System and method for removing integrated circuits from circuit boards having components mounted thereon using a hot fluid

Abstract

Some aspects of the present disclosure generally relate to systems for removing integrated circuits (ICs) designated for reuse from circuit boards (PCBs) having elements mounted thereon. In some embodiments, the ICs are designated for reuse and selective removal of the ICs from the PCBs is desirable. In some embodiments, the systems described herein facilitate relatively precise temperature control of a thermal fluid in which the PCBs are submerged. In some embodiments, the systems are configured to adjust the depth to which the PCBs are submerged in the thermal fluid, thereby allowing selective heating of some portions or the entirety of the PCBs. Other aspects relate to methods of using the systems described herein.

Description

Cross-reference to related applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 622,044, filed January 17, 2024, entitled “Systems and methods for the removal of integrated circuits from a board with mounted components using a thermal fluid”, filed under 35 USC § 119(e), the entire contents of which are incorporated herein by reference for all purposes. Technical Field

[0002] The general description includes systems and methods for removing integrated circuits designated for reuse from a board on which components are mounted. Background Technology

[0003] Typically, integrated circuits (ICs) designated for reuse are recovered from the surface of circuit boards (PCBs) where components are mounted. However, typical systems and methods for IC removal directly heat the PCB surface using infrared light or hot gas until the solder to which the IC is adhered reaches its liquidus temperature. Infrared light and hot gas each lack significant thermal mass, and therefore, the temperature applied to the PCB surface in conventional methods significantly exceeds the liquidus temperature of the solder in order to effectively heat and completely melt it. Furthermore, the surface temperature of the PCB to which it is heated cannot be precisely and / or constantly controlled, leading to inefficiencies in these methods and / or potentially overheating the IC and causing subsequent damage. Therefore, improved methods and systems are needed. Summary of the Invention

[0004] The present disclosure generally describes systems and methods for removing integrated circuits designated for reuse from a circuit board on which components are mounted. In some cases, the subject matter of this disclosure relates to a variety of different uses of interrelated products, alternative solutions to specific problems, and / or one or more systems and / or articles of manufacture.

[0005] ICs designated for reuse are removed from the PCB by immersing it in a hot bath in which the heat transfer fluid is maintained at a constant temperature not exceeding 10 degrees Celsius above the liquidus temperature of the solder that holds the IC to the PCB, and preferably not exceeding about 1 degree Celsius above the liquidus temperature, or in other embodiments, not exceeding about 2 degrees Celsius above the liquidus temperature, depending on factors such as the IC's sensitivity to thermal damage. Lead-free solders typically have a liquidus temperature of 217 to 221 degrees Celsius, such that for these solders, the heat transfer fluid is preferably maintained at about 222 degrees Celsius, or in other embodiments at about 223 degrees Celsius, or in still other embodiments between 222 and 223 degrees Celsius. Examples of solders that can be melted and / or removed from the PCB include those containing Sn, Pb, Ag, Cu, Zn, Bi, Sb, Au, Si, and / or In. PCBs containing lead-containing or lead-free solder can be processed. In some embodiments, the solder contains Sn, optionally in combination with one or more of Pb, Ag, Cu, Zn, Bi, Sb, Au, Si, and / or In. In some embodiments, the solder contains Au and / or Si.

[0006] In some implementations, the PCB may remain in the hot bath for just long enough for the solder to adhere the IC to the PCB to reach the liquidus temperature, typically 4 to 6 minutes. The hot bath may be shallow, with a depth just sufficient to allow the hot fluid to partially or just cover all designated ICs, and in some cases, its width just sufficient to accommodate ICs with the maximum intended width. The PCB may be conveyed through the bath until the solder reaches the liquidus temperature. Once the solder has reached the liquidus temperature, ICs designated for reuse may be identified by visual inspection or optical scanning and removed manually or automatically using one or more vacuum bars, mechanical grippers, and / or other removal tools. The PCB with its remaining components can then be conveyed to another, second region for bulk removal of the components, for example, by conveying it to a bucket immersed in a separate tank with the same or different types of hot fluid and rotated in the tank with or without fluid agitation until the remaining components fall off, and these components can be collected from the bucket as it is removed from the tank, for example in the system described in U.S. Patent No. 10,362,720, the entire contents of which are incorporated herein by reference. Alternatively, in some embodiments, the second region in which the remaining components of the PCB can be removed may be a section of the same hot bath in which the IC initially designated for reuse was removed: this section is located downstream of the section in which the IC designated for reuse was removed. In some embodiments, the hot fluid in the second region may be heated to a temperature different (e.g., a higher temperature) than the temperature of the hot fluid in the hot bath or the section in the hot bath in which the IC initially designated for reuse was removed.

[0007] Some aspects relate to a system. In some embodiments, the system is used to remove components designated for reuse from a circuit board on which components are mounted. In some embodiments, the system includes a container defining an internal volume, a fluid located within the internal volume of the container, and a temperature controller associated with the fluid, wherein the temperature controller is configured to maintain the temperature of the fluid within 10 degrees Celsius of a target temperature. In some embodiments, the system's temperature controller is configured to maintain the temperature of the fluid within 2 degrees Celsius of a target temperature. In some embodiments, the system's temperature controller is configured to maintain the temperature of the fluid within 1 degree Celsius of a target temperature. In some embodiments, the target temperature of the fluid in the system is equal to or just above the liquidus temperature of the solder present on the circuit board on which the components are mounted; for example, for solder with a liquidus temperature of 221 degrees Celsius (e.g., 96.5% / 3.5% tin / silver solder), the target temperature of the fluid in the system is approximately 222 degrees Celsius. In some embodiments, the system includes a container or bath defining an internal volume, fluid located within the internal volume of the container or bath, and a depth controller associated with the container or bath and configured to adjust the depth to which a circuit board with mounted components is immersed in the fluid within the container or bath. In some embodiments, the system includes a container or bath defining an internal volume, fluid located within the internal volume of the container or bath, a temperature controller associated with the container or bath, and a depth controller associated with the container, wherein the temperature controller is configured to maintain the temperature of the fluid within 1 degree Celsius or alternatively within 2 degrees Celsius of a target temperature, and wherein the depth controller unit is configured to adjust the depth to which the circuit board with mounted components is immersed in the fluid within the container.

[0008] Some aspects relate to methods. In some embodiments, the method includes: heating and controlling the temperature of a hot liquid in contact with a circuit board on which components are mounted, within 10 degrees Celsius of the liquidus temperature of the solder to which one or more integrated circuits are adhered to the circuit board on which components are mounted; and selectively removing one or more integrated circuits from the circuit board on which components are mounted. In some embodiments, the method includes: heating and controlling the temperature of a hot liquid in contact with the circuit board on which components are mounted, within 1 degree Celsius of the liquidus temperature of the solder to which one or more integrated circuits are adhered to the circuit board on which components are mounted, or alternatively within 2 degrees Celsius. In some embodiments, the method includes: selectively removing one or more integrated circuits from the circuit board on which components are mounted by using a first method. In some embodiments, the method further includes using a second method to remove remaining integrated circuits from a plurality of integrated circuits. In some embodiments, the method further includes immersing the circuit board on which components are mounted at least partially in the fluid.

[0009] Other advantages and novel features of this disclosure will become apparent from the following detailed description of various non-limiting embodiments of this disclosure when considered in conjunction with the accompanying drawings. In the event of any conflicting and / or inconsistent disclosures between this specification and other documents incorporated herein by reference, this specification shall prevail. Attached Figure Description

[0010] Non-limiting embodiments of this disclosure will be described by way of example with reference to the accompanying drawings, which are schematic and not intended to be drawn to scale unless otherwise stated. In the drawings, each identical or substantially identical component illustrated is generally indicated by a single reference numeral. For clarity, not every component is labeled in every drawing, and not every component of each embodiment of this disclosure is shown unless illustration is required to allow those skilled in the art to understand the disclosure. In the drawings:

[0011] Figure 1A and Figure 1B A schematic diagram of the various parts of a hot fluid IC removal system according to some embodiments is shown;

[0012] Figures 2A to 2C A schematic diagram of a PCB being transported along a hot fluid bath of a system, according to some embodiments, is shown.

[0013] Figure 3A and Figure 3B It depicts schematic diagrams illustrating the removal of components from a PCB according to some embodiments; and

[0014] Figure 4 This document contains a flowchart describing in detail a method for removing an IC from a PCB according to some embodiments as described herein. Detailed Implementation

[0015] Some aspects of this disclosure generally relate to systems for removing components (e.g., integrated circuits (ICs)) designated for reuse from a circuit board (PCB) containing mounted components. In some embodiments, the IC is designated for reuse, and it is desirable to selectively remove the IC from the PCB in a functional state. In some embodiments, the systems described herein facilitate relatively precise temperature control of the hot fluid in which the PCB is immersed. In some embodiments, the system is configured to adjust the depth at which the PCB is immersed in the hot fluid, thereby allowing selective heating and / or removal of some or all components of the PCB. Other aspects relate to methods using the systems described herein.

[0016] Electronic devices, including PCBs, can be used until they cease normal operation and / or until a new generation of electronic devices is released. At this point, the electronic devices can be recycled, and various components (e.g., ICs) can be designated for reuse. Typically, ICs designated for reuse are recovered from the PCB surface by directly heating the PCB surface with infrared light or hot gas until the solder adhering the IC to the PCB reaches its liquidus temperature. Infrared light and hot gas each lack significant heat capacity and thermal mass; therefore, the highest temperatures typically used to facilitate the desired removal time can be quite high, causing the IC on the PCB surface to experience temperatures significantly exceeding the solder's liquidus temperature during such conventional methods, potentially causing thermal damage to sensitive ICs. Furthermore, when using conventional methods, the surface temperature to which the PCB is heated cannot be precisely and / or consistently controlled, which can introduce inefficiencies and / or potentially overheat and damage the IC. Therefore, some aspects of this disclosure generally relate to systems and methods associated with precisely heating the PCB to facilitate the removal of ICs designated for reuse from the PCB.

[0017] Figure 1A This is an example of a part of a system 100 disclosed for the first time herein. System 100 includes a container 110 having an internal volume 115, which is partially filled with fluid 120. A temperature sensor 130 is present in the container 110 and can communicate with a control unit 140. Figure 1B As shown and as described elsewhere herein, system 100 can be configured to house one or more circuit boards 150 with mounted components within fluid 120 of container 110.

[0018] The system may include a container or bath. The container or bath may be sized and adapted to accommodate one or more circuit boards with mounted components. For example, such as... Figures 1A to 1B As shown, container 110 is sized and adapted to accommodate circuit board 150 with mounted components. The container or bath can be any shape of various types, such as cylindrical, rectangular prism, or other regular or irregular shapes. The size of the container or bath can be adjusted depending on the PCBs to be inserted into the container or bath, and / or the expected throughput associated with the number of PCBs being inserted into the container.

[0019] In some embodiments, the container or bath may contain a fluid. The fluid may be a hot fluid with a high heat capacity and may remain liquid until it reaches a temperature at least exceeding the liquidus temperature of the solder present on the board on which the components are mounted. In some embodiments, the fluid may be a hot fluid capable of maintaining its temperature while transferring heat to and / or from the board on which the components are mounted. In some embodiments, the fluid may be any one of a variety of fluids or a fluid comprising any one of a variety of fluids. Non-limiting examples of thermal fluids that may be used according to the invention (e.g., for melting solder) include: synthetic and natural oils, mineral oils, petroleum-based oils (e.g., those containing paraffinic hydrocarbons and / or cycloalkanes), aromatics (e.g., those containing compounds with a benzene-based structure, and including diphenyl ether / biphenyl fluids, diphenyl ethane, dibenzyltoluene, and terphenyl), vegetable oils, animal oils, polymeric silicone compounds and silicone oils, mixed glycol fluids, natural and synthetic waxes and paraffins, molten salts, ionic liquids and mixtures thereof, and thermal fluids sold under trademarks such as Dowtherm™, Syltherm™, Therminol™, Duratherm™, Calflo™, Petro-Therm™, Paratherm™, Xcelpherm™, Dynalene™, etc. Other fluids are also possible.

[0020] According to some embodiments, the amount of fluid in the container or bath can be any of a variety of suitable amounts. In some embodiments, the amount of fluid can be selected to achieve a certain fluid depth. For example, as described elsewhere herein, in some embodiments, the PCB having the IC can be partially submerged in the fluid, such that the board can be located in the fluid, but the IC can be substantially outside the fluid. In some embodiments, the entire PCB and IC can be submerged in the fluid. Therefore, the amount of fluid in the container or bath can be selected such that the maximum depth of the fluid (e.g., the depth to which the PCB can be inserted) is greater than or equal to 0.1 inches, greater than or equal to 0.2 inches, greater than or equal to 0.25 inches, greater than or equal to 0.3 inches, greater than or equal to 0.4 inches, greater than or equal to 0.5 inches, greater than or equal to 0.6 inches, greater than or equal to 0.7 inches, greater than or equal to 0.8 inches, greater than or equal to 0.9 inches, greater than or equal to 1 inch, greater than or equal to 1.25 inches, greater than or equal to 1.5 inches, greater than or equal to 1.75 inches, greater than or equal to 2 inches, or greater than or equal to 2.25 inches. In some implementations, the amount of fluid in the container or bath can be selected such that the maximum depth of the fluid (e.g., the depth to which a PCB can be inserted) is less than or equal to 2.5 inches, less than or equal to 2.25 inches, less than or equal to 2 inches, less than or equal to 1.75 inches, less than or equal to 1.5 inches, less than or equal to 1.25 inches, less than or equal to 1 inch, less than or equal to 0.9 inches, less than or equal to 0.8 inches, less than or equal to 0.7 inches, less than or equal to 0.6 inches, less than or equal to 0.5 inches, less than or equal to 0.4 inches, less than or equal to 0.3 inches, less than or equal to 0.25 inches, or less than or equal to 0.2 inches. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.1 inches and less than or equal to 2.5 inches). Other ranges are also possible.

[0021] The use of a liquid hot fluid may be advantageous for any of a variety of reasons compared to the use of gases or IR rays, which are conventionally used for heating PCBs. For example, the hot fluid may have a high heat capacity, thus allowing the desired temperature to be maintained with minimal fluctuations when transferring heat to or from the PCB. For instance, in some such embodiments, the temperature of the hot fluid may change, but this change may be relatively small due to the high heat capacity of the hot fluid. In some embodiments, temperature variations in the hot fluid can be mitigated by inputting heat via a temperature controller to offset heat losses in the hot fluid. Furthermore, and as described in more detail elsewhere herein, a temperature controller thermally coupled to the hot fluid can facilitate precise control of the hot fluid temperature. In some such embodiments, the temperature of the hot fluid can be maintained within a precise range from a target temperature, which can be selected to minimize and / or avoid damage to ICs present on the PCB when heating the PCB to remove ICs. In some implementations, the temperature controller is configured to heat the PCB contained in the associated container or bath to a temperature within 10 degrees Celsius of the target temperature (e.g., within 5 degrees Celsius, within 2 degrees Celsius, within 1 degree Celsius, within 0.5 degrees Celsius, within 0.25 degrees Celsius, or within 0.1 degrees Celsius).

[0022] In some implementations, the fluid can be selected such that it can be heated to a relatively high temperature without evaporating a significant amount (less than 5% by volume) during the time required to remove the IC from the PCB being processed. This relatively high temperature is, for example, a temperature corresponding to and / or above the liquidus temperature of the solder used to adhere electronic components to the circuit board.

[0023] Refer again Figure 1A System 100 may include a control unit 140. In some embodiments, the control unit may be a temperature controller. The temperature controller may be in thermal contact with the hot fluid 120 in container 110. In some embodiments, the temperature controller may be configured to control the temperature of the fluid in the container, such as the temperature measured by temperature sensor 130. In some such embodiments, the temperature controller may be configured to change the temperature of the fluid, wherein the temperature sensor can monitor the temperature of the fluid. Communication between the temperature controller and the temperature sensor can facilitate a feedback loop between the temperature sensor and the temperature controller for more precise control of the fluid temperature. Although in Figure 1A Not shown, but the temperature controller may also include features (e.g., stirring rod, electronic mixer, circulation pump, etc.) for providing agitation and / or convection within the fluid 120 to promote a relatively uniform temperature throughout the fluid 120.

[0024] To change the temperature of a fluid, a temperature controller may include components for heating the fluid. In some embodiments, the temperature is controlled via a heating element of the temperature controller, which is controlled by the temperature controller's control circuitry and / or a computer. Example heating elements include heat exchangers, and / or resistance heater elements, infrared radiation heaters, etc. Other heating elements for heating the fluid are also possible.

[0025] In some embodiments, the temperature controller is configured to controllably heat the PCB. As described above, in some embodiments, the temperature controller may be configured to heat and / or control the temperature of a fluid. According to some embodiments, the fluid is a liquid and may remain liquid until a relatively high temperature is reached, for example, at least 10 degrees Celsius above the liquidus temperature of the solder on the PCB. In some embodiments, the temperature controller may be configured to heat the fluid in the system to a temperature corresponding to a temperature above the liquidus temperature of the solder. In some embodiments, the temperature controller may be configured to heat the fluid in the system to a temperature above the liquidus temperature of the solder present on the PCB. In some embodiments, the temperature controller may be configured to control the temperature of the fluid to control the temperature of the PCB immersed therein.

[0026] For example, in some embodiments, the solder of the PCB may have a liquidus temperature of 220 degrees Celsius. Therefore, in some embodiments, the system's temperature controller may be configured to heat the system's fluid to an average temperature greater than or equal to 220 degrees Celsius, greater than or equal to 221 degrees Celsius, greater than or equal to 222 degrees Celsius, greater than or equal to 223 degrees Celsius, greater than or equal to 224 degrees Celsius, greater than or equal to 225 degrees Celsius, greater than or equal to 226 degrees Celsius, greater than or equal to 227 degrees Celsius, greater than or equal to 228 degrees Celsius, or greater than or equal to 229 degrees Celsius. In some implementations, the temperature controller may be configured to heat the fluid in the system to an average temperature less than or equal to 230°C, less than or equal to 229°C, less than or equal to 228°C, less than or equal to 227°C, less than or equal to 226°C, less than or equal to 225°C, less than or equal to 224°C, less than or equal to 223°C, less than or equal to 222°C, or less than or equal to 221°C. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 220°C and less than or equal to 230°C, greater than or equal to 220.5°C and less than or equal to 221.5°C). Other ranges are also possible. In some implementations, the temperature controller may be configured to heat the fluid to a range higher or lower than the foregoing ranges, for example, based on a target liquidus temperature of the solder on the PCB.

[0027] In some implementations, the temperature controller can be configured to heat the fluid in the system to the aforementioned range with relatively high precision. For example, in some implementations, when heated by the temperature controller, the temperature of the fluid in the system can be heated to within 2 degrees Celsius, 1 degree Celsius, 0.5 degrees Celsius, or 0.1 degrees Celsius of the target temperature. In some implementations, once the average temperature of the fluid reaches the target temperature, the average temperature of the fluid can be controlled to fluctuate less than or equal to 1 degree Celsius, less than or equal to 0.5 degrees Celsius, or less than or equal to 0.1 degrees Celsius, unless there are short-term fluctuations caused by any external stimuli (e.g., when inserting the PCB into the fluid).

[0028] Refer again Figure 1A System 100 may include a control unit 140. As described above, in some embodiments, the control unit may include a temperature control component. In some embodiments, control unit 140 (or a separate control unit (not shown)) includes sensors and control features for hot liquid depth control. In some such embodiments, the depth controller may communicate with one or more depth or pressure sensors 130 and / or weirs or skimming / liquid removal devices. In some embodiments, the depth controller controls the depth to which the PCB is immersed in the system fluid. For example, in some embodiments, the depth controller may be configured to, for example, use a method such as Figure 1A The sensor 130 shown monitors and / or changes the position of the PCB within the fluid, and / or controls the depth of the hot fluid to control the immersion depth. This position sensor can be any of a variety of devices, such as an optical sensor. In some embodiments, the depth controller can change the immersion depth of the PCB in the fluid, for example, by adjusting the amount of fluid in the container and / or changing the position of the PCB within the container.

[0029] In one exemplary embodiment, the system includes a conveyor that transports the PCB through a bath having a section with varying hot fluid depth to provide depth control during a process that can be operated as a continuous or semi-continuous process. Consider Figures 2A to 2C The diagram illustrates one embodiment, which includes a conveyor 142 in a container 110 of system 100 that conveys PCB 150 along direction 135. In some embodiments, conveyor 142 may include a first ramp portion 147 along which PCB 150 is conveyed in direction 135 to a first shallow section 146 of fluid bath 120. In some embodiments, such as Figure 2BAs illustrated, the first section 146 can be positioned relative to the fluid 120 to partially immerse the PCB 150 in the fluid. In some embodiments, during the time the PCB resides in the first section, the hot fluid in the first section or the entire bath is maintained at a first lower temperature, for example, within 1 or 2 degrees Celsius of the liquidus temperature of the solder that holds the IC to the PCB. During this removal phase, the most heat-sensitive ICs can be removed, exposing them to relatively lower temperatures while not being immersed or only partially immersed to protect them from heat damage. Once such ICs have been removed, the conveyor 142 can transport the PCB, along with any remaining ICs or other components, via the second ramp section 145 to a second, deeper section 144 of the hot bath 120. In some embodiments, the temperature in the second section can be maintained at a higher temperature (or a system-associated temperature controller can be operated to increase the temperature of the entire hot tub after the PCB 150 has been conveyed to the second section 144) to more quickly remove remaining components and solder from the PCB. In some embodiments, the system's conveyor, when present, may include any number of ramp sections and flat sections for positioning the PCB at different depths within the system's fluid. The final ramp section 143 of the conveyor 142 may be configured to convey the PCB (or its current bare portion) out of the fluid bath 120 of the system 100.

[0030] In some implementations, Figures 1A to 1B and Figures 2A to 2C The control unit 140 shown in the figure may be a temperature controller and / or a depth controller. In some embodiments, although not shown, both a temperature controller and a separate depth or pressure controller may be included in the system, such that the depth to which the PCB is immersed in the fluid can be controlled, while the temperature of the fluid is controlled simultaneously and / or independently.

[0031] In some embodiments, the system for removing components from the PCB may further include elements for removing the IC from the PCB. Such elements for removing components from the PCB can remove the IC 152 from the bare board 154 of the PCB 150, such as... Figure 3A As shown. In some implementations, such as Figure 3B As shown, only certain ICs 152 are removed from the bare board 154 of the PCB 150. In some such embodiments, ICs designated for reuse may be introduced (e.g., moved, conveyed, etc.) into a second section for bulk removal of components 156 (e.g., ...). Figure 2CThe IC is selectively removed before section 144. In some such embodiments, the selectively removed IC may be designated for reuse before the PCB is introduced into a deeper and / or hotter chip removal section of the system. In some embodiments, the deeper and / or hotter chip removal section of the system is a second region for bulk removal of components (e.g., such as...). Figures 2A to 2C (As shown in the diagram).

[0032] According to some embodiments, the tool for removing components (e.g., ICs) from a PCB can be any of a variety of suitable tools known in the art for this purpose. In some embodiments, the tool for removing components from a PCB can be a "pick-and-place" machine configured to selectively and physically grip and remove components from the PCB. In some embodiments, the tool for removing components from a PCB can be configured to selectively apply suction to components (e.g., ICs) on the PCB designated for reuse to remove such components. Other tools for removing components from a PCB may also be used, as this disclosure is not limited thereto. In some embodiments, the tool for removing components from a PCB can be coupled to a processor and / or a microcontroller to automate the removal of components from the PCB (e.g., selective removal), for example, via robotics.

[0033] In some implementations, the second region for bulk component removal can be configured to remove remaining ICs from the PCB (i.e., after the initial removal of ICs designated for reuse). As described above, in some implementations, the second region of the system can be a deeper and / or hotter second segment of chip removal from the system. In some implementations, the second segment can be a continuation of the hot fluid bath in which the initial components were removed (e.g., as...). Figures 2A to 2C (As shown). In some other embodiments, the second region may be a second separate container or a separate hot fluid bath in which the PCB with remaining components can be placed. According to some embodiments, the hot fluid in the second region may be controlled to a different temperature than the hot fluid in the first (e.g., initial) region in which the initial components are removed from the PCB. In some embodiments, the different temperature may be selected to be high enough to remove any remaining components from the PCB relatively quickly and / or completely. In some embodiments, the different temperature may be greater than or equal to 220 degrees Celsius, greater than or equal to 221 degrees Celsius, greater than or equal to 222 degrees Celsius, greater than or equal to 223 degrees Celsius, greater than or equal to 224 degrees Celsius, greater than or equal to 225 degrees Celsius, greater than or equal to 228 degrees Celsius, greater than or equal to 230 degrees Celsius, or greater than or equal to 232 degrees Celsius, and / or less than or equal to 235 degrees Celsius, less than or equal to 238 degrees Celsius, or less than or equal to 240 degrees Celsius.

[0034] In some embodiments, the removal of bulk components within the second region of the system occurs through simple gravity-assisted removal of the components as the solder or other adhesive is heated and liquefied or otherwise thermally destroyed. In some embodiments, the removal of bulk components within the second region of the system is assisted by applying mechanical, pneumatic, and / or fluid forces to the components, for example, by scraping and / or brushing the component-containing surface of the PCB. In some embodiments, applying force to the components can be done using any suitable tool or method, for example, by applying force by brushing a flexible wire brush across the PCB surface. It will be understood that the PCB can be heated and force applied to remove any bulk components remaining on the PCB surface.

[0035] Some aspects of this disclosure generally relate to IC removal methods as described herein. Figure 4 An example method flowchart is shown, detailing how to implement certain methods and / or perform such methods using the system described herein. Method 400 includes, at step 410, at least partially immersing the PCB in a fluid. As described above, in some embodiments, the depth to which the PCB is immersed in the fluid can be controlled, for example, by a depth controller. In some embodiments, the PCB may be only partially immersed in the fluid. In some embodiments, the PCB may be completely immersed in the fluid.

[0036] According to some embodiments, method 400 includes heating the PCB to within 10 degrees Celsius above and / or within a few degrees Celsius below the liquidus temperature of the solder to which one or more integrated circuits are adhered to the PCB 420 (e.g., within 9 degrees Celsius, within 5 degrees Celsius, within 2 degrees Celsius, within 1 degree Celsius, etc., as described elsewhere herein). In some embodiments, the PCB may be heated to a temperature precisely corresponding to about 2 degrees Celsius or 1 degree Celsius above the liquidus temperature of the solder on the PCB. In some embodiments, heating the PCB to a temperature within a specific range of the solder's liquidus temperature is advantageous because this prevents any components of the PCB (e.g., ICs designated for reuse) from being exposed to temperatures significantly above the solder's liquidus temperature, which can prevent degradation and / or other damage to the components on the PCB and can facilitate their reuse. The heating of the PCB may be performed using a temperature controller, as described in more detail elsewhere herein.

[0037] During the heating of the PCB, the solder adhering the components to the PCB can be sufficiently melted to remove selected ICs. Method 400 may also include selectively removing one or more such ICs from the PCB—step 430. In some embodiments, the removal of one or more ICs from the PCB can be performed while the PCB remains submerged in the fluid. In some embodiments, the PCB can be removed from the fluid before one or more ICs are removed from the PCB. In other embodiments, the PCB can be partially removed from the fluid before one or more ICs are removed from the PCB. For example, refer again... Figures 2A to 2C PCB 150 can be moved to, for example Figure 2C The positions shown are such that the PCB is only slightly or partially immersed in the system fluid. According to some such embodiments, the PCB is positioned such that the solder of the board and adhered components (e.g., ICs) remains substantially submerged in the fluid, while the components are substantially removed from the fluid. In some embodiments, this positioning of the PCB relative to the fluid can facilitate selective removal of one or more components of the PCB because the solder of the adhered components can remain heated by the fluid and thus remain at their liquidus temperature (e.g., and substantially melt).

[0038] Again, as mentioned above, selectively removing components from a PCB can include removing only a portion of the components on the PCB, such as... Figure 3B As illustrated. In some such embodiments, components selectively removed, for example by step 430, may be designated for reuse before performing step 440 to remove additional / residual components. That is, in some embodiments, method 400 may include designating at least some of the components of the PCB for removal by the first method step 430. In other embodiments, all components present on the PCB may be removed by the first method step 430. In other embodiments, not all components on the PCB may be removed by the first method step 430.

[0039] As described above, method 400 may further include removing remaining integrated circuits from the PCB using a second method step 440, for example, when selective removal of one or more components of the PCB has not removed all components from the PCB. In some embodiments, after some ICs from the PCB have been removed via the first method, the PCB may be kept at least partially immersed in a hot fluid to maintain heating until any remaining components present on the PCB are ready to be removed by the second method. In some embodiments, this may be desirable to minimize the energy required to heat the PCB during the second method. Any of the various second method steps 440 may be used to remove any remaining components from the PCB. For example, in some embodiments, the PCB with remaining components may be moved to a second region. In some embodiments, the second region may be a second portion of a continuous hot bath designated for reuse, in which the initial components were also removed. In some embodiments, the second region may be a separate container or a separate hot fluid bath in which the PCB is placed. In some embodiments, the hot fluid in the second region may be heated to a temperature different from (e.g., higher) than the temperature of the hot fluid in the hot bath. In some embodiments, the different temperature may be selected to be high enough to remove any remaining components while avoiding any unnecessary energy usage. As another example, a method for removing residual components from a PCB is described in U.S. Patent No. 10,362,720, which has been previously cited and incorporated herein by reference.

[0040] While several embodiments of the invention have been described and illustrated herein, those skilled in the art will readily conceive of various other means and / or structures for performing the functions described herein and / or obtaining the results and / or one or more advantages described herein, and each of such variations and / or modifications is considered to be within the scope of the invention. More generally, those skilled in the art will readily understand that all parameters, dimensions, materials, and configurations described herein are intended to be exemplary, and actual parameters, dimensions, materials, and / or configurations will depend on one or more specific applications in which the teachings of the invention are applied. Those skilled in the art will recognize, or be able to determine, many equivalents of the specific embodiments of the invention described herein using only conventional experiments. Therefore, it should be understood that the foregoing embodiments are presented by way of example only, and that the invention can be practiced in ways other than those specifically described and claimed within the scope of the appended claims and their equivalents. The invention relates to each individual feature, system, article, material, and / or method described herein. Furthermore, any combination of two or more such features, systems, articles, materials, and / or methods is included within the scope of the invention if such features, systems, articles, materials, and / or methods are not inconsistent with each other.

[0041] As used herein in the specification and claims, unless expressly indicated to the contrary, the indefinite articles “a” and “an” shall be understood to mean “at least one”.

[0042] As used herein in the specification and claims, the phrase “and / or” should be understood to mean “any one or both” of the elements so connected, that is, elements that exist together in some cases and separately in others. Other elements may optionally exist in addition to those specifically identified by the “and / or” clause, whether related to or unrelated to those specifically identified elements, unless explicitly indicated to the contrary. Thus, as a non-limiting example, reference to “A and / or B”, when used in conjunction with open-ended language such as “comprising,” may in one embodiment refer to only A without B (optionally including elements other than B); in another embodiment refer to only B without A (optionally including elements other than A); in yet another embodiment refer to both A and B (optionally including other elements); and so on.

[0043] As used herein in the specification and claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” should be interpreted as inclusive, that is, including at least one of a plurality or series of elements, but also including more than one, and optionally including additional unlisted items. Only terms that explicitly indicate the opposite, such as “only one” or “exactly one”, or when used in the claims, “consisting of…”, will refer to exactly one of a plurality or series of elements. Generally, the term “or” as used herein should only be interpreted as indicating an exclusive alternative (i.e., “one or the other but not both”) when preceded by an exclusive term such as “any,” “one of,” “only one,” or “exactly one.” “Substantially consisting of…”, when used in the claims, should have its ordinary meaning as used in the field of patent law.

[0044] As used herein in the specification and claims, the phrase "at least one" referring to a list of one or more elements should be understood to mean at least one element selected from any one or more elements in the list of elements, but does not necessarily include at least one element from each element specifically listed in the list of elements, and does not exclude any combination of elements in the list of elements. This definition also allows for the optional presence of other elements besides those specifically identified in the list of elements referred to by the phrase "at least one," whether related to or unrelated to those specifically identified elements. Thus, as a non-limiting example, "at least one of A and B" (or equivalently, "at least one of A or B," or equivalently, "at least one of A and / or B") in one embodiment may mean at least one, optionally including more than one A, with no B present (and optionally including elements other than B); in another embodiment, it may mean at least one, optionally including more than one B, with no A present (and optionally including elements other than A); in yet another embodiment, it may mean at least one, optionally including more than one A, and at least one, optionally including more than one B (and optionally including other elements); and so on.

[0045] Some implementations may embody a method, and various examples of such methods have been described. Actions performed as part of a method can be ordered in any suitable manner. Therefore, implementations in which actions are performed in a different order than illustrated can be constructed, which may include (e.g., more or fewer) actions different from those described, and / or may involve performing some actions simultaneously, even if the actions are shown as being performed sequentially in the implementations specifically described above.

[0046] The use of ordinal terms such as "first," "second," and "third" in the claims to modify a claim element does not imply any priority, order of precedence, or sequence of one claim element relative to another, nor does it imply the chronological order in which the method actions are performed. Rather, it is merely used as a label to distinguish one claim element with a certain name from another element with the same name (but using ordinal terms) to differentiate claim elements.

[0047] In the claims and in the above description, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” etc., shall be understood as open-ended, that is, meaning including but not limited to. Only the transitional phrases “consisting of” and “consisting substantially of” shall be closed or semi-closed transitional phrases, respectively, as specified in Section 2111.03 of the U.S. Patent and Trademark Office Patent Examination Procedure Manual.

Claims

1. A system for removing components designated for reuse from a circuit board on which components are mounted, the system comprising: Container or bathtub; The fluid located in the container or bath; as well as Temperature controller associated with fluid, The temperature controller is configured to maintain the temperature of the fluid within 10 degrees Celsius of the target temperature.

2. The system according to claim 1, wherein, The temperature controller is configured to maintain the temperature of the fluid within 2 degrees Celsius of the target temperature.

3. The system according to claim 1, wherein, The temperature controller is configured to maintain the temperature of the fluid within 1 degree Celsius of the target temperature.

4. The system according to any one of the preceding claims, wherein, The target temperature is the liquidus temperature of the solder present on the circuit board on which the components are mounted, and the liquidus temperature is optionally 220 degrees Celsius.

5. The system according to claim 1, wherein, The fluid is a hot liquid.

6. The system according to claim 1, wherein, The container or bath holds a circuit board on which components are mounted.

7. A system for removing components designated for reuse from a circuit board on which components are mounted, the system comprising: Container or bathtub; The fluid located in the container or bath; as well as A depth controller associated with the container or bath and configured to adjust the depth at which the circuit board with mounted components is immersed in the fluid within the container or bath.

8. The system according to claim 7, wherein, The fluid is a hot liquid.

9. The system according to claim 8, wherein, The container or bath contains the circuit board with mounted components, which is partially immersed in a hot liquid.

10. A system for removing components designated for reuse from a circuit board on which components are mounted, the system comprising: Container or bathtub; The fluid located in the container or bath; A temperature controller associated with the container or bathtub; as well as A fluid depth controller associated with the container or bath. The temperature controller is configured to maintain the temperature of the fluid within 10 degrees Celsius of a target temperature, and the depth controller unit is configured to adjust the depth at which the circuit board with mounted components is submerged in the fluid within the container.

11. The system according to claim 10, wherein, The fluid is a hot liquid.

12. The system according to claim 11, wherein, The container or bath contains the circuit board with mounted components, which is partially immersed in a hot liquid.

13. The system according to claim 10, wherein, The target temperature is the liquidus temperature of the solder used to fix the component to the circuit board on which the component is mounted.

14. The system according to claim 10, wherein, The temperature controller is configured to maintain the temperature of the fluid within 2 degrees Celsius of the target temperature.

15. The system according to claim 10, wherein, The temperature controller is configured to maintain the temperature of the fluid within 1 degree Celsius of the target temperature.

16. A method comprising: The temperature of the hot liquid in contact with the circuit board on which the components are mounted is heated and controlled within 10 degrees Celsius of the liquidus temperature of the solder to which one or more integrated circuits are adhered to the circuit board on which the components are mounted; and Selectively remove one or more of the integrated circuits from the circuit board on which the components are mounted.

17. The method of claim 16, comprising: The temperature of the hot liquid in contact with the circuit board on which the components are mounted is heated and controlled within 2 degrees Celsius of the liquidus temperature of the solder to which one or more integrated circuits are adhered to the circuit board on which the components are mounted.

18. The method of claim 16, comprising: The temperature of the hot liquid in contact with the circuit board on which the components are mounted is heated and controlled within 1 degree Celsius of the liquidus temperature of the solder to which one or more integrated circuits are adhered to the circuit board on which the components are mounted.

19. The method according to any one of claims 16 to 18, wherein, Selectively removing one or more of the integrated circuits from the circuit board on which the components are mounted includes using a first method.

20. The method according to any one of claims 16 to 19, further comprising using a second method to remove any remaining integrated circuits from the plurality of integrated circuits.

21. The method according to any one of claims 16 to 20, further comprising immersing the circuit board on which the components are mounted at least partially in a fluid.

22. A system for removing components designated for reuse from a circuit board on which components are mounted, the system comprising: Container or bathtub; as well as The temperature controller associated with the container or bath, The temperature controller is configured to heat the circuit board on which the components are mounted to a temperature within 10 degrees Celsius of the target temperature.

23. The system according to claim 22, wherein, The temperature controller is configured to heat the circuit board with the mounted components to within 2 degrees Celsius of the target temperature.

24. The system according to claim 22, wherein, The temperature controller is configured to heat the circuit board with the mounted components to within 1 degree Celsius of the target temperature.

25. The system according to any one of claims 22 to 24, wherein, The target temperature is the liquidus temperature of the solder present on the circuit board on which the components are mounted, and the liquidus temperature is optionally 220 degrees Celsius.

Images