JP2013105817A - Optical semiconductor device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem in which, in a conventional manufacturing method in which a multi-faced substrate on which a plurality of LED chips are mounted is pressure-bonded onto a metal mold made of a fluoro resin and having recesses potted with a liquid resin, centers of the LED chips are not matched with centers of the recesses on the multi-faced substrate due to a difference in thermal expansion coefficient between the mold made of the fluoro resin and the multi-faced substrate when the substrate is composed of ceramic.SOLUTION: A method of manufacturing an optical semiconductor device includes: pressure-bonding discrete ceramic substrates 2 each having an LED chip 1 mounted thereon onto respective recesses 3a on a non-adhesive resin mold 3, each having a transparent resin layer 4 formed therein; and curing the transparent resin layers 4 at a temperature of 150°C for about one hour. As a result, the discrete ceramic substrates 2 are horizontally stored in level differences 3a-1 of the recesses 3a on the non-adhesive resin mold 3 without inclination.

Description

  The present invention relates to an optical semiconductor device and a method for manufacturing the same.

In general, as a method of manufacturing an optical semiconductor device such as a light emitting diode (LED) device, there is a method using a resin mold as follows (refer to Patent Document 1).
(1) Preparatory step: A mold made of a fluororesin having recesses formed so that a resin of a material for a multi-sided substrate on which a plurality of LED chips are mounted and a lens for an LED package enters.
(2) Potting step: A fixed amount of liquid resin serving as a lens material is injected into the concave portion of the mold.
(3) Crimping step: A multi-sided substrate on which LED chips are mounted on a mold into which a liquid resin is injected is crimped to temporarily cure the liquid resin.
(4) Separation step: After separating the mold, the liquid resin is completely cured.
(5) Dividing step: Finally, the multi-cavity substrate is divided by dicing or the like for each LED chip with a lens to complete an LED package.

JP 2008-66733 A

  However, the LED device manufacturing method disclosed in Patent Document 1 has the following problems.

First, when a ceramic substrate is used as the multi-sided substrate, the thermal expansion coefficient of the ceramic substrate is about 7.1 × 10E ⁻⁶ / ° C., whereas the thermal expansion coefficient of a mold such as a fluororesin is used. Is 5-12 × 10E ⁻⁵ / ° C., and the coefficient of thermal expansion is different by almost one digit. The number of LED chips on the substrate is actually a large number, for example, about 20. Therefore, it is difficult for the center of all LED chips to coincide with the center of the recess of the fluororesin mold in the crimping process. As a result, the lens (transparent resin layer) of the completed package and the center of the LED chip do not coincide with each other, and there is a problem that desired optical directivity characteristics cannot be obtained.

  Secondly, in the crimping step, leakage of the transparent resin layer to the outside is prevented by pressure contact between the flat part on the LED chip side of the multi-sided substrate and the flat part other than the concave part of the mold made of fluororesin. This alone cannot completely prevent the resin leakage due to the pressure increase of the transparent resin layer at the time of temporary curing at a high temperature, and as a result, the multi-sided substrate is lifted, and the desired optical directivity characteristics cannot be obtained. There was a problem.

  Thirdly, there is a possibility that bubbles generated during temporary curing at a high temperature are caught in the transparent resin layer. As a result, there is still a problem that desired optical directivity characteristics cannot be obtained.

  Fourthly, since a dividing step by dicing or the like of the multi-sided substrate is required, there is a problem that the manufacturing cost is increased.

  In order to solve the above-described problem, an optical semiconductor device manufacturing method according to the present invention includes a step of preparing a plurality of individual substrates on which at least one light emitting element is mounted, and a resin mold in which a plurality of recesses are formed. A step of preparing, a step of injecting a light-transmitting resin into each recess of the resin mold, a step of pressing each individual substrate to each of the recesses of the resin mold into which the light-transmitting resin is injected, and curing the light-transmitting resin Each of the recesses has a side portion that contacts the side surface of the individual substrate and an upper surface portion that contacts a part of the mounting surface of the light emitting element of the individual substrate in the step of crimping. is there. As a result, the individual substrate is horizontally accommodated without being inclined in the resin-shaped recess.

Further, before the step of crimping the individual substrate, the opening size of the recess is smaller than the outer size of the individual substrate. A second step is formed in the recess below the first step composed of the side surface and the top surface. This prevents the resin from leaking to the outside and prevents the substrate from floating.
Furthermore, a bubble removal slit is provided in the first step between the outside of the recess and the second step, and the bubble removal slit extends to the upper surface of the resin mold outside the recess.

  Furthermore, the manufacturing method includes a step of separating the resin mold after the light-transmitting resin is cured.

  Furthermore, the manufacturing method includes a step of dividing the resin mold between adjacent individual substrates after the light-transmitting resin is cured.

  An optical semiconductor device according to the present invention includes a substrate on which at least one light emitting element is mounted, a resin mold disposed so as to surround the light emitting element on the substrate, and a resin mold so as to cover the light emitting element on the substrate. And a part of the inner surface of the resin mold is in contact with the side surface of the substrate.

  According to the present invention, since the individual substrate on which the light emitting element is mounted can be crimped to each recess of the resin mold without tilting the substrate, the center of all the light emitting elements is the center of each recess of the resin mold. As a result, the optical directivity of the completed package can be improved.

It is a figure which shows 1st Embodiment of the manufacturing method of the LED device which concerns on this invention. It is a figure which shows 1st Embodiment of the manufacturing method of the LED device which concerns on this invention. It is a figure which shows 1st Embodiment of the manufacturing method of the LED device which concerns on this invention. It is a figure which shows 1st Embodiment of the manufacturing method of the LED device which concerns on this invention. It is a figure which shows 2nd Embodiment of the manufacturing method of the LED device which concerns on this invention. It is a figure which shows 2nd Embodiment of the manufacturing method of the LED device which concerns on this invention. It is a figure which shows 2nd Embodiment of the manufacturing method of the LED device which concerns on this invention. It is a figure which shows 2nd Embodiment of the manufacturing method of the LED device which concerns on this invention. It is a figure which shows 3rd Embodiment of the manufacturing method of the LED device which concerns on this invention. It is a figure which shows 3rd Embodiment of the manufacturing method of the LED device which concerns on this invention. It is a figure which shows 3rd Embodiment of the manufacturing method of the LED device which concerns on this invention. It is a figure which shows 3rd Embodiment of the manufacturing method of the LED device which concerns on this invention.

  1-4 is a figure which shows 1st Embodiment of the manufacturing method of the LED device based on this invention.

  First, referring to FIG. 1 showing a preparation process, an individual ceramic substrate 2 made of alumina or the like on which at least one LED chip 1 is mounted is prepared (FIG. 1A), and an LED package lens is prepared. A non-adhesive resin mold 3 in which a recess 3a is formed so that the material resin enters is prepared ((B1), (B2), (B3) in FIG. 1). 1B is a perspective view, FIG. 1B2 is a top view of one recess 3a, and FIG. 1B3 is a cross-sectional view through the center of (B2).

  The individual ceramic substrate 2 on which the LED chip 1 shown in FIG. 1A is mounted is set on the dedicated carrier jig after the individual ceramic substrate 2 on which the LED chip 1 is not mounted. It is obtained by bonding and then removing the dedicated carrier jig from the individual ceramic substrate 2. Alternatively, after mounting a plurality of LED chips on a single ceramic substrate having a groove, the ceramic substrate may be divided along the groove. In this case, burrs may occur in the individual ceramic substrate 2, but even if burrs occur, the non-adhesive resin mold 3 has elasticity in the press-bonding process described later, so that it will fit in the recess 3 a. Can do. The number of LED chips 1 mounted on the individual ceramic substrate 2 may be one or two or more. In the case of two or more, LED chips of different colors or the same color such as a blue LED chip may be used.

  The non-adhesive resin mold 3 shown in (B1), (B2), and (B3) of FIG. 1 is obtained by polymerization of a fluorine-containing olefin typified by polytetrafluoroethylene, which is widely known as a registered trade name Teflon. Made of fluororesin. This resin has releasability with low heat resistance, elasticity, and friction coefficient. Since this non-adhesive resin mold 3 is difficult to cut, it is preferable to produce and mold a mold.

  Moreover, as shown to (B2) and (B3) of FIG. 1, the two level | step differences 3a-1 and 3a-2 are provided in the recessed part 3a of the non-adhesive resin type | mold 3. The side surface of the step 3a-1 acts so as to come into contact with the side surface of the individual ceramic substrate 2 in a later-described pressing step, while the upper surface of the step 3a-1 is the LED chip 1 of the individual ceramic substrate 2 in the later-described pressing step. It acts to abut against the flat surface on the side. Further, the step 3a-2 acts as a reservoir for the resin filled in the press-bonding process described later, and receives the escape of the resin.

Next, referring to FIG. 2 showing the potting process, a liquid light-transmitting resin 4a as a lens material, for example, a silicone resin or an epoxy resin is quantitatively injected into the recess 3a of the non-adhesive resin mold 3 with a dispenser or the like (FIG. 2). 2 (A)). As a result, the transparent resin layer 4 is formed in the recess 3a of the non-adhesive resin mold 3 ((B) in FIG. 2). In this case, if the amount of the light-transmitting resin 4a is too small, a press-bonding failure occurs in the press-bonding process described later. Therefore, the amount of the light-transmitting resin 4a is the same as that of the filled light-transmitting resin 4a in the press-bonding process described later. The amount is such that the upper part is in contact with the substrate and spreads. That is, it is preferable to fill, for example, as a raised shape so as to exceed the upper surface (flat surface) of the step 3a-1. Therefore, in this case, the transparent resin layer 4 extends to the step 3a-2 of the resin reservoir in the press-bonding process described later. Further, the liquid light-transmitting resin 4a is filled so as not to contact the upper surface and the side surface of the step 3a-1. This ensures that the upper surface of the individual ceramic substrate 2 and the upper surface of the step 3a-1 and the side surface of the substrate 2 and the side surface of the step 3a-1 are brought into contact with each other without passing through the light-transmitting resin 4a in the crimping step described later. Therefore, the individual ceramic substrate 2 can be fixed without being inclined.

  Next, referring to FIG. 3 showing the crimping process, the individual ceramic substrate 2 on which the LED chip 1 is mounted is crimped on each recess 3a of the non-adhesive resin mold 3 on which the transparent resin layer 4 is formed (FIG. 3). 3 (A)), the transparent resin layer 4 is cured in a heating furnace at a high temperature of about 150 ° C. for about 1 hour (FIG. 3B).

As shown in FIG. 3A, before the press bonding, the opening size of the recess 3a of the non-adhesive resin mold 3, that is, the outer size d31 of the step 3a-1, is the outer shape of the individual ceramic substrate 2 as shown in the following equation. It is smaller than the size d2.
d31 = α · d2
However, 0.9 ≦ α <1.0
Thereby, since the non-adhesive resin mold 3 has elasticity, the individual ceramic substrate 2 is fitted with the opening of the recess 3a being somewhat expanded so as to be accommodated in the step 3a-1. That is, the individual ceramic substrate 2 can be pressure-bonded to the non-adhesive resin mold 3, and when the pressure-bonding is performed, the side surface of the individual ceramic substrate 2 is securely in contact with the side surface of the step 3 a-1. The plane on the LED chip 1 side of the piece ceramic substrate 2 is surely in contact with the upper surface of the step 3a-1. As a result, as shown in FIG. 3B, the individual ceramic substrate 2 can be horizontally accommodated without being inclined in the step 3 a-1 of the recess 3 a of the non-adhesive resin mold 3. At this time, the center of the individual ceramic substrate 2 surely coincides with the center of the non-adhesive resin mold 3 by pressure contact with the side surface of the step 3a-1. Further, the external size d32 of the step 3a-2 on which the resin pool acts is
d32 <d31
It is.

  Finally, referring to FIG. 4 showing the separation process, the LED package is completed by separating the non-adhesive resin mold 3 after the transparent resin layer 4 is cured. 4A is a sectional view, and FIG. 4B is a perspective view.

  5-8 is a figure which shows 2nd Embodiment of the manufacturing method of the LED device based on this invention.

  First, referring to FIG. 5 showing the preparation process, at least an individual ceramic substrate 2 on which the LED chip 1 is mounted is prepared ((A) of FIG. 5), and the resin of the LED package lens material enters. A non-adhesive resin mold 3 having a recess 3a formed thereon is prepared ((B1), (B2), (B3) in FIG. 5). 5B1 is a perspective view, FIG. 5B2 is a top view of one recess 3a, and FIG. 5B3 is the center of the recess 3a in FIG. 5B, that is, a bubble removal slit 3a-3. It is sectional drawing which passes through.

The individual ceramic substrate 2 on which the LED chip 1 shown in FIG. 5A is mounted is the same as that in FIG.

  In the non-adhesive resin mold 3 shown in FIG. 5 (B), there are four steps 3a-1 in the recess 3a of the non-adhesive resin mold 3 shown in (B1), (B2), and (B3) of FIG. A bubble removal slit 3a-3 is provided. The bubble removal slit 3a-3 has the same depth as the step 3a-2, and is used for releasing bubbles when bubbles are generated in the liquid resin in the press-bonding process described later. The bubble removal slit 3a-3 is provided at the step 3a-1 between the outside of the recess 3a and the step 3a-2, and extends to the upper surface of the outside of the recess 3a. That is, it is formed in a groove shape extending from the upper surface (flat surface) of the step 3a-1 to the upper surface of the non-adhesive resin mold 3 beyond the step 3a-1. Therefore, a part of the bubble removal slit 3a-3 (a region other than the upper surface of the step 3a-1) is not covered with the individual ceramic substrate 2 even after the individual substrate pressing process, and the transparent resin 4 Acts as a discharge port for bubbles generated inside.

  Next, referring to FIG. 6 showing the potting process, in the same manner as in FIG. 2, a light-transmitting resin 4a as a lens material, such as a silicone resin or an epoxy resin, is dispensed to the recess 3a of the non-adhesive resin mold 3 with a dispenser or the like. A fixed amount is injected ((A) in FIG. 6). As a result, the transparent resin layer 4 is formed in the recess 3a of the non-adhesive resin mold 3 ((B) in FIG. 6). Also in this case, if the amount of the light-transmitting resin 4a is too small, a press-bonding failure occurs in the press-bonding process described later. Therefore, the amount of the light-transmitting resin 4a is the same as that of the light-transmitting resin 4a filled in the press-bonding process described later. The amount that the upper part of the substrate is expanded in contact with the substrate. That is, it is preferable to fill, for example, as a raised shape so as to exceed the upper surface (flat surface) of the step 3a-1. Therefore, in this case, the transparent resin layer 4 extends to a part of the resin reservoir level difference 3a-2 and a part of the bubble removal slit 3a-3 in the press-bonding step described later. Further, the liquid light-transmitting resin 4a is filled so as not to contact the upper surface and the side surface of the step 3a-1. Thereby, in the crimping | compression-bonding process mentioned later, the upper surface of the board | substrate 2 and the upper surface of level | step difference 3a-1 and the side surface of the board | substrate 2 and the side surface of level | step difference 3a-1 can be reliably contact | abutted without passing through the translucent resin 4a. Therefore, the individual ceramic substrate 2 can be fixed without being inclined.

  Next, referring to FIG. 7 showing the crimping process, the individual ceramic substrate 2 on which the LED chip 1 is mounted is crimped on each recess 3a of the non-adhesive resin mold 3 on which the transparent resin layer 4 is formed (FIG. 7). 7 (A)), the transparent resin layer 4 is cured in a heating furnace at a high temperature of about 150 ° C. for about 1 hour (FIG. 7B). In this case, for example, if the LED chip 1 is a flip-chip type, air in the gaps between the bumps or air adsorbed on the bonding wires is generated as bubbles in the transparent resin layer 4. Such bubbles escape through the bubble removal slit 3a-3 as shown by the arrow in FIG.

  6 and 7, the cross-sectional view passing through the bubble removal slit 3a-3 has been described, but also in the second embodiment, the first embodiment is performed in a cross section (not shown) during the crimping process. Similarly to the embodiment, the side surface of the individual ceramic substrate 2 is in contact with the side surface of the step 3a-1, and the LED mounting surface of the individual ceramic substrate 2 is in contact with the upper surface of the step 3a-1. The ceramic substrate 2 is fixed to the recess 3a.

Finally, referring to FIG. 8 showing the separation process, as in the case of FIG. 4, the non-adhesive resin mold 3 is separated after the transparent resin layer 4 is cured to complete the LED package. In this case, the transparent resin layer 4 may have a protruding portion 4b with respect to the bubble removal slit 3a-3. Although FIG. 8 shows a state in which the protruding portion 4b is formed on all of the transparent resin layer 4, the protruding portion 4b is not necessarily formed, and is formed according to the amount of the light transmissive resin 4a. Is done.

  In the first and second embodiments of the present invention described above, the non-adhesive resin mold 3 can be reused after being separated, which is advantageous in terms of manufacturing cost. The non-adhesive resin mold 3 is a non-adhesive resin mold made of an integral type of non-adhesive resin, but a non-adhesive resin coated with a mold may be used, and release is possible. Various resin molds can be used as appropriate.

  FIGS. 9-12 is a figure which shows 3rd Embodiment of the manufacturing method of the LED device based on this invention.

  First, referring to FIG. 9 showing a preparation process, an individual ceramic substrate 2 made of alumina or the like on which at least one LED chip 1 is mounted is prepared ((A) of FIG. 9), and an LED package lens is prepared. A transparent resin mold 5 in which a recess 5a is formed so that the material resin enters is prepared ((B1), (B2), (B3) in FIG. 9). 9B is a perspective view, FIG. 9B2 is a top view of one recess 5a, and FIG. 9B3 is a cross-sectional view passing through the center of the recess 5a.

  The individual ceramic substrate 2 on which the LED chip 1 shown in FIG. 9A is mounted is the same as that in FIG.

  The transparent resin mold 5 shown in (B1), (B2), and (B3) of FIG. 9 is made of, for example, a silicone resin. Since cutting is difficult, it is preferable to produce and mold a mold.

  Further, as shown in (B2) and (B3) of FIG. 9, the recess 5a of the transparent resin mold 5 has two steps 3a-1 and 3a-2 in (B2) and (B3) of FIG. Two corresponding steps 5a-1 and 5a-2 are provided. That is, the side surface of the step 5a-1 acts so as to come into contact with the side surface of the individual ceramic substrate 2 in a later-described pressing step, while the upper surface of the step 5a-1 is the LED of the individual ceramic substrate 2 in the later-described pressing step. It acts so as to come into contact with the flat surface on the chip 1 side. Further, the step 5a-2 acts as a reservoir of the resin filled in the press-bonding process described later, and receives the escape of the resin.

Next, referring to FIG. 10 showing the potting process, a light-transmitting resin 4a as a lens material, for example, a silicone resin or an epoxy resin is quantitatively injected into the concave portion 5a of the transparent resin mold 5 with a dispenser or the like ( A)). As a result, the transparent resin layer 4 is formed in the recess 5a of the transparent resin mold 5 ((B) of FIG. 10). Also in this case, if the amount of the light-transmitting resin 4a is too small, a press-bonding failure occurs in the press-bonding process described later. Therefore, the amount of the light-transmitting resin 4a is the same as that of the light-transmitting resin 4a filled in the press-bonding process described later. The amount that the upper part of the substrate is expanded in contact with the substrate. That is, it is preferable to fill, for example, as a raised shape so as to exceed the upper surface (flat surface) of the step 5a-1. Therefore, in this case, the transparent resin layer 4 extends to the step 5a-2 of the resin reservoir in the press-bonding process described later. The liquid light-transmitting resin 4a is filled so as not to contact the upper surface and the side surface of the step 5a-1. Thereby, in the crimping | compression-bonding process mentioned later, the upper surface of the board | substrate 2 and the upper surface of level | step difference 5a-1 and the side surface of the board | substrate 2 and the side surface of level | step difference 5a-1 can be reliably contact | abutted without passing through the translucent resin 4a. Therefore, the individual ceramic substrate 2 can be fixed without being inclined.

  Next, referring to FIG. 11 showing the crimping process, as in the case of FIG. 3, the individual ceramics in which the LED chip 1 is mounted on each recess 5a of the transparent resin mold 5 on which the transparent resin layer 4 is formed. The substrate 2 is pressed (FIG. 11A), and the transparent resin layer 4 is cured in a heating furnace at a high temperature of about 150 ° C. for about 1 hour (FIG. 11B).

  Finally, referring to FIG. 12 showing the dividing step, the LED package is completed by dividing the transparent resin mold 5 along the dividing surface DF of FIG. 11 by dicing or the like after the transparent resin layer 4 is cured. In the completed LED package, a part of the inner surface of the resin mold 5, that is, a portion corresponding to the side surface of the step 5 a-1 of the recess 5 a is in contact with the side surface of the substrate 2.

  As described above, in the third embodiment of the present invention, the separation step of the first and second embodiments does not exist. That is, the transparent resin mold 5 is integrated with the individual ceramic substrate 2 as it is without being separated into an LED package.

  In the above-described third embodiment of the present invention, the bubble removal slit 3a-3 in the second embodiment can be provided in the recess 5a of the transparent resin frame 5.

  When the optical semiconductor device according to each embodiment of the present invention described above is used as a white LED device, a fluorescent layer may be applied to the surface of the LED chip 1 or a phosphor may be dispersed in the transparent resin layer 4.

  The present invention can also be applied to light emitting chips other than LED chips, such as semiconductor laser chips.

1: LED chip 2: Individual ceramic substrate 3: Non-adhesive resin mold 3a: Recess 3a-1, 3a-2: Step
3a-3: Bubble removal slit 4: Transparent resin layer 4a: Resin 4b: Protrusion 5: Transparent resin mold 5a: Recess 5a-1, 5a-2: Step

Claims (8)

Preparing a plurality of individual substrates on which at least one light emitting element is mounted;
Preparing a resin mold in which a plurality of recesses are formed;
Injecting a light transmissive resin into each recess of the resin mold;
Crimping each individual substrate to each recess of the resin mold into which the light-transmitting resin is injected;
Curing the light transmissive resin,
In the optical semiconductor device, each of the recesses includes a side surface portion that contacts the side surface of the individual substrate and an upper surface portion that contacts a part of the mounting surface of the light emitting element of the individual substrate in the crimping step. Production method.   The method of manufacturing an optical semiconductor device according to claim 1, wherein the size of the concave portion is smaller than the outer size of the individual substrate before the step of pressure-bonding the individual substrate.   The method of manufacturing an optical semiconductor device according to claim 1, wherein the individual substrate is a ceramic substrate.   4. The method of manufacturing an optical semiconductor device according to claim 1, wherein a second step is formed in the concave portion below a first step composed of the side surface portion and the upper surface portion. .   The bubble removal slit is provided in the first step between the outside of the recess and the second step, and the bubble removal slit extends to the upper surface of the resin mold outside the recess. The manufacturing method of the optical semiconductor device of description.   The method for manufacturing an optical semiconductor device according to claim 1, further comprising a step of separating the resin mold after the light-transmitting resin is cured.   6. The method of manufacturing an optical semiconductor device according to claim 1, further comprising a step of dividing the resin mold between the adjacent individual substrates after the light transmissive resin is cured. A substrate on which at least one light emitting element is mounted;
A resin mold disposed on the substrate so as to surround the light emitting element;
Comprising a light-transmitting resin layer filling the resin mold so as to cover the light emitting element on the substrate in the previous period,
An optical semiconductor device in which a part of the inner surface of the resin mold is in contact with the side surface of the substrate.