Chip-on-board packaging light source

Abstract

The utility model discloses a chip-on-board packaging light source, which relates to the technical field of light sources and comprises a substrate, a box dam, an adhesive coating layer, a plurality of first wafers, a plurality of second wafers, a plurality of adhesive drawing strips and a plurality of retaining walls. A plurality of first wafers are fixedly arranged in each first subarea side by side, a plurality of second wafers are fixedly arranged in each second subarea side by side, the painting adhesive tapes are in one-to-one correspondence with the first subareas, the painting adhesive tapes fixedly cover the first wafers of the first subareas, and retaining walls are fixedly arranged between any adjacent painting adhesive tape and the second subarea; the glue coating layer fixedly covers the painting glue strips, the retaining walls and the second wafers, and the box dam surrounds the glue coating layer and is fixedly arranged on the top surface of the substrate; according to the utility model, the matching in the trial matching process is more accurate, the matching release speed is improved, the yield in the mass production process is improved, the light color uniformity of a finished product is improved, and the light quality of the finished product is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to light source technical field, especially a kind of chip-on-board package light source. BACKGROUND

[0002] COB (full name Chips on Board) surface light source, i.e. chip-on-board package light source, is to transfer and attach semiconductor chip on printed circuit board, and the electrical connection of chip and substrate is realized by lead stitching method, and resin is covered to ensure reliability. COB surface light source coming from COB packaging form is also called COB light source, COB planar light source, COB integrated light source or ceramic COB light source.

[0003] Benefiting from the cost reduction of intelligent lighting, the increasing demand of terminal consumers for intelligent lighting system, and the development of intelligent lighting industry, adjustable color temperature COB light source is the most suitable product for the development of intelligent lighting industry.

[0004] The forward mounting drawing glue process is the most widely used implementation method for the current forward mounting double-color COB light source product due to its high efficiency, small process implementation difficulty, easy control, less raw material waste and high yield.

[0005] The forward mounting drawing glue process of the forward mounting double-color COB light source needs die bonding, wire welding and dam before dispensing. Due to the need of low color temperature fluorescent glue drawing, the wafer is arranged in a straight line in the mirror aluminum functional area during die bonding. In the dispensing process: first, mix the low color temperature fluorescent powder needed by the low color temperature fluorescent glue with high viscosity and high thixotropy to obtain the low color temperature fluorescent glue, linearly coat the low color temperature fluorescent glue on the wafer for presenting low color temperature light output and high temperature baking for preforming, then dispense the high color temperature fluorescent glue obtained by mixing the fluorescent powder needed by the high color temperature with the glue of conventional viscosity (the mixed viscosity of single glue is usually 3000-8000 mPa.s) and flow flat, and then complete baking.

[0006] When the wafer corresponding to the low color temperature fluorescent glue is lit, low color temperature light is presented, and when the wafer not covered by the low color temperature fluorescent glue is lit, high color temperature light is presented. By using PWM dimming mode, the light color adjustment between high and low color temperature is realized by changing the current ratio of high and low color temperature channels.

[0007] The current forward mounting drawing glue process of the forward mounting double-color COB light source is prone to the problem that the low color temperature fluorescent glue is attached to the adjacent wafer not covered by the low color temperature fluorescent glue (especially after high temperature baking) during drawing glue, which leads to uneven light color or light color not in the required color zone. This problem, if it occurs during trial ratio, will affect the accuracy of ratio and the period required for trial ratio, and if it occurs during mass production, will reduce the color zone yield of production, and the uniformity of finished product light color will also be affected. UTILITY MODEL CONTENTS

[0008] The utility model discloses a chip on board package light source provides to solve the problem of above -mentioned prior art, can make the process of trial production more accurate, improve the release speed of proportioning, improve the yield of mass production process, improve the finished product light color uniformity, improve the light quality of finished product.

[0009] To achieve the above object, the utility model provides the following scheme:

[0010] The utility model provides a chip on board package light source, including substrate, dam, glue layer, a plurality of first wafer, a plurality of second wafer, a plurality of draw glue strip and a plurality of retaining wall, the top of substrate has functional area, the functional area includes a plurality of first subarea and a plurality of second subarea, the first subarea with the second subarea is set side by side, each first subarea is set side by side, each second subarea is set side by side, each first subarea is fixed and is equipped with a plurality of first wafer side by side, each second subarea is fixed and is equipped with a plurality of second wafer side by side, the number of draw glue strip is equal with the number of first subarea, draw glue strip with first subarea one to one corresponds, draw glue strip is fixed and covers on first wafer of first subarea, and the draw glue strip with second subarea between any adjacent is fixed and is equipped with retaining wall, glue layer is fixed and covers each draw glue strip, each retaining wall and each second wafer, and the dam is fixed on the top of substrate around glue layer.

[0011] Preferably, each first subarea and each second subarea are staggered.

[0012] Preferably, the substrate is a ceramic plate.

[0013] Preferably, the top of the substrate is fixedly provided with a solder pad layer, and the solder pad layer is covered by the dam.

[0014] Preferably, the substrate is a mirror surface aluminum plate.

[0015] Preferably, the top of the substrate is fixedly provided with an insulating layer, the top of the insulating layer is fixedly provided with a solder pad layer, and the solder pad layer is covered by the dam.

[0016] Preferably, the top of the retaining wall is higher than the top of the second wafer.

[0017] Preferably, the top of the retaining wall is lower than the top of the draw glue strip.

[0018] Preferably, the retaining wall is a glue wall.

[0019] Preferably, the retaining wall is divided into a plurality of layers from bottom to top.

[0020] Compared with the prior art, the utility model has the following technical effects:

[0021] The chip-on-board packaging light source provided by the utility model, the drawing glue strip is obtained through drawing glue operation by using low-color-temperature fluorescent glue, the glue covering layer is obtained through point glue operation by using high-color-temperature fluorescent glue, the first wafer and the drawing glue strip are used for presenting low-color-temperature light emission, the second wafer is used for presenting high-color-temperature light emission, the baffle is fixedly arranged between any adjacent drawing glue strip and the second partition, the diffusion range of the low-color-temperature fluorescent glue in the drawing glue operation process is limited through the baffle, the low-color-temperature fluorescent glue is prevented from diffusing to the second partition, the second wafer in the second partition is effectively protected, the second wafer in the second partition is prevented from being contaminated by the low-color-temperature fluorescent glue, so that the matching in the trial process can be more accurate, the matching release speed is improved, the yield in the mass production process is improved, the light color uniformity of the finished product is improved, and the light quality of the finished product is improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without creative labor.

[0023] Figure 1 The schematic diagram of the chip-on-board packaging light source provided by the utility model is shown in the figure.

[0024] In the figure, 1 is a substrate, 2 is a dam, 3 is a glue covering layer, 4 is a first wafer, 5 is a second wafer, 6 is a drawing glue strip, 7 is a baffle, and 8 is an insulating layer. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model, and obviously, the described embodiments are only some embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

[0026] The utility model aims at providing a kind of chip-on-board packaging light source, to solve the problems existing in the prior art described above, can make the matching in the trial process more accurate, improve the matching release speed, improve the yield in the mass production process, improve the light color uniformity of finished product, improve the light quality of finished product.

[0027] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the utility model will be further described in detail with reference to the drawings and specific embodiments.

[0028] Embodiment one

[0029] As Figure 1 shown, the embodiment provides a chip-on-board packaged light source, comprising a substrate 1, a dam 2, a glue layer 3, a plurality of first dies 4, a plurality of second dies 5, a plurality of glue lines 6, and a plurality of barriers 7. The top surface of the substrate 1 has a functional area, which comprises a plurality of first sub-areas and a plurality of second sub-areas. The first sub-areas and the second sub-areas are arranged side by side. Each first sub-area is arranged side by side, and each second sub-area is arranged side by side. Each first sub-area is fixedly provided with a plurality of first dies 4 side by side, and each second sub-area is fixedly provided with a plurality of second dies 5 side by side. The number of glue lines 6 is equal to the number of first sub-areas, and each glue line 6 corresponds to a first sub-area. The glue line 6 is fixedly covered on the first dies 4 of the first sub-area. The barrier 7 is fixedly arranged between any adjacent glue line 6 and second sub-area. The glue layer 3 is fixedly covered on each glue line 6, each barrier 7, and each second die 5. The dam 2 is fixedly arranged on the top surface of the substrate 1 around the glue layer 3.

[0030] The chip-on-board packaged light source provided by the embodiment uses low-color-temperature fluorescent glue to obtain the glue lines 6 through drawing glue operation, and uses high-color-temperature fluorescent glue to obtain the glue layer 3 through dispensing glue operation. The first dies 4 and the glue lines 6 are used to present low-color-temperature light emission, and the second dies 5 are used to present high-color-temperature light emission. The barrier 7 is fixedly arranged between any adjacent glue line 6 and second sub-area to limit the diffusion range of the low-color-temperature fluorescent glue during the drawing glue operation, so as to avoid the diffusion of the low-color-temperature fluorescent glue to the second sub-area, effectively protect the second dies 5 in the second sub-area, and avoid the second dies 5 in the second sub-area from being contaminated by the low-color-temperature fluorescent glue. Therefore, the matching process can be more accurate, the matching release speed can be improved, the yield in the mass production process can be improved, the light color uniformity of the finished product can be improved, and the light quality of the finished product can be improved.

[0031] As a more preferred embodiment of the embodiment, the first sub-areas and the second sub-areas are staggered, which can improve the light color uniformity of the finished product.

[0032] As a more preferred embodiment of the embodiment, the substrate 1 is a mirror aluminum plate, which has high light efficiency and an attractive appearance.

[0033] Further, the top surface of the substrate 1 is fixedly provided with an insulating layer 8, and the top surface of the insulating layer 8 is fixedly provided with a pad layer. The pad layer is covered by the dam 2. By arranging the insulating layer 8, the pad layer is prevented from being conductive with the substrate 1, and the use stability is improved.

[0034] Further, the top surface of the barrier 7 is higher than the top surface of the second die 5, so as to effectively protect the second die 5.

[0035] Further, the top surface of the barrier 7 is lower than the top surface of the glue line 6, so as to reduce the interference of the barrier 7 on the light emission effect.

[0036] As a more preferred embodiment of the present embodiment, the retaining wall 7 is a glue wall, which is convenient to make.

[0037] As a more preferred embodiment of the present embodiment, the retaining wall 7 is divided into several layers from bottom to top, which is suitable for the case that the gap between the adjacent first wafer 4 and the second wafer 5 is small. The retaining wall 7 is obtained by dispensing glue several times from bottom to top.

[0038] A more preferred preparation method of the chip-on-board packaged light source provided by the present embodiment is as follows:

[0039] Take the semi-finished light source with the die-bonding wire and the dam 2, take glue with high viscosity and high thixotropy index, which can be single-component glue or double-component glue, and can be transparent glue or milky white glue, select a suitable dispensing needle head according to the gap between the adjacent first wafer 4 and the second wafer 5, draw the retaining wall 7 between the adjacent first wafer 4 and the second wafer 5 using a dispensing machine or a dam 2 machine, and bake it after drawing. If the gap between the adjacent first wafer 4 and the second wafer 5 is small and the thickness of the first wafer 4 and the second wafer 5 is thick, a dispensing needle head with a smaller diameter needs to be selected. At this time, if the height of the retaining wall 7 drawn at one time cannot be higher than the thickness of the first wafer 4 and the second wafer 5, the height of the retaining wall 7 can be increased by drawing multiple layers. After the retaining wall 7 is completed, draw low-color-temperature fluorescent glue, and then bake it to obtain the glue strip 6. The thickness of the low-color-temperature fluorescent glue is higher than the height of the retaining wall 7. Point high-color-temperature fluorescent glue to the entire functional area. If no fluorescent powder sedimentation is required, directly bake it. If sedimentation is required, realize the sedimentation of the fluorescent powder through centrifugal or thermal sedimentation after the glue is leveled, and then bake it to obtain the glue coating layer 3.

[0040] Specific implementation case 1: The gap between the adjacent first wafer 4 and the second wafer 5 is 0.5 mm, the thickness of the first wafer 4 and the second wafer 5 is 0.2 mm, and high-thixotropy glue with a viscosity of 30000 CPS is selected to draw the retaining wall 7. The gap between the adjacent first wafer 4 and the second wafer 5 is large enough. By adjusting the height of the needle head of the dam 2 machine or the dispensing machine and the dispensing air pressure and speed, the width of the retaining wall 7 can be 0.3 mm and the height can be 0.35 mm at one time. The height of the low-color-temperature fluorescent glue is 0.55 mm and the height of the high-color-temperature fluorescent glue is 0.8 mm.

[0041] Specific implementation case 2: the interval between the adjacent first wafer 4 and the second wafer 5 is 0.25mm, the thickness of the first wafer 4 and the second wafer 5 is 0.3mm, the high thixotropic glue with viscosity of 30000CPS is selected as the dam wall 7, the interval between the adjacent first wafer 4 and the second wafer 5 is narrow, the width of the dam wall 7 is 0.15mm, the height of the dam wall 7 can only reach 0.2mm through one time of drawing, and the height of 0.4mm of the dam wall 7 is realized through 2 to 3 times of drawing; the height of the low color temperature fluorescent glue is 0.6mm, and the height of the high color temperature fluorescent glue is 0.8mm.

[0042] Embodiment two

[0043] The embodiment provides a chip-on-board packaging light source, and only the material of the substrate 1 is different from that of the chip-on-board packaging light source in the embodiment one.

[0044] Further, the top surface of the substrate 1 is fixedly provided with a pad layer, and the pad layer is covered by the dam 2, so that the structure is simple and convenient to manufacture.

[0045] The principle and implementation mode of the utility model are described by applying specific examples in the utility model, and the above embodiment is only used for helping to understand the method and core idea of the utility model; meanwhile, for the general technical personnel in the field, the specific implementation mode and application range will be changed according to the idea of the utility model. In conclusion, the content of the specification should not be understood as the limitation of the utility model.

Claims

1. A chip-on-board packaged light source, characterized by: The application relates to a substrate, a dam, a glue layer, a plurality of first wafers, a plurality of second wafers, a plurality of glue strips and a plurality of retaining walls, wherein the top surface of the substrate is provided with a functional area, the functional area comprises a plurality of first subareas and a plurality of second subareas, the first subareas and the second subareas are arranged side by side, each first subarea is arranged side by side, each second subarea is arranged side by side, a plurality of first wafers are fixedly arranged side by side in each first subarea, a plurality of second wafers are fixedly arranged side by side in each second subarea, the number of the glue strips is equal to the number of the first subareas, the glue strips correspond to the first subareas one by one, the glue strips are fixedly covered on the first wafers of the first subareas, the retaining walls are fixedly arranged between any adjacent glue strips and the second subareas, the glue layer is fixedly covered on each glue strip, each retaining wall and each second wafer, and the dam is fixedly arranged on the top surface of the substrate and surrounds the glue layer.

2. The chip-on-board packaged light source of claim 1, wherein: Each first subarea and each second subarea are arranged alternately.

3. The chip-on-board packaged light source of claim 1, wherein: The substrate is a ceramic plate.

4. The chip-on-board packaged light source of claim 3, wherein: A pad layer is fixedly arranged on the top surface of the substrate, and the pad layer is covered by the dam.

5. The chip-on-board packaged light source of claim 1, wherein: The substrate is a mirror surface aluminum plate.

6. The chip-on-board packaged light source of claim 5, wherein: An insulating layer is fixedly arranged on the top surface of the substrate, a pad layer is fixedly arranged on the top surface of the insulating layer, and the pad layer is covered by the dam.

7. The chip-on-board packaged light source of claim 1, wherein: The top surface of the retaining wall is higher than the top surface of the second wafer.

8. The chip-on-board packaged light source of claim 7, wherein: The top surface of the retaining wall is lower than the top surface of the glue strip.

9. The chip-on-board packaged light source of claim 1, wherein: The retaining wall is a glue wall.

10. The chip-on-board packaged light source of claim 9, wherein: The retaining wall is divided into a plurality of layers from bottom to top. The retaining wall is divided into a plurality of layers from bottom to top.

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