JP6721029B2 - Element mounting method and light-emitting device manufacturing method - Google Patents

Description

Embodiments of the present invention relate to an element mounting method and a light emitting device manufacturing method.

2. Description of the Related Art In recent years, a light emitting device including a light emitting element such as a light emitting diode has been used as a light source used for vehicle headlights, various kinds of lighting, and the like. In such a light emitting device, from the viewpoint of manufacturing efficiency, in the manufacturing process, a plurality of light emitting elements are arranged on an adhesive layer such as a resin, and these light emitting elements are collectively transferred by transfer onto a collective substrate having a wiring pattern. It is mounted and electrically connected to the wiring pattern of the light emitting element and arranged on each light emitting element such as various members (for example,
Patent Documents 1 and 2).

JP 2004-273596 A JP, 2004-281630, A

However, in the manufacturing process of the light emitting device, when the adhesive layer or the like is exposed to a heat cycle for fixing and connecting the element, the adhesive layer expands and contracts, and the element is accurately fixed and connected on the substrate. Becomes difficult.

Therefore, it is an object of an embodiment of the present invention to provide an element mounting method and a light emitting apparatus manufacturing method capable of manufacturing a light emitting apparatus including a light emitting element with high accuracy, in a simple, easy and reliable manner. ..

The mounting method of the element according to the embodiment,
Preparing a substrate having a plurality of first recesses;
A step of temporarily fixing an element including a pair of electrodes in the first recess,
A step of preparing a collective substrate having a plurality of pairs of wiring on the mounting surface,
A step of bringing the wiring into contact with the electrodes and fixing a plurality of the elements to the collective substrate by heating at a time;
Removing the substrate from the element.

Further, the method for manufacturing the light emitting device according to the embodiment,
After using the light emitting element as an element and performing the above-described mounting method of the element,
The method may further include a step of dividing the collective substrate for each of the light emitting elements or for each of a plurality of light emitting element groups.

According to the embodiment, it is possible to provide an element mounting method and a light emitting apparatus manufacturing method capable of manufacturing a light emitting apparatus including a plurality of light emitting elements with high accuracy, in a simple, easy and reliable manner.

FIG. 3 is a plan view showing a base body used in the element mounting method according to the embodiment. It is the sectional view on the A-A' line of FIG. 1A. It is a B-B' line sectional process drawing of Drawing 1A showing a mounting method of an element concerning an embodiment. It is a B-B' line sectional process drawing of Drawing 1A showing a mounting method of an element concerning an embodiment. It is a B-B' line sectional process drawing of Drawing 1A showing a mounting method of an element concerning an embodiment. It is a B-B' line sectional process drawing of Drawing 1A showing a mounting method of an element concerning an embodiment. It is a B-B' line sectional process drawing of Drawing 1A showing a mounting method of an element concerning an embodiment. It is a B-B' line sectional process drawing of Drawing 1A showing a mounting method of an element concerning an embodiment. It is a B-B' line sectional process drawing of Drawing 1A showing a mounting method of an element concerning an embodiment. FIG. 6 is a manufacturing process diagram illustrating an embodiment of a method for manufacturing a light emitting device. FIG. 6 is a manufacturing process diagram illustrating an embodiment of a method for manufacturing a light emitting device. FIG. 6 is a manufacturing process diagram illustrating an embodiment of a method for manufacturing a light emitting device. It is a schematic sectional drawing which shows one Embodiment of a light-emitting device. It is a manufacturing-process figure which shows another embodiment of the manufacturing method of a light-emitting device. It is a manufacturing-process figure which shows another embodiment of the manufacturing method of a light-emitting device. It is a manufacturing-process figure which shows another embodiment of the manufacturing method of a light-emitting device. It is a schematic sectional drawing which shows embodiment by another light-emitting device.

In the embodiments and examples, the sizes and positional relationships of members shown in the drawings may be exaggerated for clarity of explanation. In the following description, the same names and reference numerals indicate the same or similar members, and detailed description thereof will be appropriately omitted. The contents described in one embodiment and one example can be applied to other embodiments and the like.

In the embodiments described below, a substrate having a plurality of recesses is prepared, and the device is temporarily fixed in the recesses. Then, a collective substrate is prepared, and a plurality of elements temporarily fixed to the base are mounted on the collective substrate. The order of each step, the selection method, the material used, and the like can be appropriately changed.
[Device mounting method]
(Process of preparing the base)
The base body is used to hold the element in a predetermined position in advance in order to mount the element on a mounting substrate.
The substrate is preferably rigid, and is preferably made of a material that does not easily expand and contract due to heat. As a result, the element can be accurately mounted on a proper place of the collective substrate. For example, an inorganic material having a coefficient of linear expansion of 50×10 ⁻⁶ /° C. or less may be used, and 30×10
^It is preferably ⁻⁶ /° C. or lower, 25×10 ⁻⁶ /° C. or lower, and more preferably 20×10 ⁻⁶ /° C. or lower. It is more preferable that the material has a coefficient of linear expansion close to that of the aggregate substrate to be prepared. The base is
Those containing no organic material are preferable. Specific examples include metals, ceramics, and glass. Examples of the metal include metals such as copper, aluminum, zinc, tin, gold, silver, tungsten, iron, nickel and platinum, and iron-nickel alloys, phosphor bronze, alloys such as stainless steel, and the like. Examples of ceramics include alumina, aluminum nitride, and mullite. SUS304 (stainless steel), which does not easily deteriorate and has a small thermal expansion, is particularly preferable.

The base has a plurality of first recesses on its surface. The first recess is used to accommodate the element. The shape, diameter, and depth of the first recess are not particularly limited, and can be appropriately set depending on the type of element to be mounted. The first recess does not necessarily have to have a shape that matches the element, but it is preferable that the first recess has a substantially similar shape that is larger than the element to be housed in plan view. For example, the plan view shape of the first recess may be, for example, a circle or an ellipse, a polygon such as a quadrangle, and a shape similar to these. The diameter of the first recess is preferably several tenths mm to several mm larger than the diameter of the light-emitting element to be temporarily fixed in plan view. For example, the diameter is several hundred μm
It can be about several tens of mm. The diameter of the recess is preferably smaller than the diagonal line of the temporarily fixed element in plan view. As a result, the element does not easily rotate in the recess, and the mounting accuracy on the collective substrate can be further improved. The diameter means the opening width of the recess in plan view.

The depth of the first recess is sufficient if it can accommodate all or part of the element in the thickness direction, and is, for example, several tens of μm to several mm, and several hundreds of μm. When the depth of the first concave portion is about the total thickness of the thickness of the element and the thickness of the temporary fixing material for temporarily fixing the element in the first concave portion, the first concave portion is stably bonded to the bonding member provided on the collective substrate. be able to.

The surface of the substrate may be provided with second recesses of a different type from the first recesses, in addition to the first recesses having the same shape, diameter, and depth. The second recess has, for example, a different shape, arrangement pattern, diameter and/or depth from the first recess. Hereinafter, the first concave portion and the second concave portion may be collectively referred to as “concave portion”.
The positions of the plurality of first recesses and/or the second recesses can be appropriately set depending on the design of the collective board on which the elements are mounted (portions on the collective board on which the elements are to be mounted), and may be randomly arranged. , May be regularly arranged. When the first recesses are regularly arranged, it is preferable that the second recesses are also regularly arranged.

It is preferable that the surface of the base body other than the concave portion facing the collective substrate is flat, because it is easy to stably mount the element on the collective substrate. In particular, when the entire element in the thickness direction is housed in the concave portion at the time of temporary fixing, that is, when the surface of the collective substrate and the surface other than the concave portion of the base body may come into contact with each other, the surface other than the concave portion of the base body It is preferably flat. The substrate may have any thickness as long as it can ensure appropriate strength. The first concave portion and/or the second concave portion can be provided by laser processing or the like on the substantially flat plate-shaped SUS304 if it is a substrate of SUS304, for example. First
The recess and/or the second recess can be formed by pressing or bending the substrate.

(Step of temporarily fixing the element)
The element is temporarily fixed in the first recess of the base. When the substrate has the second recess, the element can be temporarily fixed in the second recess. The first recess and/or the second recess for accommodating the element can be appropriately selected depending on the design of the aggregate substrate, and there may be a recess not accommodating the element.
A temporary fixing material may be used for temporary fixing. That is, the temporary fixing material may be arranged in the first concave portion and/or the second concave portion, and the element may be housed thereon to be temporarily fixed. By using the temporary fixing material, it is not necessary to match the shape and diameter of the first recess and/or the second recess with the element to be housed, which is preferable. In addition, the element can be easily taken in and out.
If the diameter of the first recess and/or the second recess is substantially the same as the element, without using a temporary fixing material,
It is possible to temporarily fix the element by fitting the element with the side surface of the first recess and/or the second recess. In this case, the strength with which the element is fitted into the recess needs to be smaller than the strength with which the element is fixed to the collective substrate. On the other hand, by temporarily fixing the element in the concave portion using the temporary fixing material, there is no risk of element damage.
A hole may be provided in the bottom surface of the recess of the base and the element may be temporarily fixed in the recess by sucking the element with air or the like through the hole. This will not damage the element, without using a temporary fixing material,
The element can be temporarily fixed to the substrate.

The strength of the temporary fixing is not particularly limited, and it is preferable that the holding is low or weak, low adhesion or slight adhesion. Usually, the substrate on which the element is temporarily fixed is inverted so that the electrode of the element comes into contact with the wiring of the collective substrate described later. Therefore, it is preferable to have a temporary fixing strength to the extent that the element does not fall off from the base due to its own weight. The adhesive strength is preferably capable of holding the weight of the element. Specifically, when the element is inverted by 180° (the base is rotated so that the opening surface of the recess of the base is arranged on the mounting surface side of the collective substrate, that is, in the gravity direction),
Those that can be temporarily fixed with a strength such that they can be held for several seconds to several tens of seconds or more are preferable. From another point of view, it is preferable to temporarily fix with a strength weaker than the strength of fixing the element and the collective substrate described later. By temporarily fixing with such strength, after mounting the element on the collective board, the element can be easily peeled off from the base simply by removing the base, and reliable collective fixing of all the elements to the collective board is possible. Becomes As will be described later, when the element and the base body are temporarily fixed by a temporary fixing material and a treatment for reducing the strength of the temporary fixing material is possible, that is, a temporary fixing material that volatilizes by heat treatment or the like. In the case of using, for example, the element and the collective substrate may be temporarily fixed with the same strength as or higher than the fixing strength.

The temporary fixing material is not particularly limited as long as it can fix the element to the substrate, and known materials (for example, various solvents and organic substances such as resins) can be used. In particular, a substance that volatilizes or sublimes at about 300° C. or lower is preferable, and a substance that volatilizes or sublimes at about 250° C. or lower is more preferable. Volatilization or sublimation here means to completely disappear by heating for several seconds, several minutes to several tens of minutes, but the heating residue is 1 by heating for 5 minutes or 1 minute.
It is preferably 0% by weight or less, 5% by weight or less, and 1% by weight or less. By using such a temporary fixing material, it is possible to completely eliminate the temporary fixing material by heating in the subsequent steps, eliminating the step of cleaning and removing the temporary fixing material, and preventing contamination by the temporary fixing material such as elements. This can be avoided and the process can be simplified.

Specifically, acetone, methyl ethyl ketone, methyl isobutyl ketone (boiling point: 150
C. or less), holon (boiling point: 198° C.), cyclohexanone (boiling point: 155° C.), methylcyclohexanone (boiling point: 170° C.), and other ketone solvents, tetrahydrofuran, dioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether),
Ethyl acetate, methylpropyl diglycol, hexyl carbitol, butyl propylene diglycol, benzyl alcohol, butyl carbitol, cyclohexane, methylcyclohexane, cyclohexanone (boiling point: 150°C or less), methylphenyl ether (boiling point:
153°C), ethyl phenyl ether (172°C), methoxytoluene (boiling point: 172°C)
), benzyl ethyl ether (boiling point: 189° C.), diethylene glycol dimethyl ether (boiling point: 160° C.), diethylene glycol diethyl ether (boiling point: 188° C.), diethylene glycol monomethyl ether (boiling point: 194° C.), diethylene glycol monobutyl ether (boiling point: 231° C.) Ether solvents such as diethylene glycol monobutyl ether acetate (boiling point: 247°C), ethylene glycol monobutyl ether (boiling point: 171°C), ethylene glycol monoisoamyl ether (boiling point: 181°C), butyl carbitol (boiling point: 231°C), etc. Are listed.

Methanol, ethanol, isopropyl alcohol, n-butyl alcohol (boiling point: 1
50°C or less), 1-hexanol (boiling point: 157°C), 1-heptanol (boiling point: 176)
℃), 2-heptanol (boiling point: 160 ℃), 3-heptanol (boiling point: 156 ℃), 1
-Octanol (boiling point: 195°C), 2-octanol (boiling point: 179°C), 2-ethyl-1-hexanol (boiling point: 184°C), cyclohexanol (boiling point: 161°C), 1-
Methylcyclohexanol (boiling point: 155°C), 2-methylcyclohexanol (boiling point:
165°C), 3-methylcyclohexanol (boiling point: 173°C), 4-methylcyclohexanol (boiling point: 174°C), furfuryl alcohol (boiling point: 170°C), benzyl alcohol ((boiling point: 205°C), 1, 2-octanediol (boiling point: 131°C), 1,8-octanediol (boiling point: 172°C), 2-ethyl-1,3-hexanediol (boiling point: 2)
43°C), ethylene glycol (boiling point: 198°C), propylene glycol (boiling point: 18)
7° C.), 1,2-butylene glycol (boiling point: 191° C.), hexylene glycol (boiling point: 197° C.), 3-methyl-3-methoxybutanol (boiling point: 174° C.), butyl propylene diglycol (boiling point: 231) Alcohol solvents such as (° C.) and the like.

Aromatic organic solvents such as benzene, toluene, xylene (boiling point: 150°C or lower), 3-methoxy-3-methyl-1-butyl acetate (boiling point: 188°C), ethylene glycol monoacetate (boiling point: 182°C), Acetate solvents such as diethylene glycol monobutyl ether acetate (boiling point: 247°C), propylene carbonate (boiling point: 241°C)
Cyclic carbonate solvent such as γ-butyrolactone (boiling point: 204° C.), lactone solvent such as N-methyl-2-pyrrolidone (boiling point: 202° C.), pyrrolidone solvent, α-pinene (boiling point: 156° C.) , Terpenes such as β-pinene (boiling point: 161°C), limonene (boiling point: 177°C), terpineol (boiling point: 217°C), dihydroterpineol (boiling point: 207°C), dihydroterpinyl acetate (boiling point: 220°C) Examples include system solvents.

Dimethylformamide (boiling point: 153°C), dimethylsulfoxide (boiling point: 189°C)
And so on. These may be used alone or in combination of two or more. These can be used by appropriately adding an organic binder, a viscosity modifier and the like. Known organic binders and viscosity modifiers can be used, but the boiling point is 300° C. or lower or 2
It is preferably 50° C. or lower.

When such a temporary fixing material is used, temporary fixing can be easily performed by simply placing the element in the same state without performing heat treatment for temporary fixing. As will be described later, when removing the base, that is, when removing the base from the element fixed to the collective substrate, the base can be easily removed without performing a special process (for example, heating and cleaning).
The temporary fixing material can be arranged in the first concave portion and/or the second concave portion by using a known method such as dispensing, pin transfer, or printing.

The element including the pair of electrodes is not particularly limited, but a semiconductor element is preferable. For example, a light emitting diode, a light emitting element such as a laser, a power supply rectifying diode, a Zener diode, a variable capacitance diode, a PIN diode, a Schottky barrier diode,
Photodiode, solar cell, surge protection diode, 2-terminal element such as varistor, transistor, bipolar transistor, field effect transistor, phototransistor, CC
Examples thereof include 3-terminal elements such as a D image sensor, a thyristor, and an optical trigger thyristor.
It is preferable that these elements, for example, accommodate elements of the same type in the first recess and accommodate elements different from the elements accommodated in the first recess in the second recess. For example, the first
The recess and the second recess can accommodate light emitting elements of different emission colors. Further, it is possible to store the light emitting element in the first concave portion and the different kinds of elements such as the protective element in the second concave portion.

The element is preferably temporarily fixed to the base so that the electrode of the element is arranged on the opening surface side of the first recess and/or the second recess. That is, the element is preferably flip-chip mounted on the wiring of the substrate. Alternatively, the electrodes of the element may be temporarily fixed so as to be arranged on the bottom surface side of the first recess and/or the second recess. That is, face-up mounting may be performed in which the surface of the element opposite to the electrode formation side is joined to the wiring of the collective substrate. In that case, after the element is fixed to the substrate, the electrode of the element and the wiring of the substrate are electrically connected by a wire or the like.

(Process of preparing aggregate substrate)
The collective board is a board on which elements are mounted. The collective substrate includes a plurality of at least a pair of wirings on the surface on which the elements are mounted. The pair of wirings corresponds to the pair of electrodes of the above-described element, and preferably has a number corresponding to the number of the plurality of elements.
As such a collective substrate, a substrate which is known in the art and used for mounting the above-described elements such as a light emitting element can be used.

The collective substrate is composed of wiring and a base material which is an insulating material such as glass epoxy, resin, ceramics (HTCC, LTCC) or a composite material of an insulating material and a metal member. As the base material, one using ceramics having high heat resistance and weather resistance is preferable. Alumina, aluminum nitride, mullite, and the like can be given as examples of the ceramic material, and these are less likely to expand or contract due to heat, and the elements can be collectively mounted easily. For these ceramic materials,
For example, an insulating material such as BT resin, glass epoxy, or epoxy resin may be combined.
The size, shape, etc. of the collective substrate itself are not particularly limited, and any of those used in the relevant field can be applied.

The wiring arranged on the mounting surface of the collective substrate may be provided by a metal such as copper, aluminum, gold, silver, tungsten, iron, nickel, or an alloy of iron-nickel alloy, phosphor bronze, or the like. The surface of the wiring may be coated with plating or the like. The wiring can be provided on the surface or inside of the collective substrate.
On the mounting surface of the collective substrate, it is preferable that the region where the device is mounted is projected more than the other regions. For example, when the element is mounted on the wiring, it is preferable that the arrangement projects from the base material. Thereby, the element and the collective substrate can be more stably connected. The wiring on the mounting surface of the collective substrate is preferably provided so as not to come into contact with the surface of the substrate in the step of collectively mounting the elements on the collective substrate. Alternatively, when the base and the wiring come into contact with each other, it is preferable that a protective film or the like is provided on the surface of the wiring that comes into contact. A notch or the like may be provided in the base so that the wiring and the base do not come into contact with each other. This can prevent damage to the wiring.

It is preferable that a joining member for fixing the element is arranged on the surface of the wiring of the collective substrate. The joining member is provided on the collective substrate and fixes the collective substrate and the element. Usually, in a step described later, by heating and melting, the wiring and the electrode are wetted and spread over a wide range, and by curing in that state, it can be used to electrically connect the wiring and the electrode of the element. it can.

The joining member is, for example, a tin-bismuth-based solder, a tin-copper-based solder, a tin-silver-based solder, a gold-tin-based solder (specifically, an alloy containing Ag, Cu and Sn as main components, Cu and Sn). An alloy consisting mainly of and Bi
And Sn as main components), eutectic alloys (alloys containing Au and Sn as main components, alloys containing Au and Si as main components, alloys containing Au and Ge as main components, etc.) Examples thereof include conductive pastes such as silver, gold and palladium, bumps, anisotropic conductive materials, and brazing materials such as low melting point metals.
Instead of the joining member, a material capable of functioning as a joining member may be arranged as a part of the electrode or a part of the wiring on the electrode surface provided on the element and/or the wiring surface of the collective substrate.
When the device is mounted face-up on the collective substrate, the joining member may not have conductivity. For example, the above-mentioned resin or the like can be used. The resin can be used in any desired form such as paste or sheet. It is preferable that the joining member is a sheet-shaped resin, because when the element temporarily fixed to the base body is brought into contact with the collective substrate, positional deviation of the element is unlikely to occur. When using a non-conductive joining member such as resin, the joining member may be arranged on the base material.

(Process of fixing elements at once)
In order to collectively fix a plurality of elements to the collective substrate, the electrodes of the respective elements of the base body in which the respective elements are temporarily fixed to the first concave portion and/or the second concave portion are provided on the mounting surface of the corresponding collective substrate. Abutted wiring. The substrate can be inverted by an aligner. It is preferable that the electrodes of the element and the wiring of the collective substrate are indirectly brought into contact with each other via the above-mentioned joining member or the like.

After the wiring is brought into contact with the electrodes of the element, heating is performed. The substrate and/or the aggregate substrate on which the elements are temporarily fixed may be directly heated, or the atmosphere around them may be heated. The heating may be an infrared method, a hot air method, or a vapor phase soldering method. The heating temperature is preferably a temperature at which the above-mentioned joining member melts, and more preferably about 250° C. or less. By applying pressure during heating, it can be more firmly fixed. The pressure is not particularly limited, but is, for example, several N/s to several tens of N per 100 elements, and preferably several N/s to 10 N per 10 minutes. The heating time is, for example, about 1 to 10 minutes, preferably about several minutes. By such heating and arbitrary pressurization, a part of the above-mentioned joining member or the electrode of the element or the wiring of the collective substrate is melted, and the electrodes of the plurality of elements and the wiring of the collective substrate are collectively connected. It Then, by cooling or stopping heating, a part of the bonding member, the electrode, or the wiring of the collective substrate is cured, and the element and the collective substrate are fixed together.

The heating may be performed in stages. For example, the temperature is gradually raised (preheated) in order to relieve the stress caused by heat on the base body, the collective substrate, the element, etc., or to improve the familiarity of the joining member, and finally the temperature of the melting point of the joining member or higher. (Reflow) is preferable. Reflow is
It is preferable to carry out under a reducing gas atmosphere. Hydrogen gas can be used as the reducing gas here, but formic acid is preferably used. By using formic acid, it is possible to eliminate a cleaning step for a collective substrate or the like, which is usually necessary, and reduce manufacturing cost.
In the case where the temperature is gradually raised and the reflow is performed in this manner, the substrate to be described later may be removed after these, or the joining member is softened by, for example, preheating to temporarily fix the element. After that, it may be performed before completely fixing the element by reflow. Thereby, the self-alignment action of the element by the joining member can be effectively exhibited. Less than,
The term "fixed" is sometimes used to include both elements temporarily fixed or completely fixed to the collective substrate.

(Step of removing the substrate)
After collectively fixing the elements to the collective substrate, the base is removed from the elements on the light collecting substrate. If it is possible to reduce the strength of the temporary fixing material, the treatment is performed. For example, when a temporary fixing material that volatilizes due to heat treatment or the like is used, part or all of the temporary fixing material volatilizes due to the above-mentioned heat treatment, so that the substrate and the element can be very It will be temporarily fixed with weak adhesive strength. On the other hand, a part of the bonding member, the electrode, or the wiring of the collective substrate is fixed by heating including the above-mentioned preheating and optional cooling, and the element and the collective substrate are firmly fixed. Therefore, by removing the substrate in this state, the element and the substrate are separated from each other, the element remains on the aggregate substrate side, and only the substrate can be removed. As a result, all the elements can be surely mounted on the collective substrate.

As described above, through the steps described above, it is possible to prevent the positional deviation of the plurality of elements by the concave portions provided in the base body in advance, and to securely temporarily fix the elements at predetermined positions. By arranging the elements by utilizing the concave portions of the base body, unlike the conventional arrangement of the elements on the pressure-sensitive adhesive sheet, the positioning accuracy can be significantly improved.
Unlike conventional materials such as adhesive sheets, by using a material that does not easily expand and contract due to heat as the base, it is possible to avoid positional displacement due to heat during the mounting process such as collective fixing, and to integrate the elements into a collective substrate with no variation in accuracy. It becomes possible to implement. In other words, since the displacement of the element occurs only within the width of the recess of the base, the element can be mounted on the collective substrate with high accuracy.
As in the case of using a conventional adhesive sheet or the like, each element can be arranged without being fixed to the collective substrate by thermocompression bonding or the like, so that the time required for collectively fixing the elements to the collective substrate is shortened. be able to. As a result, the manufacturing cost can be reduced.

When arranging the joining member on the surface of the wiring of the collective substrate, there is a problem that, depending on the shape of the element such as narrow width and lateral length, when the individual element is arranged on the joining member, the element falls off from the joining member. there were. On the other hand, when temporarily fixing the elements in the recesses of the base body that are difficult to be deformed by heat or the like, all the elements are supported by the base body and can be reliably placed on the joining member, so that the above-mentioned dropout is prevented. The elements can be efficiently mounted on the collective substrate.
The higher the density of the elements mounted on the collective board, the more accurately the elements need to be mounted on the collective board. Therefore, it is preferable to mount the elements by the steps described above.

[Method of manufacturing light emitting device]
In the above-described element mounting method, a light emitting device is used as an element, a plurality of light emitting devices are mounted on the collective substrate, and then the collective substrate is appropriately divided for each light emitting device to manufacture the light emitting device.
The element mounting method described above is particularly preferably applied to a light emitting element. In other words, the positional deviation of the light emitting element during mounting on the collective substrate is likely to affect the characteristics of the light emitting device, and therefore it is necessary to fix the light emitting element to the collective substrate with high accuracy and reliability.
In a light-emitting device having a COB (Chip on Board) structure in which a plurality of light-emitting elements are mounted on a substrate at relatively short intervals, using the above-described element mounting method allows a plurality of light-emitting elements to be mounted accurately and easily. You can Also, as will be described later, when including a step of dividing the aggregate substrate,
The number of light emitting devices can be increased by accurately mounting a plurality of light emitting elements on a collective substrate using the above-described element mounting method.

The light emitting element may be either a light emitting diode or a laser, but a light emitting diode is preferable. In particular, a laminated structure including a light emitting layer of various semiconductors such as nitride semiconductors such as InN, AlN, GaN, InGaN, AlGaN, and InGaAlN, III-V group compound semiconductors, II-VI group compound semiconductors, and the like is provided. Are listed.

The light emitting element may have positive and negative electrodes provided on opposite surfaces, respectively, but preferably has positive and negative electrodes provided on the same surface side.
The material, film thickness, and structure of the electrode are not particularly limited, and may be a single layer structure or a laminated structure containing gold, copper, lead, aluminum or an alloy thereof. Further, a single layer film or a laminated film of a metal or alloy such as Ni, Ti, Au, Pt, Pd, W may be provided on the surface of each electrode as a pad electrode. The thickness of the pad electrode is not particularly limited, but above all, the final layer (
It is preferable that Au is arranged on the outermost surface side and the film thickness is about 100 nm or more.

By performing the above-mentioned mounting using such a light emitting element, a plurality of light emitting elements can be collectively fixed to the collective substrate.

(Process of dividing the collective substrate)
The collective substrate can be divided for each light emitting element or for each of a plurality of light emitting element groups. The division here can be performed using a method known in the art. Examples thereof include blade dicing and laser dicing. By the division, a light emitting device including one or a plurality of light emitting elements can be obtained.

The light reflecting member and/or the light transmitting member may be formed before and after the step of dividing the collective substrate.
(Formation of light reflecting member)
By covering the side surface of the light emitting element with a light reflecting member, a light emitting device having a desired light distribution can be formed.
The light reflecting member is preferably made of a material having a reflectance of 60% or more, more preferably 70%, 80%, or 90% or more with respect to the light emitted from the light emitting element.
The base material of the light reflecting member is not particularly limited, and examples thereof include ceramics, resins, dielectrics, pulp, glass, and composite materials thereof. In particular, a resin that can be easily molded into an arbitrary shape is preferable.

Examples of the resin include thermosetting resins and thermoplastic resins. Specifically, epoxy resin composition, silicone resin composition, modified epoxy resin composition such as silicone modified epoxy resin; modified silicone resin composition such as epoxy modified silicone resin; polyimide resin composition, modified polyimide resin composition; Polyphthalamide (PPA); Polycarbonate resin; Polyphenylene sulfide (PPS); Liquid crystal polymer (LCP); ABS resin;
Phenol resin; acrylic resin; PBTj resin.
For the above-mentioned base material, for example, resin, titanium dioxide, silicon dioxide, zirconium dioxide,
Potassium titanate, alumina, aluminum nitride, boron nitride, mullite, niobium oxide,
A light reflecting material such as barium sulfate or various rare earth oxides (eg, yttrium oxide, gadolinium oxide) is contained. In addition, a light scattering material or a coloring agent such as carbon black may be contained. Further, glass fiber, fibrous filler such as wollastonite, and inorganic filler such as carbon may be contained. It is preferable that these are contained in an amount of about 10 to 40% by weight based on the total weight of the light reflecting member.

The light reflecting member preferably covers at least the side surface of the light emitting element, and preferably completely covers all the side surfaces. Thereby, the light from the light emitting element can be efficiently reflected to the light extraction surface side. The light reflecting member is preferably formed between the collective substrate and the light emitting element. This can improve the light extraction of the light emitting device.
The light reflecting member can be formed by screen printing, potting, transfer molding, compression molding, or the like. The light reflecting member is preferably arranged not only on the side surface of the light emitting element but also between the light emitting element and the collective substrate. With this, the light from the light emitting element can be more efficiently reflected to the light extraction surface.

When the light reflecting member is formed before dividing the collective substrate, it is preferable to divide the light reflecting member at the same time as dividing the collective substrate. Even after the division of the light reflecting member, the light reflecting member
It is preferable that the light emitting element is arranged so as to cover all side surfaces thereof.
As described above, when a light reflecting member is formed on a collective substrate on which a plurality of elements are accurately mounted and the collective substrate is divided to manufacture a light emitting device, a highly reliable light emitting device can be obtained.

(Formation of translucent member)
By covering the light extraction surface of the light emitting element with a light transmitting member, a light emitting device having a desired light distribution can be formed. The translucent member can cover the upper surface (the surface opposite to the surface on which the pair of electrodes joined to the collective substrate are arranged) and/or the side surface of the light emitting element.
The translucent member transmits at least 60% of the light emitted from the light emitting layer, and further 70%,
Those that transmit 80% or 90% or more are preferable.
Such a member can be formed by using the above-mentioned translucent resin. In particular, a silicone resin having excellent light resistance and heat resistance is more preferable.

The translucent member preferably contains a wavelength conversion member such as a phosphor. This allows
A light-emitting device that emits light with a desired color tone can be formed.
As the phosphor, those known in the art can be used. For example, cerium-activated yttrium-aluminum-garnet (YAG)-based phosphor, cerium-activated lutetium-aluminum-garnet (LAG)-based phosphor, europium- and/or chromium-activated nitrogen-containing calcium aluminosilicate _{(CaO-Al 2 O 3 -SiO} 2)
-Based phosphors, europium-activated silicate ((Sr,Ba) ₂ SiO ₄ )-based phosphors, β-sialon phosphors, KSF-based phosphors (K ₂ SiF ₆ :Mn), semiconductors called quantum dot phosphors, etc. And the like. As a result, a light-emitting device that emits mixed-color light (for example, white light) of primary light and secondary light having a visible wavelength and a light-emitting device that emits secondary light having a visible wavelength when excited by primary light of ultraviolet light can be provided. it can.
The phosphor is not limited to being contained in the translucent member, and may be disposed on the upper surface or the lower surface of the translucent member.

The translucent member may further contain a filler (for example, a diffusing agent, a coloring agent, etc.). For example, silica, titanium oxide, zirconium oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, calcium carbonate, calcium hydroxide, calcium silicate, zinc oxide, barium titanate, aluminum oxide, iron oxide, chromium oxide, manganese oxide, glass. , Carbon black, crystal or sintered body of phosphor, sintered body of phosphor and inorganic binder, and the like. The filler is preferably, for example, about 10 to 60% by weight based on the weight of the translucent member.

The method of forming the translucent member is a method of molding the translucent member into a sheet shape and bonding it with a hot melt method or an adhesive, an electrophoretic deposition method, potting, compression molding, spraying, an electrostatic coating method, a printing method. Etc. At this time, silica (Aerosil) or the like may be added in order to adjust the viscosity or the fluidity.

The thickness of the translucent member is not particularly limited and may be, for example, about 10 μm to 300 μm. By setting such a thickness, the light extracted from the light emitting element can be efficiently emitted even if the end surface of the translucent member is aligned with the end surface of the light reflecting member or is covered with the light reflecting member. Can lead to the surface.
The surface of the translucent member may be a convex surface, a concave surface, or an uneven surface in order to control the light distribution.

The translucent member may be provided on the light emitting device by being adhered to the upper surface of the light emitting element before the light emitting element is mounted on the collective substrate. Further, after the light reflecting member is formed on the side surface of the light emitting element, the light reflecting member may be arranged so as to reach the upper surface of the light reflecting member. In this case, it is preferable to divide both the light reflecting member and the light transmitting member together with the division of the aggregate substrate. Further, the translucent member may be arranged on the upper surface of the light emitting element after the collective substrate is divided and before and after the light reflecting member is formed. When the translucent member is formed before forming the light reflecting member, it is preferable that the side surface of the translucent member is also covered with the light reflecting member. Accordingly, light can be efficiently extracted from only the upper surface of the translucent member, and a light emitting device capable of emitting light with a good parting property can be formed. The good parting property means that the directivity in a desired light emitting direction is high.

Only one light-transmitting member needs to be arranged in one light-emitting device. In this case, one light transmissive member may be arranged for one light emitting device in which one light emitting element is mounted,
One plate-shaped translucent member may be arranged for one light emitting device on which a plurality of light emitting elements are mounted. Further, two or more translucent members may be arranged for one light emitting device mounted with a plurality of light emitting elements. In this case, a light transmissive member may be arranged in each of the light emitting elements, or one light transmissive member may be arranged in two or more light emitting element groups.
As described above, when the translucent member is formed on the aggregate substrate on which the plurality of light emitting elements are mounted with high accuracy, the translucent member can be easily formed, and a highly reliable light emitting device can be manufactured. ..

[Example 1: Element mounting method]
As shown in FIG. 2A, the base 10 is prepared. As shown in FIGS. 1A and 1B, the base body 10 is a rigid plate-shaped body formed of SUS304 (stainless steel). On the surface of the base body 10, a plurality of first concave portions 11 having a depth of 0.15 mm and 1.0×1.0 mm in plan view are regularly arranged in the column direction. Also, smaller than the first recess 11, second recess 12 in plan view 0.44 mm × 0.44 m m are alternately and columns of the first recess 11, are regularly arranged in the column direction.

As shown in FIG. 1B, the light emitting element 13 and the protective element 14 are temporarily fixed to the first recess 11 and the second recess 12 of the base 10, respectively. The light emitting element 13 has, for example, 0.8 mm×0.8 mm in plan view and a height of 0.14 mm, and the protective element 14 may be 0.24 mm ×0.24 mm in plan view. In advance, for temporary fixing, a temporary fixing material is arranged by pin transfer in the first concave portion 11 and the second concave portion 12, and the light emitting element 13 and the protective element 14 are mounted thereon. In this embodiment, the element is placed in the recess so that the electrode of the element is located on the opening surface side of the recess. As the temporary fixing material, for example, a mixed solvent of 2-ethyl-1,3-hexanediol and cyclohexanol can be used, and it can be arranged in each recess so as to have a thickness of about several tens of μm.

As shown in FIG. 2C, a collective substrate 20 is prepared. The collective substrate 20 includes, for example, a glass epoxy base material and a plurality of pairs of wirings 21 made of copper on a surface which is a mounting surface of the light emitting element.
A eutectic alloy made of Au—Sn can be arranged on the upper surface of each wiring 21 as the bonding member 22.

As shown in FIG. 2D, the substrate 10 in which the light emitting element 13 and the protective element 14 are temporarily fixed in the first recess 11 and/or the second recess 12 is inverted, and the electrodes of each light emitting element 13 correspond to them. The wiring 21 provided on the mounting surface of the collective substrate 20 is brought into contact with the joint member 22.
After that, as shown in FIG. 2E, the electrodes of the light emitting element 13 and the protective element 14 are heated while being in contact with the wiring 21 via the bonding member 22. At this time, a few N to several N per element
Pressurize with. The heating is performed gradually, for example, and is maintained at about 150 to 250° C. for several minutes.
As a result, the light emitting element 13 and the protective element 14 are temporarily fixed to the wiring 21.

Subsequently, as shown in FIG. 2F, the base 10 is removed. At this time, the light emitting element 13 and the protective element 14 are temporarily fixed to the collective substrate 20 by the joining member 22, and the fixing strength thereof is that of the light emitting element 13 and the protective element 14 and the first recess 11 and the second recess 12. It is fixed with greater strength than temporary fixing. Therefore, the base 10 can be easily peeled off from the light emitting element 13 and the protective element 14, and only the base 10 is removed while keeping the light emitting element 13 and the protective element 14 on the collective substrate 20. As a result, all the light emitting elements 13 and the protective elements 14 can be securely fixed to the collective substrate 20 at once.

As shown in FIG. 2G, by raising the heating temperature to about 350° C. and maintaining it in the formic acid atmosphere for several minutes, the joining member 22 is melted and the self-alignment action of the element can be exhibited. Then, by stopping the heating, the bonding member 22 is cured, and the light emitting element 13
Also, the protection element 14 can be firmly fixed to the collective substrate 20. The heating temperature is 3
By reaching about 50° C., the temporary fixing material attached to the element is completely volatilized.

As described above, by going through the steps described above, all the elements are supported by the base, and they can be surely arranged at appropriate positions on the joining member, and the elements can be efficiently mounted on the collective substrate. Further, the first concave portion 11 and the second concave portion 12 of the base body which are not easily deformed can surely prevent the positional deviation of the plurality of elements due to the expansion and contraction due to the load of the thermal cycle. As a result, there is no variation in accuracy, the alignment accuracy can be significantly improved, and the element can be reliably fixed at a predetermined position on the collective substrate.

Example 2: Method of manufacturing light emitting device
As shown in FIG. 3A, the plurality of light emitting elements 13 mounted on the collective substrate 20 obtained in Example 1 is covered with the light reflecting member 23 by, for example, transfer molding. In the second embodiment, as the light reflecting member 23, a silicone resin containing 20% by weight of titanium oxide can be used. The light reflecting member 23 covers the entire side surface of the light emitting element 13, does not cover the upper surface of the light emitting element 13, and is also filled between the light emitting element 13 and the wiring 21 of the collective substrate 20.

As shown in FIG. 3B, the transparent member 24 is provided on the upper surface of the light emitting element 13 and the upper surface of the light reflecting member 23.
To place. In this case, the translucent member 24 can be fixed to the upper surface of the light emitting element 13 with an adhesive such as a translucent silicone resin. For the translucent member 24, for example, a silicone resin containing 10% by weight of YAG phosphor can be used.

As shown in FIG. 3C, at the position shown by line B, the collective substrate 20, the light reflecting member 23, and the light transmitting member 24 are divided for each light emitting element 13. The division can be performed by blade dicing, for example. Thereby, as shown in FIG. 4, a light emitting device 25 including one light emitting element 13 can be obtained.
In the light emitting device 25, the light reflecting member 23 covers the entire side surface of the light emitting element 13. The upper surface of the light emitting element 13 and the upper surface of the light reflecting member 23 are flush with each other, and the light transmitting member 24 is arranged so as to cover these upper surfaces.

[Example 3: Manufacturing method of light emitting device]
5A to 5C, the light reflecting member 23 and the light transmitting member 3 are arranged in the order different from that of the second embodiment.
4 is formed. The collective substrate and the light emitting element can be fixed together by the same method as in the second embodiment. As shown in FIGS. 5A and 5B, with respect to the plurality of light emitting elements 13 mounted on the collective substrate 20 obtained in Example 1, the transparent substrate having the same planar shape as the light emitting element 13 is formed on the upper surface of the light emitting element 13. The light members 34 are arranged respectively.

As shown in FIG. 5B, the light reflection member 23 is covered by transfer molding. The light reflecting member 23 covers the entire side surface of the light emitting element 13 and the entire side surface of the translucent member 34.
4 and the upper surface of the light reflecting member 23 are flush with each other.

As shown in FIG. 5C, at the position indicated by line B, the collective substrate 20 and the light reflecting member 23 are divided for each light emitting element 13. Thereby, as shown in FIG. 6, a light emitting device 35 including one light emitting element 13 can be obtained.
In this light emitting device 35, the light reflecting member 23 covers the entire side surface of the light emitting element 13 and the entire side surface of the light transmitting member 34, and the upper surface of the light transmitting member 34 and the upper surface of the light reflecting member 23 are flush with each other. There is.
Except for this, the method is substantially the same as the method for manufacturing the light emitting device of the second embodiment.

As the element and the base, for example, an element having a rectangular shape in plan view and a base having a concave opening surface may be used. Further, for example, a base body in which the first recesses are arranged in several columns and several rows and the pattern in which one second recess is arranged on one side of the first recesses may be regularly arranged.

The method for mounting the element and the method for manufacturing the light emitting device according to the embodiments include a light source for various display devices, a light source for illumination, a light source for various indicators, an in-vehicle light source, a light source for display, a light source for liquid crystal backlight, a traffic light, in-vehicle parts, It can be used not only for manufacturing various light sources such as signboard channel letters but also for manufacturing all semiconductor devices.

DESCRIPTION OF SYMBOLS 10 Base|substrate 11 1st recessed part 12 2nd recessed part 13 Light emitting element 14 Protective element 20 Collective substrate 21 Wiring 22 Joining member 23 Light reflecting member 24, 34 Light transmitting member 25, 35 Light emitting device

Claims (7)

A plurality of first recesses having the same diameter and depth and a plurality of second recesses having different diameters or depths from the first recesses are provided , and holes are formed in the bottom surfaces of the first recesses and the second recesses, respectively. comprising the steps of: providing a substrate that Yusuke,
A first element having a pair of electrodes in the first recess, a second element having a pair of electrodes in the second recess, and the pair of electrodes having opening surfaces of the first recess and the second recess. So as to be arranged on each side, without temporarily using a temporary fixing material, temporarily fixing by sucking with air from the hole ,
A step of preparing a collective substrate having a plurality of pairs of wiring on the mounting surface,
A step of bringing the wirings into contact with the electrodes of the first element and the second element at the same time and via a bonding member, and fixing the plurality of the first elements and the second elements to the collective substrate by heating all together. ,
And a step of removing the base from the first element and the second element after the collective fixing . The element mounting method according to claim 1, wherein the step of preparing the base body is a step of preparing a base body made of a metal having rigidity. It said first element, mounting method of the device according to claim 1 or 2 which is a light-emitting element. The first recess in a plan view, mounting method of the device according to substantially any one of claims 1 to 3 is a similar shape larger than the first element to be housed. After performing the mounting method of the element according to any one of claims 1 to 5 ,
A method of manufacturing a light emitting device, comprising a step of dividing the aggregate substrate for each element or for each of a plurality of element groups. The light emitting device according to claim 3 , wherein the side surface of the light emitting element is covered with a light reflecting member before and after the step of dividing the aggregate substrate. Method. The light emitting device according to claim 3 , wherein the light extraction surface of the light emitting element is covered with a light transmissive member before and after the step of dividing the collective substrate. Manufacturing method.