Soldering flux dipping device and chip mounting system

Abstract

The embodiment of the utility model provides a soldering flux dipping device and a chip mounting system. The soldering flux dipping device comprises a soldering flux platform and a plurality of dipping assemblies, the plurality of dipping assemblies are telescopically arranged on the soldering flux platform and covered by the soldering flux on the soldering flux platform, and the plurality of dipping assemblies correspond to a plurality of chip bumps of the flip chip; wherein when the chip salient points are dipped in the soldering flux, the chip descends until the chip salient points are in contact with the soldering flux, and after the soldering flux platform and the soldering flux pool rise to a preset height at the same time, the soldering flux platform continues to rise, so that the dipping assembly is exposed out of the soldering flux pool and abuts against the corresponding chip salient points after dipping the soldering flux; and furthermore, each chip bump is uniformly dipped with the soldering flux. Through the soldering flux dipping device, the problem of poor dipping of the soldering flux caused by chip warping is solved, and the reliability of chip welding is improved.

Description

TECHNICAL FIELD

[0001] The embodiment of the present disclosure belongs to the technical field of semiconductor packaging, and particularly relates to a flux dipping device and a chip mounting system. BACKGROUND

[0002] As shown in Figure 1 , the existing flip chip welding needs to suck the chip, dip the flux on the flux platform, so that each chip bump is evenly dipped with the flux on the chip bump surface, and then is mounted on the substrate. This way requires high levelness for chip suction and high warpage control for the chip. As shown in Figure 2 , with the increasing size of the 2.5D product packaging, the chip size is also increasing, and the corresponding chip warpage is also increasing, which leads to the problem of poor welding caused by the fact that part of the bump cannot dip the flux in the existing flip chip dipping flux mode.

[0003] In order to solve the above problems, there is no effective method to solve this problem in the industry at present, and the only way to confirm the good and bad of welding is through open short circuit test, and there is no rework method, and the product can only be scrapped.

[0004] In view of the above problems, it is necessary to propose a flux dipping device and a chip mounting system which is reasonable in design and can effectively improve the above problems. INVENTION CONTENTS

[0005] The embodiment of the present disclosure aims to at least solve one of the technical problems existing in the prior art, and provides a flux dipping device and a chip mounting system.

[0006] An aspect of the embodiment of the present disclosure provides a flux dipping device for mounting of flip chip, comprising a flux platform and a plurality of dipping assemblies;

[0007] The plurality of dipping assemblies are telescopically arranged on the flux platform and are used to be covered by the flux in the flux pool;

[0008] The plurality of dipping assemblies correspond to a plurality of chip bumps of the chip; wherein,

[0009] When the chip bumps dip the flux, the chip is lowered to contact the flux, the flux platform and the flux pool are simultaneously raised to a preset height, then the flux platform continues to rise, so that the dipping assembly dips the flux and is exposed to the flux pool and abuts against the corresponding chip bump, thereby making each chip bump evenly dip the flux.

[0010] Optionally, the dipping assembly comprises an elastic member and a dipping member;

[0011] The first end of the elastic member is connected with the flux platform, and the second end of the elastic member is connected with the dipping member; wherein,

[0012] When the chip bump dips the flux, the dipping member dips the flux and then elastically abuts against the corresponding chip bump.

[0013] Optionally, the diameter size of the dipping member is smaller than the diameter size of the chip bump.

[0014] Optionally, the diameter size of the dipping member is 70% to 80% of the diameter size of the chip bump.

[0015] Optionally, the dipping member is a needle.

[0016] Optionally, the elastic member is a spring.

[0017] Optionally, the plurality of dipping assemblies are distributed in a matrix.

[0018] Optionally, the positions of the plurality of dipping assemblies correspond to the positions of the plurality of chip bumps one by one.

[0019] Optionally, the flux dipping device further comprises a driving member for driving the flux platform to ascend and descend.

[0020] Another aspect of the embodiments of the present disclosure provides a chip mounting system, which comprises a flux pool and the flux dipping device described above.

[0021] The flux dipping device and the chip mounting system of the embodiments of the present disclosure, the flux dipping device comprises a flux platform and a plurality of dipping assemblies; the plurality of dipping assemblies are telescopically arranged on the flux platform and are covered by the flux on the flux platform, and the plurality of dipping assemblies correspond to a plurality of chip bumps of a flip chip; wherein, when the chip bump dips the flux, the chip is lowered to contact the flux bump, the flux platform and the flux pool are simultaneously raised to a preset height, then the flux platform continues to rise, so that the dipping assembly dips the flux and then exposes the flux pool and abuts against the corresponding chip bump, thereby making each chip bump uniformly dip the flux. The flux dipping device solves the problem of poor flux dipping caused by chip warping and improves the reliability of chip welding. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a process schematic diagram of the flip chip mounting in the prior art;

[0023] Figure 2 It is a process schematic diagram of the chip bump dipping flux when the chip warps in the prior art;

[0024] Figure 3A structural schematic diagram of a flux dipping device according to an embodiment of the present disclosure;

[0025] Figure 4 A structural schematic diagram of a flux dipping device according to another embodiment of the present disclosure;

[0026] Figure 5 A working process schematic diagram of a flux dipping device according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solutions of the embodiments of the present disclosure, the embodiments of the present disclosure are further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] As shown in Figure 3 An aspect of the present disclosure provides a flux dipping device 100 for flip chip mounting, which includes a flux platform 110 and a plurality of dipping assemblies 120.

[0029] The plurality of dipping assemblies 120 are telescopically arranged on the flux platform 110 and are used to be covered by the flux of the flux pool 300, and the plurality of dipping assemblies 120 correspond to the plurality of chip bumps 210 of the chip 200.

[0030] When the chip bumps 210 dip the flux, the chip 200 is lowered to contact the flux, the flux platform 110 and the flux pool 300 are simultaneously raised to a preset height, then the flux platform 110 continues to rise, so that the dipping assemblies 120 dip the flux and then are exposed to the flux pool 300 and abut against the corresponding chip bumps 210, thereby making each chip bump 210 evenly dip the flux.

[0031] Specifically, as shown in Figure 4As shown, in the present embodiment, the warping of the chip edge region upward is taken as an example for illustration. When the chip bumps 210 dip into the flux, the chip 200 is lowered to a preset position so that the chip bumps 210 contact the flux. Then, after the flux platform 110 and the flux pool 300 are raised to a preset height, the limiting device prevents the flux pool 300 from continuing to rise, and only the flux platform 110 continues to rise so that the dip assembly 120 dips into the flux and then is exposed to the flux pool 300. As a result, the dip assembly 120 located at the central position of the flux platform 110 first abuts against the chip bumps 210 located at the central region of the chip 200, and then the chip bumps 210 located at the central region of the chip 200 are dipped into the flux. The flux platform 110 continues to rise, and the dip assembly 120 located at the central region of the flux platform 110 is compressed and shortened, so that the dip assembly 120 located at the edge region abuts against the chip bumps 210 located at the edge region of the chip 200, and then the chip bumps 210 located at the edge region of the chip 200 are dipped into the flux, and then each chip bump 210 is uniformly dipped into the flux.

[0032] It should be noted that, when the edge region of the chip warps downward, the flux dipping device of the present embodiment can also make each chip bump of the chip uniformly dipped into the flux.

[0033] The flux dipping device of the present embodiment comprises a flux platform and a plurality of dip assemblies. The plurality of dip assemblies are telescopically arranged on the flux platform and are covered by the flux on the flux platform, and the plurality of dip assemblies correspond to a plurality of chip bumps of a flip chip. When the chip bumps dip into the flux, the chip is lowered so that the chip bumps contact the flux. After the flux platform and the flux pool are simultaneously raised to a preset height, the flux platform continues to rise so that the dip assembly dips into the flux and then is exposed to the flux pool and abuts against the corresponding chip bump, and then each chip bump is uniformly dipped into the flux. The flux dipping device solves the problem of poor flux dipping caused by the warping of the chip and improves the reliability of the chip welding.

[0034] As shown in the examples of FIGS. 1 to 3, the dip assembly 120 comprises an elastic member 121 and a dip member 122. Figure 3 and Figure 4 As shown, the dip assembly 120 comprises an elastic member 121 and a dip member 122.

[0035] The first end of the elastic member 121 is connected to the flux platform 110, and the second end of the elastic member 121 is connected to the dip member 122. When the chip bumps 210 dip into the flux, the dip member 122 dips into the flux and then elastically abuts against the corresponding chip bump 210.

[0036] In one embodiment, the flux pool 300 can be made of a flexible material. A flux platform 110 is positioned at the bottom of the flux pool 300. The dipping component 122 passes through the bottom of the flexible flux pool 300 and enters the flux pool 300, where it is covered by flux. When the chip bump 210 dips in flux, the flux platform 110 and the flux pool 300 rise simultaneously to a preset height. The flux pool 300 then stops rising, while the flux platform 110 continues to rise, pressing against the flexible flux pool 300. This causes the dipping component 122 to be exposed in the flux pool 300 after dipping in flux and to abut against its corresponding chip bump 210. In this embodiment, because the dipping component 122 passes through the bottom of the flexible flux pool 300, leakage may occur. Therefore, a tray needs to be placed at the bottom of the flux platform 110 to collect any leaked flux.

[0037] In another embodiment, the flux pool 300 can also be made of a rigid material. The flux platform 110 is disposed on the inner bottom wall of the flux pool 300, and both the flux platform 110 and the dipping member 122 are covered by flux in the flux pool 300. When the chip bump 210 dips in flux, the flux pool 300 rises, causing the flux platform 100 located in the flux pool 300 to rise simultaneously to a preset height. After that, the flux pool 300 stops rising, and only the flux platform 100 rises, so that the dipping member 122, after dipping in flux, is exposed in the flux pool 300 and abuts against its corresponding chip bump 210.

[0038] It should be noted that the positional relationship between the flux platform 110 and the flux pool 300 is not specifically limited in this embodiment. As long as the dipper 122 can be exposed in the flux pool 300 after being dipped in flux and abut against its corresponding chip bump 210, it can be selected according to actual needs.

[0039] Specifically, such as Figure 4 As shown, taking the upward warping of the chip's edge region as an example, when the chip bump 210 is dipped in flux, the chip 200 descends to a preset position so that the chip bump 210 contacts the flux. Then, the flux platform 110 and the flux pool 300 rise together to a preset height, and a limiting device prevents the flux pool 300 from rising further; only the flux platform 110 continues to rise, so that the dipping component 120, after being dipped in flux, is exposed in the flux pool 300. This allows the dipping component 122, located in the center of the flux platform 110, to first abut against the chip bump 210 located in the central region of the chip 200. As the flux platform 110 continues to rise, the elastic component 121 in the central region is compressed and shortened, causing the dipping component 122 located in the edge region of the flux platform 110 to abut against the chip bump 210 located in the edge region of the chip 200, thereby ensuring that each chip bump 210 is evenly dipped in flux.

[0040] Exemplarily, as shown in Figure 3 and Figure 4 In the embodiment, the diameter of the dipper 122 is smaller than the diameter of the chip bump 210. In this way, each chip bump 210 can be dipped into the flux when the chip bump 210 is dipped into the flux.

[0041] Preferably, in the embodiment, the diameter of the dipper 122 is 70% to 80% of the diameter of the chip bump 210. Further preferably, the diameter of the dipper 122 for dipping into the flux is selected to be 70% of the diameter of the chip bump 210, so that each chip bump 210 can be dipped into the flux and covered with at least 70% of the flux.

[0042] Exemplarily, in the embodiment, the dipper 122 can be a needle. The elastic member 121 can be a spring. That is, the first end of the spring is connected to the flux platform 110, and the second end of the spring is connected to the needle. When the chip bump 210 is dipped into the flux, the needle elastically abuts against the corresponding chip bump 210.

[0043] It should be noted that the specific structure of the dipper 122 and the elastic member 121 is not limited in the embodiment, and can be selected according to actual needs.

[0044] Exemplarily, the plurality of dipper assemblies 120 are arranged in a matrix. The specific arrangement manner is not limited in the embodiment, and can be set according to the arrangement manner of the chip bumps 210.

[0045] Exemplarily, in the embodiment, the positions of the plurality of dipper assemblies 120 correspond to the positions of the plurality of chip bumps 210 one by one. In this way, each chip bump 210 can be dipped into the flux.

[0046] Exemplarily, the flux dipping device 100 further comprises a driving member for driving the lifting of the flux platform 110. Specifically, in the embodiment, the driving member can be a motor or the like. The specific structure of the driving member is not limited in the embodiment, and can be selected according to actual needs.

[0047] As shown in Figure 5 The working process of the flux dipping device 100 of the embodiment is as follows:

[0048] Step 1: The back of the chip 200 is sucked by the suction nozzle 400.

[0049] Step 2: Dip into the flux.

[0050] 2.1: The suction nozzle 400 is lowered to a position where the chip bump 210 contacts the flux.

[0051] 2.2: The height of the flux platform 110 is precisely controlled by the motor (accuracy control + / - 10um). The motor drives the flux platform 110 to rise.

[0052] 2.3: After the dip assembly 120 on the flux platform 110 and the flux pool 300 rise to the preset height, the limiting device prevents the flux pool 300 from continuing to rise, and only the flux platform 110 continues to rise, so that the dip assembly 120 is exposed from the flux pool 300 after dipping the flux, so that the dipper 122 located in the central position of the flux platform 110 first abuts against the chip bump 210 located in the central region of the chip 200. The elastic member 121 located in the central region is compressed and shortened, and the dipper 122 located in the edge region of the flux platform 110 abuts against the chip bump 210 located in the edge region of the chip 200, thereby uniformly dipping the flux on each chip bump 210.

[0053] Step 3: After the flux dipping is completed, each chip bump 210 is uniformly dipped with flux.

[0054] Step 4: Flip chip 200 is flip-chip mounted to the substrate 500.

[0055] It should be noted that in the new product stage, the warpage data of the chip is tested and used to set the rising height of the flux platform. In the new product stage, the shadow moire and warpage measurement data are collected, and in this embodiment, the chip warpage of the product at room temperature is about 382um, and the warpage of the edge region is the largest. According to the Shadow mario and the chip warpage data collection, the edge warpage is 382um, and considering the accuracy of the motor, the rising height of the flux platform is set to 392um.

[0056] Another aspect of the embodiment of the present disclosure provides a chip mounting system, which comprises the flux pool 300 and the flux dipping device 100 described above. The specific structural features of the flux dipping device 100 have been described in detail above, and will not be repeated here.

[0057] The chip mounting system of the embodiment of the present disclosure uses the flux dipping device described throughout to dip the flux on the chip bumps, ensuring that each chip bump is uniformly dipped with flux. The problem of poor flux dipping caused by chip warpage is solved, the reliability of chip welding is improved, and the reliability of chip mounting is improved.

[0058] It can be understood that the above implementation is only an exemplary implementation adopted for illustrating the principles of the embodiments of the present disclosure, however, the embodiments of the present disclosure are not limited thereto. Various modifications and improvements can be made by those of ordinary skill in the art without departing from the spirit and principle of the embodiments of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the embodiments of the present disclosure.

Claims

1. A flux application device for flip chip mounting, characterized in that, Includes a flux platform and multiple dispensing components; Multiple of the aforementioned dipping components are retractably disposed on the flux platform and are used to be covered by flux in the flux pool; The plurality of the aforementioned dipping components correspond to the plurality of chip bumps on the chip; wherein, When the chip bumps are dipped in flux, the chip descends until the chip bumps contact the flux. The flux platform and the flux pool rise simultaneously to a preset height. The flux platform continues to rise, so that the dipping component is exposed in the flux pool after dipping in the flux and abuts against its corresponding chip bump, thereby ensuring that each chip bump is evenly dipped in flux.

2. The apparatus according to claim 1, characterized in that, The dipping assembly includes an elastic element and a dipping element; The first end of the elastic element is connected to the flux platform, and the second end of the elastic element is connected to the dipping element; wherein... When the chip bump is dipped in flux, the dipping component elastically abuts against the corresponding chip bump after being dipped in flux.

3. The apparatus according to claim 2, characterized in that, The diameter of the dip-adhesive is smaller than the diameter of the chip bump.

4. The apparatus according to claim 3, characterized in that, The diameter of the pick-up piece is 70% to 80% of the diameter of the chip bump.

5. The apparatus according to any one of claims 2 to 4, characterized in that, The dipping component is a jack.

6. The apparatus according to any one of claims 2 to 4, characterized in that, The elastic element is a spring.

7. The apparatus according to any one of claims 1 to 4, characterized in that, The multiple dipping components are arranged in a matrix.

8. The apparatus according to claim 7, characterized in that, The positions of the multiple dipping components correspond one-to-one with the positions of the multiple chip bumps.

9. The apparatus according to any one of claims 1 to 4, characterized in that, It also includes a drive unit for driving the flux platform to rise and fall.

10. A chip mounting system, characterized in that, It includes a flux pool and a flux applicator as described in any one of claims 1 to 9.

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