CN210272424U

CN210272424U - LED flip substrate

Info

Publication number: CN210272424U
Application number: CN201921324625.8U
Authority: CN
Inventors: 訾青松; 吴疆; 丁磊
Original assignee: Coreach Electronic Technology Co ltd
Current assignee: Coreach Electronic Technology Co ltd
Priority date: 2019-08-15
Filing date: 2019-08-15
Publication date: 2020-04-07
Anticipated expiration: 2029-08-15

Abstract

The utility model discloses a LED flip-chip substrate, including aluminium base board and copper product conducting layer, the top horizontally connected with insulating layer of aluminium base board, the top horizontally connected with copper product conducting layer of insulating layer, the top of copper product conducting layer is provided with the tin layer. The top middle end of the copper product conducting layer is provided with a groove, and the upper portion of the copper product conducting layer is connected with a flip chip through the groove. The tin layer can not change color after being oxidized, and the product performance is not influenced; when the tin layer is used for die bonding, tin paste is not needed; the tin layer has a greater cost advantage than silver/gold; the thickness of the tin layer is controllable, usually within 8-25um, and has a shorter heat conduction path compared with the thickness of 100-130um of the tin paste. The temperature of the heating block is 230 ℃, the ink can not be discolored, and the flip chip can be uniformly conductive in use.

Description

LED flip substrate

Technical Field

The utility model relates to a flip-chip base plate, concretely relates to LED flip-chip base plate belongs to LED lamp processing application.

Background

In recent years, the flip LED technology with smaller size, more dense arrangement and larger current resistance is widely applied to various fields, the existing LED flip substrate is an aluminum-based copper plate, wherein the aluminum base plays roles of heat conduction and heat dissipation, an insulating layer is arranged between the aluminum base and the copper plate and plays a role of isolating current, the copper plate is a conductive layer and plays a role of conducting electricity, ink is covered on the surface of the copper plate in a non-welding area to protect the copper plate from being scratched, oxidized, salt mist and other external influences, the copper layer is exposed in a welding area and is reserved as a groove, a die bonder drips tin paste onto the reserved groove of the aluminum-based copper plate, a flip chip is transferred onto the tin paste by a swing arm, when the flip chip contacts the tin paste, the flip chip is loosened by the swing arm of the die bonder, the flip chip is remained on the tin paste, the next flip chip is sucked by the swing arm of the die bonder to repeat the actions until the die bonding of, the solder paste is solidified, the fixed flip chip and the conductive effect are achieved, and a flip substrate can be arranged into 1-8K flip chips according to different sizes.

However, the existing LED flip-chip substrate still has certain defects in use. The existing solder paste generates stress in the curing process to cause the displacement and rotation of the wafer. The reflow temperature exceeded 260 ℃, and the substrate ink began to discolor. After the solder paste is passed through the furnace, the periphery of the solder joint of the substrate is easy to turn yellow. The tin paste is printed unevenly or deviates too much, one side of the tin paste is thick, the tensile force is large, the other side of the tin paste is thin, the tensile force is small, so that one end of the element is pulled to one side to form empty soldering, and the other end of the element is pulled to form a tombstone. Solder paste is too much to cause short circuit. The offset and the lack of glue can cause insufficient solder and void. The solder paste needs to be refrigerated and stored, and needs to be reheated, manually stirred, put on a machine to adjust the height of the steel mesh and the scraper, adjust the temperature of the reflow soldering machine and the like before use, so that the steps are complicated and time-consuming. The phenomenon of ink discoloration, cracking and the like can easily occur when the ink passes through a reflow oven at 260 ℃ for many times.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a LED flip-chip substrate can solve current tin cream and produce stress in curing process and cause wafer displacement, rotation. The reflow temperature exceeded 260 ℃, and the substrate ink began to discolor. After the solder paste is passed through the furnace, the periphery of the solder joint of the substrate is easy to turn yellow. The tin paste is printed unevenly or deviates too much, one side of the tin paste is thick, the tensile force is large, the other side of the tin paste is thin, the tensile force is small, so that one end of the element is pulled to one side to form empty soldering, and the other end of the element is pulled to form a tombstone. Solder paste is too much to cause short circuit. The offset and the lack of glue can cause insufficient solder and void. The solder paste needs to be refrigerated and stored, and the steps of returning the temperature, manually stirring, adjusting the height of the steel mesh and the scraper by using a machine, adjusting the temperature of the reflow soldering machine and the like are complex and time-consuming before use.

The purpose of the utility model can be realized by the following technical scheme:

the utility model provides a LED flip-chip substrate, includes aluminium base board and copper product conducting layer, the top horizontally connected of aluminium base board has the insulating layer, the top horizontally connected of insulating layer has the copper product conducting layer, the top of copper product conducting layer is provided with the tin layer.

The top middle end of the copper product conducting layer is provided with a groove, and the upper portion of the copper product conducting layer is connected with a flip chip through the groove.

Preferably, the bottom of the aluminum substrate is connected with a heating block, the top of the heating block is parallel to the bottom of the aluminum substrate, and the aluminum substrate is movably connected with the heating block.

Preferably, the top of the tin layer is provided with an ink layer around the flip chip, and the bottom edge of the flip chip is in contact with the tin layer.

Preferably, the thickness of the tin layer is 8-25um, and the thickness of the tin layer is larger than that of the ink layer.

Preferably, the bottom end of the flip chip is inserted into the groove, and the bottom end of the flip chip is fixedly connected with the copper conducting layer.

The utility model has the advantages that:

1. set up the one deck tin layer through the upper portion at the copper product conducting layer and be for wholly place on the heating block and heat up to 230 ℃ after, the tin layer can reach solid-liquid coexistence state, gu on the brilliant machine shifts flip chip to the recess that tin base plate reserved on the copper, the tin layer did not reach the liquid state this moment, and the wafer does not produce displacement, rotation. And the flip chip moves downwards to enter the groove, and when the flip chip contacts the tin layer in a solid-liquid coexisting state, the swing arm of the die bonder is separated from the flip chip. When the temperature is lower than 230 ℃, the tin layer is solidified, the LED flip chip and the substrate are tightly welded together by the tin layer, and the white ink of the support does not change color at 230 ℃.

2. The tin layer can not change color after being oxidized, and the product performance is not influenced; when the tin layer is used for die bonding, tin paste is not needed; the tin layer has a greater cost advantage than silver/gold; the thickness of the tin layer is controllable, usually within 8-25um, and has a shorter heat conduction path compared with the thickness of 100-130um of the tin paste. The temperature of the heating block is 230 ℃, the ink can not be discolored, and the flip chip can be uniformly conductive in use.

Drawings

In order to facilitate understanding for those skilled in the art, the present invention will be further described with reference to the accompanying drawings.

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a schematic view of a conventional flip-chip substrate structure.

In the figure: 1. an aluminum substrate; 2. an insulating layer; 3. a copper conductive layer; 4. a tin layer; 5. an ink layer; 6. flip chip mounting; 7. and heating the block.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

Referring to fig. 1, an LED flip chip substrate includes an aluminum substrate 1 and a copper conductive layer 3, wherein the top of the aluminum substrate 1 is horizontally connected to an insulating layer 2, the top of the insulating layer 2 is horizontally connected to the copper conductive layer 3, and a tin layer 4 is disposed on the top of the copper conductive layer 3;

the top middle-end of copper product conducting layer 3 is provided with the recess, and there is flip chip 6 on the upper portion of copper product conducting layer 3 through fluted connection.

The bottom of the aluminum substrate 1 is connected with a heating block 7, the top of the heating block 7 is parallel to the bottom of the aluminum substrate 1, the aluminum substrate 1 is movably connected with the heating block 7, the aluminum substrate 1 can be in uniform contact with the heating block 7, and heating is uniform in the heating process. The aluminum substrate 1 can be freely attached to and detached from the upper portion of the heating block 7.

The top of tin layer 4 is provided with printing ink layer 5 around flip chip 6, and flip chip 6's bottom edge and the contact of tin layer 4, and printing ink layer 5 can play the effect of protection in the upper portion.

The thickness of the tin layer 4 is 8-25um, the thickness of the tin layer 4 is larger than that of the ink layer 5, and the thickness of the tin layer is within 8-25um, so that the heat conduction path is shorter than that of 100-130um of the tin paste.

The bottom of flip chip 6 is pegged graft in the inside of recess, and flip chip 6's bottom and 3 fixed connection of copper product conducting layer, and flip chip 6 is difficult for droing with the fixed back of copper product conducting layer, the condition of contact failure can not appear, can electrically conduct evenly.

When the utility model is used, the aluminum substrate 1 is placed on the upper part of the heating block 7, the aluminum substrate 1 is heated to 230 ℃ by the heating block 7, and the tin layer 4 on the upper part reaches the state of solid-liquid coexistence; the flip chip 6 is moved to the upper part of the copper conductive layer 3 by using a die bonder, and the bottom of the flip chip 6 is moved to the upper part of the groove. The temperature only needs to be raised to 230 ℃ during heating, and the ink is not easy to discolor and crack at the temperature of 230 ℃.

The swing arm that will gu the brilliant machine is pushed down, and when flip chip 6's bottom contacted solid-liquid coexistence state tin layer 4 and entered into the inside of recess, gu the brilliant machine swing arm breaks away from flip chip 6, and flip chip 6 stays in the recess on 3 upper portions of copper product conducting layer, and gu the brilliant machine swing arm is inhaled and is taken off next flip chip 6, repeats above-mentioned action, and the installation is accomplished until a plurality of flip chip 6. The recess makes things convenient for flip chip 6's installation, and need not add the tin cream in the inside of recess during the installation, need not control the volume of tin cream, and is more convenient during the installation.

After the die bonding is finished, the aluminum substrate 1 is transferred away from the heating block 7, the aluminum substrate 1 starts to be cooled, when the temperature is lower than 230 ℃, the tin layer 4 is solidified, and the flip chip 6 and the copper conducting layer 3 are welded together by the tin layer 4. In the inside of recess, can carry out comprehensive even fixed to flip chip 6 after tin layer 4 cools off, the electric conductivity is good in the follow-up use.

The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best understand the invention for and utilize the invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. The LED flip substrate is characterized by comprising an aluminum substrate (1) and a copper conducting layer (3), wherein the top of the aluminum substrate (1) is horizontally connected with an insulating layer (2), the top of the insulating layer (2) is horizontally connected with the copper conducting layer (3), and the top of the copper conducting layer (3) is provided with a tin layer (4);

the top middle end of copper product conducting layer (3) is provided with the recess, and there is flip chip (6) on the upper portion of copper product conducting layer (3) through the fluted connection.

2. The LED flip-chip substrate according to claim 1, wherein the bottom of the aluminum substrate (1) is connected with a heating block (7), the top of the heating block (7) is parallel to the bottom of the aluminum substrate (1), and the aluminum substrate (1) is movably connected with the heating block (7).

3. An LED flip-chip substrate according to claim 1, characterized in that the top of the tin layer (4) is provided with an ink layer (5) around the flip-chip (6) and the bottom edge of the flip-chip (6) is in contact with the tin layer (4).

4. The LED flip-chip substrate according to claim 1, wherein the thickness of the tin layer (4) is 8-25um, and the thickness of the tin layer (4) is larger than the thickness of the ink layer (5).

5. The LED flip-chip substrate according to claim 1, wherein the bottom end of the flip-chip (6) is inserted into the groove, and the bottom end of the flip-chip (6) is fixedly connected with the copper conductive layer (3).