A spray valve cleaning device

Abstract

This utility model relates to a spray valve cleaning device, comprising: a platform body for fixing the spray valve to be cleaned; a temperature control strip, which is attached to the outer circumferential surface of the spray valve and forms a thermally conductive contact with the spray valve, wherein a heating element is disposed within the temperature control strip; and a compressed air source having a pneumatic pipeline; the pneumatic pipeline connecting the compressed air source to the glue inlet of the spray valve. This application can provide effective and non-damaging cleaning and maintenance for precision spray valves, thus effectively extending the service life of the spray valves.

Description

Technical Field

[0001] This application relates to the field of chip packaging technology, and in particular to a spray valve cleaning device. Background Technology

[0002] In the field of high-density integrated circuit (IC) packaging, the underfill process involves precisely applying adhesive (such as epoxy resin) to the gap between the chip and the substrate. After curing, this significantly enhances structural strength, resists thermal stress, and improves product reliability. Dispensing accuracy and stability directly affect product yield and performance, and the core component for dispensing is the precision spray valve. To meet the increasingly stringent requirements of highly integrated electronic components for tiny adhesive dots, the bottom dispensing orifice of the UNDERFILL spray valve is designed to be extremely small (typically on the order of tens to hundreds of micrometers) to ensure the formation of precise and controllable micro-dots. However, during long-term operation, the spray valve inevitably comes into contact with and retains contaminants such as adhesive, flux volatiles, and environmental dust. If these residues are not removed, they will directly affect the accuracy, consistency, and smoothness of dispensing, leading to poor dispensing, stringing, adhesive breakage, or even equipment failure. Therefore, the spray valve needs to be cleaned and replaced with adhesive every 24 hours. Daily cleaning and maintenance of the spray valve is a crucial step in maintaining the stable operation and production yield of the UNDERFILL station.

[0003] The traditional method commonly used in the industry is to use a lint-free cloth soaked in alcohol to wipe and clean the inner wall of the spray valve cavity, and to use a needle to physically unclog the tiny glue outlet hole at the bottom of the spray valve.

[0004] However, this method has serious drawbacks:

[0005] Needle tool failure: Due to the small size of the glue outlet, there is a lack of needles on the market that combine sufficient fineness and rigidity. Needles that are too thin are prone to bending and breaking, which not only makes it difficult to effectively clear the blockage, but the broken residue can also exacerbate the blockage.

[0006] Alcohol cleaning side effects: When cleaning the cavity with alcohol (such as IPA), it can induce the formation of silica (SiO2) polymers. These polymers are highly adhesive, difficult to dissolve, and easily aggregate and deposit inside the spray valve, especially on the inner wall of the tiny dispensing orifice, forming exceptionally hard and stubborn blockages.

[0007] The above problems overlap, creating a vicious cycle: the cleaning needle cannot effectively clear the initial micropore blockage; alcohol cleaning attempts to dissolve the residue, but instead introduces more difficult-to-remove silica polymer deposits, further aggravating the channel blockage, causing the spray valve to be frequently scrapped due to irreparable blockage (precision spray valves are expensive), affecting the stability of dispensing quality and production yield. Summary of the Invention

[0008] The purpose of this application is to solve the problem that existing cleaning methods are incomplete and easily lead to the failure of spray valves. This application provides a spray valve cleaning device.

[0009] To achieve the above objectives, this application adopts the following technical solution:

[0010] This application provides a spray valve cleaning device, comprising:

[0011] The main body of the platform is used to fix the spray valve to be cleaned;

[0012] A temperature control strip is attached to the outer circumferential surface of the spray valve and forms a thermally conductive contact with the spray valve. A heating element is provided inside the temperature control strip.

[0013] The pneumatic cleaning mechanism includes a compressed air source and a pneumatic pipeline, wherein the pneumatic pipeline connects the compressed air source to the glue inlet of the spray valve.

[0014] In one possible implementation, the platform body has a longitudinally extending support, a cantilever beam connected to the upper part of the support and extending laterally, and a bottom platform located below the cantilever beam, wherein the cantilever beam has a retaining ring for fixing the spray valve.

[0015] In one possible implementation, the spray valve cleaning device further includes a container for holding liquid, the container being located directly below the spray valve.

[0016] In one possible implementation, the spray valve cleaning device further includes an image recognition device for acquiring images of the ripples in the liquid inside the container and identifying the size of the ripples.

[0017] In one possible implementation, the end of the pneumatic conduit is directly connected to the glue inlet of the spray valve.

[0018] In one possible implementation, a pressure sensor is also provided at the end of the pneumatic pipeline. In another possible implementation, the pneumatic cleaning mechanism further includes a pure water tank for storing pure water, the end of the pneumatic pipeline being airtightly connected to the pure water tank, and the outlet of the pure water tank being connected to the glue inlet of the spray valve.

[0019] This invention abandons the traditional cleaning methods of alcohol and non-woven cloth, avoiding the aggregation of silica polymers and the blockage of the dispensing hole by broken needles. Compared with the prior art, this application has no limitation on the size of the dispensing hole, and can perform non-destructive and rapid cleaning of the spray valve. It is suitable for the daily cleaning and maintenance of precision spray valves and helps to extend the service life of the spray valve. Attached Figure Description

[0020] Figure 1This is a schematic diagram of an IC chip packaging structure;

[0021] Figure 2 This is a schematic diagram of the bottom filling process;

[0022] Figure 3 This is a top view of a spray valve cleaning device in one embodiment of this application;

[0023] Figure 4 This is a side view of the spray valve cleaning device in Embodiment 1 of this application;

[0024] Figure 5 This is a side view of the spray valve cleaning device in Embodiment 1 of this application;

[0025] The components include: 1. Underfill adhesive; 2. Bottom solder pad metal; 3. IC chip; 4. Solder ball; 5. Passivation material; 6. Solder mask; 7. Packaging substrate; 8. Contact pad; 9. Spray valve; 91. Adhesive outlet.

[0026] 11. Support frame; 12. Cantilever beam; 13. Temperature control belt; 14. Pressure sensor; 15. Air pressure pipeline; 16. Container; 17. Base platform; 18. Pure water tank. Detailed Implementation

[0027] To illustrate the technical content, structural features, achieved objectives, and effects of this application in detail, the technical solutions in the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. In the following description, for illustrative purposes, numerous specific details are set forth to provide a detailed description of various exemplary embodiments or implementations of the invention. However, various exemplary embodiments may also be implemented independently without these specific details or in one or more equivalent arrangements. Furthermore, the various exemplary embodiments may differ, but are not necessarily exclusive. For example, the specific shape, structure, and characteristics of the exemplary embodiments may be used or implemented in another exemplary embodiment without departing from the inventive concept.

[0028] Figure 1 This is a schematic diagram of the structure of the chip packaged using UNDERFILL. The IC chip 3 is bonded to the packaging substrate 7 by flip-chip bonding. There are still many gaps between the IC chip 3 and the packaging substrate 7, except for the solder balls 4. The UNDERFILL process is to fill these gaps with underfill adhesive 1 (such as epoxy resin) using a spray valve. Figure 2 A diagram illustrating the filling process is shown.

[0029] Figure 3 This is a top view of the spray valve cleaning device of this application. Example

[0030] Please refer to Figure 4 This spray valve cleaning device includes:

[0031] The platform body includes a longitudinal support 11, a transverse suspension beam 12, and a base platform 17. The support 11 is mounted on the base platform 17. One end of the suspension beam 12 is connected to the upper part of the support 11, and the other end of the suspension beam 12 has a fixing ring for securing the spray valve 9. The fixing ring can clamp the spray valve 9, ensuring that the valve body's glue outlet 91 faces vertically downwards. The base platform 17 has a certain thickness and weight, allowing it to be stably supported on the tabletop and keeping the suspension beam 12 and the spray valve 9 horizontal.

[0032] The temperature control strip 13 is installed on the suspension beam 12 and wraps around the outer periphery of the spray valve 9. The temperature control strip 13 is made of a flexible material (such as a silicone heating film) with an embedded nickel-chromium alloy heating wire. The flexible material allows for better wrapping of the spray valve 9, enabling good thermal contact and sufficient heat exchange. The temperature control strip 13 can adjust the temperature in real time via a PID temperature control module (not shown in the figure), with an operating range of 65-120℃ (the temperature during glue injection production is generally 60℃, and the operating temperature of the temperature control strip is higher than the operating temperature of the spray valve during glue injection production), reducing the viscosity of the residual epoxy resin to a flowable state.

[0033] The pneumatic cleaning mechanism includes a compressed air source (15-200 kPa) and a pneumatic pipe 15, the end of which is directly connected to the glue inlet of the spray valve 9.

[0034] A water-filled container 16 is placed on the base platform 17, located directly below the spray valve, to collect residual adhesive and impurities. Upon initiation of cleaning, the temperature control belt 13 heats the spray valve 9, while the pneumatic cleaning mechanism blows compressed air into the spray valve 9, causing the hot melt adhesive inside to be extruded from the bottom outlet 91 under air pressure. The container 16 serves two purposes: collecting waste adhesive and checking for airflow from the spray valve. Ripples appear in the water within the container as airflow exits the valve, allowing staff to determine if the valve is clogged. Example

[0035] In this embodiment, an image recognition device (not shown in the figure) is installed at the lower part of the cantilever beam 12 or at the opening of the container 16. The image recognition device captures images of the liquid surface ripples inside the container 16, and analyzes the ripple amplitude using an AI algorithm (such as a convolutional neural network) to identify the ripple size. If the ripple amplitude is large, it indicates that the colloid has good fluidity and cleaning is effective; if there are no ripples or only small ripples, it indicates that the dispensing hole is blocked, and the cleaning time needs to be extended. An audible alert can be used to remind the staff. Example

[0036] See Figure 5 The pneumatic cleaning mechanism further includes a pure water tank 18 for storing pure water. The upper end of the pure water tank 18 is airtightly connected to a compressed air source through a pneumatic pipe 15. The lower end of the pure water tank 18 has an outlet, which is connected to the glue inlet of the spray valve 9 through a hose.

[0037] During the cleaning process, the spray valve is heated to increase the fluidity of the residual colloid in the inner cavity of the spray valve. At the same time, pure water is forced into the cavity of the spray valve by air pressure. The flowing pure water not only assists the flow of colloid, but also improves the temperature uniformity of various parts of the cavity. Example

[0038] This embodiment adds a pressure sensor (not shown in the figure) to the first embodiment. The pressure sensor is set in the air pressure pipeline 15 near the glue inlet of the spray valve. When the detected pressure is greater than the set pressure of the compressed air source and does not drop for 3 seconds, it is determined that the glue outlet is blocked and an alarm sound is automatically issued.

[0039] The above structure gives this invention the following advantages:

[0040] Using temperature-controlled air pressure physical cleaning, the micropore blockage problem caused by alcohol-induced silica polymer deposition is completely avoided in traditional methods, and secondary chemical pollution can be eradicated.

[0041] The cleaning method uses a combination of heating and softening with air pressure to replace the easily broken needle, breaking through the bottleneck of ultra-micro hole cleaning technology, avoiding the risk of needle breakage, and allowing for a smaller range of adhesive outlet size.

[0042] The temperature is precisely controlled by a temperature control belt, and the temperature can be maintained at 65-120℃±1℃ through a PID algorithm. This can both fully soften the colloid (reduce viscosity) and eliminate the risk of overheating and carbonization.

[0043] Using a pressure sensor to detect pressure can promptly identify stubborn blockages and prevent damage to the valve body from ineffective air pressure.

[0044] Since this application can provide effective and non-damaging cleaning and maintenance for precision spray valves, it can effectively extend the service life of the spray valves.

[0045] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Various changes and modifications can be made to this application without departing from the spirit and scope of the invention. The scope of protection claimed by this application is defined by the appended claims, specification, and their equivalents.

Claims

1. A spray valve cleaning device, characterized in that, include: The main body of the platform is used to fix the spray valve to be cleaned (9); The temperature control strip (13) is attached to the outer circumferential surface of the spray valve (9) and forms a thermally conductive contact with the spray valve (9). A heating element is provided inside the temperature control strip (13). The pneumatic cleaning mechanism includes a compressed air source and a pneumatic pipe (15), wherein the pneumatic pipe (15) is connected to the compressed air source and the glue inlet of the spray valve (9).

2. The spray valve cleaning device according to claim 1, characterized in that, The platform body has a support (11) extending longitudinally, a cantilever beam (12) connected to the upper part of the support (11) and extending laterally, and a bottom platform (17) located below the cantilever beam (12). The cantilever beam (12) has a fixing ring for fixing the spray valve.

3. A spray valve cleaning device according to claim 1 or 2, characterized in that, It also includes a container (16) for holding liquid, which is located directly below the spray valve (9).

4. The spray valve cleaning device according to claim 3, characterized in that, It also has an image recognition device, which is used to acquire images of the ripples of the liquid inside the container and identify the size of the ripples.

5. The spray valve cleaning device according to claim 1, characterized in that, The end of the pneumatic pipe (15) is directly connected to the glue inlet of the spray valve (9).

6. The spray valve cleaning device according to claim 5, characterized in that, A pressure sensor is also provided at the end of the pneumatic pipe (15).

7. A spray valve cleaning device according to claim 1, characterized in that, The pneumatic cleaning mechanism further includes a pure water tank (18) for storing pure water, the end of the pneumatic pipe (15) is airtightly connected to the pure water tank (18), and the outlet of the pure water tank (18) is connected to the glue inlet of the spray valve (9).

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