CN217280763U

CN217280763U - Small-size thickened LED chip structure

Info

Publication number: CN217280763U
Application number: CN202123093213.8U
Authority: CN
Inventors: 陶燕兵; 刘跃斌; 盛刚; 陶韵; 李凯; 彭嘉彬
Original assignee: Changzhou Amicc Optoelectronics Technology Co ltd
Current assignee: Changzhou Amicc Optoelectronics Technology Co ltd
Priority date: 2021-12-10
Filing date: 2021-12-10
Publication date: 2022-08-23
Anticipated expiration: 2031-12-10

Abstract

The utility model discloses a LED chip structure of small-size thickening, two first pads set up the bottom surface at the base plate, two second pads set up the top surface at the base plate, it has two vertical through-holes to open on the base plate, it has electrically conductive heat conduction substrate all to fill in two vertical through-holes, the LED chip passes through the welding agent and welds the upper surface at two second pads, the one side of keeping away from the second pad at the LED chip is pasted to the silica gel piece, the encapsulation is glued the encapsulation and is filled at the second pad, the LED chip, the silica gel piece around and the upper surface of base plate, and encapsulation glue flushes with the silica gel piece upper surface. The utility model discloses a CSP correlation technique, the characteristics that its size of make full use of is little adapt to the miniaturized requirement of current electronic components, through the transformation to the chip pad simultaneously, under the prerequisite that does not influence length and wide size, has increased the thickness of LED flash light, makes its play plain noodles uprise to solve at present because the mainboard is too far away from cell phone case light-emitting port, can't throw away the problem of light.

Description

Small-size thickened LED chip structure

Technical Field

The utility model relates to a LED chip structure of small-size thickening belongs to LED components and parts.

Background

The existing LED products, especially the LED products applied to household electrical appliance digital products, have the characteristics of smaller and smaller size and more functions. For example, in the mobile phone industry, as the functions of mobile phones increase and the battery endurance increases, more and more devices are mounted on the main board. But the space of the mainboard is smaller and smaller due to the increase of the battery. Further shrinking of all electronic components, especially LED flashlights, is required to allow for more additional electronic components to be mounted. However, as the battery is enlarged and thickened, the upper part of the main board is farther away from the mobile phone shell, which causes that the LED flash lamp which is a device needing to emit light to the external space cannot project the light because the LED flash lamp is far away from the light outlet of the mobile phone shell. In order to project light, the LED flash lamp needs to be heightened to be closer to a light outlet of a mobile phone shell, so as to obtain a better light-emitting effect. However, due to the structural particularity of the LED flashlight, the increase of the thickness of the LED flashlight will inevitably increase the length and width dimensions of the LED flashlight, which is inconsistent with the requirement that the size of the electronic component is initially required to be smaller and smaller, and this contradiction greatly affects the performance of the functions of the mobile phone.

SUMMERY OF THE UTILITY MODEL

For solving not enough among the prior art, the utility model provides a small-size thickening chip structure adopts the relevant technique of CSP, and the small-size characteristics of its size of make full use of adapt to the miniaturized requirement of current electronic components, through the transformation to the chip pad simultaneously, under the prerequisite that does not influence length and wide size, increased the thickness of LED flash light, make its play plain noodles uprise to solve at present because the mainboard is too far away from cell-phone shell light-emitting mouth, can't throw away the problem of light.

The utility model discloses the technical scheme who mainly adopts among does:

a small-size thickened LED chip structure comprises a substrate, two first bonding pads, two second bonding pads, an LED chip, a silica gel sheet and packaging adhesive, wherein the two first bonding pads are arranged on the bottom surface of the substrate and are symmetrically arranged at intervals, the two second bonding pads are arranged on the top surface of the substrate and are symmetrically arranged at intervals, the vertical symmetrical center line of the two first bonding pads is overlapped with the vertical symmetrical center lines of the two second bonding pads, the substrate is provided with two vertical through holes which are symmetrically arranged on two sides of the vertical symmetrical center line of the two first bonding pads, the two vertical through holes are filled with a heat-conducting base material, the LED chip is welded on the upper surfaces of the two second bonding pads through a welding agent, and the silica gel sheet is attached to one side of the LED chip, which is far away from the second bonding pads, the packaging glue is packaged and filled around the second bonding pad, the LED chip and the silica gel sheet and on the upper surface of the substrate, and the packaging glue is flush with the upper surface of the silica gel sheet.

Preferably, a copper substrate is electroplated in each hole of each vertical through hole, so as to form an electrically and thermally conductive copper cylinder, and two ends of the copper cylinder are respectively contacted with the first bonding pad and the second bonding pad.

Preferably, the second pads are in a trapezoid structure, and the short sides of the trapezoids of the two second pads are arranged in parallel relatively.

Preferably, the second bonding pad is of a boss structure, and bosses of the two second bonding pads are arranged in parallel relatively.

Preferably, the solder is solder paste.

Preferably, the silica gel sheet is a silica gel sheet mixed with fluorescent powder.

Preferably, the length of the silica gel sheet is 0.01-10mm longer than that of the LED chip, and the width of the silica gel sheet is 0.01-10mm longer than that of the LED chip.

Preferably, the packaging adhesive is white silica gel.

Preferably, the substrate is an FR4 board, a CEM-3 board or a BT board.

Has the advantages that: the utility model provides a small-size thickening chip structure has following advantage:

1. the utility model can change the thickness of the product according to the requirement at any time without changing the length and width and ensuring the luminous efficiency, and has high flexibility;

2. the utility model changes the size of the bonding pad of the body according to the design requirements of customers, is convenient to use and has stronger compatibility;

3. the utility model can change the length and width of the product at any time by adopting a cutting mode, and is not influenced by the structure of the base plate;

4. the structure of the traditional bonding pad is changed, chip position correction is realized during welding, and the LED chip is aligned in the center.

Drawings

Fig. 1 is a front view of step S1 of the present invention;

fig. 2 is a top view of step S1 according to the present invention (the second pad is a bump structure);

fig. 3 is a bottom view of step S1 of the present invention;

fig. 4 is a front view of step S2 in the present invention;

fig. 5 is a top view of step S2 in the present invention;

fig. 6 is a front view of step S3 in the present invention;

fig. 7 is a top view of step S3 according to the present invention;

fig. 8 is a front view of step S4 in the present invention;

fig. 9 is a top view of step S4 according to the present invention;

fig. 10 is a front view of step S5 of the present invention;

fig. 11 is a top view of step S5 according to the present invention;

fig. 12 is a front view of step S6 of the present invention, which is an overall structure diagram of the product;

FIG. 13 is a schematic diagram of LED chip bonding of a conventional bonding pad;

fig. 14 is a schematic view of the LED chip soldering according to the present invention.

In the figure: the LED packaging structure comprises a substrate 1, a vertical through hole 2, a first bonding pad 3, a second bonding pad 4, a boss 4-1, an LED chip 5, a welding agent 6, a silica gel sheet 7, packaging glue 8 and a traditional bonding pad 9.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

A small-size thickened LED chip structure comprises a substrate 1, two first bonding pads 3, two second bonding pads 4, an LED chip 5, a silica gel sheet 7 and packaging adhesive 8, wherein the two first bonding pads 3 are arranged on the bottom surface of the substrate 1, the two first bonding pads 3 are symmetrically arranged at intervals, the two second bonding pads 4 are arranged on the top surface of the substrate 1, the two second bonding pads 4 are symmetrically arranged at intervals, the vertical symmetrical center lines of the two first bonding pads 3 are overlapped with the vertical symmetrical center lines of the two second bonding pads 4, two vertical through holes 2 are formed in the substrate 1, the two vertical through holes 2 are symmetrically arranged on two sides of the vertical symmetrical center lines of the two first bonding pads 3, electric and heat conducting base materials are filled in the two vertical through holes 2, the LED chip 5 is welded on the upper surfaces of the two second bonding pads 4 through a welding agent 6, the silica gel piece 7 is pasted and is covered in one side that the second pad 4 was kept away from at LED chip 5, the encapsulation is glued 8 encapsulation and is filled around second pad 4, LED chip 5, silica gel piece 7 and the upper surface of base plate 1, just the encapsulation is glued 8 and is flushed with the upper surface of silica gel piece 7.

Preferably, each vertical via 2 is plated with a copper substrate within the hole, thereby forming an electrically and thermally conductive copper cylinder, both ends of which contact the first pad 3 and the second pad 4, respectively.

Preferably, the second pads 4 are in a trapezoid structure, and the shorter sides of the trapezoids of the two second pads 4 are arranged in parallel relatively.

Preferably, the second bonding pads 4 are in a boss structure, and bosses 4-1 of the two second bonding pads are arranged in parallel relatively.

Preferably, the solder 6 is a solder paste.

Preferably, the silica gel sheet 7 is a silica gel sheet mixed with phosphor, and the mixing ratio of the phosphor in the silica gel sheet is prior art, so detailed description is not added.

Preferably, the second pad 4 presents a convex or trapezoidal shape.

Preferably, the length of the silicone sheet 7 is 0.01-10mm longer than that of the LED chip, and the width of the silicone sheet 7 is 0.01-10mm longer than that of the LED chip.

Preferably, the packaging adhesive 8 is white silica gel.

Preferably, the substrate 1 is an FR4 board, a CEM-3 board or a BT board.

CSP techniques, i.e. soldering using the pads of the chip itself. And the utility model discloses design chip pad (being the second pad), adopt double-deck pad structure to adopt BT, in the middle of the material such as CEM-3 is filled, be the base plate between the double-deck pad structure promptly, thereby do the chip pad greatly and do thickly. The utility model discloses a processing design principle specifically as follows:

s1: design base plate 1, the BT board is selected for use to the material of base plate 1, beat vertical through-hole 2 on base plate 1, and electroplate copper in vertical through-hole 2, form electrically conductive and heat conducting copper cylinder, and two first pads 3 that the customer needs are designed to the bottom surface at base plate 1, two second pads 4 of welding LED chip are designed to the top surface at base plate 1, wherein, the second pad of welding LED chip is boss structure, and the boss of two second pads is parallel arrangement relatively, as shown in fig. 2. The second bonding pads can also be in a trapezoidal structure, and the trapezoidal short sides of the two second bonding pads are arranged in parallel relatively. As shown in fig. 1-3, the utility model discloses in, two 3 interval symmetries of first pad set up, two 4 interval symmetries of second pad set up, and the vertical symmetry center line of two first pads 3 overlaps with the vertical symmetry center line of two second pads, as shown in fig. 1, one-to-one sets up about first pad 3 and the second pad 4, and two 2 symmetries of vertical through-hole set up the both sides at the vertical symmetry center line of two first pads 3. The material of the middle base plate of the utility model can also be selected from FR4 board or CEM-3 board. The utility model discloses in, can design a plurality of LED chip structures of arranging with the array on the base plate, can process a plurality of LED chip structures simultaneously in proper order promptly.

S2: and welding the LED chip 5 on the designed second bonding pad 4 through the welding agent 6, wherein the LED chip 5 needs to be welded on the boss side or the trapezoid short side of the second bonding pad 4, as shown in fig. 4-5. In the utility model, the soldering flux can be solder paste or other soldering fluxes.

S3: transparent silica gel is sprayed on the surface of the LED chip 5, and the whole silica gel sheet 7 mixed with the fluorescent powder is stuck over the LED chip 5 and is baked and cured as shown in figures 6-7.

S4: the method comprises the following steps of grinding the silica gel sheet 7 containing the fluorescent powder by using a cutting blade with the same thickness (a blade with the thickness of 0.1-10 mm is selected according to the length and width of the LED chip), omitting a process step of removing residual silica gel sheets after cutting, only keeping the silica gel sheet 7 above the LED chip 5, wherein the size of the kept silica gel sheet is slightly larger than that of the LED chip, and the length and width of the silica gel sheet 7 is generally selected to be 0.01-10mm larger than that of the LED chip, as shown in figures 8-9.

S5: the gap between the silicone sheet 7 and the silicone sheet 7 is filled with the encapsulating adhesive 8 (white silicone) so that the encapsulating adhesive 8 is flush with the upper surface of the silicone sheet 7 and is baked and cured, as shown in fig. 10-11 below.

S6: the substrate 1 is cut along with the packaging adhesive 8 thereon again by using a dicing blade, and cut into a desired size, and finally, a separate LED flash is formed, as shown in fig. 12.

Fig. 13 is a schematic diagram illustrating LED chip bonding of a conventional bonding pad. As can be seen from the figure, the conventional bonding pad 9 is designed to be large in consideration of heat dissipation, i.e. the contact area of the solder 6 and the conventional bonding pad 9 is large, which causes the LED chip 5 to move up and down under the action of the melted solder, resulting in the LED chip 5 being not centered. And as shown in fig. 14, the utility model discloses a LED chip welding schematic diagram, can see from the picture that the second pad is dwindling (being the convex structure) in the place that is close to positive negative pole, and welding agent 6 diminishes with 4 area of contact of second pad promptly for the chip does not have the space to reciprocate, thereby corrects the chip position when playing the welding, makes the effect of LED chip 5 alignment placed in the middle. Furthermore, the utility model provides a structural design of second pad realizes that the chip corrects the function under the prerequisite of guaranteeing not to influence the total area of heat dissipation.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A small-size thickened LED chip structure is characterized by comprising a substrate, two first bonding pads, two second bonding pads, an LED chip, a silica gel sheet and packaging adhesive, wherein the two first bonding pads are arranged on the bottom surface of the substrate, the two first bonding pads are symmetrically arranged at intervals, the two second bonding pads are arranged on the top surface of the substrate, the two second bonding pads are symmetrically arranged at intervals, the vertical symmetrical center line of the two first bonding pads is overlapped with the vertical symmetrical center lines of the two second bonding pads, the substrate is provided with two vertical through holes, the two vertical through holes are symmetrically arranged on two sides of the vertical symmetrical center line of the two first bonding pads, the two vertical through holes are filled with an electric-conductive heat-conducting base material, the LED chip is welded on the upper surfaces of the two second bonding pads through a welding agent, the silica gel sheet is attached to one side, far away from the second bonding pads, of the LED chip, the packaging glue is packaged and filled around the second bonding pad, the LED chip and the silica gel sheet and on the upper surface of the substrate, and the packaging glue is flush with the upper surface of the silica gel sheet.

2. The small-scale thickening LED chip structure of claim 1, wherein the hole of each vertical through hole is plated with a copper substrate, so as to form an electrically and thermally conductive copper cylinder, and two ends of the copper cylinder contact the first bonding pad and the second bonding pad respectively.

3. The small-scale thickened LED chip structure as claimed in claim 1, wherein the second bonding pads are in a trapezoidal structure, and the trapezoidal short sides of the two second bonding pads are arranged in parallel.

4. The small-scale thickening LED chip structure of claim 1, wherein the second bonding pads are in a bump structure, and the bumps of the two second bonding pads are arranged in parallel.

5. The small-scale thickening LED chip structure according to claim 3 or 4, wherein the solder is solder paste.

6. The small-size thickened LED chip structure according to claim 1, wherein the length of the silicone sheet is 0.01-10mm longer than that of the LED chip, and the width of the silicone sheet is 0.01-10mm longer than that of the LED chip.

7. The small-scale thickened LED chip structure of claim 1, wherein the packaging adhesive is white silica gel.

8. The small-scale thickening LED chip structure according to claim 1, wherein the substrate is an FR4 board, a CEM-3 board or a BT board.