WO2011141781A1

WO2011141781A1 - Led module

Info

Publication number: WO2011141781A1
Application number: PCT/IB2011/000431
Authority: WO
Inventors: 田中　隆; 小林　充
Original assignee: パナソニック電工株式会社
Priority date: 2010-05-14
Filing date: 2011-03-03
Publication date: 2011-11-17
Also published as: JP2011243647A

Abstract

Provided is an LED module which enables increased mounting density when a plurality of LED modules are arranged linearly. The LED module (1) is configured by housing an LED chip (2) and a protection element (3) for overvoltage protection inside a concave section (5) of a package (4). An annular conductive pattern (12) that is electrically connected to one LED chip (2) electrode and also used as a surface for joining to an optical lens (30) is disposed on the circumference of the concave section (5) and this conductive pattern (12) is electrically connected to electrode pads (15a, 15b) on the rear surface. A through hole (6) is disposed in the package (4) and the other LED chip (2) electrode is connected via the through hole (6) to an electrode pad (17) disposed on the rear surface of the package (4). The LED chip (2), the protection element (3), and the through hole (6) are disposed side-by-side inside the concave section (5) in the package (4).

Description

LED module

The present invention relates to an LED module.

2. Description of the Related Art Conventionally, there has been provided an ultraviolet irradiation apparatus that irradiates an ultraviolet curable resin such as a paint, an adhesive, or a pigment with ultraviolet rays to cure and dry the resin. In such an ultraviolet irradiation device, a discharge lamp has been used as an ultraviolet irradiation source. However, in recent years, a light emitting diode is used as an ultraviolet irradiation source instead of a discharge lamp for the purpose of reducing power consumption and extending the life. Have been proposed (see, for example, Patent Document 1). In an ultraviolet irradiation device using a light emitting diode, since the light emitting diode is a point light source, when irradiating an object to be irradiated with a line of ultraviolet light, a plurality of light emitting diodes are arranged in a straight line, In the form of ultraviolet light.
Utility Model Registration No. 3151132

As described above, when a plurality of light emitting diodes are linearly arranged and irradiated with line-shaped ultraviolet light, it is necessary to vary the length of the line-shaped ultraviolet light depending on the size of the object to be irradiated. Therefore, UV light emitting diode chips (LED chips) and overvoltage protection protection elements (such as Zener diode chips) are arranged in a straight line in the required number of LED modules and irradiated with line-shaped ultraviolet light. An ultraviolet irradiation device designed to do this has been proposed. In such an ultraviolet irradiation device, in order to improve the ultraviolet irradiation intensity and make the irradiation intensity distribution uniform, there is a demand for mounting the LED modules at a high density in the arrangement direction of the plurality of LED modules. The downsizing of was desired.
The present invention has been made in view of the above problems, and an object of the present invention is to provide an LED module capable of increasing the mounting density when a plurality of lines are arranged in a straight line.
In order to solve the above-described problems, an LED module of the present invention includes an LED chip, a protection element connected in reverse parallel to the LED chip, and an LED chip and a protection in a concave portion formed on an injection molding product. A package on which the element is mounted, and is electrically connected to one electrode of the LED chip on the surface of the package, and used as a joint surface of the optical lens when the optical lens is attached to cover the recess A conductive pattern is provided in the recess, and a through-hole is formed on the inner peripheral surface of the through-hole plating that is electrically connected to the other electrode of the LED chip. The first electrode pad that is electrically connected to the conductive pattern, and the other electrode of the LED chip that is electrically connected through the through hole Second electrode pads are provided to be, in the recess of the package, characterized in that the LED chip and the protective element and the through-holes are provided side by side.
In this LED module, it is also preferable that the LED chip is disposed at the center of the surface of the package, the protective element is mounted on one side with the LED chip in between, and the through hole is provided on the opposite side.
Moreover, in this LED module, ribs that protrude toward the opening side of the recesses are provided at the bottom of the recesses, at the site between the LED chip and the protective element, and between the LED chip and the through hole, respectively. It is also preferable that a bonding pad that is electrically connected to the second electrode pad through a through hole and wire-bonded to the electrode of the LED chip and the protection element through a fine metal wire is preferably provided on the rib.
Further, in this LED module, a bonding pad for bonding to the heat radiating member is provided on the back surface of the package, and a step is provided between the bonding pad and the portion provided with the bonding pad, thereby making the LED module more than the bonding pad. It is also preferable that a recess located on the surface side is provided, and the first and second electrode pads and a through hole are provided in this recess.
Furthermore, in this LED module, it is also preferable that the through hole is provided with a large-diameter portion having a larger diameter than the front-side portion in the opening portion on the back surface side.
Further, in this LED module, a sealing portion that seals the inside of the package by filling the through hole with a sealing resin in a state where the optical lens is bonded so as to cover the concave portion on the surface side of the package Is also preferably provided.
Further, in this LED module, the shape of the concave portion in plan view is a substantially rectangular shape in which the arrangement direction of the LED chip, the protective element, and the through hole is a long side direction, and the concave portion is formed at the corner of the inner side wall of the concave portion. It is also preferable that an overhang portion that projects in the center direction is provided.
Furthermore, in this LED module, the package has a substantially rectangular parallelepiped shape in which the arrangement direction of the LED chip, the protection element, and the through hole is a long side direction, and an anode of the LED chip is provided on one end surface of the package in the long side direction. First and second connection patterns connected to the electrode and the cathode electrode, respectively, are provided, and the other end surface of the package in the long side direction is connected to one of the anode electrode and the cathode electrode of the LED chip. It is also preferable that three connection patterns are provided.
According to the present invention, the size of the package can be shortened in a direction orthogonal to the arrangement direction of the LED chip, the protection element (such as a Zener diode chip) and the through hole, and a plurality of LED modules are arranged linearly in this direction. As a result, a higher mounting density can be realized.

Objects and features of the present invention will become apparent from the following description of the preferred embodiment given in conjunction with the accompanying drawings.
The LED module of this embodiment is shown, (a) is a top view, (b) is AA sectional drawing, (c) is a back view. The package used for an LED module same as the above is shown, (a) is a plan view, (b) is an AA sectional view, (c) is a rear view, and (d) is a BB sectional view. The state which the conductive pattern was formed in the package used for an LED module same as the above is shown, (a) is a top view, (b) is a side view seen from the lower side, (c) is a back view, (d) is a left side. (E) is a side view seen from the right side. The other form of a LED module same as the above is shown, (a) is a side view, (b) is a back view. It is a reverse view of the principal part which shows another form of the LED module same as the above. It is sectional drawing of the principal part which shows another form of the LED module same as the above. (A) (b) is explanatory drawing explaining the wiring method of a some LED module.

Embodiments of the present invention will be described below with reference to the drawings.
The LED module of the present embodiment is used as an ultraviolet irradiation source in an ultraviolet irradiation apparatus that irradiates an ultraviolet curable resin such as a paint, an adhesive, or a pigment with ultraviolet rays to cure and dry the resin.
As shown in FIG. 1, the LED module 1 includes an LED chip 2 and an overvoltage protection protective element (such as a Zener diode chip) 3 that limits a voltage applied to the LED chip 2. It is housed in a recess 5 provided in In the following description, unless otherwise specified, the vertical and horizontal directions are defined in the direction shown in FIG. 1B, and the vertical direction in FIG.
The package 4 is an injection-molded product formed in a substantially rectangular parallelepiped shape with the left-right direction as the longitudinal direction, using a molding material such as ceramics (for example, alumina, aluminum nitride) or plastic (for example, polyphthalamide, liquid crystal polymer, etc.). Composed. Conductive patterns and electrode pads are patterned on the surface of the package 4 by using MID (three-dimensional injection molded circuit component) technology (FIGS. 1A to 1C and 3A to 3). e)).
Further, as shown in FIGS. 1A to 1C and FIGS. 2A to 2D, the surface of the package 4 (the upper surface of FIG. 1B) has a shape viewed from above in the left-right direction. A recess 5 formed in the shape of a long hole with a long side direction is provided. On the bottom of the recess 5, the LED chip 2 is disposed at a central position in the left-right direction and the front-rear direction of the package 4. Further, at the bottom of the recess 5, the protective element 3 is disposed on one end side (for example, the right side) in the left-right direction with respect to the LED chip 2, and a through hole 6 described later is provided on the other end side (left side) in the left-right direction. Yes. Here, the bottom of the recess 5 protrudes from the portion between the LED chip 2 and the protective element 3 and the portion between the LED chip 2 and the through hole 6 toward the opening side (upper side) of the recess 5.

Ribs

7a and 7b are provided. These

ribs

7 a and 7 b are provided between the inner walls of the recess 5 facing the short width direction (front-rear direction) of the package 4. Therefore, the bottom of the recess 5 is divided by the

ribs

7a and 7b into a region 5a where the LED chip 2 is mounted, a region 5b where the protective element 3 is mounted, and a region 5c where the through hole 6 is provided. . Note that the upper surfaces of the

ribs

7a and 7b are located above the upper surface of the LED chip 2 mounted in the region 5a (see FIG. 1B).
Further, a recess 8 is provided on the back surface of the package 4 (the lower surface in FIG. 2B) from the left end of the package 4 to the area beyond the through hole 6. A step is provided between the recess 8 and another part on the back surface of the package 4, and the bottom surface of the recess 8 is located above the back surface of the package 4 (excluding the recess 8).
By the way, the LED chip 2 and the protection element 3 have electrodes on both upper and lower surfaces. In this embodiment, as shown in FIG. 3A, in the

regions

5a and 5b, a die pad portion 10 to which the lower surface electrode (anode electrode) of the LED chip 2 and the lower surface electrode (cathode electrode) of the protection element 3 are die-bonded, respectively. , 11 are formed. The

die pad portions

10 and 11 may be die-bonded so that the lower surface electrode of the LED chip 2 becomes the cathode electrode and the lower surface electrode of the protection element 3. On the surface of the package 4, a frame-like conductive pattern 12 is formed around the periphery of the recess 5, and this conductive pattern 12 is provided continuously with the above-described

die pad portions

10 and 11. A connection pattern 14 a extending from the conductive pattern 12 is formed on one end surface (for example, the left end surface) of the package 4 in the longitudinal direction, and further extended from the connection pattern 14 a to the back surface of the package 4. Thus, an electrode pad 15a is formed. A connection pattern 14b extending from the conductive pattern 12 is also formed on the other end surface (for example, the right end surface) of the package 4 in the longitudinal direction. The connection pattern 14b is further extended from the connection pattern 14b to the back surface of the package 4 to form an electrode pad. 15b is formed.
The rib 7a is formed with a bonding pad 13a to which the upper electrode (cathode electrode) of the LED chip 2 and the upper electrode (anode electrode) of the protection element 3 are connected via bonding wires (metal thin wires) 9a and 9b, respectively. ing. Similarly, a bonding pad 13b is formed on the rib 7b to connect the upper surface electrode (cathode electrode) of the LED chip 2 via a bonding wire (metal thin wire) 9c. In addition, a conductive pattern 22 electrically connected to the through hole 6 is formed in almost the entire region 5c. The conductive pattern 22 is continuous with the

bonding pads

13a and 13b formed on the

ribs

7a and 7b. Is provided.
The through-hole 6 opens into a recess 8 provided on the back surface of the package 4, the through-hole plating 6 a is applied to the inner peripheral surface, and the electrode pad 17 provided outside the recess 8 is electrically connected via the conductive pattern 18. Connected. Therefore, the conductive pattern 22 provided on the front surface of the package 4 is electrically connected to the electrode pad 17 provided on the back surface through the through hole 6. Here, the recess 8 is provided at the center in the front-rear direction on the back surface on one end side in the longitudinal direction of the package 4, and the electrode pad 15 a and the electrode pad 17 are arranged on both front and rear sides across the recess 8. Yes. Further, a connection pattern 16 is provided so as to extend from the electrode pad 17 to one end surface in the longitudinal direction of the package 4.
Thus, on the back surface of the package 4, the

electrode pads

15 a and 15 b (first electrode pads) connected to the anode electrode of the LED chip 2 and the electrode pads 17 (second electrode) connected to the cathode electrode of the LED chip 2. Electrode pad). Further, a connection pattern 14a connected to the anode electrode of the LED chip 2 and a connection pattern 16 connected to the cathode electrode are provided on the end face on one end side in the longitudinal direction of the package 4 (left side in the present embodiment). Yes. On the other hand, only the connection pattern 14 b connected to the anode electrode of the LED chip 2 is provided on the end surface on the other end side (right side) in the longitudinal direction of the package 4.
In addition, on the back surface of the package 4, a rectangular plate-shaped bonding pad 19 for bonding to, for example, a metal heat dissipating member 19 a is provided in the central portion in the left-right direction.
An optical lens 30 may be attached to the upper surface of the package 4 as shown by an imaginary line in FIG. The optical lens 30 is attached to the package 4 by an appropriate method such as adhesion or AuSn bonding. Here, in order to improve the airtightness of the joint portion between the package 4 and the optical lens 30, it is necessary to flatten the joint portion of the optical lens 30 on the surface of the package 4. Therefore, in the present embodiment, an annular conductive pattern 12 is formed on the periphery of the recess 5 and this conductive pattern 12 is used as an adhesive surface or a bonding surface. However, when the lenses are bonded using an adhesive, bonding is possible even if the conductive pattern 12 is not provided in a ring shape at the peripheral edge of the recess. When the lens is bonded by metal bonding other than the adhesive, the annular conductive pattern 12 must be provided on the peripheral edge of the recess. Then, after the optical lens 30 is attached to the surface of the package 4, the inside of the package 4 is kept airtight when the sealing portion 20 is provided by filling the through hole 6 with the sealing resin from the back surface side. It is drunk.
The optical lens 30 is formed in an oval shape with the left-right direction as a long side when viewed from above, and the corners are rounded so as to obtain desired light distribution characteristics. Therefore, if the corner of the inner wall of the recess 5 is formed at a substantially right angle, a gap is generated between the corner of the recess 5 and the optical lens 30 when the optical lens 30 is attached to the package 4. , Airtightness may be impaired. Therefore, in the present embodiment, as shown in FIG. 2A, the overhanging portion 21 that protrudes toward the center of the concave portion 5 is formed at the corner portion of the inner wall of the concave portion 5 rather than the corner portion when formed in a rectangular shape. The overhanging portion 21 is obliquely intersected with the inner wall of the recess 5. Therefore, even when the oval optical lens 30 is bonded to the surface side of the package 4, the protruding portion 21 contacts the arc-shaped corner of the optical lens 30, so that the optical lens is formed at the corner of the recess 5. 30 can be reliably closed. Further, the package 4 is molded by injection molding. However, by forming the overhanging portion 21 that obliquely intersects with the inner surface of the recess 5, it is possible to improve the releasability from the molding die.
The LED module 1 of the present embodiment has the above-described configuration, and the LED chip 2, the protective element 3, and the through hole 6 are provided side by side inside the recess 5 of the package 4.
Thereby, the width dimension of the package 4 can be reduced in the direction orthogonal to the arrangement direction of the LED chip 2, the protection element 3, and the through hole 6. Therefore, when a plurality of LED modules 1 are arranged in a straight line and irradiated with line light, if the plurality of LED modules 1 are arranged in a direction orthogonal to the arrangement direction, the LED modules 1 can be arranged with high density, and ultraviolet rays are emitted. The irradiation intensity can be improved and the irradiation intensity distribution can be made uniform.
Further, the LED chip 2 is disposed at the center of the surface of the package 4 (the center position in the left-right direction and the front-rear direction), and the protective element 3 is disposed on one side with respect to the LED chip 2 and on the opposite side to the LED chip 2. A through-hole 6 is provided in the front.
Thus, since the LED chip 2 is disposed at the center of the surface of the package 4, the center of the optical axis of the LED chip 2 is located at the center of the surface of the package 4, and the optical axis of the LED chip 2 is mounted when the package 4 is mounted. There is an effect that it is easy to align.
In addition,

ribs

7 a and 7 b that protrude toward the opening side of the concave portion 5 are provided at the bottom portion of the concave portion 5 at the portion between the LED chip 2 and the protective element 3 and the portion between the LED chip 2 and the through hole 6. It has been. The

ribs

7a and 7b are provided with

bonding pads

13a and 13b that are electrically connected to the electrode pads 17 through the through holes 6. The electrodes of the LED chip 2 and the protection element 3 are wire bonded to the

bonding pads

13a and 13b via bonding wires 9a to 9c.
As described above, since the

bonding pads

13a and 13b are formed on the

ribs

7a and 7b protruding from the bottom of the recess 5, even if the package 4 is small, there is an advantage that the bonding head can easily enter during wire bonding. is there. Further,

ribs

7a and 7b that are taller than the upper surface of the LED chip 2 are provided on both sides of the LED chip 2, so that the

rib

7a and 7b allow the LED chip 2 to protect the protective element 3 and the through-hole 6 from each other. It is possible to block light sneaking to the side. Further, in order to efficiently release the heat generated by the LED chip 2 to the heat radiating member 19a to which the package 4 is attached, it is preferable to form the package 4 thin. However, the rib 7a reduces the strength of the package 4 due to the thinning. 7b can be reinforced. Further, by providing the

ribs

7a and 7b, the package 4 is less likely to warp, and the flatness of the back surface can be increased. Furthermore, when the sealing material for sealing the through hole 6 flows to the LED chip 2 side, there is a possibility of affecting the optical characteristics, but the rib 7b blocks the sealing material from flowing to the LED chip 2 side. The optical influence of the sealing material can be suppressed.
In the present embodiment, a bonding pad 19 for bonding to the heat dissipation member 19 a is provided on the back surface of the package 4, and a portion where the bonding pad 19 is provided and the recess 8 in which the through hole 6 is opened. There is a step between them. Therefore, the bottom surface of the recess 8 where the through hole 6 is opened is located above the back surface of the package 4 provided with the bonding pad 19, and the opening portion of the through hole 6 and the bonding pad 19 are provided. There is a gap between them. Here, in this embodiment, the

electrode pads

15a and 17 are provided outside the recess 8. However, as shown in FIGS. It is also preferable to provide a recess 8a continuous with the recess 8a between the portion where the pad 19 is provided. By forming the conductive pattern 18 connecting the through hole 6 and the electrode pad 17 in the recess 8a, the possibility that the bonding pad 19 and the conductive pattern 18 are short-circuited can be reduced. In addition, by providing the recess 8a, the periphery of the portion where the

electrode pads

15a and 17 are formed is surrounded by the

recesses

8 and 8a, thereby reducing the possibility that the

electrode pads

15a and 17 and the bonding pad 19 are short-circuited. You can also.
Moreover, it is also preferable to provide the first and

second electrode pads

15a and 17 and the through hole 6 in the recess 8 as shown in FIG.
Accordingly, the

electrode pads

15a and 17 and the through hole 6 are provided in the recess 8 having a step with the back surface of the package 4, so that the

electrode pads

15a and 17 and the through hole 6 and the bonding pad provided on the back surface are provided. An insulation distance from 19 can be ensured. In addition, since the solder bonding pad for soldering the

electrode pads

15a and 17 to the mounted portion is provided at a portion facing the recess 8, the

electrode pad

15a or 17 and the bonding pad 19 are connected to the solder bonding pad. It is possible to reduce the possibility of short-circuiting via.
In the present embodiment, the inner diameter of the through hole 6 is formed to be substantially constant. However, as shown in FIG. 6, the through hole 6 has an opening portion on the back surface side, as compared with the front side portion (small diameter portion 6 a). It is also preferable to provide a large-diameter portion 6b having a large diameter.
As a result, when the sealing resin is filled in the through hole 6 and the small-diameter portion 6a is sealed, the sealing resin hardly protrudes outward from the large-diameter portion 6b, and the bonding pad 19 provided on the back surface. And the possibility that the sealing material is short-circuited.
By the way, when the optical lens 30 is bonded to the front surface side of the package 4, if the through hole 6 is sealed before bonding, the inside of the package 4 has a high pressure due to the heat generated in the bonding process of the optical lens 30. There is a possibility. Therefore, it is preferable to seal the through hole 6 in a state where the optical lens 30 is bonded to the package 4 after the optical lens 30 is bonded to the surface side of the package 4. Thereby, when the optical lens 30 is bonded to the package 4, the through-hole 6 is opened, so that the internal pressure of the package 4 does not increase due to the influence of heat generated in the bonding process of the optical lens 30.
In the present embodiment, the first and

second connection patterns

14a and 16 connected to the anode electrode and the cathode electrode of the LED chip 2 are provided on one end surface (left end surface) of the package 4 in the long side direction. ing. A third connection pattern 14 b connected to the anode electrode of the LED chip 2 is provided on the other end surface (right end surface) of the package 4 in the long side direction.
Thereby, when a plurality of LED modules 1 are arranged side by side in the short side direction of the package 4 as shown in FIG. 7A, the connection patterns 14a of the LED modules 1 arranged adjacent to each other are arranged. The plurality of LED modules 1 can be connected in series by electrically connecting the 16 via the wiring pattern 41 provided on the mounted portion side. Further, as shown in FIG. 7B, the connection pattern 14b provided on one end side in the long side direction is commonly connected to the wiring pattern 42 on the mounted portion side and provided on the other end side in the long side direction. The plurality of LED modules 1 can be connected in parallel by commonly connecting the connection pattern 16 thus formed to the wiring pattern 43 on the connected portion side. Therefore, a plurality of LED modules 1 arranged in a straight line can be connected in series or in parallel using the

connection patterns

14a, 14b, 16 provided on the side surface of the package 4, and according to the usage pattern. The wiring format can be freely selected.
Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these specific embodiments, and various changes and modifications can be made without departing from the scope of the following claims. Can be said to belong to the scope of the present invention.

Claims

An LED chip;
A protective element connected in reverse parallel to the LED chip;
A package comprising the LED chip and the protection element mounted in a recess made of an injection molded product and provided on the surface;
On the surface of the package, a conductive pattern electrically connected to one electrode of the LED chip is provided in the recess,
Through holes are provided on the inner peripheral surface of through hole plating that penetrates the package on the front and back and is electrically connected to the other electrode of the LED chip,
A first electrode pad electrically connected to the conductive pattern and a second electrode pad electrically connected to the other electrode of the LED chip through the through hole are provided on the back surface of the package. Provided,
The LED module, wherein the LED chip, the protection element, and the through hole are provided side by side in the recess of the package.
2. The LED chip is disposed at the center of the surface of the package, the protection element is mounted on one side with the LED chip in between, and the through hole is provided on the opposite side. LED module.
Ribs that protrude toward the opening side of the recess are provided at the bottom of the recess, at the site between the LED chip and the protective element, and at the site between the LED chip and the through hole, respectively.
These ribs are provided with bonding pads that are electrically connected to the second electrode pads through the through holes, and the electrodes of the LED chip and the protective element are wire bonded through bonding wires. The LED module according to claim 2.
A bonding pad for bonding to the heat dissipation member is provided on the back surface of the package, and a step is provided between the bonding pad and the portion where the bonding pad is provided, so that the package is positioned on the front surface side of the bonding pad. A recess is provided,
4. The LED module according to claim 1, wherein the first and second electrode pads and the through hole are provided in the recess. 5.
5. The LED module according to claim 1, wherein the through-hole is provided with a large-diameter portion having a diameter larger than that of the front-side portion in the opening portion on the back surface side. .
The LED module further includes an optical lens attached to the front surface side of the package so as to cover the concave portion, and the optical lens is attached to the concave portion with the conductive pattern as a joining surface, and the optical lens is joined. The sealing part which seals the inside of the said package by being filled with sealing resin in the said through hole in the state was provided in any one of Claim 1 thru | or 5 characterized by the above-mentioned. LED module.
The shape of the recess in plan view is a substantially rectangular shape in which the arrangement direction of the LED chip, the protection element, and the through hole is a long side direction, and the center of the recess is formed at a corner of the inner wall of the recess The LED module according to any one of claims 1 to 6, wherein an overhang portion that projects in a direction is provided.
The package has a substantially rectangular parallelepiped shape in which the arrangement direction of the LED chip, the protection element, and the through hole is a long side direction,
On one end surface of the package in the long side direction, first and second connection patterns connected to the anode electrode and the cathode electrode of the LED chip are provided,
The third connection pattern connected to one of an anode electrode and a cathode electrode of the LED chip is provided on the other end surface of the package in the long side direction. The LED module according to any one of the above.