A nozzle structure suitable for selective wave soldering

Abstract

The utility model provides a kind of nozzle structure suitable for selective wave-soldering, including nozzle body and spring;The nozzle body includes the flow guide block and end block being connected, the end block is opened and is supplied with the nozzle for solder, the inside of the nozzle body is equipped with flow guide cavity, the flow guide cavity is connected with the nozzle communication;The spring is installed in the flow guide cavity, for the rectification of solder in flow guide cavity;Wherein, the setting direction of the spring is perpendicular with the flow direction of solder in the flow guide cavity.The utility model is by setting spring in flow guide cavity, using the fluid mechanics intervention of spring helical structure, solve the disorder and fluctuation of tin liquid flow, realize the double regulation of tin liquid flow direction and pressure, can effectively guarantee that the wave peak formed finally is flat and stable, significantly improve the welding quality of wave-soldering.

Description

Technical Field

[0001] This utility model relates to the field of welding technology, and more specifically, to a nozzle structure suitable for selective wave soldering. Background Technology

[0002] Selective wave soldering essentially transforms the "surface" contact of traditional wave soldering into precisely controlled "point" contact. Through programmable control, it ensures that only the solder wave peaks precisely contact the specific via pads on the PCB that need soldering. Selective wave soldering is a precise, flexible, and efficient soldering solution that emerged in response to the trend towards higher density, higher reliability, and environmental friendliness in electronic assembly technology. It successfully overcomes the technical bottlenecks of traditional wave soldering and is particularly suitable for the manufacturing of modern complex mixed-assembly circuit boards, making it an indispensable key technology in high-end electronics manufacturing.

[0003] The specific steps of selective wave soldering nozzles are as follows: molten solder is pumped from the solder bath to form a miniature laminar solder wave. Under the action of an electromagnetic pump, the solder is discharged from the nozzle outlet to solder the circuit board. Currently, the solder exhibits disorder during transport, easily forming turbulence and eddies. Furthermore, due to pressure fluctuations in the electromagnetic pump, the molten solder cannot reach the nozzle outlet at a constant pressure. These two issues result in an uneven and undulating wave peak, severely affecting the soldering quality. Utility Model Content

[0004] In view of this, the present invention provides a nozzle structure suitable for selective wave soldering to solve the problems existing in the background art.

[0005] The objective of this utility model is achieved through the following technical solution.

[0006] A nozzle structure suitable for selective wave soldering includes: a nozzle body comprising a flow guide block and an end block connected together, the end block having an opening for solder to pass through, the nozzle body having a flow guide cavity inside, the flow guide cavity being connected to the opening; and a spring installed in the flow guide cavity for rectifying the solder within the flow guide cavity; wherein the spring is positioned perpendicular to the flow direction of the solder within the flow guide cavity.

[0007] In the above scheme, the end block is installed at the end of the guide block. During welding, molten solder (i.e., solder) enters the guide cavity from the end of the guide block furthest from the end block, and is then ejected from the nozzle on the end block. A spring is installed in the guide cavity, perpendicular to the flow direction of the molten solder. This spring rectifies the flow of the molten solder, and its helical structure breaks the surface tension of the solder, mitigating the impact force and eliminating turbulence and eddies within the molten solder, allowing it to reach the nozzle smoothly and stably. Furthermore, the spring has elastic deformation capability; under the pressure of the molten solder, it can produce slight elastic expansion and contraction, acting as a pressure buffer. This transforms the fluctuating pressure of the molten solder into a stable average pressure, ensuring a constant pressure output to the nozzle and preventing fluctuations in the solder flow.

[0008] This invention utilizes a spiral spring to address the disorder and fluctuation of molten solder flow through the hydrodynamic intervention of the spiral structure. It achieves dual regulation of the molten solder flow direction and pressure, effectively ensuring that the final wave peak is flat and stable, and significantly improving the welding quality of wave soldering.

[0009] In one example of this utility model, the end faces of the guide block and the end block that cooperate with each other are provided with mounting grooves, and the mounting grooves cooperate to form a receiving groove for accommodating the spring.

[0010] In the above scheme, mounting slots are respectively located at the positions where the guide block and the end block meet. Both the guide block and the end block have two mounting slots. After the guide block and the end block mate, the mounting slots are joined to form a receiving groove that mates with the spring. The receiving groove is used to limit the spring's movement, preventing it from shifting and ensuring the rectification effect. Furthermore, setting the receiving groove to be composed of two mounting slots facilitates spring installation. During installation, the spring can be placed first in the mounting slot at the end of the guide block, and then the end of the end block with the mounting slot is aligned with the guide block. Finally, the guide block and the end block are fixedly connected, allowing the spring to remain inside the guide block and the end block. This simple operation simplifies the installation process and improves convenience.

[0011] In one example of this utility model, the sidewall of the mounting groove is an arc surface.

[0012] In the above solution, by setting the side wall of the mounting groove to an arc surface to match the shape of the spring, it is easier to install and can fit more tightly with the spring, thus enhancing the limiting effect on the spring.

[0013] In one example of this utility model, the flow guiding cavity includes a first flow guiding section and a second flow guiding section, the width of the first flow guiding section is smaller than the width of the second flow guiding section, and the second flow guiding section is located between the first flow guiding section and the nozzle.

[0014] In the above scheme, after the molten solder enters the guiding cavity, it passes through the first guiding section and the second guiding section in sequence. The first guiding section is narrower than the second guiding section, which increases the molten solder conveying speed and allows the molten solder to obtain sufficient kinetic energy and pressure. When the molten solder reaches the second guiding section, the flow rate and pressure of the molten solder can be reduced due to the wider second guiding section, which plays a role in buffering and decompression, avoiding wave peak loss of control and ensuring wave peak stability.

[0015] In one example of this utility model, a guide groove is provided on the side wall of the guide cavity, and the two ends of the guide groove extend into the first guide section and the second guide section, respectively.

[0016] In the above scheme, when the molten solder enters the second guide section from the first guide section, the flow velocity and pressure will change abruptly due to the widening of the channel width, which can easily cause the molten solder to spread laterally, causing flow field turbulence and boundary layer separation (generating eddies). However, by setting a guide channel that spans the first and second guide sections, the molten solder can be guided from the high-pressure area to the low-pressure area, playing a transition buffer role and making the flow of the molten solder more stable and smooth.

[0017] In one example of this utility model, the guide groove is conical in shape, and the width of the guide groove gradually decreases along the solder flow direction in the guide cavity.

[0018] In the above scheme, the width of the guide channel gradually decreases from the first guide section to the second guide section. That is, the tip of the guide channel is located in the second guide section. When the molten solder flows, the conical guide channel can form a gradually narrowing channel, which can effectively alleviate the eddy phenomenon caused by the sudden widening of the channel and the sudden change in flow rate and pressure of the molten solder.

[0019] In one example of this utility model, the bottom surface of the guide channel is a conical surface.

[0020] In the above scheme, the conical surface is used to match the conical shape of the guide channel. At the same time, the structure of the surface will not produce dead corners, which is conducive to the discharge of bubbles and avoids the accumulation of bubbles in the guide cavity.

[0021] In one example of this utility model, the flow guiding cavity further includes a feeding section, which is located at the end of the first flow guiding section away from the second flow guiding section.

[0022] In the above scheme, the feeding section is connected to the first guide section and is used to transport molten tin. The molten tin entering the guide cavity passes through the feeding section, the first guide section and the second guide section in sequence and is discharged from the nozzle.

[0023] In one example of this utility model, the cross-sectional shape of the feeding section is circular.

[0024] In the above scheme, the circular channel has no dead corners, which is conducive to the flow of molten solder and achieves good conveying function.

[0025] In one example of this invention, the spring is made of a metal material that is paramagnetic.

[0026] In the above solution, since electromagnetic pumps are commonly used to drive the flow of molten solder in wave soldering equipment, paramagnetic materials are not attracted by magnetic fields. This prevents the spring from shifting, deforming, or vibrating due to the magnetic field, ensuring the positional stability of the spiral structure. Furthermore, the high strength and high melting point of the metallic material effectively adapt to the high-temperature and high-pressure environment within the flow guiding cavity, ensuring the rectification effect.

[0027] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention rectifyes the flow of molten solder by incorporating a spring within the flow guide cavity. The helical structure of the spring disrupts the surface tension of the molten solder, mitigating the impact force and eliminating turbulence and eddies within the solder, allowing it to reach the nozzle smoothly and stably. Furthermore, the spring's elastic deformation capability allows for slight elastic expansion and contraction under the pressure of the molten solder, acting as a pressure buffer and transforming the fluctuating pressure into a stable average pressure. This ensures a constant pressure output to the nozzle, preventing wave crest fluctuations. In summary, this invention utilizes the hydrodynamic intervention of the spring's helical structure to address the disorder and fluctuation of molten solder flow, achieving dual regulation of both flow direction and pressure. This effectively ensures a smooth and stable final wave crest, significantly improving the welding quality of wave soldering. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is an exploded view of the nozzle structure according to an embodiment of the present invention.

[0030] Figure 2 This is a perspective view (in perspective) of the nozzle structure of this utility model.

[0031] Figure 3 for Figure 2 A side view of the nozzle structure.

[0032] Figure 4 for Figure 3 A cross-sectional view at position AA in the diagram.

[0033] Figure 5This is a half-sectional view of the guide block of this utility model.

[0034] Figure 6 This is a perspective view of the flow guide block of this utility model.

[0035] Figure 7 This is a perspective view of the end block of this utility model.

[0036] Explanation of the reference numerals in the figure: 1- Nozzle body; 11- Guide block; 111- Feed inlet; 12- End block; 121- Nozzle; 13- Guide cavity; 131- Feed section; 132- First guide section; 133- Second guide section; 14- Guide groove; 15- Receiving groove; 151- Mounting groove; 2- Spring. Detailed Implementation

[0037] To facilitate understanding of this invention, a more comprehensive description will be provided below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of the invention. However, this invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0038] Please refer to Figures 1 to 7 In a preferred embodiment, this embodiment provides a nozzle structure suitable for selective wave soldering, including a nozzle body 1 and a spring 2. The nozzle body 1 includes a flow guide block 11 and an end block 12 connected together. The end block 12 has an opening 121 for solder to pass through. The nozzle body 1 has a flow guide cavity 13 inside, which is connected to the opening 121. The spring 2 is installed in the flow guide cavity 13 and is used to rectify the solder in the flow guide cavity 13. The direction of the spring 2 is perpendicular to the flow direction of the solder in the flow guide cavity 13.

[0039] Among them, according to Figure 2 As shown, end block 12 is mounted on top of flow guide block 11, and flow guide block 11 has a feed inlet 111 at its bottom. Flow guide cavity 13 is located inside flow guide block 11. In this embodiment, the solder is tin, and the molten tin flows from bottom to top.

[0040] Specifically, during the welding process, molten solder (i.e., solder) is drawn into the guide cavity 13 from the inlet 111 at the bottom of the guide block 11 by the electromagnetic pump of the equipment. After passing through the guide cavity 13, it is ejected from the nozzle 121 on the end block 12. A spring 2 is installed in the guide cavity 13 to rectify the flow of the molten solder. The spiral structure of the spring 2 breaks the surface tension of the molten solder, mitigating the impact force and eliminating turbulence and eddies within the molten solder, allowing it to reach the nozzle 121 smoothly and stably. Furthermore, the spring 2 has elastic deformation capability; under the pressure of the molten solder, it can produce slight elastic expansion and contraction, acting as a pressure buffer. This transforms the fluctuating pressure of the molten solder into a stable average pressure, ensuring a constant pressure output to the nozzle 121 and preventing fluctuations in the solder flow.

[0041] It should be noted that by setting spring 2 horizontally so that it is perpendicular to the flow direction of the molten solder, the spiral structure of spring 2 divides the cross-section of the guide cavity 13 into multiple microchannels. The molten solder must pass through these microchannels to reach the nozzle. These microchannels disrupt the surface tension of the molten solder, preventing it from forming large-scale turbulence. At the same time, these microchannels can disperse the formed eddies, making the flow of the molten solder more stable. In addition, the cross-sectional dimensions and length of each microchannel are consistent. According to the principles of fluid mechanics, under the same viscosity and pressure difference, the flow velocity of the molten solder through each microchannel is basically consistent, thereby achieving flow velocity homogenization. This transforms the originally chaotic and fluctuating flow of the molten solder into a parallel laminar flow, ensuring pressure stability and making the final wave crest flat and stable, thus guaranteeing the welding quality of wave soldering.

[0042] Furthermore, since the flow of molten solder is driven by an electromagnetic pump, and the pressure provided by the electromagnetic pump cannot be kept absolutely constant, there will always be slight fluctuations. The molten solder will amplify these pressure fluctuations during the flow process, resulting in undulating peaks. Spring 2 has good elastic deformation capability and can produce slight elastic expansion and contraction under the pressure of molten solder. This deformation can play a role in pressure buffering, transforming the originally fluctuating pressure into a stable average pressure, so that the molten solder is output to nozzle 121 at a constant pressure, thus eliminating the peak fluctuation phenomenon.

[0043] Please refer to Figures 4 to 7 The guide block 11 and the end block 12 are provided with mounting grooves 151 on their mating end faces. The mounting grooves 151 are mated to form a receiving groove 15 for accommodating the spring 2.

[0044] Specifically, mounting grooves 151 are provided on the end faces of the guide block 11 and the end block 12 that meet. Two mounting grooves 151 are symmetrically provided on both the guide block 11 and the end block 12. After the guide block 11 mates with the mounting grooves 151, the four mounting grooves 151 are joined together to form a receiving groove 15 that mates with the spring 2. The receiving groove 15 is used to limit the spring 2, preventing it from shifting and ensuring the rectification effect. Furthermore, setting the receiving groove 15 to be composed of two mounting grooves 151 facilitates the installation of the spring 2. Specifically, during installation, the spring 2 can be first placed in the mounting groove 151 at the end of the guide block 11, and then the end of the end block 12 with the mounting groove 151 is connected to the guide block 11. Finally, the guide block 11 and the end block 12 are fixedly connected, allowing the spring 2 to remain inside the guide block 11 and the end block 12. This simple operation simplifies the installation process and improves convenience.

[0045] Furthermore, the sidewall of the mounting groove 151 is an arc surface. By setting the sidewall of the mounting groove 151 to an arc surface to match the shape of the spring 2, it is easier to install and can fit more tightly with the spring 2, thus strengthening the limiting effect on the spring 2.

[0046] Preferably, the guide block 11 and the end block 12 are connected and fixed by welding. In specific operation, firstly, the mounting groove 151 is milled into the guide block 11 and the end block 12, then the spring 2 is placed into the mounting groove 151 of the guide block 11, then the end block 12 is assembled onto the guide block 11, and finally the guide block 11 and the end block 12 are fixed by welding.

[0047] Preferably, the surface of the nozzle body 1 is provided with a coating (not specifically shown in the figure). After the guide block 11 and the end block 12 are welded, the surface of the obtained nozzle body 1 is then coated to form a whole.

[0048] Please refer to Figures 3 to 5 The flow guiding cavity 13 includes a first flow guiding section 132 and a second flow guiding section 133. The width of the first flow guiding section 132 is smaller than the width of the second flow guiding section 133. The second flow guiding section 133 is located between the first flow guiding section 132 and the nozzle 121.

[0049] After the molten solder enters the guide cavity 13, it passes through the first guide section 132 and the second guide section 133 in sequence. The first guide section 132 is narrower than the second guide section 133, which increases the molten solder delivery speed and allows the molten solder to obtain sufficient kinetic energy and pressure. When the molten solder reaches the second guide section 133, the wider second guide section 133 can reduce the flow rate and pressure of the molten solder, play a role in stabilizing the flow, avoid excessive flow rate and pressure leading to uncontrolled wave peaks, and ensure the stability of the final wave peak.

[0050] Understandably, in addition to preventing the wave crest from getting out of control, making the second guide section 133 wider is also to match the shape of the nozzle 121 in order to form the required wave crest.

[0051] Please refer to Figure 4 and Figure 5 The side wall of the flow guiding cavity 13 is provided with a flow guiding groove 14, and the two ends of the flow guiding groove 14 extend into the first flow guiding section 132 and the second flow guiding section 133, respectively.

[0052] When the molten solder enters the second guide section 133 from the first guide section 132, the flow rate and pressure will change abruptly due to the widening of the channel width, which can easily cause the molten solder to spread laterally, causing flow field turbulence and boundary layer separation (generating eddies). However, by setting a guide channel 14 that spans the first guide section 132 and the second guide section 133, the molten solder can be guided from the high-pressure area to the low-pressure area, playing a transition buffer role and making the flow of the molten solder more stable and smooth.

[0053] Preferably, there are two guide channels 14, which are symmetrically arranged on the opposite side walls of the guide cavity 13.

[0054] Please refer to Figures 1 to 5 The guide channel 14 is conical in shape, and the bottom surface of the guide channel 14 is a conical curved surface. The width of the guide channel 14 gradually decreases along the direction of solder flow in the guide cavity 13.

[0055] Specifically, the width of the guide channel 14 gradually decreases from the first guide section 132 to the second guide section 133, meaning the tip of the guide channel 14 is located within the second guide section 133. When the molten solder flows, the conical guide channel 14 forms a gradually narrowing channel, effectively mitigating the eddy phenomenon caused by sudden widening of the channel and abrupt changes in flow velocity and pressure. The bottom surface of the guide channel 14 is a curved conical surface. This conical surface structure avoids dead angles, facilitating the discharge of air bubbles and preventing their accumulation within the guide cavity 13.

[0056] Furthermore, the flow guiding cavity 13 also includes a feeding section 131, which is located at the end of the first flow guiding section 132 away from the second flow guiding section 133. The feeding section 131 is connected to the first flow guiding section 132 and is used to transport molten solder. The molten solder entering the flow guiding cavity 13 passes through the feeding section 131, the first flow guiding section 132 and the second flow guiding section 133 in sequence, and is then discharged from the nozzle 121.

[0057] Preferably, the cross-sectional shape of the feed section 131 is circular. The circular channel has no dead corners, low resistance, and is conducive to the flow of molten tin, so as to achieve good conveying function.

[0058] In this embodiment, the spring 2 is made of a metallic material. Metallic materials have high strength and a high melting point, effectively adapting to the high-temperature and high-pressure environment within the flow guiding cavity 13 to ensure the rectification effect.

[0059] Preferably, spring 2 is made of titanium alloy. Titanium alloy has a high melting point and will not soften or deform in molten solder, maintaining the integrity of the spiral structure for a long time and ensuring the rectification effect on the molten solder. Simultaneously, since molten solder is corrosive and metal oxidation is accelerated at high temperatures, titanium alloy can form a dense oxide film (TiO2) at high temperatures, exhibiting strong corrosion resistance. This effectively prevents molten solder from eroding, avoiding spring 2 from corroding and breaking or generating impurities that contaminate the molten solder, ensuring high reliability. Furthermore, since wave soldering equipment often uses electromagnetic pumps to drive the flow of molten solder, titanium alloy is a paramagnetic material and will not be attracted by a magnetic field, thus preventing spring 2 from shifting, deforming, or vibrating due to a magnetic field, ensuring the positional stability of the spiral structure. If a ferromagnetic material were used, spring 2 would be attracted by a magnetic field, causing the spiral structure to fail, unable to achieve flow channel segmentation and guidance, and thus losing its rectification effect on the molten solder.

[0060] In this embodiment, by installing a spring 2 within the flow guiding cavity 13, the flowing molten solder can be rectified. The spiral structure of the spring 2 disrupts the surface tension of the molten solder, mitigating the impact force and eliminating turbulence and eddies within the molten solder, allowing it to reach the nozzle 121 smoothly and stably. Furthermore, the spring 2 has elastic deformation capabilities, capable of slight elastic expansion and contraction under the pressure of the molten solder, acting as a pressure buffer. This transforms the fluctuating pressure of the molten solder into a stable average pressure, ensuring a constant pressure output to the nozzle 121 and preventing wave crest undulations. In summary, this invention utilizes the hydrodynamic intervention of the spiral structure of the spring 2 to address the disorder and fluctuation of molten solder flow, achieving dual regulation of the flow direction and pressure. This effectively ensures a smooth and stable final wave crest, significantly improving the welding quality of wave soldering.

[0061] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0062] Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0063] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0064] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A nozzle structure suitable for selective wave soldering, characterized in that, include: The nozzle body includes a flow guide block and an end block connected together. The end block has an opening for solder to pass through. The nozzle body has a flow guide cavity inside, and the flow guide cavity is connected to the opening. A spring, installed inside the flow guiding cavity, is used to rectify the solder inside the flow guiding cavity; The spring is positioned perpendicular to the direction of solder flow within the guide cavity.

2. The nozzle structure for selective wave soldering according to claim 1, characterized in that, The guide block and the end block are both provided with mounting grooves on their mating end faces, and the mounting grooves are mated to form a receiving groove for accommodating the spring.

3. The nozzle structure for selective wave soldering according to claim 2, characterized in that, The sidewall of the mounting groove is an arc surface.

4. The nozzle structure for selective wave soldering according to claim 1, characterized in that, The flow guiding cavity includes a first flow guiding section and a second flow guiding section. The width of the first flow guiding section is smaller than the width of the second flow guiding section, and the second flow guiding section is located between the first flow guiding section and the nozzle.

5. The nozzle structure for selective wave soldering according to claim 4, characterized in that, The sidewall of the flow guiding cavity is provided with a flow guiding groove, and the two ends of the flow guiding groove extend into the first flow guiding section and the second flow guiding section, respectively.

6. The nozzle structure for selective wave soldering according to claim 5, characterized in that, The guide channel is conical in shape, and the width of the guide channel gradually decreases along the direction of solder flow within the guide cavity.

7. The nozzle structure for selective wave soldering according to claim 6, characterized in that, The bottom surface of the guide channel is a conical surface.

8. The nozzle structure for selective wave soldering according to claim 4, characterized in that, The flow guide cavity also includes a feeding section, which is located at the end of the first flow guide section away from the second flow guide section.

9. The nozzle structure for selective wave soldering according to claim 8, characterized in that, The feed section has a circular cross-sectional shape.

10. The nozzle structure suitable for selective wave soldering according to any one of claims 1 to 9, characterized in that, The spring is made of a paramagnetic metallic material.

Images