KR20090130638A - Method of manufacturing led package - Google Patents

Abstract

PURPOSE: A method of manufacturing an LED package is provided to improve optical efficiency by forming a reflector with a white tiO2, znO, lithopone, znS, baSO4, siO2 and PTFE. CONSTITUTION: In a device, a sheet(10) for a lower plate and a white sheet(20) for a reflector are prepared. A via hole(10a) is formed by punching the sheet, and the via hole is filled with the conductor paste. Electrode patterns(12a,12b,12c) are formed on the sheet having a via hole. The sheet and electrode pattern are combined through a plastic process. A white sheet for the reflector is laminated on the sheet for the lower plate. The lower plate and a white sheet for reflector are rigidly combined through a thermal process. A plurality of unit elements are formed by a cutter.

Description

Method of manufacturing LED package

The present invention relates to a method for manufacturing an LED package, and more particularly, to a method for manufacturing an LED package having a reflecting plate.

In the conventional LED package, as illustrated in FIG. 1, a first ceramic substrate having an upper surface on which the mounting region 103 of the LED element 105 is formed and having a predetermined conductive pattern electrode formed around the mounting region 103 ( 101); At least one LED element 105 disposed in the mounting region 103 on the upper surface of the first ceramic substrate 101 and connected to a predetermined conductive pattern electrode by a wire 107; A second ceramic substrate 102 disposed on the first ceramic substrate 101 and having a cavity formed in a region corresponding to the mounting region 103 of the LED element 105; And a metal reflector plate 120 formed in a cavity of the second ceramic substrate 102 so as to surround the at least one LED 105 element, and having a latching jaw 120a formed on the top of the second ceramic substrate 102. It is configured to include).

In FIG. 1, the inner surface of the metal reflector 120 is plated to increase the reflectance. Although the reflectance can be increased by using the metal reflecting plate 120 plated in this way, there is a hassle to perform a plating process separately.

In addition, in order for the metal reflector 120 to properly maintain the position in the cavity, the use of an adhesive member (not shown) is required in addition to the locking step 120a. Since the second ceramic substrate 102 and the metal reflecting plate 120 are different materials, even if an adhesive member is used, partial separation between the second ceramic substrate 102 and the metal reflecting plate 120 often occurs. This makes it impossible to obtain the desired light directivity angle properly.

When the metal reflector 120 is used as described above, the reflectance is improved, but on the contrary, the package manufacturing process is complicated and the product error rate is high.

The present invention has been proposed to solve the above-mentioned conventional problems, and an object thereof is to provide a method of manufacturing an LED package in which the manufacturing is simple and the light efficiency is increased.

In order to achieve the above object, a method of manufacturing an LED package according to a preferred embodiment of the present invention, the first step of preparing a lower substrate; A second step of injecting a white reflective material into the molding die to produce a white reflective plate having a cavity rounded inwardly and rounded inwardly by transfer molding; And a third step of coupling the white reflector to the upper surface of the lower substrate.

The first step includes forming an electrode pattern on the upper surface of the lower substrate.

In the first step, the lower substrate is made of any one of metal, ceramic, varistor, and plastic.

In a second step, the white reflector comprises a white silicone epoxy resin.

In a second step, the white reflector comprises at least one of TiO ₂ , ZnO, Lithopone, ZnS, BaSO ₄ , SiO ₂ , PTFE (polytetrafluoroethylene).

In the second step, the white reflective material includes at least one of TiO ₂ , ZnO, lithopone, ZnS, BaSO ₄ , SiO ₂ , and PTFE (polytetrafluoroethylene) as the main material, and includes 5 to 60 wt% of the main material. Add in%

In the second step, the white reflective material is used with a main material of 5-30 wt% silicone resin and 20-65 wt% epoxy resin.

The second step includes forming a hole in the rounded side of the cavity for mounting the EMI filter on the upper surface of the lower substrate.

And mounting at least one LED chip on the lower substrate.

According to the present invention having such a configuration, it is possible to produce a large number of reflecting plates quickly and accurately by producing the sheet for white reflecting plates by the transfer molding. This not only requires a separate plating process, but also provides overall simplicity and reduces defect rates.

Light in the visible range by selecting white TiO ₂ , ZnO, lithopone, ZnS, BaSO ₄ , SiO ₂ , PTFE (polytetrafluoroethylene), etc. with low light absorption and good reflectance In addition to almost no absorption, almost all the light from the light emitting device chip is reflected, thereby improving light efficiency as compared with the related art.

Hereinafter, a method of manufacturing an LED package according to an embodiment of the present invention with reference to the accompanying drawings.

Figure 2 is a view showing a manufacturing method of the LED package according to an embodiment of the present invention in sequence, Figure 3 is an enlarged perspective view of any one of the plurality of LED packages shown in (h) of FIG.

First, the lower substrate sheet 10 and the white reflector sheet 20 are prepared. The lower substrate sheet 10 is manufactured to a size that can be separated into a plurality of lower substrates. The white reflective plate sheet 20 is manufactured to a size that can be separated into a plurality of reflective plates. The lower substrate sheet 10 is divided (separated) into a plurality of lower substrates by a subsequent firing and sawing process. After that, the reference numerals of the lower substrates are the same as those of the lower substrate sheet 10. The white reflector sheet 20 is divided (separated) into a plurality of reflector plates by a later deposition and sawing process. After that, the reference numerals of the reflecting plates are the same as those of the white reflecting sheet 20.

In particular, when the sheet 10 and the sheet 20 are combined and then cut, the sheet 10 is separated into a plurality of LED packages. The separated LED package is called a unit device. Therefore, the region corresponding to each unit element in the sheet 10 and the sheet 20 may be referred to as a unit element region.

Here, the preparation of the lower substrate sheet 10 means that the sheet 10 which has been subjected to the following description, that is, the process of FIGS. 2A to 2C is manufactured. Preparing the white reflective plate sheet 20 means that the sheet 20 which has undergone the following description, that is, the process of FIG. In the embodiment of the present invention, the lower substrate may be any substrate capable of mounting the light emitting device chip at a high density. For example, alumina, quartz, calcium zirconate, forsterite, SiC, graphite, fusedsilica, mullite, cordierite, zirconia (zirconia), beryllia, aluminum nitride, low temperature co-fired ceramic (LTCC), high temperature co-fired ceramic (HTCC), plastics, metals, varistors, and the like. In particular, ZnO series varistors have high thermal conductivity. The production of ZnO-based varistor material not only functions as a varistor, but also allows the LED package to be rapidly cooled due to the high thermal conductivity of the varistor itself. When the lower substrate is made of plastic, plastic is generally weak to heat, and thus, when used for a long time, deformation of the lower substrate occurs, thereby reducing product efficiency. However, in the present invention, the reflective plate covers the upper surface of the lower substrate (that is, the region except the electrode) to minimize the portion where the light of the light emitting element directly contacts the lower substrate. This solves the problem caused by the heat generated by the light of the light emitting device. In other words, even if the lower substrate is made of plastic, the present invention eliminates efficiency deterioration due to heat generation due to long-term use compared to the existing structure.

The process of manufacturing the lower board | substrate 10 is assumed and manufactured using ceramic as a material. First, a glass ceramic powder having a predetermined weight is prepared, and PVB-based binder is weighed by a predetermined weight part with respect to the glass ceramic powder, and then dissolved in toluene / alcohol-based solvent to dissolve it in the glass ceramic powder. Blend together.

Then, the blended glass ceramic powder is placed in a container and rotated to mix uniformly. For example, a glass ceramic powder having a desired particle size is obtained through a ball mill at 50 rpm for about 20 hours. The above 50 rpm and 20 hours are just examples and vary depending on the diameter and amount of the balls in the ball mill, the amount of solvent and binder, and the like.

When milling in the ball mill, the first blended glass ceramic powder is discharged in the form of a slurry. Since the discharged slurry has some bubbles, it is degassed to remove bubbles in the discharged slurry. Is carried out. In order to prevent the slurry surface from drying rapidly during defoaming, the slurry is kept under vacuum for a predetermined time while stirring.

The mixed raw material (ie, in the form of a slurry) subjected to the defoaming process is formed into a sheet. That is, after installing the film and the blade (blade) in the tape caster, while slowly transferring the film, the degassed slurry is introduced, and the slurry passed through the blade is dried to obtain a sheet having a desired thickness (for example, 20 to 150 μm on the film). , Also known as ceramic sheets or green sheets).

The ceramic sheet wound on the roll is cut to a certain size (dimension) to make the sheet 10 as shown in Fig. 2A. Here, one sheet 10 shown in (a) of FIG. 2 may have a thickness of the lower substrate required by the present invention, and a desired thickness of the lower substrate is obtained by stacking several sheets 20. It may have a.

Thereafter, as shown in FIG. 2B, the sheet 10 is punched to form a via hole 10a, and then the conductor paste is filled into the via hole 10a. The via hole 10a serves to connect the interlayer circuit. As shown in FIG. 2C, electrode patterns 12 (12a, 12b, and 12c) are formed on the upper surface of the sheet 10 on which the via holes 10a are formed. The electrode pattern 12 is formed by printing conductive pastes such as Ag, Pt, and Pd by a thick film manufacturing method such as screen printing or thin film manufacturing methods such as sputtering, evaporation, vapor chemical vapor deposition, and sol-gel coating. Here, the electrode pattern 12a is an anode or a cathode, the electrode pattern 12b is a cathode or an anode, and the electrode pattern 12c is an electrode pattern for mounting an EMI filter (for example, a zener diode).

Subsequently, the sheet 10 and the electrode pattern 12 are baked at a predetermined temperature so as to be well bonded.

Thus, the lower substrate sheet 10 is manufactured by the process of FIG. 2 (a)-(c).

The process of manufacturing the white reflector sheet 20 is demonstrated this time. In the embodiment of the present invention, a white reflective material is used to manufacture the white reflective sheet sheet 20. Here, the white reflective material includes, for example, a white silicone epoxy resin having a reflectance of 90% or more (see Table 1 below). White silicone epoxy resin, which is used as a material of white reflective material, has thermosetting properties.

Table 1

            material           content Titanium dioxide, Zinc Oxide, Lithopone (BaSO ₂ + ZnS) ZnS, BaSO ₄ , SiO ₂ , PTFE (polytetrafluoroethylene)           5 to 60 wt%    Silicone Resin        5 to 30% by weight   Additives such as solvents, epoxy resins, etc.        20 to 65 wt%

In Table 1, TiO ₂ , ZnO, lithopone, ZnS, BaSO ₄ , PTFE (polytetrafluoroethylene) and the like were used to implement white color. Of course, in Table 1, TiO ₂ , ZnO, lithopone, ZnS, BaSO ₄ , PTFE (polytetrafluoroethylene), etc. were used to implement white color. Other materials may be used instead of ZnS, BaSO ₄ , PTFE (polytetrafluoroethylene), for example. Silicone resins and epoxy resins were used for the viscosity and tack. In Table 1, TiO ₂ , ZnO, lithopone, ZnS, BaSO ₄ , SiO ₂ , PTFE (polytetrafluoroethylene) and the like are the main materials for whitening, and silicone resins, epoxy resins, and the like are materials. . In Table 1, the use of TiO ₂ , ZnO, lithopone, ZnS, BaSO ₄ , SiO ₂ , PTFE (polytetrafluoroethylene) at less than 5% by weight is difficult to achieve white. When TiO ₂ , ZnO, Lithopone (Lithopone), ZnS, BaSO ₄ , SiO ₂ , and PTFE (polytetrafluoroethylene) are used in excess of 60% by weight, the amount of addition of silicone resin and epoxy resin is reduced and the desired viscosity and Hard to get adhesiveness If the silicone resin is used at less than 5% by weight, the viscosity becomes too low. When the silicone resin is used in excess of 30% by weight, the viscosity becomes too high. When the epoxy resin is used in less than 20% by weight, the adhesive strength is weakened. When the epoxy resin is used in excess of 65% by weight, the content of TiO ₂ , ZnO, lithopone, ZnS, BaSO ₄ , SiO ₂ , PTFE (polytetrafluoroethylene) or silicone resin is insufficient, resulting in white color. This makes it difficult to achieve the desired viscosity. Light in the visible range by selecting white TiO ₂ , ZnO, lithopone, ZnS, BaSO ₄ , SiO ₂ , PTFE (polytetrafluoroethylene), etc. with low light absorption and good reflectance Not only is there almost no absorption, and almost all the light from the light emitting device chip (not shown) is reflected, thereby improving the light efficiency.

In order to manufacture the white reflective plate sheet 20 as shown in FIG. 2 (d), the above-mentioned white reflective material is injected into a molding die (not shown), and the cavity 28 rounded and centered inward is formed. A white reflector plate (e.g., a circular shape) is produced by transfer molding. Here, since the sheet 20 is a molded body made by a transfer molding method, it may be called a transfer mold. The transfer molding method is a variation of the injection molding of the thermosetting resin and is also called a transfer molding method. The transfer molding method converts a plastic material into a cured state while injecting a material (ie, a white reflective material) into a closed heating mold and transferring the material. In general, the transfer molding method is performed in the order of preforming → preheating → mold closing → material supply → hardening → mold opening → removing the molded article. In FIG. 2D, a sheet 20 having a plurality of cavities 28 is manufactured. There is a perforated hole 22 in the bottom of each cavity 28, each cavity 28 has a hole 24 for mounting the EMI filter (e.g. Zener diode) on the lower substrate 10 and Holes 26 for wire bonding are formed together. Of course, depending on the situation, it can also be set as the shape without the holes 24 and 26. FIG. The diameter of the hole 22 is smaller than the diameter of the hole formed in the upper part of the cavity 28.

As described above, the white reflective plate sheet 20 is formed by the transfer molding, thereby making it possible to quickly and accurately produce a large number of reflective plates. This will provide overall simplicity of operation and reduce defect rates.

As described above, the steps from (a) to (d) of FIG. 2 may be performed in order to manufacture the lower substrate sheet 10 and the white reflector sheet 20, or the white reflector sheet 20 It may be prepared first. Alternatively, the process of manufacturing the lower substrate sheet 10 and the process of manufacturing the white reflector sheet 20 may be simultaneously performed.

Subsequently, after laminating the white reflective plate sheet 20 on the upper surface of the lower substrate sheet 10 manufactured as shown in FIG. 2 (e), the lower substrate sheet 10 and the white reflective plate sheet ( 20) is heat-treated at a predetermined temperature to bond well. By the heat treatment, the lower substrate sheet 10 and the white reflector sheet 20 are firmly bonded as shown in FIG. 2 (f).

Then, as shown in (g) of FIG. 2, a cutter (not shown) is cut along the imaginary cutting line and separated into a plurality of unit elements. For example, by sawing along the cutting line using the blade 30, it is separated into a plurality of unit elements (single item) (refer to FIG. 3) as shown in FIG.

In this way, it is possible to complete the desired LED package in the present invention. That is, the LED package 40 formed on the lower substrate 10 with the white reflective plate 20 having the rounded cavity 28 inwardly as shown in FIG. 3 is completed.

Of course, although the light emitting device is not illustrated in FIGS. 2 and 3, wire (not shown) bonding is performed after the light emitting device (for example, a chip-shaped LED) is mounted on the upper surface of the electrode pattern 12a. The chip type light emitting device may be connected by a wire bonding method, or may be connected by eutectic bonding or flip bonding. That is, the presence or absence of a wire is determined according to the bonding method, and the zener diode is optional since it can be used only when necessary. Therefore, the holes 24 and 26 of the cavity (28 in Fig. 3) may be formed only when necessary.

On the other hand, the present invention is not limited only to the above-described embodiment, but can be modified and modified within the scope not departing from the gist of the present invention, the technical idea to which such modifications and variations are also applied to the claims Must see

1 is a view showing the configuration of a conventional LED package.

2 is a view sequentially showing a method of manufacturing an LED package according to an embodiment of the present invention.

FIG. 3 is an enlarged perspective view of any one of a plurality of LED packages illustrated in FIG. 2H.

<Description of Symbols for Major Parts of Drawings>

10: lower substrate 20: reflector

22, 24, 26: hole 28: cavity

30: blade 40: LED package

Claims (9)

Preparing a lower substrate; A second step of injecting a white reflective material into the molding die to produce a white reflective plate having a cavity rounded inwardly and rounded inwardly by transfer molding; And And a third step of coupling the white reflective plate to an upper surface of the lower substrate. The method according to claim 1, The first step of manufacturing an LED package, characterized in that for forming an electrode pattern on the upper surface of the lower substrate. The method according to claim 1, The first step is a method of manufacturing an LED package, characterized in that the material of the lower substrate is any one of metal, ceramic, varistor, plastic. The method according to claim 1, In the second step, the white reflective material is a manufacturing method of the LED package, characterized in that it comprises a white silicone epoxy resin. The method according to claim 1, In the second step, the white reflective material LED package, characterized in that at least one of TiO ₂ , ZnO, Lithopone (Lithopone), ZnS, BaSO ₄ , SiO ₂ , PTFE (polytetrafluoroethylene) Manufacturing method. The method according to claim 1, In the second step, the white reflective material includes at least one of TiO ₂ , ZnO, lithopone, ZnS, BaSO ₄ , SiO ₂ , and PTFE (polytetrafluoroethylene) as a main material, and includes the main material. Method for producing an LED package, characterized in that added in 5 ~ 60wt%. The method according to claim 6, In the second step, the white reflective material is a method of manufacturing an LED package, characterized in that the use of a subsidiary material with a silicone resin of 5 ~ 30wt% and an epoxy resin of 20 ~ 65wt% with the main material. The method according to any one of claims 1 to 7, The second step is a method of manufacturing an LED package, characterized in that for forming a hole for mounting the EMI filter on the upper surface of the lower substrate, the rounded side of the cavity. The method according to any one of claims 1 to 7, And mounting at least one LED chip on the lower substrate.

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