LED and IC flip-chip packaging process and packaging product

Abstract

The present application relates to LED and IC overlay welding packaging process and packaging product, the process includes the following steps: preset IC pad, print tin paste, fix LED to wafer, reflow soldering, fix IC wafer, wire bonding, mould pressing, cutting and testing and packaging;The novel processing technology of the application does not need wire bonding, the reliability and reliability can be greatly improved, and has better heat dissipation and conductive effect, the process is relatively simple, the cost is cheap, and the overlay welding mode is used, the volume of material can be very small, can be suitable for a variety of miniature application scenarios, which is beyond the reach of the existing conventional process and its product.

Description

Technical Field

[0001] This invention relates to the field of LED packaging technology, and more specifically, to an LED and IC cascade packaging process and packaging product. Background Technology

[0002] LED (Light Emitting Diode) packaging refers to the packaging of the light-emitting chip, which differs significantly from integrated circuit packaging. LED packaging not only needs to protect the chip but also allow light to pass through. Therefore, LED packaging has special requirements for packaging materials.

[0003] Currently, LEDs and ICs are packaged in a single casing using wire bonding to complete the circuit connection. This process is complex due to the need to solder multiple wires, and there are many potential defects at the solder joints. In addition, products produced by this process are also bulky, taking up a lot of space when used in displays and micro-electronic devices, and making it inconvenient to make them smaller and more precise. A packaging process that can improve these issues is needed. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an LED and IC cascade packaging process and an LED and IC cascade packaging product, in view of the above-mentioned defects of the prior art.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] Constructing an LED-IC cascade packaging process includes the following steps:

[0007] Preset IC pads: Pads are laid out on the front side of the IC according to the preset circuit diagram. After the driver IC wafer is formed, the driver IC wafer is cut and separated into individual units from the blue film. The laid-out pads include soldering pads for mounting LED light-emitting chips and bracket pads for soldering to the substrate.

[0008] Solder paste printing: Solder paste is printed on the driver IC wafer using a stencil according to the preset pad size and position on the driver IC wafer;

[0009] Fixing LEDs onto the wafer: Transfer the LED light-emitting chip to the driver IC wafer, so that the reserved solder pins on the LED light-emitting chip correspond one-to-one with the solder pads on the driver IC wafer;

[0010] Reflow soldering: The driver IC wafer with the LED light-emitting chips mounted is placed into a reflow soldering oven for reflow curing;

[0011] IC wafer fixing: The IC wafer that has passed through the oven is fixed on the substrate by applying adhesive to the substrate using a die bonder, and then placed in an oven for baking and curing according to the set conditions;

[0012] Wire bonding: The baked substrate is passed through a wire bonding machine to ultrasonically bond the support pads on the IC wafer to the pads on the substrate;

[0013] Molding: The substrate with the soldered IC wafer is placed in a molding machine, and epoxy resin or silicone is heated to cover and encapsulate the entire substrate. Then it is placed in an oven to bake and cure according to the set conditions.

[0014] Cutting: The cured substrate is cut horizontally and vertically according to the pre-set isolation channels to form individual LED and IC wafer stacked devices.

[0015] The LED and IC cascading packaging process of the present invention further includes:

[0016] Testing and Packaging: Place the individual LED and IC wafer stacked device into the testing machine, adjust the corresponding parameters, and test various parameters of the IC wafer and LED light-emitting chip. After passing the test, put them into the material tape for packaging.

[0017] The LED and IC cascading packaging process described in this invention, wherein the LED light-emitting chip is a micro LED or a hybrid of a micro LED and an LED wafer.

[0018] The LED and IC cascading packaging process of the present invention further includes:

[0019] LED chip packaging: LED chips are manufactured into miniature LEDs with multiple colors built in through die bonding, wire bonding, film pressing, cutting, and testing.

[0020] In the LED and IC cascading packaging process of the present invention, the baking temperature in the IC wafer fixing process is 160-200℃ and the baking time is 1-3 hours.

[0021] In the LED and IC cascading packaging process described in this invention, the baking temperature in the molding process is 180-220℃, and the baking time is 10-14 hours.

[0022] An LED and IC cascade package is provided, wherein the LED and IC cascade package is manufactured by the LED and IC cascade package process described above.

[0023] The beneficial effects of this invention are as follows: the novel processing technology of this application eliminates the need for wire bonding, significantly improving reliability and dependability, while also providing better heat dissipation and conductivity. The process is relatively simple and inexpensive, and the use of lap bonding allows for very small material volumes, making it suitable for a variety of micro-application scenarios. This is something that existing conventional processes and their products cannot achieve. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart of the LED and IC cascade packaging process according to a preferred embodiment of the present invention;

[0026] Figure 2 This is a top view of the LED and IC stacking packaging process driver IC wafer before it is cut, according to a preferred embodiment of the present invention.

[0027] Figure 3 This is a cross-sectional view of the LED and IC cascade packaging process substrate before cutting, according to a preferred embodiment of the present invention.

[0028] Figure 4 This is a cross-sectional view of the finished LED and IC wafer cascaded packaging process according to a preferred embodiment of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, a clear and complete description will be provided below in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0030] The preferred embodiment of the LED and IC cascading packaging process of the present invention, such as... Figure 1 As shown, it includes the following steps:

[0031] S01: Preset IC pads;

[0032] According to the preset circuit diagram, the pads are laid out on the front side of the IC. After the driver IC wafer is formed, the driver IC wafer is cut from the blue film into individual units. The laid-out pads include soldering pads for mounting LED light-emitting chips and support pads for soldering to the substrate.

[0033] The preset pads can be soldered according to the size of the LED pads, which facilitates the reliability and accuracy of stacking.

[0034] S02: Solder paste for printing;

[0035] Solder paste is printed on the driver IC wafer using a stencil according to the preset pad size and position on the driver IC wafer;

[0036] Printing solder paste directly onto IC wafers is a high-precision printing method that can further improve circuit connectivity and reliability, and reduce the internal resistance and signal transmission interference caused by wire bonding on the circuit.

[0037] S03: Fix the LED onto the wafer;

[0038] Transfer the LED light-emitting chip to the driver IC wafer, so that the reserved solder pins on the LED light-emitting chip correspond one-to-one with the solder pads on the driver IC wafer;

[0039] S04: Reflow soldering;

[0040] Place the driver IC wafer with the LED light-emitting chips mounted into a reflow oven for reflow curing;

[0041] S05: Fixing IC wafers;

[0042] The IC wafers are fixed onto the substrate by applying adhesive to the substrate using a die bonder, and then placed in an oven for baking and curing according to the set conditions; the circuit size can be defined according to the application requirements.

[0043] Preferably, the baking temperature is 160-200℃ and the baking time is 1-3 hours; a more preferred implementation temperature and time is: baking temperature of 180℃ and baking time of 2 hours.

[0044] S06: Wire bonding;

[0045] The baked substrate is ultrasonically bonded to the pads on the IC wafer and the substrate using a wire bonding machine; the circuit size can be defined according to application requirements.

[0046] S07: Molding;

[0047] The substrate with the soldered IC wafer is placed in a molding machine, and epoxy resin or silicone is heated to cover and encapsulate the entire substrate. Then it is placed in an oven to bake and cure according to the set conditions.

[0048] Compression molding is a one-piece molding process based on a mold. The dimensional accuracy of each unit is very high, with a tolerance of less than 0.02 mm. Compression molding is performed using a 200-ton press, and the airtightness between the unit and the substrate is very high, ensuring the lifespan and reliability of the components.

[0049] Preferably, the baking temperature is 180-220℃ and the baking time is 10-14 hours; a more preferred implementation temperature and time is: baking temperature of 200℃ and baking time of 12 hours.

[0050] S08: Cutting;

[0051] The cured substrate is cut horizontally and vertically according to the pre-set isolation channels to form individual LED and IC wafer stacked devices.

[0052] S09: Testing and Packaging;

[0053] The individual LED and IC wafer cascade device are placed into the testing machine, the corresponding parameters are adjusted, and various parameters of the IC wafer and LED light-emitting chip are tested. After passing the test, they are placed into the material tape for packaging.

[0054] The novel processing technology of this application eliminates the need for wire bonding, significantly improving reliability and dependability, while also providing better heat dissipation and conductivity. The process is relatively simple and inexpensive, and the use of lap bonding allows for very small material volumes, making it suitable for a variety of micro-application scenarios—something that existing conventional processes and products cannot achieve.

[0055] Preferably, the process also includes:

[0056] LED chip packaging: LED chips are manufactured into miniature LEDs with multiple colors built in through die bonding, wire bonding, lamination, cutting, and testing.

[0057] Depending on the size of the LED chip and the chip form (either upright or flip-chip), several colors can be integrated into a multi-chip LED component in one model. This allows for further definition of appropriate pad sizes and component height and size according to individual needs.

[0058] Understandably, the LED light-emitting chips in this process can be micro LEDs or a hybrid of micro LEDs and LED wafers.

[0059] like Figure 2-4 As shown in the figure, 1 is an uncut driver IC wafer, 2 is an LED light-emitting chip, 3 is the first dicing line, 4 is an uncut PCB substrate, 5 is a single driver IC wafer after dicing, 6 is the second dicing line, 7 is the encapsulation colloid, and 8 is a single PCB substrate after dicing.

[0060] An LED and IC cascade package, such as Figure 4 As shown, the LED and IC cascade package is manufactured using the LED and IC cascade packaging process described above.

[0061] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. An LED and IC cascade packaging process, characterized in that, Includes the following steps: Preset IC pads: Pads are laid out on the front side of the IC according to the preset circuit diagram. After the driver IC wafer is formed, the driver IC wafer is cut and separated into individual units from the blue film. The laid-out pads include soldering pads for mounting LED light-emitting chips and bracket pads for soldering to the substrate. Solder paste printing: Solder paste is printed on the driver IC wafer using a stencil according to the preset pad size and position on the driver IC wafer; Fixing LEDs onto the wafer: Transfer the LED light-emitting chip to the driver IC wafer, so that the reserved solder pins on the LED light-emitting chip correspond one-to-one with the solder pads on the driver IC wafer; Reflow soldering: The driver IC wafer with the LED light-emitting chips mounted is placed into a reflow soldering oven for reflow curing; IC wafer fixing: The IC wafer that has passed through the oven is fixed on the substrate by applying adhesive to the substrate using a die bonder, and then placed in an oven for baking and curing according to the set conditions; Wire bonding: The baked substrate is passed through a wire bonding machine to ultrasonically bond the support pads on the IC wafer to the pads on the substrate; Molding: The substrate with the soldered IC wafer is placed in a molding machine, and epoxy resin or silicone is heated to cover and encapsulate the entire substrate. Then it is placed in an oven to bake and cure according to the set conditions. Cutting: The cured substrate is cut horizontally and vertically according to the pre-set isolation channels to form individual LED and IC wafer stacked devices.

2. The LED and IC cascading packaging process according to claim 1, characterized in that, The process also includes: Testing and Packaging: Place the individual LED and IC wafer stacked device into the testing machine, adjust the corresponding parameters, and test various parameters of the IC wafer and LED light-emitting chip. After passing the test, put them into the material tape for packaging.

3. The LED and IC cascading packaging process according to claim 1, characterized in that, The LED light-emitting chip is a micro LED or a hybrid of a micro LED and an LED wafer.

4. The LED and IC cascading packaging process according to claim 3, characterized in that, The process also includes: LED chip packaging: LED chips are manufactured into miniature LEDs with multiple colors built in through die bonding, wire bonding, film pressing, cutting, and testing.

5. The LED and IC cascading packaging process according to claim 1, characterized in that, In the IC wafer fixing process, the baking temperature is 160-200℃ and the baking time is 1-3 hours.

6. The LED and IC cascading packaging process according to claim 1, characterized in that, In the molding process, the baking temperature is 180-220℃ and the baking time is 10-14 hours.

7. An LED and IC cascade package, characterized in that, The LED and IC cascade package is manufactured using the LED and IC cascade packaging process as described in any one of claims 1-6.

Images