A device and method for removing gold from bottom heat sink devices

Abstract

This invention provides a device and method for removing gold from bottom heat sink devices, including a base and at least one set of tinning assemblies located on the base. The tinning assemblies include a protective groove, a tinning port, and a lead support. The base supports other structural components. The tinning port is a through-hole penetrating the base, exposing the bottom heat sink of the device during tinning. The protective groove is located on the outer periphery of the tinning port and is used to accommodate the device leads. The lead support is a solid structure located between the tinning port and the protective groove, serving as a single-sided sidewall of the protective groove to support the device leads, allowing the device leads to fall into the protective groove and maintaining the device lead structure. This invention's gold removal device has an excellent design, is easy to operate, and effectively protects the device leads from damage while simultaneously meeting the bottom tinning requirements after device forming, achieving a 100% tinning pass rate.

Description

Technical Field

[0001] This invention belongs to the field of electrical assembly technology, and specifically relates to a device and method for removing gold from bottom heat sink devices. Background Technology

[0002] Components are typically mounted on printed circuit boards using a "soft soldering" process. According to aerospace-related electrical assembly standards, the solder is generally limited to Sn. 63 Pb 37 Sn 60 Pb 40 Sn 62 Pb 36 Several lead-containing eutectic solders, such as Ag2, are used to shorten the time for solder to transform from a liquid to a solid state, improve the metallographic structure of the solder, and reduce the formation of "whiskers." To prevent oxidation of circuit boards and component leads and improve soldering performance, gold-plated PCBs and component leads are widely used. However, in the 1980s, a product failure analysis raised the issue of a "gold embrittlement" mechanism. Scientific testing by a relevant department's failure mechanism analysis center revealed that the product failure was caused by the failure to remove gold from the gold-plated leads, resulting in a gold-tin alloy after soldering and causing gold embrittlement at the solder joint. This phenomenon attracted attention, and subsequently, within the aerospace system, the need for tinning of gold-plated leads before soldering was proposed. In recent years, the issue of gold removal has been increasingly raised in aerospace and other military products requiring high-reliability soldering.

[0003] The heatsink and leads on the bottom of the device are gold-plated, requiring gold removal and tinning processes on each. However, the bottom heatsink pads are large and dissipate heat quickly, making traditional gold removal methods ineffective in ensuring both the leads remain unaffected and the gold removal process is successful. When removing gold from the bottom of devices with large heatsinks, temperature-controlled soldering irons are often used, employing a "manual soldering iron gold removal + tinning" method. This approach yields poor gold removal results and can easily deform or cause solder adhesion to the device's leads, potentially rendering the device unusable. Summary of the Invention

[0004] To overcome the shortcomings of existing manual gold removal technology, such as cumbersome operation, high risk, and low processing efficiency, a gold removal device and method for bottom heat sink devices are provided to achieve automatic gold removal, making the operation simple and effective, improving production efficiency, thus completing the present invention.

[0005] The technical solutions provided by the present invention are as follows:

[0006] In a first aspect, a device for removing gold from a bottom heat sink device includes a base and at least one set of tinning components located on the base. The tinning components include a protective groove, a tinning port, and a lead support. The base supports other structural components. The tinning port is a through hole penetrating the base, exposing the bottom heat sink of the device during tinning. The protective groove is located on the outer periphery of the tinning port and is used to accommodate device leads. The lead support is a solid structure located between the tinning port and the protective groove, serving as a single-sided sidewall of the protective groove to support the device leads, allowing the device leads to fall into the protective groove and maintaining the device lead structure.

[0007] Secondly, a method for removing gold from a bottom heat sink device includes the following steps:

[0008] The formed bottom heat sink device is aligned with the protective tank and the soldering port and placed on the base. The bottom heat sink falls into the soldering port, and the device leads fall into the protective tank after being supported by the leads.

[0009] Place the base above the solder, control the contact distance between the bottom of the device and the solder in the soldering port, and remove the gold from the bottom heat sink area.

[0010] The gold removal device and method for bottom heat sink devices provided by the present invention have the following beneficial effects:

[0011] (1) The gold removal effect is obvious, and the tinning qualification rate of the device reaches 100%.

[0012] Scanning electron microscopy analysis of the samples showed that the combination of the device and the tin pot tinning achieved the best gold removal effect for the bottom heat sink devices, with a gold removal pass rate of 100%.

[0013] (2) The gold removal device is simple in design and the components are well protected.

[0014] The gold removal device is well-designed and easy to operate. It can effectively protect the device leads from damage and also meet the requirement of tinning the bottom of the device after it has been formed.

[0015] (3) The gold removal process is easy to operate and has excellent tinning efficiency.

[0016] During the gold removal process, the operator holds the device at a 30° to 45° angle to ensure full contact between the solder and the heat sink. The gold removal and tinning are completed in succession with the gold pot and the tin pot. The entire process takes only 7 minutes, which is a significant improvement in efficiency compared to traditional soldering irons. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the gold removal device for the bottom heat sink.

[0018] Figure 2 This is a schematic diagram of the structural partitioning of the gold removal device for the bottom heat sink.

[0019] Figure 3 A schematic diagram of the overall use of the gold removal device for the bottom heat sink components;

[0020] Figure 4 This is a partial schematic diagram of the gold removal device used for the bottom heat sink.

[0021] Explanation of icon numbers

[0022] 1-Base; 2-Fixing frame; 3-Handle; 4-Protective groove; 5-Soldering port; 6-Component placement groove; 7-Leader support. Detailed Implementation

[0023] The features and advantages of the present invention will become clearer and more apparent from the following detailed description.

[0024] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0025] This invention provides a gold removal device for bottom heat sink devices, such as... Figure 1 As shown, the device includes a base 1 and at least one set of tinning components located on the base. The tinning components include a protective groove 4, a tinning port 5, and a lead support 7. The base 1 supports the structural components thereon. The tinning port 5 is a through hole penetrating the base 1. When the device is placed on the base, the bottom heat sink falls into the tinning port. During tinning, the bottom heat sink of the device can be exposed, and gold can be removed by soldering. The protective groove 4 is located on the outer periphery of the tinning port 5 and is a non-penetrating structure used to accommodate the device lead. It protects the device lead from structural damage when the bottom heat sink is removed. The lead support 7 is a solid structure located between the tinning port 5 and the protective groove 4. It serves as a single-sided sidewall of the protective groove 4 to support the device lead, allowing the device lead to fall into the protective groove 4 and preventing the lead from deforming under stress.

[0026] In a preferred embodiment, the number of protective grooves 4 is not less than the number of sides of the leads of the device to be processed, and preferably the number of protective grooves 4 is the same as the number of sides of the leads of the device to be processed. Figure 1 and Figure 2 As shown, the device has leads on all four sides, so protective grooves are machined on all four sides of the tinning port.

[0027] In a preferred embodiment, the width of the protective groove 4 is not less than the extension distance of the device lead in the plane.

[0028] In a preferred embodiment, the height of the lead support 7 is such that the device lead naturally falls into the protective groove 4, and preferably the end of the lead contacts the protective groove 4.

[0029] During use, the inventors discovered that the high temperature during tinning and frequent use could cause deformation of the base, posing a risk to the device structure. Therefore, the inventors installed a fixing frame 2 along the outer edge of the base 1. The fixing frame 2 has lower thermal deformability than the base 1 (e.g., if the base is made of synthetic stone, the fixing frame is made of bakelite), thus ensuring the quality of the device during the gold removal process. Furthermore, a handle 3 is machined onto the fixing frame 2. The fixing frame 2 is connected to the base 1 via a threaded connector such as a screw, and the handle 3 is integrated with the fixing frame 2. During gold removal, the handle 3 controls the distance between the device and the solder surface.

[0030] After the gold removal is completed, the device can be removed from the base 1 using a suction pen. To avoid the inconvenience of removal due to the suction pen not being nearby, a device placement slot 6 is machined on the base 1. The device placement slot 6 is connected to the protective slot 4, which facilitates clamping the device when placing and removing it. Preferably, the device placement slot 6 is located in the corner direction of the solder joint 5, where there are no leads on the device, making it easy to clamp.

[0031] like Figure 2 As shown, the functional structure of the gold removal device can be divided into a fixed area, a protection area, and a gold removal area.

[0032] The fixing area includes a fixing frame 2 and a handle 3, which are connected to the base 1 by screws to prevent the base 1 from deforming due to heat.

[0033] The gold zone includes tin-plated 5.

[0034] The protected area includes lead support 7 and protective groove 4. After the device is formed, the lead has an airfoil structure. When the device is placed in the apparatus, the lead supports the device body, maintaining the lead's state after forming. However, under the weight of the device body, the lead will deform. Therefore, lead support 7 is needed to support the lead in place. When gold is removed from the device, since the lead and the bottom heat sink are not coplanar, it is impossible to ensure that the lead is removed simultaneously when removing gold from the bottom of the device. Therefore, the protective groove 4 is needed to protect the lead, allowing for separate gold removal operations on the lead and the bottom heat sink.

[0035] like Figure 3 and Figure 4 As shown, when the device uses the bottom heat sink device gold removal device, the device leads are protected by the protective groove 4 and the lead support 7. The purpose of removing gold from the bottom heat sink part of the device is achieved through the soldering port 5. Furthermore, by adjusting the angle between the device and the gold pot and the solder in the solder pot, the solder is dissolved and the gold layer on the surface of the device is separated.

[0036] This invention also provides a method for removing gold from bottom heat sink devices, such as... Figure 3 and Figure 4 As shown, the method includes the following steps:

[0037] Step 1: Align the formed bottom heat sink device with the protective groove 4 and the soldering port 5 and place it on the base 1. The bottom heat sink will fall into the soldering port, and the device leads will fall into the protective groove 4 after passing through the lead support 7.

[0038] Step 2: Hold handle 3 and place base 1 above solder. Control the contact distance between the bottom of the device and the solder in the soldering port 5 through handle 3. Adjust the angle between the device (bottom of the device) and the solder (30°~45°) to remove gold from the bottom heat sink.

[0039] Step 3: After removing the gold, clamp the two corners of the device at position 6 of the device placement slot, or use a suction pen to remove the device from the base 1.

[0040] This invention provides a gold removal device that can be used directly. The device, combined with a soldering pot, achieves optimal gold removal for bottom heat sink components, resulting in a 100% gold removal pass rate. The device is well-designed, easy to operate, and effectively protects the component leads from damage while fulfilling the requirements for bottom soldering after component forming. During gold removal, the operator holds the device at a 30° to 45° angle, sequentially working with both the gold and solder pots to complete the gold removal and soldering process. The entire process takes only 7 minutes, significantly improving efficiency compared to traditional soldering irons.

[0041] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0042] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A device for removing gold from a bottom heat sink device, characterized in that, The device includes a base (1) and at least one set of tinning components on the base. The tinning components include a protective groove (4), a tinning port (5), and a lead support (7). The tinning port (5) is a through hole that penetrates the base (1) and exposes the heat sink at the bottom of the device during tinning. The protective groove (4) is located on the outer periphery of the tinning port (5) and is used to accommodate the device lead. The lead support (7) is a solid structure located between the tinning port (5) and the protective groove (4) and serves as a single-sided sidewall of the protective groove (4) to support the device lead. The height of the lead support (7) is such that the device lead naturally falls into the protective groove (4) to maintain the device lead structure.

2. The gold removal device for bottom heat sink devices according to claim 1, characterized in that, The number of the protective grooves (4) is not less than the number of sides of the leads of the device to be processed.

3. The gold removal device for bottom heat sink devices according to claim 1, characterized in that, The width of the protective groove (4) is not less than the extension distance of the device lead on the plane.

4. The gold removal device for bottom heat sink devices according to claim 1, characterized in that, A fixing frame (2) is installed on the outer edge of the base (1), and the thermal deformation of the fixing frame (2) is lower than that of the base (1).

5. The gold removal device for bottom heat sink devices according to claim 4, characterized in that, The fixed frame (2) is machined with a handle (3). The fixed frame (2) and the base (1) are connected by a threaded connector. The handle (3) and the fixed frame (2) are integrated. When removing gold, the distance between the device and the solder surface is controlled by the handle (3).

6. The gold removal device for bottom heat sink devices according to claim 1, characterized in that, The base (1) is machined with a device placement slot (6), which is connected to the protective slot (4) and is used to hold the device when placing or taking it out.

7. The gold removal device for bottom heat sink devices according to claim 6, characterized in that, The device pick-and-place slot (6) is located at the corner of the tin-plating port (5).

8. A method for removing gold from a bottom heat sink device, characterized in that, The gold removal device for bottom heat sink devices according to any one of claims 1 to 7 includes the following steps: The formed bottom heat sink device is aligned with the protective groove (4) and the tinning port (5) and placed on the base (1). The bottom heat sink falls into the tinning port (5), and the device lead falls into the protective groove (4) after passing through the lead support (7). Place the base (1) above the solder, control the contact distance between the bottom of the device and the solder in the soldering port (5), and remove the gold from the bottom heat sink.

9. The method for removing gold from a bottom heat sink device according to claim 8, characterized in that, When removing gold, the angle between the bottom of the device and the solder should be 30°~45°.

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