CN203659818U - Cleaning equipment - Google Patents

Abstract

A cleaning equipment suitable for removing residual flux on a wafer stack structure, wherein the wafer stack structure has at least one micro gap between the wafer and the substrate, and the micro gap has a hole that allows liquid to flow On the inflow side and an outflow side, the cleaning equipment includes a cleaning chamber, a carrying platform, a liquid supply device and a liquid pumping device, wherein the carrying platform is disposed in the cleaning chamber, the liquid supply device and The liquid pumping device is disposed above the carrying platform, wherein the liquid supply device can apply a chemical cleaning liquid on the substrate and enter the small gap from the inflow side, and the liquid pumping device can The chemical cleaning liquid flow is driven through the micro gap and discharged from the outflow side to completely take away the flux remaining in the micro gap.

Description

Cleaning equipment

technical field

The utility model relates to a semiconductor cleaning technology (Clean technology), in particular to a cleaning device with a stacked wafer structure.

Background technique

By the way, a microprocessor chip includes a logic unit and multiple cache memories. If both the logic unit and the cache memory are arranged in a two-dimensional (2-D) pattern, the physical size of the chip will limit the fast memory. The amount of memory (due to poor manufacturing process of large-area chips), thus limiting the performance of the microprocessor.

In order to solve the problem of 2-D resources on a chip, methods for constructing three-dimensional (3-D) integrated circuits are being actively developed. Generally speaking, a typical 3-D IC manufacturing process includes: Via Formation, Via Filling, Wafer Thinning, and Wafer Bonding. Large steps, and wafer cleaning steps must be performed before and after each step to avoid contamination of the wafer during processing.

Further, the steps of wafer bonding can be roughly divided into three types: chip to wafer (Chip to Wafer, C2W), chip to chip (Chip to Chip, C2C), and wafer to wafer (Wafer to Wafer, W2W). type. However, the gap formed by wafer-to-wafer or wafer-to-chip bonding is usually 20-50 μm, so how to remove the residual flux or other impurities in such a small gap has become a technical bottleneck that urgently needs to be overcome. .

At present, semiconductor wafers are mostly cleaned by high-pressure cleaning, immersion cleaning, ultrasonic cleaning and other processes in the industry. Among them, the high-pressure cleaning process generally sprays the cleaning liquid onto the workpiece to be cleaned. Since this cleaning method requires a very high liquid supply pressure, a high-pressure pump with a working pressure of more than 80 kg is usually used, resulting in the cleaning process. High cost; the immersion cleaning process generally soaks the workpiece to be cleaned in the cleaning solution, but this cleaning method often cannot effectively remove the residual flux or other impurities in the tiny gap of 20-50 μm; ultrasonic cleaning The cleaning process generally applies ultrasonic vibration to the workpiece to be cleaned. However, in order to improve the cleanliness of the workpiece, it is usually necessary to increase the output of ultrasonic vibration. As the output increases, the wafers, patterns, etc. on the substrate will be damaged. Possibility is also relatively increased, causing adverse effects on the electrical properties of the components.

Therefore, in view of the fact that the traditional cleaning method has its improvement necessity, the present inventor has been engaged in the creative design and professional manufacturing experience in related fields for many years, and actively researches and improves the cleaning method in the tiny gap. Under the prudent consideration of condition, develop the utility model at last.

Utility model content

The utility model aims at the deficiency of the prior art, and proposes a cleaning device, which can control the flow direction of the chemical cleaning liquid, so as to completely remove the three-dimensional, vertically interconnected wafer stacking structure between 20-50 μm Flux or other impurities in the tiny gaps, which can improve the yield of subsequent processes.

In order to achieve the above purpose and effect, the utility model adopts the following technical solutions: a cleaning device for removing residual flux on a chip stack structure, wherein the chip stack structure has at least one chip located between the chip and the substrate There is a tiny gap, and the tiny gap has an inflow side and an outflow side through which liquid can flow. The cleaning equipment includes a cleaning chamber, a carrying platform, a liquid supply device and a liquid pumping device.

Wherein, the carrying platform is arranged in the cleaning chamber; the liquid supply device is arranged above the carrying platform, and is used to apply a chemical cleaning solution on the substrate, and make the chemical cleaning solution flow in from the substrate along the substrate. The side enters the tiny gap; the pumping device is arranged above the carrying platform to drive the chemical cleaning liquid flow through the tiny gap and discharge from the outflow side, so as to completely take away the flux remaining in the tiny gap .

Therefore, the utility model provides chemical cleaning liquid through a liquid supply device and a liquid pumping device, and controls the chemical cleaning liquid to flow in a specific direction through the tiny gap of 20-50 μm in the three-dimensional, vertically interconnected chip stacking structure, It can avoid damage to the chips and/or patterns on the substrate, and can completely remove the residual flux in the tiny gaps to obtain a chip stack structure with better cleanliness and ensure the electrical characteristics of the components.

The above description about the content of the utility model and the description of the following implementation modes are used to illustrate and explain the principle of the utility model, and provide further explanation of the patent application scope of the utility model.

Description of drawings

FIG. 1 is a schematic diagram of the process of the cleaning method of the wafer stack structure of the present invention.

FIG. 2 is a flow chart of the cleaning method of the wafer stack structure of the present invention.

Fig. 3 is a schematic diagram of the cleaning equipment of the present invention.

Fig. 4 is a diagram of the use state of the liquid supply device and the liquid pumping device of the present invention.

1 washing equipment

10 cleaning chamber

11 carrying platform

12 liquid supply device

121 infusion tube

122 nozzles

13 pumping device

131 drain pipe

132 pumping seat

1321 Slip Structure

1321a roller type sliding structure

1321b brush type sliding structure

14 heating device

W chip stack structure

S substrate

C chip

G tiny gap

Gi inflow side

Go outflow side

Detailed ways

The utility model discloses a novel cleaning equipment, which provides chemical cleaning liquid through a liquid supply device and a liquid pumping device, and controls the flow direction of the chemical cleaning liquid to effectively remove three-dimensional, vertically interconnected chip stacking structures Flux or other impurities in the tiny gap of 20-50μm. Hereinafter, a preferred embodiment will be cited together with the attached drawings to further elaborate the technological features of the wafer stacking structure cleaning equipment of the present invention; those skilled in the art can easily understand the present invention from the contents disclosed in the present invention. advantages and effects, and without departing from the spirit of the utility model, various modifications and changes are made to implement or apply the equipment of the utility model.

Please refer to Figure 2, the utility model first discloses a cleaning method of the stacked structure, which can completely remove the flux (Flux) in the chip stacked structure to obtain a good cleanliness (Cleanliness) chip stacked structure .

As shown in FIG. 2 , the cleaning method first executes step S10 , providing a wafer stack structure W (as shown in FIG. 1 ) to be cleaned. Specifically, the chip stack structure W includes a substrate S and at least one chip C on the substrate S, wherein the chip C is fixed on the substrate S in a flip-chip manner; when the flip-chip operation is completed, the chip C and the substrate S Solder inherent bumps or solder balls (not marked) between them, so there is a tiny gap G of 20-50 μm between the chip C and the substrate S, and the tiny gap G has an inflow side Gi and an outflow that allow liquid to flow Side Go.

It should be noted that, since the soldering operation needs to use flux (Flux) to remove the solder joints on the substrate S or the oxides and oil stains on the bumps on the chip C to achieve a good soldering effect, the chip stacking There is usually quite a lot of flux remaining on the structure W, especially the flux remaining in the tiny gap G is very difficult to remove.

Please refer to Figure 1, in order to completely remove the flux in the tiny gap G, the utility model then executes step S12 to provide a chemical cleaning solution, and make the chemical cleaning solution enter the tiny gap G from the inflow side Gi, and further flow out Side Go discharge. It is worth noting that in this step, a liquid supply device 12 and a liquid pumping device 13 are used to achieve the above purpose.

When the liquid supply device 12 and the liquid pumping device 13 are in use, the chemical cleaning liquid is applied on the substrate S by the liquid supply device 12, and the application position is adjacent to the inflow side Gi, and the liquid pumping device 13 is used in conjunction with the supply from the outflow side Go. The suction force makes the chemical cleaning solution flow along the surface of the substrate S from the inflow side Gi into the tiny gap G, and further flow through the tiny gap G to flow out from the outflow side Go to take away the flux in the tiny gap G. It should be noted that, the utility model does not limit the type of chemical cleaning liquid, and the chemical cleaning liquid used can be changed according to the type of flux.

Please refer to Fig. 3, in order to implement the above-mentioned cleaning operation (step S12) related to the wafer stacking structure W, the utility model provides a cleaning device 1, which only needs to put the wafer stacking structure W into the Among them, the flux remaining in the tiny gap G can be completely removed. As shown in the figure, the cleaning device 1 includes a cleaning chamber 10 , a carrying platform 11 , a liquid supply device 12 , a liquid pumping device 13 and a heating device 14 .

In this specific embodiment, the carrying platform 11 is fixed in the cleaning chamber 10 by a supporting structure (not shown) to carry the wafer stack W to be cleaned; the liquid supply device 12 and the liquid pumping device 13 respectively pass through The suspension structure (not shown) is movably arranged above the carrying platform 11 to provide and control the chemical cleaning solution to remove the flux; the heating device 14 is fixed on the supporting structure and is adjacent to the carrying platform 11 to allow the chips to be stacked The structure W is cleaned at an appropriate temperature, preferably between 70°C and 80°C, and more preferably 75°C.

It should be mentioned that as long as the support structure and suspension structure can achieve the effect of fixing specific components, the utility model does not limit the specific form of the support structure and suspension structure; The upper liquid supply device 12 and the liquid pumping device 13 provide the chemical cleaning liquid and control the flow direction of the chemical cleaning liquid, all of which fall into the category of the present invention.

In more detail, the liquid supply device 12 has an infusion tube 121 and a nozzle 122, wherein the infusion tube 121 is connected to a cleaning liquid supply end (not shown), and the nozzle 122 is affixed to one end of the infusion tube 121 and the two are connected to each other. Connected, the chemical cleaning solution can be applied to the tiny gap G from above the wafer C and the substrate S; preferably, a solenoid valve (not shown) can be set on the infusion tube 121 to control the delivery amount of the chemical cleaning solution.

The liquid pumping device 13 includes a liquid discharge pipe 131 and a liquid suction seat 132. The liquid discharge pipe 131 has a first end and a second end, wherein the first end is connected to a vacuum suction device (not shown) , the second end is connected to the bottom of the liquid pumping seat 132; moreover, the bottom of the liquid pumping seat 132 is also provided with a sliding structure 1321, which can be a roller type sliding structure 1321a or a brush type sliding structure 1321b, In order to slide on the substrate S and accurately move to any position to be cleaned. It should be noted that the present invention does not limit the specific form of the sliding structure 1321 , as long as the sliding structure 1321 can make the liquid pumping seat 132 slide on the substrate S arbitrarily.

According to a preferred embodiment of the present utility model, after the cleaning operation of the chemical cleaning solution is completed, the cleaning method of the wafer stack structure further includes step S14, changing the pure water and removing the chemical cleaning solution by the same cleaning method . Specifically, in this step, pure water enters the tiny gap G from the inflow side Gi of the tiny gap G through the liquid supply device 12 and the liquid pumping device 13, and is further discharged from the outflow side Go to take away the inside of the tiny gap G. The chemical cleaning liquid, and then the subsequent drying process of the wafer stack structure W can achieve a good drying effect. It is worth mentioning that the wafer/wafer stack structure W cleaned by the cleaning method of the wafer stack structure of the present invention can be applied to any drying method, such as IPA steam drying, and the present invention does not impose restrictions on this .

To sum up, compared with the way of removing flux in the existing wafer cleaning process, the utility model provides chemical cleaning liquid through a liquid supply device and a liquid pumping device, and controls the chemical cleaning liquid to flow through in a specific direction The tiny gaps of 20-30μm in the three-dimensional, vertically interconnected chip stacking structure can avoid damage to patterns and/or chips on the substrate, and can completely take away the residual flux in the tiny gaps to obtain better cleanliness The chip stacking structure ensures the electrical characteristics of the product.

However, the above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the scope of patent protection of the present utility model. Therefore, all equivalent changes made by using the utility model specification and accompanying drawings are all included in the same reason. Within the protection scope of the rights of the present utility model, it is agreed to Chen Ming.

Claims (7)

1. A cleaning device for removing residual flux on a wafer stack structure, wherein the wafer stack structure has at least one tiny gap between the wafer and the substrate, and the tiny gap has a An inflow side and an outflow side for liquid circulation, characterized in that the cleaning equipment includes: a cleaning chamber; A carrying platform is arranged in the cleaning chamber; A liquid supply device, arranged above the carrying platform, is used to apply a chemical cleaning solution on the substrate, and make the chemical cleaning solution enter the tiny gap from the inflow side along the substrate ;and A pumping device, arranged above the carrying platform, used to drive the chemical cleaning liquid flow through the tiny gap and discharge from the outflow side, so as to completely take away the flux remaining in the tiny gap . 2. The cleaning equipment according to claim 1, wherein said liquid supply device comprises a liquid infusion tube and a nozzle communicating with the liquid infusion tube. 3. The cleaning device according to claim 1, wherein said liquid pumping device comprises a liquid discharge pipe and a liquid suction seat communicated with the liquid discharge pipe. 4. The cleaning device according to claim 3, wherein a sliding structure is provided at the bottom end of the liquid suction seat. 5. The cleaning device according to claim 4, wherein said sliding structure is a roller type sliding structure. 6. The cleaning device according to claim 4, wherein said sliding structure is a brush type sliding structure. 7. The cleaning equipment according to claim 1, further comprising a heating device, the heating device is arranged under the carrying platform.

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