plate 2 so as to be relatively movable in a direction crossing the opposite direction (Z direction) (XY direction).

Further, either the first plate 1 or the second plate 2 is immobilized and detachable by bringing the film-attached chip EF into contact with the first electrode 1a or the second electrode 2a. It is desirable to provide a holding chuck (not shown) for holding as much as possible. Specific examples of the holding chuck include a vacuum adsorption chuck, a chuck equipped with a mechanical gripping mechanism such as an adhesive chuck or a claw, or a combination thereof.

The driving power source 3 is composed of an AC voltage source or a DC voltage source, and an AC voltage is applied from the driving power source 3 to the plurality of light emitting circuits C through the first electrode 1a and the second electrode 2a. Or DC (DC) voltage.

When an AC voltage is applied from the AC voltage source serving as the driving power source 3 to the plurality of light emitting circuits C, a plurality of semiconductor light emitting elements are formed by the rectifying action of the semiconductor diodes serving as the plurality of semiconductor light emitting elements E. With respect to (E), a current flows in the forward direction to emit the light emitting portion E1.

The optical machine 4 has a plurality of semiconductor light emitting elements E from either side of the first plate 1 (first electrode 1a) or second plate 2 (second electrode 2a). It consists of an inspection camera or the like to observe the luminance of the light emission.

That is, a plurality of light emitting circuit parts C, which are individually separated by connecting a capacitor made of an insulating film F to each of the plurality of semiconductor light emitting elements E in series, and the first optical device 4 are disposed. One side of the plate 1 (first electrode 1a) or the second plate 2 (second electrode 2a) may be formed of a transparent material, and the other side may be formed of an opaque material.

When a plurality of semiconductor light emitting elements E emit visible light as the inspection camera of the optical machine 4, it is preferable to use a visible light CCD camera or the like. In the case where the plurality of semiconductor light emitting elements E emit infrared light, it is preferable that the infrared camera is used to arrange the semiconductor light emitting elements E so as to be suitable for a predetermined resolution in accordance with the field of view of the inspection area. .

The placement of the inspection camera uses a high-resolution fixed camera 41, or a movable camera 42 movable in accordance with the movement of the first plate 1 or the second plate 2, or a fixed camera ( 41) and the mobile camera 42 are used together. In particular, in the case where a plurality of semiconductor light emitting elements E are formed in a plurality of micro sized arrays such as micro LEDs, it is preferable to use the mobile camera 42. Thereby, since the inspection area for the plurality of semiconductor light emitting elements E is limited, it is possible to sufficiently secure the observation resolution even with a low-resolution camera.

The average luminance data of the plurality of semiconductor light emitting elements E obtained by the fixed camera 41, the mobile camera 42, or the like relates the average luminance data for each inspection batch to the position of each semiconductor light emitting element E. By making it, it can be created as a database that can be referred to in a subsequent process.

In detail, as inspection data by the fixed camera 41, the mobile camera 42, or the like, a plurality of semiconductor light emitting elements E in a light emitting state are measured as one image data, and each semiconductor light emitting element ( E. The luminance average value of each semiconductor light emitting element E is obtained from a plurality of pixel data corresponding to the area of E), and the presence or absence of light emission of each semiconductor light emitting element E and the representative light emission luminance are determined as quantitative data. A luminance database for each (batch) is created. Further, by emitting light when the applied voltage from the driving power supply 3 is varied, it is possible to measure and match the luminance difference between the lowest light emission voltage of each semiconductor light emitting element E and the luminance.

In particular, when the plurality of semiconductor light emitting elements E are RGB chip LEDs, a color camera that sufficiently secures the resolution of the RGB chip LEDs is used as an inspection camera, and the luminance components of the RGB tricolors are databased as respective shades. It is preferred.

In addition, the database of these chip emission luminances can link the positions and data of the plurality of semiconductor light emitting elements E in each inspection batch. In this case, in the mounting process of each semiconductor light emitting element E by a die bonder or the like, which becomes the next step, it can be used as a selection criterion for the target chip immediately before taking out each semiconductor light emitting element E.

To perform a more accurate inspection according to the luminescence test, as shown in Figs. 5 (a) and (b), the inspection device (A) according to the embodiment of the present invention is provided in the dark room (D) of the inspection device (B) , It is preferable to perform a light emission test in a state where no external light enters.

The reason for performing the light emission test in the dark room D is that when external light less than the light emission frequency of each semiconductor light emitting element E is incident on the plurality of semiconductor light emitting elements E, the internal charge of each semiconductor light emitting element E is applied. This is because the excitation phenomenon occurs, making it difficult to observe an accurate light emission state.

Conversely, such an excitation phenomenon due to external light can be used as a method of observing the light excitation of each semiconductor light emitting element E by assisting the excitation. The dark room D is provided with a light source (not shown) that emits short wavelength light less than the emission frequency of the plurality of semiconductor light emitting elements E, and the light emitting unit E1 of the plurality of semiconductor light emitting elements E is provided from the light source. It is desirable to irradiate the short-wavelength light evenly in small quantities in a uniform amount. This makes it possible to lower the minimum voltage required for light emission. For this reason, light emission of each semiconductor light emitting element E can be observed even if the driving power supply 3 is set to a low voltage. For example, the red LED can be carried out by irradiating weakly blue or ultraviolet light which becomes a short wavelength.

In detail, with respect to the observation field of view of the inspection camera for observing light emission in the plurality of semiconductor light emitting elements E, an illumination device made of short wavelength light less than the emission frequency of each semiconductor light emitting element E (not shown) It is desirable to match the irradiation area. Specifically, a short-wavelength lighting device is juxtaposed to the fixed camera 41 or to the mobile camera 42.

With such a configuration, the suggestion level of the observation value in the camera field of view only by irradiation of the short-wavelength lighting device is measured in advance, and at the time of inspection, the data is corrected by subtracting the suggestion level from the camera observation value. In addition, if the external light intensity of each semiconductor light emitting element E is too strong, light excitation light emission due to the photoluminescence effect occurs, so that the illuminance level of the short-wavelength lighting device is preset so as not to generate light emission that does not depend on the driving current. It is desirable to adjust to.

In addition, when determining the color tone of the light emission state of the RGB chip LED as the plurality of semiconductor light emitting elements E, the light emission state is observed by a color camera, and an observation value for each RGB component may be used. When a short-wavelength lighting device is used together at the time of observation, the suggestive level of the color tone of the RGB component in the observation value in the camera's field of view only by irradiation of the short-wavelength lighting device is measured in advance. It is desirable to correct the data by subtracting the implicit level of.

Either the first electrode 1a of the first plate 1 or the second electrode 2a of the second plate 2, or both of the first electrode 1a and the second electrode 2a, , It is preferable to provide the dielectric layer 5 according to the surface of the first electrode 1a or the surface of the second electrode 2a.

That is, as the dielectric layer 5, in the plurality of semiconductor light emitting elements E, the opaque two-side dielectric layer 5a arranged to face the opposite side of the light emitting portion E1, or in the plurality of semiconductor light emitting elements E There is a transparent light emitting side dielectric layer 5b disposed to face the light emitting portion E1.

The back dielectric layer 5a and the light emitting side dielectric layer 5b can be made of a dielectric material having a high relative dielectric constant, and as a specific example, a high dielectric material such as titanium oxide having a relative dielectric constant of about 80 is used.

As a method of forming the dielectric layer 5 for the first electrode 1a of the first plate 1 or the second electrode 2a of the second plate 2, in addition to the formation of a hard thin film by sputtering or the like, ultraviolet irradiation or There is a method of forming a soft film in which a soft resin having a curable property by heating is used as a base material and cured by thinly applying a soft resin in which a fine non-dielectric material in a fine powder state is dispersed and mixed in a liquid.

Particularly, when the soft film serving as the dielectric layer 5 is formed of a silicone resin or the like having flexibility even after curing, displacement absorption against irregularities or distortion of the surface shape or the back side shape of the insulating film F or the semiconductor light emitting element E can be obtained. I can expect. Thereby, the surface contact property is improved also on the surface or the back surface of the insulating film F or the semiconductor light emitting element E, which lacks flexibility, and the electrostatic capacitance generated between the first electrode 1a and the second electrode 2a is improved. Can be more stabilized.

On the first plate 1 or the second plate 2, a film-attached chip EF (a plurality of semiconductor light emitting elements E and an insulating film (between the first electrode 1a and the second electrode 2a)) F)), the driving part 6 for relatively moving either the first plate 1 or the second plate 2 or both of the first plate 1 and the second plate 2 It is desirable to provide.

The driving part 6 is connected to either the first plate 1 or the second plate 2 or both of the first plate 1 and the second plate 2, and moves up and down, slides, or reverses. It is composed of an actuator and the like to be reciprocated by, it is controlled by the control unit 7 to be described later.

As a relative movement direction of the first plate 1 or the second plate 2 by the driving unit 6, as well as the opposite directions (Z direction) of the first plate 1 and the second plate 2, as necessary Therefore, the direction crossing the opposite direction (Z direction) (XY direction) is also included.

That is, as the drive unit 6, at least the first plate (1) or the second plate (2) in the Z direction for relatively moving the drive unit 61, the first plate (1) or the second plate (2) ) Has a driving unit 62 for horizontal movement that moves relative to the XY direction.

As a control example of the drive unit 61 for lifting by the control unit 7 to be described later, the first plate 1 is used when carrying in and taking out the film-attached chip EF, which is indicated by a two-dot chain line in FIG. And the second plate 2 are relatively spaced apart in the Z direction. Otherwise, as shown by a solid line in FIG. 1 (a), the first plate 1 and the second plate 2 are relatively moved in the Z direction, and the first electrode 1 of the first plate 1 ( 1a) and the second electrode 2a of the second plate 2 are pressed against the film-attached chip EF, either directly or indirectly through the dielectric layer 5 to energize it.

1 to 6 show specific examples of the film-attached chip EF (multiple semiconductor light-emitting elements E and the insulating film F), the optical machine 4, the dielectric layer 5 and the driver 6, 7 shows the equivalent circuit.

Examples (a), (b) of FIG. 1, (a), (b), (c) of FIG. 2, and the examples shown in FIGS. 4 to 6 are light emitting units E1 in the plurality of semiconductor light emitting elements E. ) Is disposed so as to be downward, and through the transparently formed first electrode 1a or the first plate 1 and the like, the light emitting state of the light emitting part E1 is first plate 1 by the optical machine 4. ).

In particular, in the examples shown in FIGS. 1 (a), 1 (b), 2 (c) and FIGS. 4-6, the second dielectric layer 5a is formed along the surface of the second electrode 2a, and In the case of (a), (b) and FIGS. 4 to 6, it differs in that the back dielectric layer 5a is brought into contact with the back insulating film F2. In the case of Fig. 2 (c), the back dielectric layer 5a is in direct contact with the back surface side of the plurality of semiconductor light emitting elements E, and differs in that there is no back insulating film F2.

2 (a) and 2 (b), the light emitting side dielectric layer 5b is formed along the surface of the first electrode 1a, and in the case of FIG. 2 (a), the light emitting side dielectric layer 5b ) Is different in that it contacts the light-emitting side insulating film F1. In the case of Fig. 2B, the light emitting side dielectric layer 5b is brought into direct contact with the surface side where the light emitting portion E1 is disposed in the plurality of semiconductor light emitting elements E, so that the light emitting side insulating film F1 It is different from the absence of).

In addition, the examples shown in FIGS. 1 (a), (b), 2 (a), (b), (c), and FIG. 4 show the second plate by the driving unit 61 for lifting of the driving unit 6. (2) differs in that the movement is controlled in the Z direction toward the first plate 1.

On the contrary, in the examples shown in FIGS. 3, 5 (a), (b), and 6, the first plate 1 is attached to the second plate 2 by the elevation driving portion 61 of the driving portion 6. It is different in that it is headed and controlled to move in the Z direction. In the case of FIG. 3, in the plurality of semiconductor light emitting elements E, the light emitting portion E1 is disposed so as to be upward, and the transparent light emitting side insulating film F1, the back side dielectric layer 5a, the second electrode 2a, or the like. 1 (a), (b) in FIG. 1 in that the second plate 2 is transmitted and the light emission state of the light emitting portion E1 is observed from the side of the second plate 2 by the optical machine 4 It is different from the case.

In addition, although not shown as other examples, in the examples shown in FIGS. 1 (a), (b), 2 (a), (b), (c), and FIG. 4, the driving unit 6 moves up and down. In the example shown in (b), (c) and FIG. 2 of FIG. 2, the first plate 1 is moved and controlled in the Z direction toward the second plate 2 with the dragon driving unit 61. Changes such as observing the light emission state of (E1) from the second plate 2 side with the optical machine 4 are possible.

In addition, in the examples shown in FIGS. 4 and 5 (a) and (b), the area of the second plate 2 is smaller than the area of the first plate 1, and the first plate 1 is It is different in that the second plate 2 is moved in the XY direction to the driving unit 62 for horizontal movement of the driving unit 6.

In particular, in the case of (a) and (b) of FIG. 5, the first plate 1 and the second plate 2 or the optical machine 4 are housed and arranged in the dark room D of the inspection machine B, and the dark room In (D), the elevating driving portion 61 for elevating the support member 11 of the first plate 1 toward the second plate 2 in the Z direction, and the first plate 1 in the darkroom D ) Is provided with a driving unit 62 for horizontal movement that moves the second plate 2 in the XY direction with respect to the supporting member 11.

The dark room D is formed by shading from external light inside the inspection machine B, and an actuator such as a slider or a linear guide is used as the drive unit 61 for lifting provided in the dark room D.

As the driving unit 62 for horizontal movement provided in the dark room D, an actuator such as an XY stage is used.

When the optical machine 4 arranged in the dark room D is a fixed camera 41, it is an extension of the central axis of the first plate 1 and is fixedly arranged at the optical focus position. In the case of the moving camera 42, it is an extension of the central axis of the second plate 2 and is arranged at the optical focus position, and is synchronized with the movement of the second plate 2 in the XY direction by the driving unit 62 for horizontal movement. It is supported to move.

Moreover, although not shown as another example, when a plurality of semiconductor light emitting elements E to be inspected are LEDs, it is also possible to provide a light source that emits short wavelength light from the emission frequency of the LEDs. In this case, it is preferable to uniformly irradiate the inspection target area with low light, such as by moving the light source following the movement of the moving camera 42 in the dark room D.

The example shown in FIG. 6 is a film-attached chip EF (a plurality of semiconductor light emitting elements E and an insulating film F) for a space formed between the first electrode 1a and the second electrode 2a. ) Is allowed to be transported (carried in and taken out).

In the case of Fig. 6, the first plate 1 on which the film-attached chip EF is placed is transportable to the support member 11 shown in Fig. 5A. In detail, by the holding chuck (not shown) provided on the support member 11, the membrane-attached chip EF and the first plate 1 are incapable of moving with respect to the support member 11 and are detachable. It is maintained.

Further, although not shown as other examples, in the examples shown in FIGS. 1 (a), 2 (a), (b), (c), 3 and 4, the film-attached chip EF It is possible to change the mounted first plate 1 to a transportable structure, or it is also possible to change the second plate 2 supported by the membrane-attached chip EF to a transportable structure.

The equivalent circuit shown in Fig. 7A corresponds to the example shown in Figs. 1 and 3 to 6, and a capacitor made of an insulating film F is connected in series to each of the plurality of semiconductor light emitting elements E in series. The AC voltages of the driving power supply (AC voltage source) 3 are applied to the plurality of individually separated light emitting circuit parts C through the dielectric layer 5 from the first electrode 1a and the second electrode 2a. An induced current flows in the plurality of light emitting circuits C by application of an alternating voltage. The equivalent circuit corresponding to the example shown in Figs. 2A to 2C is omitted because it becomes an equivalent circuit similar to Fig. 7A.

The induced current in the plurality of light emitting circuits C flows in a forward direction due to the rectification action of the plurality of semiconductor light emitting elements (semiconductor diodes) E. In detail, the AC voltage applied from the driving power supply 3 to the plurality of light-emitting circuit portions C is half-wave rectified by the plurality of semiconductor light-emitting elements E.

For this reason, only when a current in a forward direction flows through the plurality of semiconductor light emitting elements E, the plurality of semiconductor light emitting elements E emit light by generating an induced current. By observing this light emission state with the optical machine 4, it is possible to select whether or not it is defective based on the light emission states of the plurality of semiconductor light emitting elements E.

In the case of Fig. 7A, a current limiting resistor R _{L for} semiconductor diode protection is connected in series in the circuit to constitute a series RC circuit. That is, only the AC voltage within the reverse withstand voltage range is applied to the plurality of semiconductor light emitting elements E. Thereby, excessive current flows from the current limiting resistor R _L to the plurality of semiconductor light emitting elements E, thereby preventing destruction.

At this time, in order to secure the current required for the light emission of the semiconductor light emitting element E, the magnitude of the impedance of the series RC circuit becomes important. The impedances of the plurality of light-emitting circuit units C vary depending on the capacitance and frequency. The impedance (Z) of an ideal capacitor is expressed by the following equation when the frequency is ω and the capacitance is C.

Z = 1 / jωC

That is, since the impedance Z, the frequency ω, and the capacitance C are inversely related, the impedance Z decreases when the capacitance C increases, and the impedance Z increases when the frequency ω increases. Z) is lowered. However, the response range of the frequency ω in the light emission of the semiconductor light emitting element E is limited and cannot be made high. When the impedance Z is high, a high voltage is required for driving, but it is preferable to take a large capacitance C capable of maintaining a low voltage, since there is a risk of damage to the semiconductor light emitting element E in the light emission test by the high voltage. .

To increase the electrostatic capacity C, it is also effective to take a large projected area (electrode area) between the first electrode 1a and the second electrode 2a, but the electrode area is a semiconductor light emitting device (E) for emitting test It is limited because it depends on the number of.

Therefore, in order to increase the dielectric constant between the first electrode 1a and the second electrode 2a, a dielectric layer 5 made of a dielectric material having a high relative dielectric constant is added.

The equivalent circuit shown in Fig. 7B is a circuit aimed at emitting light at a voltage as low as possible in order to avoid destruction in the light emission test of the plurality of semiconductor light emitting elements E.

The forward half-wave current applied from the driving power supply (AC voltage source) 3 to the plurality of light-emitting circuit portions C is the same as in the case of Fig. 7A, but the voltage in the reverse direction (- E ₂ ). By applying a voltage waveform having a lower limit as a reverse withstand voltage (-E ₂ ) from the driving power supply 3 to the plurality of semiconductor light emitting devices E, a low voltage light emission test is enabled.

In the equivalent circuits shown in Figs. 7A and 7B, reference numeral C ₁ is the capacitance by the dielectric layer 5, symbol C ₂ is the capacitance by each semiconductor light emitting element E, and symbol C ₃ is The electrostatic capacity by the insulating film F, reference numeral C ₄ is an electrostatic capacity by a gap (air layer) disposed between the separated plurality of semiconductor light emitting elements E.

7A and 7B, only the sinusoidal waveform is described as the driving power source (AC voltage source) 3. Although not shown in the AC waveform, a rectangular wave, a triangular wave, or a trapezoidal wave may be used instead of the sinusoidal waveform.

Moreover, although it differs depending on the ease of static elimination of the semiconductor light emitting element E by induction emission and the static electricity elimination management, if the voltage (-E ₂ ) of the driving power source 3 is set to a zero potential, instead of an alternating voltage source It is also possible to use a DC voltage source.

The control unit 7 is a controller that electrically connects not only the driving power supply 3 or the driving unit 6 but also the carrying mechanism and the carrying mechanism of the film-attached chip EF.

The controller, which becomes the control unit 7, is operated and controlled respectively at a preset timing in accordance with a program preset in the control circuit (not shown).

Then, the program set in the control circuit of the control unit 7 will be described as an optical inspection method of the plurality of semiconductor light emitting elements E by the inspection device A.

In the inspection method according to the embodiment of the present invention, the film-mounting chip EF is sandwiched between the first electrode 1a of the first plate 1 and the second electrode 2a of the second plate 2. The set process to be arranged, the supply process to apply a voltage to the film-mounted chip EF from the driving power supply 3, and the light emission state of the film-mounted chip EF are the first plate 1 or the second plate 2 The observation process observed by the optical machine 4 on either side is included as a main process.

Moreover, it is preferable to include the carrying-in process of carrying in the film-attached chip EF before the set process, and the carrying out process of carrying out the film-attached chip EF after the inspection is completed after the observation process.

In the set process, each of the plurality of semiconductor light-emitting elements E is connected by electrically connecting the imported film-attached chip EF to a predetermined position between the first electrode 1a and the second electrode 2a. A plurality of light-emitting circuit portions C, which are individually separated in which capacitors made of the insulating film F are connected in series, are formed.

In the supply step, an AC voltage is applied to the plurality of light-emitting circuit portions C by supplying the voltage of the driving power source 3 from the first electrode 1a and the second electrode 2a to the film-mounting chip EF.

In the observation process, the plurality of semiconductor light emitting elements E that emit light in response to the application of an alternating voltage to the plurality of light emitting circuits C, include a first plate 1 and a first electrode 1a or a second plate 2. And a semiconductor light emitting element E having good light emission and poor light emission based on the light emission states of the plurality of semiconductor light emitting elements E by observation of the optical machine 4 from either side of the second electrode 2a. It is selected as a semiconductor light emitting element (E).

As a screening method based on the light emission state in the plurality of semiconductor light emitting elements E, it is preferable to perform it according to predetermined criteria such as discrimination of defects due to presence or absence of light emission, screening by luminance variation, screening of color tone, and the like. Do.

According to the inspection device A and the inspection method according to the embodiment of the present invention, the AC voltage of the driving power source 3 is supplied from the first electrode 1a and the second electrode 2a to a plurality of semiconductor light emitting elements ( By providing a plurality of individually separated light emitting circuit parts C in which capacitors made of an insulating film F are connected in series to each of E), current is generated by rectification of a plurality of semiconductor light emitting elements (semiconductor diodes) E. Flows in the forward direction.

For this reason, when a forward current flows through the plurality of semiconductor light emitting elements E, an induced current is generated and the good semiconductor light emitting element E emits light. By observing the light-emitting states of the plurality of semiconductor light-emitting elements E with the optical machine 4, the light-emitting states of the plurality of semiconductor light-emitting elements E are each optically inspected, and selection of defects based on the light-emitting state is performed. It becomes possible.

Therefore, a plurality of separated semiconductor light emitting devices E can be collectively inspected immediately before mounting to select the semiconductor light emitting devices E having poor light emission.

As a result, a plurality of semiconductor light emitting elements E can be removed only by peeling the insulating film F from the plurality of semiconductor light emitting elements E, compared to the conventional one in which the plurality of LED devices are tested for light emission in a half-cut unseparated state. Since they are separated, it is not necessary to separate the plurality of inspected semiconductor light emitting elements E before mounting, and it is possible to prevent the occurrence of new defects due to this separation process, which is excellent in reliability and easy to handle.

In particular, even when the plurality of semiconductor light emitting elements E are micro LEDs, workability that can be easily carried out is excellent and convenience is improved.

Thereby, the mounting of the semiconductor light emitting element E which is functionally (optically) defective can be prevented beforehand, and the yield can be improved.

In particular, it is preferable that the dielectric layer 5 is provided on either or both surfaces of the first electrode 1a or the second electrode 2a, and the dielectric layer 5 is made of a material having a high relative dielectric constant. Do.

In this case, the alternating voltage of the driving power source 3 is applied to the plurality of light-emitting circuit portions C through the dielectric layer 5 from the first electrode 1a and the second electrode 2a, so that the high dielectric constant dielectric layer 5 ), The capacitance between the first electrode 1a and the second electrode 2a increases.

Since the capacitance and the impedance are inversely related, the impedance between the first electrode 1a and the second electrode 2a decreases, and current flows easily.

Therefore, the plurality of semiconductor light emitting elements E can emit light at a low voltage.

As a result, it is possible to prevent the intrinsic destruction of the semiconductor light emitting element E due to high voltage and at the same time reduce the risk of short circuit (short). With this, the withstand voltage and leakage countermeasures on the device side can also be taken.

In addition, as shown in FIGS. 4 and 5 (a) and (b), one of the first plate 1 or the second plate 2 is formed with a smaller area than the other, and the first plate 1 ) Or to support the other side with respect to one side of the second plate 2 so as to be movable in a direction crossing the opposite direction (Z direction) of the first plate 1 and the second plate 2 (XY direction). desirable.

In this case, the plurality of light-emitting circuit portions C between the first electrode 1a and the second electrode 2a is the larger of the first plate 1 or the second plate 2 (the first plate ( 1)) is formed in the same size as the contact area of the smaller side (second plate 2).

The smaller side (the second plate 2) is moved with respect to the larger side (the first plate 1) in the direction (XY direction) that intersects the opposite direction (Z direction), and the driving power source 3 is also provided. By applying an alternating voltage to the plurality of light-emitting circuit portions C, the entire area of the larger one (first plate 1) is divided into a plurality, and the light-emitting states of the plurality of semiconductor light-emitting elements E are divided in units of the divided areas. Inspection becomes possible.

Therefore, a plurality of semiconductor light emitting elements E arranged separately in the insulating film F can be inspected for each appropriate number of divided regions.

As a result, it is effective when inspecting a large-sized film-attached chip EF in which a number of semiconductor light-emitting elements E are arranged.

Moreover, it is preferable to arrange | position the inspection apparatus A in the dark room D shielded from the external light of the inspection machine B.

In this case, by performing a light emission test of the plurality of semiconductor light emitting elements E in the dark room D, external light below the emission frequency of each semiconductor light emitting element E is shielded, and the interior of each semiconductor light emitting element E The luminescence test is performed in a state in which no excitation phenomenon occurs in the electric charge.

Therefore, it is possible to observe the accurate light emission of the plurality of semiconductor light emitting elements E with respect to the driving power source 3.

As a result, the semiconductor light emitting element E having poor light emission can be more accurately selected, and further improvement in reliability is achieved.

In particular, the dark room D is provided with a light source that emits short-wavelength light beams less than the emission frequency of the plurality of semiconductor light-emitting elements E, and is short-wavelength from the light source toward the light-emitting section E1 of the plurality of semiconductor light-emitting elements E. It is desirable to irradiate the light beam evenly.

In this case, it is possible to lower the minimum voltage required for the light emission of the light emitting units E1 of the plurality of semiconductor light emitting elements E.

Therefore, even when the driving power supply 3 is at a low voltage, light emission of the plurality of semiconductor light emitting elements E can be observed.

As a result, destruction of the plurality of semiconductor light emitting elements E can be further prevented by lowering the voltage.

In addition, in the embodiment of the exhibition, only the case where the dielectric layer 5 (the two-side dielectric layer 5a, the light-emitting side dielectric layer 5b) is provided on the first electrode 1a or the second electrode 2a has been described, but is not limited to this. Without, the dielectric layer 5 may be omitted. Instead of the dielectric layer 5, in order to secure insulation, it is also possible to make it non-contact by interposing an air layer between the film-attached chip EF and the first electrode 1a or the second electrode 2a.

In addition, in the example shown in FIG. 4, the second plate 2 is formed with a smaller area than the first plate 1, and the second plate 2 is moved from the driving unit 62 for horizontal movement relative to the first plate 1. Although it is moved in the XY direction, it is not limited thereto, and the first plate 1 is formed with a smaller area than the second plate 2, and the first plate 1 is driven horizontally with respect to the second plate 2. 62), or both of the first plate 1 and the second plate 2 may be moved relative to the XY direction by the driving unit 62 for horizontal movement.

A Inspection device 1 First plate
1a 1st electrode 2 2nd plate
2a 2nd electrode 3 driving power
4 Optical machine 5 Dielectric layer
C Light-emitting circuit part E Semiconductor light-emitting element
E1 light emitting part F insulating film
B Checker D Darkroom

Claims (6)

An inspection device for optically inspecting a plurality of semiconductor light emitting elements arranged separately in an insulating film,
A first plate having a first electrode,
A second plate having a second electrode provided so as to face the plurality of semiconductor light emitting elements and the insulating layer between the first electrode and
A driving power source electrically connected to the first electrode and the second electrode;
And an optical machine for observing light emission of the plurality of semiconductor light emitting elements from either side of the first plate or the second plate,
Between the first electrode and the second electrode, a plurality of individually separated light emitting circuit parts are disposed in which capacitors made of the insulating film are connected in series to each of the plurality of semiconductor light emitting elements,
The plurality of light-emitting circuit units, an inspection device characterized in that the plurality of semiconductor light-emitting elements emit light by generating an induced current when a forward current flows from the driving power source to the plurality of semiconductor light-emitting elements. The method according to claim 1,
And a dielectric layer provided on one or both surfaces of the first electrode or the second electrode, wherein the dielectric layer is made of a material having a high relative dielectric constant. The method according to claim 1 or claim 2,
The area of either the first plate or the second plate is formed with a smaller area than the other, and the other side or both sides of the first plate or the second plate, the first plate and the An inspection device characterized in that the second plate is relatively movably supported in a direction intersecting the opposite direction of the plate. A tester equipped with the inspection device according to claim 1 or 2,
An inspection machine, characterized in that the inspection device is arranged in a dark room shielded from external light of the inspection machine. The method according to claim 4,
The dark room is provided with a light source that emits short-wavelength light rays less than the emission frequency of the plurality of semiconductor light-emitting elements, and the short-wavelength light beam is uniformly irradiated from the light source toward the light-emitting portions of the plurality of semiconductor light-emitting elements. Checker. An inspection method for optically inspecting a plurality of semiconductor light-emitting elements arranged separately in an insulating film,
A set step of forming a plurality of individually separated light-emitting circuit portions in which a capacitor made of the insulating film is serially connected to each of the plurality of semiconductor light-emitting elements between the first electrode of the first plate and the second electrode of the second plate. and,
A supply step of applying a voltage of a driving power source from the first electrode and the second electrode to the plurality of light-emitting circuit parts
And an observation process of observing the plurality of semiconductor light emitting elements that emit light by supplying a voltage to the plurality of light emitting circuit units by an optical machine on either side of the first plate or the second plate,
In the observation step, an inspection current is generated when a current in a forward direction flows from the driving power source to the plurality of semiconductor light emitting elements, and the inspection method is characterized in that the plurality of semiconductor light emitting elements emit light.

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