CN116571469A

CN116571469A - Point measurement and sorting method for LED chip packaging body

Info

Publication number: CN116571469A
Application number: CN202310373999.3A
Authority: CN
Inventors: 章冰霜
Original assignee: Dongguan HCP Technology Co Ltd
Current assignee: Dongguan HCP Technology Co Ltd
Priority date: 2023-04-07
Filing date: 2023-04-07
Publication date: 2023-08-11

Abstract

The invention discloses a point measurement and sorting method of an LED chip packaging body, wherein the LED chip packaging body comprises a unit substrate and an LED chip, the unit substrate comprises a first surface and a second surface which are opposite to each other, and a third surface positioned at the side; a first bonding pad is arranged on the first surface; the second surface is provided with a second bonding pad corresponding to the first bonding pad, the third surface is provided with a connecting circuit, and the connecting circuit is electrically connected with the first bonding pad and the second bonding pad; the spot measurement sorting method comprises the following steps: providing a supporting surface, and attaching and fixing the second surface of the LED chip packaging body to be tested on the supporting surface; the detection electrode is electrically connected to a connecting circuit positioned on the third surface of the unit substrate so as to provide detection power for the LED chip packaging body to be detected, so that the LED chip packaging body is in a lighting state. By the method, the light sensor in the spot measurement sorting equipment can accurately collect the light emitted by the LED chip packaging body, so that the authenticity of the test result is improved.

Description

Point measurement and sorting method for LED chip packaging body

Technical Field

The invention relates to the technical field of LED chip packaging, in particular to a spot measurement sorting method for LED chip packaging bodies.

Background

Micro LEDs meet the requirements of various pixel densities and various size displays, such as AR/VR, smart watches, large screen televisions, and the like, by virtue of the characteristics of low energy consumption, high brightness, high contrast and high reliability. Micro LEDs gradually show great application potential by virtue of a plurality of advantages and become the best novel high-definition display scheme.

Wherein MIP (Micro LED in Package) is a novel packaging architecture based on Micro LEDs, and the technological process of MIP packaging technology is as follows: and transferring the Micro LED chips onto a carrier plate through a mass transfer technology, packaging, cutting into single or multiple-in-one chip packages, carrying out light splitting and light mixing on the chip packages, and carrying out a surface mounting process, screen surface packaging or film coating to finally finish the manufacturing of the display screen. At present, the carrier plate is mainly a BT substrate, and a glass substrate can be used. Whether a BT substrate or a glass substrate is used, conductive vias H are fabricated on the carrier, as shown in fig. 7, to connect pads on both surfaces of the substrate, so as to meet the requirement of circuit conduction.

For the LED chip packaging body formed by the carrier plate with the conductive through holes, after the manufacturing is finished, the LED chip packaging body enters a spot measurement sorting procedure, and the spot measurement sorting process comprises the following steps: the probes are adopted to contact the positive electrode connecting pad and the negative electrode connecting pad exposed from the bottom of the chip package body, and the top of the LED chip package body is supported by a sucker or other supporting tools. The probe is conductive to enable the LED chip to be lightened, the top of the chip packaging body emits light, and the probe is combined with spot measurement sorting equipment to collect optical signals and electrical signals, so that information such as voltage, brightness and wavelength of the LED chip is obtained, and the LED chip packaging body is classified. In the spot measurement sorting process flow, because tools such as a sucker are needed to support the top of the LED chip, the optical sensor of the spot measurement sorting equipment can be influenced to a certain extent to collect optical signals, and therefore the authenticity of a measurement result is influenced.

Disclosure of Invention

The invention aims to provide the LED chip package point measurement sorting method which can effectively improve the accuracy of light signal acquisition in the LED chip package point measurement sorting process flow so as to ensure the authenticity of a measurement result.

In order to achieve the above object, the present invention discloses a spot measurement sorting method of an LED chip package, the LED chip package comprising a unit substrate and an LED chip, the unit substrate comprising a first surface and a second surface opposite to each other, and a third surface located at a side of the first surface and the second surface and connected to the first surface and the second surface; the first surface is provided with a first bonding pad, and the LED chip is welded on the unit substrate through the first bonding pad; the second surface is provided with a second bonding pad corresponding to the first bonding pad, the second bonding pad is used for installing and fixing the unit substrate, the third surface is provided with a connecting circuit, and the connecting circuit is electrically connected with the first bonding pad and the second bonding pad; the spot measurement sorting method comprises the following steps:

providing a supporting surface, and attaching and fixing the second surface of the LED chip packaging body to be tested on the supporting surface;

the detection electrode is electrically connected to a connecting circuit positioned on the third surface of the unit substrate so as to provide a detection power supply for the LED chip packaging body to be detected, so that the LED chip packaging body is in a lighting state;

and acquiring optical signal data and electrical signal data of the LED chip package body to evaluate the performance of the current LED chip package body.

Preferably, the supporting surface is provided with a negative pressure suction hole.

Preferably, the detection electrode comprises a conductive probe.

Preferably, a single LED chip is disposed on the unit substrate, the connection lines are disposed on a pair of opposite third surfaces of the unit substrate, and two detection electrodes are abutted to the corresponding two connection lines.

Preferably, the unit substrate is provided with a first light color chip, a second light color chip and a third light color chip which form a single pixel set and have different light colors; the first photochromic chip, the second photochromic chip and the third photochromic chip are provided with a common electrode, and the common electrode is a common cathode or a common anode; two opposite third surfaces of the unit substrate are respectively provided with two connecting circuits.

Preferably, two detection electrodes are provided, one of the detection electrodes is abutted against the public electrodes of the first light color chip, the second light color chip and the third light color chip, and the other detection electrode is abutted against the private electrodes of the first light color chip, the second light color chip and the third light color chip in sequence.

Preferably, four detection electrodes are provided, one of the detection electrodes is abutted against the common electrodes of the first light color chip, the second light color chip and the third light color chip, and the other three detection electrodes are abutted against the private electrodes of the first light color chip, the second light color chip and the third light color chip respectively.

Preferably, the first light color chip, the second light color chip and the third light color chip are sequentially lightened.

Preferably, the first light color chip, the second light color chip and the third light color chip are lightened simultaneously.

Preferably, the unit substrate is a ceramic substrate.

Compared with the prior art, the LED chip packaging body spot measurement sorting method aims at the LED chip packaging body with the connecting lines arranged on the side face of the unit substrate, and during testing, the two detection electrodes are respectively connected to the connecting lines arranged on the side face of the unit substrate, so that the bottom space of the unit substrate is vacated, and the LED chip packaging body to be tested is supported and fixed through the bottom space of the unit substrate, so that light rays emitted by the LED chip packaging body are prevented from being blocked by the supporting and fixing piece, light rays emitted by the LED chip packaging body can be accurately collected by the light sensor in the spot measurement sorting equipment, and the authenticity of a testing result is further improved.

Drawings

Fig. 1 is a flow chart of a spot measurement sorting method of an LED chip package according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a front structure of an LED chip package according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a back structure of an LED chip package according to an embodiment of the present invention.

Fig. 4 is a schematic side view of an LED chip package according to an embodiment of the present invention.

Fig. 5 is a cross-sectional view of a single chip package according to an embodiment of the invention.

Fig. 6 is a schematic diagram of an LED chip package in a testing state according to an embodiment of the present invention.

Fig. 7 is a plan view of a conventional LED chip substrate.

Detailed Description

In order to describe the technical content, the constructional features, the achieved objects and effects of the present invention in detail, the following description is made in connection with the embodiments and the accompanying drawings.

The embodiment discloses an LED chip package and a spot measurement sorting method of the LED chip package based on the LED chip package, wherein the sorting method is used for testing and screening electrical performance and optical performance of the manufactured LED chip package.

As shown in fig. 2 to 4, the LED chip package M includes a unit substrate 100 and an LED chip D. The unit substrate 100 includes opposite first and second surfaces S1 and S2, and a third surface located laterally of the first and second surfaces S1 and S2 and connected to the first and second surfaces S1 and S2. In this embodiment, the first surface S1 is a front surface of the unit substrate 100, the second surface S2 is a back surface of the unit substrate 100, and the third surface is a side surface of the unit substrate 100.

The first surface S1 is provided with a first pad P1 including a positive electrode pad and a negative electrode pad, and the LED chip D is soldered on the unit substrate 100 through the first pad P1, that is, the positive electrode pad is connected to the positive electrode of the LED chip D and the negative electrode pad is connected to the negative electrode of the LED chip D. The second surface S2 is provided with second pads P2 corresponding to the first pads P1, the second pads P2 being used for mounting the fixing unit substrate 100. The second pad P2 includes a positive connection pad corresponding to the positive pad and a negative connection pad corresponding to the negative pad, that is, the unit substrate 100 is soldered on the PCB mother board to be assembled through the positive connection pad and the negative connection pad.

The third surface is provided with a connection line C0, and the connection line C0 is electrically connected to the first pad P1 and the second pad P2, that is, the connection line C0 on one third surface is used to connect the positive electrode pad and the positive electrode connection pad, and the connection line C0 on the other third surface is used to connect the negative electrode pad and the negative electrode connection pad, so that the conduction of the front and back sides of the unit substrate 100 is realized.

Referring to fig. 1 to 4 and fig. 6 in combination, the method for sorting point measurement in the present embodiment includes:

s1: providing a supporting surface, and attaching and fixing a second surface S2 of the LED chip packaging body M to be tested, which is positioned at the bottom, on the supporting surface;

s2: the detection electrode is electrically connected to a connection circuit C0 on the third surface of the unit substrate 100 to provide a detection power supply for the LED chip package M to be detected, so that the LED chip package M is in a lighting state;

s3: and collecting optical signal data and electrical signal data of the LED chip package M to evaluate the performance of the current LED chip package M. Specifically, optical signal data is collected by the optical sensor, and electrical signal data is collected by the detection electrode at the same time.

In the method for spot measurement and sorting of the LED chip packages M according to the embodiment, the LED chip packages M with the connection line C0 provided on the side surface of the unit substrate 100 are targeted, and during testing, the detection electrode is connected to the connection line C0 of the unit substrate 100, so that the bottom space of the unit substrate 100 is vacated, and thus, the LED chip packages M to be tested are supported and fixed through the bottom space of the unit substrate 100, so that light emitted by the LED chip packages M is prevented from being blocked by the supporting and fixing member, and the light emitted by the LED chip packages M can be accurately collected by the light sensor in the spot measurement and sorting device, so that the authenticity of the test result is improved.

In order to ensure the stability of the LED chip packaging body M in the testing process, a negative pressure suction hole is formed in the supporting surface, the LED chip packaging body M to be tested is adsorbed on the supporting surface through the negative pressure suction hole, and meanwhile, the connection of the detection electrode and connecting lines of the positive electrode and the negative electrode on the LED chip packaging body M to be tested is not influenced.

For ease of operation, the detection electrode comprises a conductive probe.

Further, the collected optical signal data of the LED chip package M includes parameters such as wavelength and brightness, and the collected electrical signal parameters of the LED chip package M include parameters such as voltage, current and resistance.

Further, the LED chip package M may be a single chip package or a single pixel package.

For the single chip package, as shown in fig. 5, only one LED chip D is disposed on the unit substrate 100. Then, the first pad P1 includes a positive electrode pad and a negative electrode pad on the front surface of the unit substrate 100, and the second pad P2 includes a positive electrode connection pad and a negative electrode connection pad on the rear surface of the unit substrate 100. Therefore, connection lines C0 are provided on two opposite third surfaces of the unit substrate 100, respectively, and the two side lines C0 are connected to the positive electrode pad and the positive electrode connection pad, and the negative electrode pad and the negative electrode connection pad, respectively. In this embodiment, during test screening, two conductive probes are abutted against two corresponding connection circuits C0.

For the single pixel package, as shown in fig. 2 to 4, that is, the LED chip D disposed on the unit substrate 100 includes a first light color chip R, a second light color chip G, and a third light color chip B that constitute a single pixel set and have different light colors. In this embodiment, the first light color chip R emits red light, the second light color chip G emits green light, and the third light color chip B emits blue light, so as to form three primary colors of light, so that the LED chip package M can output different light colors.

For convenient assembly, the first photochromic chip R, the second photochromic chip G and the third photochromic chip B share a cathode or a common anode. When the first light color chip R, the second light color chip G and the third light color chip B share the cathode, the first surface S1 has three positive electrode pads P1a, P1B, P1c and one negative electrode pad P1d. Accordingly, the second surface S2 has three positive connection pads P2a, P2b, P2c and one negative connection pad P2d thereon. In addition, when the first photochromic chip R, the second photochromic chip G and the third photochromic chip B share the anode, there are one positive electrode pad and three negative electrode pads on the first surface S1, and correspondingly, there are one positive electrode connection pad and three negative electrode connection pads on the second surface S2.

For the single pixel package, two connection lines C0 are respectively disposed on two opposite third surfaces of the unit substrates 100, that is, four side lines C0 are formed at both ends of both sides of each unit substrate 100, and the four side lines C0 are respectively connected to three positive electrode pads P1a, P1b, P1C and three positive electrode connection pads P2a, P2b, P2C and the negative electrode pads P1d and the negative electrode connection pad P2d. In this embodiment, at the time of test screening, two or four conductive probes are applied to the connection lines C0 serving as the positive electrode and the negative electrode, respectively.

Specifically, when testing with two conductive probes: and the conductive probes of one corresponding electrode are abutted on the public electrodes of the first photochromic chip R, the second photochromic chip G and the third photochromic chip B, and the other conductive probes are respectively abutted on the private electrodes of the first photochromic chip R, the second photochromic chip G and the third photochromic chip B one by one. When the first light color chip R, the second light color chip G and the third light color chip B share the cathode, the negative electrode conductive probe is abutted on the common electrode of the first light color chip R, the second light color chip G and the third light color chip B, and the positive electrode conductive probe is abutted on the positive electrodes of the first light color chip R, the second light color chip G and the third light color chip B one by one respectively, so that the first light color chip R, the second light color chip G and the third light color chip B are lighted one by one.

When testing with four conductive probes: and the conductive probes of one corresponding electrode are abutted on the public electrodes of the first photochromic chip R, the second photochromic chip G and the third photochromic chip B, and the other three conductive probes are respectively abutted on the private electrodes of the first photochromic chip R, the second photochromic chip G and the third photochromic chip B. In this embodiment, the first light color chip R, the second light color chip G and the third light color chip B share a cathode, during testing, the negative electrode conductive probe is abutted against the common electrode of the first light color chip R, the second light color chip G and the third light color chip B, the other three positive electrode probes are respectively abutted against the positive ends of the first light color chip R, the second light color chip G and the third light color chip B, and then each LED chip D is respectively turned on to separately test the optical signal data and the electrical signal data of the single LED chip D, and the three LED chips D can also be turned on at the same time, thereby testing the performance of the single pixel package under white light.

In addition, it should be noted that, in this embodiment, the first light color chip R is a vertical mounting structure chip, the second light color chip G and the third light color chip B are flip chips, and then, an electrode on a side of the first light color chip R, which is close to the unit substrate 100, is welded to a negative electrode pad serving as a common electrode pad, and an electrode on a side of the first light color chip R, which is away from the unit substrate 100, is connected to one of the positive electrode pads through a lead.

Specifically, the connection line C0 is a metal conductive layer disposed on the third surface. In this embodiment, the metal conductive layer is formed by plating a metal conductive material on the third surface through a vacuum plating process.

Further, when the metal conductive layer is covered on the third surface, two ends of the metal conductive layer cover the corresponding outer sides of the first pad P1 and the second pad P2 respectively, so that stable conduction between the connection circuit C0 and the first pad P1 and the second pad P2 is realized, and virtual connection is avoided.

Still further, the first pad P1 and the second pad P2 include connection walls near the third surfaces on which the connection lines C0 are disposed, the connection walls being coplanar with the respective third surfaces. In this embodiment, since the connecting walls on the sides of the first and second pads P2 and P2 are coplanar with the corresponding third surfaces, in the batch manufacturing process, since each LED chip package M is cut from the original substrate (also called motherboard), when the third surfaces are exposed by cutting, the first and second pads P1 and P2 are also exposed at the same time, so that the manufacturing of the connection line C0 is facilitated, and the connection stability of the connection line C0 with the first and second pads P1 and P2 can be effectively improved.

Further, the unit substrate 100 in the present embodiment is preferably a ceramic substrate. Compared with a resin substrate, a metal substrate and a glass substrate which are used conventionally, the ceramic substrate has low price, good heat conducting property, strong insulativity, strong dimensional stability and difficult thermal expansion after being heated. The ceramic material of the ceramic substrate may be alumina (Al 203), aluminum nitride (AlN), beryllium oxide (BeO), or the like.

Further, the first surface S1 of the unit substrate 100 is further covered with an encapsulation layer 2, and the encapsulation layer 2 is used for encapsulating the LED chip D and the unit substrate 100 together.

The foregoing description of the preferred embodiments of the present invention is not intended to limit the scope of the claims, which follow, as defined in the claims.

Claims

1. The spot measurement sorting method of the LED chip package is characterized in that the LED chip package comprises a unit substrate and an LED chip, wherein the unit substrate comprises a first surface and a second surface which are opposite to each other, and a third surface which is positioned at the side of the first surface and the second surface and is connected with the first surface and the second surface; the first surface is provided with a first bonding pad, and the LED chip is welded on the unit substrate through the first bonding pad; the second surface is provided with a second bonding pad corresponding to the first bonding pad, the second bonding pad is used for installing and fixing the unit substrate, the third surface is provided with a connecting circuit, and the connecting circuit is electrically connected with the first bonding pad and the second bonding pad; the spot measurement sorting method comprises the following steps:

2. The method for sorting LED chip packages according to claim 1, wherein the support surface is provided with a negative pressure suction hole.

3. The LED chip package spot-testing sorting method of claim 1, wherein said detection electrode comprises a conductive probe.

4. The method according to claim 1, wherein a single LED chip is disposed on the unit substrate, the connection lines are disposed on a pair of opposite third surfaces of the unit substrate, and two detection electrodes are abutted on the two corresponding connection lines.

5. The method according to claim 1, wherein the unit substrate is provided with a first light color chip, a second light color chip and a third light color chip which form a single pixel set and have different light colors; the first photochromic chip, the second photochromic chip and the third photochromic chip are provided with a common electrode, and the common electrode is a common cathode or a common anode; two opposite third surfaces of the unit substrate are respectively provided with two connecting circuits.

6. The method according to claim 5, wherein two detection electrodes are provided, one of the detection electrodes is abutted against a common electrode of the first light color chip, the second light color chip and the third light color chip, and the other detection electrode is abutted against a private electrode of the first light color chip, the second light color chip and the third light color chip in this order.

7. The method according to claim 5, wherein four detection electrodes are provided, one of the detection electrodes is abutted against the common electrodes of the first light color chip, the second light color chip and the third light color chip, and the other three detection electrodes are abutted against the private electrodes of the first light color chip, the second light color chip and the third light color chip, respectively.

8. The LED chip package spot measurement sorting method of claim 7, wherein said first light color chip, said second light color chip, and said third light color chip are sequentially illuminated.

9. The LED chip package spot measurement sorting method of claim 7, wherein said first light color chip, said second light color chip and said third light color chip are illuminated simultaneously.

10. The LED chip package spot measurement sorting method of claim 1, wherein said unit substrate is a ceramic substrate.