A method for soldering high-density pins
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUNAN VATHIN MEDICAL INSTR CO LTD
- Filing Date
- 2023-09-25
- Publication Date
- 2026-06-30
Smart Images
Figure CN117226210B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of assembly and manufacturing technology in the electronics industry, and more particularly to a method for soldering high-density pins. Background Technology
[0002] In the debugging or repair of hardware devices such as circuit boards, it is necessary to connect the chip pins to the testing equipment or other solder joints through wires. Usually, the wires are fixedly connected to the chip pins by soldering.
[0003] However, the inventors discovered that soldering wires to pins is more difficult when the pin spacing is small (also known as high-density pins) or when only a small portion of the pins are exposed. Specifically, for high-density pins, the pin spacing is very small. Existing methods of directly soldering with solder on a soldering iron can easily cause adjacent or multiple pins to connect with the solder, resulting in short circuits. Subsequent soldering requires cleaning away the short-circuited solder before resoldering; sometimes, multiple attempts are necessary to succeed. The denser the pins, the greater the difficulty and the significantly lower the success rate.
[0004] Therefore, providing a soldering method suitable for high-density pins to improve the soldering success rate is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0005] This invention discloses a method for soldering high-density pins to solve the technical problem in related technologies where soldering high-density pins is difficult and requires repeated attempts to succeed.
[0006] To solve the above problems, the present invention adopts the following technical solution:
[0007] The high-density pin soldering method of the present invention includes the following steps:
[0008] Step S100: Apply flux to one end of the wire to be soldered, and use the flux to adhere the solder to the wire to be soldered;
[0009] Step S200: Heat the solder to make it molten, place the wire to be soldered vertically, and make the molten solder form an ellipsoidal solder ball at the end of the wire to be soldered;
[0010] Step S300: Bring the wire to be soldered close to the pin to be soldered, heat the ellipsoidal solder ball to melt it, and use the melted ellipsoidal solder ball to solder the wire to be soldered to the pin.
[0011] According to a preferred embodiment, before step S100, a step of preparing solder is further included, and the preparation of solder includes the following steps:
[0012] The solder is thinned and shortened based on the density of the leads to be soldered, ensuring that the thickness and length of the processed solder are both less than or equal to the spacing between the leads to be soldered and adjacent leads; and / or
[0013] The solder is thinned and shortened based on the length of the exposed portion of the pin to be soldered, so that the thickness and length of the processed solder are both less than or equal to the length of the exposed portion of the pin to be soldered; and / or
[0014] The solder is thinned and shortened based on the diameter of the pin to be soldered, so that the thickness and length of the solder after the process are both less than or equal to the diameter of the pin to be soldered.
[0015] According to a preferred embodiment, before bringing the wire to be soldered close to the pin to be soldered, the method further includes a step of cooling the ellipsoidal solder ball for 1 to 3 seconds and solidifying the ellipsoidal solder ball.
[0016] According to a preferred embodiment, in step S100, the flux is a paste; the weight ratio of flux to solder is 1:1 to 1:2.
[0017] According to a preferred embodiment, step S200 further includes the following steps: after placing the wire to be welded vertically, observe whether the molten solder is located at the end of the wire to be welded. When the lower end of the molten solder is located above the end of the wire to be welded, and the distance between the lower end of the molten solder and the end of the wire to be welded exceeds a preset length, cut off the excess part of the end of the wire to be welded and / or add material.
[0018] According to a preferred embodiment, the formulation used for patching includes flux and solder, and the weight ratio of flux to solder is 1:1 to 1:2.
[0019] According to a preferred embodiment, in step S200, a hot air source is used to intermittently heat the solder, which melts under the action of heat, and the hot air source maintains a minimum wind speed, with the angle between the outlet direction of the hot air source and the wire to be soldered being 30 to 60°.
[0020] According to a preferred embodiment, in step S300, when the wire to be soldered is brought close to the pin to be soldered, the wire to be soldered is located above the pin to be soldered, or the wire to be soldered is located to the side of the pin to be soldered, and the vertical distance between the end of the wire to be soldered and the pin to be soldered is 3 to 5 mm, the wire to be soldered and the pin to be soldered are kept parallel, or the angle between the wire to be soldered and the pin to be soldered is less than 10°.
[0021] According to a preferred embodiment, in step S300, based on at least one of the molten state of the ellipsoidal solder ball, the molten state of the pin to be soldered, the wind speed of the hot air gun, and the wind speed of the soldering station, the ellipsoidal solder ball is intermittently or continuously heated using a hot air source, and the ellipsoidal solder ball melts again under the action of heat.
[0022] According to a preferred embodiment, the angle between the outlet direction of the hot air source and the wire to be welded is 30 to 90°.
[0023] The high-density pin soldering method provided by this invention can achieve at least the following beneficial effects:
[0024] The high-density pin soldering method of this invention includes the steps of applying solder to the wire to be soldered, melting and shaping the solder, and remelting and soldering the solder. Compared with the existing soldering method using a soldering iron, this method allows the wire to be soldered to be made much smaller than the pin, thus requiring less solder to be applied to the wire. When the wire is brought close to the pin, there is no short circuit caused by solder connecting to a non-pin. Therefore, compared with the existing soldering method using a soldering iron, the high-density pin soldering method of this invention easily achieves precise soldering between the wire and the pin, is simple to operate, easy to implement, and efficient. It solves the technical problem in related technologies where high-density pin soldering is difficult to operate and requires multiple attempts to succeed.
[0025] Secondly, the high-density pin soldering method of the present invention involves heating the solder to a molten state, then placing the wire to be soldered vertically. This allows the flux and solder to move towards the end of the wire under gravity. Since the mixture of flux and solder has a certain viscosity, as it moves towards the end of the wire under gravity, some flux and solder adhere to the wire, while some flows downwards. This results in a slender, ellipsoidal solder ball at the end of the wire. This slender, ellipsoidal structure allows for a smaller diameter and width, further preventing short circuits caused by solder connecting to non-pins when the wire is brought closer to the pin. Simultaneously, if the solder ball is located to the side of the pin, remelting it increases the contact area between the solder ball and the pin, allowing for more solder to contact the pin and improving the reliability of the soldering between the wire and the pin.
[0026] Thirdly, current high-density pin soldering requires highly precise soldering irons. However, the high-density pin soldering method of this invention directly uses the wire to be soldered to apply flux and solder. Compared to existing technologies that require specialized soldering equipment like high-precision soldering irons, this invention only requires a hot air source, such as a hot air gun or soldering station. Therefore, the high-density pin soldering method of this invention only requires a conventional hot air source and does not require high-precision equipment. Compared to existing technologies that require high-precision soldering irons, the equipment required by this invention is undoubtedly easier to obtain and less expensive. Furthermore, using wires with a diameter smaller than the diameter and / or spacing of the pins to be soldered is undoubtedly easier than using soldering irons with end dimensions smaller than the diameter and / or spacing of the pins to be soldered. Therefore, the high-density pin soldering method of this invention also has the advantage of being easy to implement. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0028] Figure 1 This is a first flowchart of a high-density pin soldering method according to an embodiment of this application;
[0029] Figure 2 This is a second flowchart of the high-density pin soldering method according to an embodiment of this application;
[0030] Figure 3 This is a third flowchart of the high-density pin soldering method according to an embodiment of this application;
[0031] Figure 4 This is a schematic diagram of the first structure of forming an ellipsoidal solder ball at the end of the wire to be welded according to an embodiment of this application;
[0032] Figure 5 This is a schematic diagram of the second structure of forming an ellipsoidal solder ball at the end of the wire to be welded according to an embodiment of this application;
[0033] Figure 6 It is Figure 5 A schematic diagram showing the cut-off portion of the wire to be welded.
[0034] Figure 7 This is a schematic diagram of the structure after the wire to be soldered approaches the first type of pin to be soldered;
[0035] Figure 8 This is a schematic diagram of the structure after the wire to be soldered approaches the second type of pin to be soldered.
[0036] In the figure: 101, wire to be soldered; 1011, end of wire to be soldered; 102, ellipsoidal solder ball; 201, pin; 2011, side pin; 2012, front pin; 201a, inclined part of pin; 201b, horizontal part of pin; 202, chip body; 301, air outlet. Detailed Implementation
[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.
[0038] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.
[0039] In related technologies, when the pin spacing is small, if a conventional soldering iron is used for soldering the wire to the pin, the large size of the soldering iron causes the end of the iron to cross the pin when it approaches the pin to be soldered, making it easy for the solder to connect with adjacent or multiple pins, causing a short circuit. The solder causing the short circuit must be cleaned up before soldering can continue, making soldering difficult and inefficient. On the other hand, even if a high-precision soldering iron is used, short circuits are still unavoidable. Moreover, high-precision soldering irons are expensive and not readily available, and are not available in all working conditions.
[0040] Therefore, this application provides a high-density pin soldering method. The method involves directly applying flux and solder to the wire to be soldered, then melting and shaping the flux and solder. Finally, the wire is brought close to the pin to be soldered, and the flux and solder are melted again, thus achieving soldering between the wire and the pin. This method easily achieves precise soldering between the wire and the pin, is simple to operate, easy to implement, and efficient, and does not require high-precision equipment.
[0041] The following is in conjunction with the appendix Figures 1 to 8 The high-density pin soldering method provided in this application will be described in detail through specific embodiments and application scenarios.
[0042] The high-density pins mentioned in this embodiment refer to chip pins with a relatively high density, such as LQFP (Quad Flat Package, package body thickness of 1.4mm), QFP (Quad Flat Package), TSSOP (Thin Small Size Package), etc., and the pins are exposed.
[0043] Figure 1 A flowchart illustrating a high-density pin soldering method is shown. (For example...) Figure 1 As shown, the high-density pin soldering method includes the following steps:
[0044] Step S100: Apply flux to one end of the wire 101 to be soldered, and use the flux to adhere the solder to the wire 101. The diameter of the wire 101 to be soldered is smaller than the diameter of the pin to be soldered, and / or the diameter of the wire 101 to be soldered is smaller than the distance between the pin to be soldered and the adjacent pin.
[0045] Specifically, the wire 101 to be soldered can be made of copper wire or tinned copper wire, especially bare copper wire or tinned copper wire. If the copper wire or tinned copper wire has an enameled coating, the coating at the soldering end must be removed first. The diameter of the bare copper wire or tinned copper wire should also be smaller than the diameter of the pin to be soldered (this refers to the diameter of the pin to be soldered when the pin is cylindrical; and the width of the pin to be soldered when the pin is plate-shaped), and / or the diameter of the wire 101 to be soldered should be smaller than the distance between the pin to be soldered and the adjacent pin.
[0046] Currently, high-density pin soldering requires highly precise soldering irons. However, the high-density pin soldering method in this embodiment directly uses the wire to be soldered 101 to apply flux and solder. Compared to existing technologies that require specialized soldering equipment such as high-precision soldering irons, this embodiment only requires a hot air source, such as a hot air gun or soldering station. Therefore, the high-density pin soldering method in this embodiment only requires a conventional hot air source and does not require high-precision equipment. Compared to existing technologies that require high-precision soldering irons, the equipment required in this embodiment is undoubtedly easier to obtain and less expensive. Furthermore, using wires with a diameter smaller than the diameter and / or spacing of the pins to be soldered is undoubtedly easier than using soldering irons with end dimensions smaller than the diameter and / or spacing of the pins to be soldered. Therefore, the high-density pin soldering method in this embodiment also has the advantage of being easy to implement.
[0047] Apply flux to one end of the wire 101 to be soldered. The flux improves the soldering quality and efficiency between the wire 101 and the pin. Specifically, firstly, the flux removes oxides, grease, dust, and other impurities from the soldering surface, keeping the soldering area clean and promoting weld formation. Secondly, during soldering, the flux reacts with oxygen in the air to form a protective oxide layer, preventing re-oxidation of the soldering area and reducing the oxide content in the weld. Thirdly, the flux components lower the melting point of the solder, making it easier to melt and flow, improving weld wettability, aiding in the bonding between the metals, and saving the heat required to melt the solder, thus achieving energy conservation. Fourthly, the flux components absorb and expel moisture and other volatile substances from the soldering area, reducing gas accumulation in the weld and lowering the risk of cold cracking and porosity. Fifthly, the use of flux improves weld morphology, increases weld strength and sealing, reduces the probability of welding defects, and enhances soldering quality and the reliability of the welded connection. In other words, flux plays multiple roles in the welding process, such as cleaning the surface, preventing oxidation, wetting, removing impurities, and eliminating porosity, which helps to achieve high-quality welded joints.
[0048] Preferably, the flux in this application is a paste. More preferably, the flux is brazing paste, solder paste, stainless steel soldering paste, copper soldering paste, or aluminum soldering paste. The paste flux not only has the functions of the above-mentioned fluxes, but also has a certain viscosity, which facilitates the flux to adhere to the wire 101 to be soldered, and also facilitates the flux to adhere the solder to the wire 101 to be soldered; at the same time, it is also easy to control the amount of flux used, making the soldering operation more convenient and precise.
[0049] Preferably, the weight ratio of flux to solder is 1:1 to 1:2. More preferably, the solder is tin. Flux also has the function of reducing the surface tension of tin. If the proportion of flux is too small, its effect of reducing the surface tension of tin is weakened, which is not conducive to the flow of solder to the end 1011 of the wire to be soldered. Since flux has a lower melting point than solder, if the proportion of flux is too large, the flux that melts first will coat the solder, which is not conducive to the melting of the solder and also not conducive to the formation of ellipsoidal solder balls 102.
[0050] Step S200: The solder is heated to a molten state. The wire 101 to be soldered is placed vertically, and the molten solder forms an ellipsoidal solder ball 102 at the end of the wire 101. A schematic diagram of the molten solder forming an ellipsoidal solder ball 102 at the end of the wire 101 is shown below. Figure 4 As shown.
[0051] Specifically, conventional equipment that provides a hot air source, such as a hot air source, can be used to heat the solder. Heating the solder to above 232°C will melt it. After the solder melts, the wire 101 to be soldered is placed vertically, allowing the flux and solder to move towards the end of the wire 101 under gravity. Because the mixture of flux and solder has a certain viscosity, as the flux and solder move towards the end of the wire 101 under gravity, some flux and solder adhere to the wire, while some flows downwards, resulting in a slender ellipsoidal solder ball at the end of the wire 101. The hot air source can be, for example, a hot air gun or a soldering station.
[0052] The slender, ellipsoidal structure of the solder ball allows for a smaller diameter, meaning a smaller width. When the wire 101 to be soldered is brought close to the pin to be soldered, it further avoids short circuits caused by solder connecting to non-pins. At the same time, if the solder ball is located on the side of the pin to be soldered, after the solder ball is remelted, the solder ball and the pin to be soldered have a larger contact area, allowing as much solder as possible to contact the pin to be soldered, thus improving the reliability of the soldering between the wire 101 to be soldered and the pin to be soldered.
[0053] Step S300: Bring the wire 101 to be soldered close to the pin to be soldered, heat the ellipsoidal solder ball 102 to melt the ellipsoidal solder ball, and use the melted ellipsoidal solder ball 102 to solder the wire 101 to the pin to be soldered.
[0054] Specifically, since the diameter of the wire to be soldered 101 is smaller than the diameter of the pin to be soldered, and / or the diameter of the wire to be soldered 101 is smaller than the distance between the pin to be soldered and the adjacent pin, when the wire to be soldered 101 is brought closer to the pin to be soldered, the wire to be soldered 101 will not occupy the position of the other pins, so it is not easy for the solder to connect with the non-pin to be soldered and cause a short circuit.
[0055] Similarly, conventional equipment that provides a hot air source, such as a hot air source, can still be used to heat the ellipsoidal solder ball 102. Heating the ellipsoidal solder ball 102 to above 232°C will remelt it. After the ellipsoidal solder ball 102 remelts, the molten solder is brought into contact with the pin to be soldered. Then the hot air source is removed, and the solder is allowed to cool before the wire 101 to be soldered is soldered to the pin.
[0056] The aforementioned high-density pin soldering method includes the steps of dipping the wire 101 to be soldered into solder, melting and shaping the solder, and remelting and soldering the solder. Compared to the existing soldering method using a soldering iron, this method allows the wire 101 to be soldered to be made much smaller than the pin, thus requiring less solder to be dipped into it. When the wire 101 is brought close to the pin, there is no short circuit caused by solder connecting to a non-pin. Therefore, compared to the existing soldering method using a soldering iron, the high-density pin soldering method of this embodiment easily achieves precise soldering between the wire 101 and the pin, is simple to operate, easy to implement, and efficient. It solves the technical problem in related technologies where high-density pin soldering is difficult to operate and requires multiple attempts to succeed.
[0057] Figure 2 Another flowchart illustrating a high-density pin soldering method is shown. (See diagram below.) Figure 2 As shown, before step S100, a solder preparation step is also included. Specifically, the solder preparation includes the following steps:
[0058] Solder is thinned and shortened based on the density of the leads to be soldered, ensuring that the thickness and length of the processed solder are both less than or equal to the spacing between the leads and adjacent leads. Alternatively, solder is thinned and shortened based on the length of the exposed portion of the leads to be soldered, ensuring that the thickness and length of the processed solder are both less than or equal to the length of the exposed portion of the leads to be soldered. Or, solder is thinned and shortened based on the diameter of the leads to be soldered, ensuring that the thickness and length of the processed solder are both less than or equal to the diameter of the leads to be soldered.
[0059] Specifically, the solder here is tin wire. The tin wire is thinned and shortened, that is, its thickness and length are reduced. This can be done using tools such as pliers. The denser the pins of the chip to be soldered, the thinner and shorter the processed tin wire; the shorter the exposed portion of the pins to be soldered, the thinner and shorter the processed tin wire; the smaller the diameter (or width) of the pins to be soldered, the thinner and shorter the processed tin wire. The preferred soldering method in this embodiment, by thinning and shortening the solder, facilitates control of the amount of solder used, avoiding excessive solder that could melt and overflow onto adjacent pins, causing a short circuit.
[0060] Not limited to this, solder balls can also be used directly as solder raw materials.
[0061] Figure 3 A third flowchart of the high-density pin soldering method is shown. (See diagram below.) Figure 3As shown, before bringing the wire 101 to be soldered close to the pin, the method further includes cooling the ellipsoidal solder ball 102 for 1-3 seconds and solidifying it. Specifically, the hot air source is turned off, allowing the hot air source to supply hot air to the wire 101. The molten ellipsoidal solder ball 102 solidifies naturally after 1-3 seconds. In this preferred embodiment, the soldering method solidifies the ellipsoidal solder ball 102 by cooling before bringing the wire 101 close to the pin. This ensures that the ellipsoidal solder ball 102 maintains its ellipsoidal shape during the process of bringing the wire 101 close to the pin, preventing changes in its shape during movement. Simultaneously, solidification enhances the connection strength between the ellipsoidal solder ball 102 and the wire 101, ensuring that the ellipsoidal solder ball 102 remains at the lower end of the wire 101, preventing dripping during movement.
[0062] According to a preferred embodiment, step S200 further includes the following steps: After vertically placing the wire to be soldered 101, observe whether the molten solder is located at the end of the wire to be soldered 101. When the molten solder is located above the end of the wire to be soldered, and the distance between the molten solder and the end of the wire to be soldered 101 exceeds a preset length, cut off the excess portion at the end of the wire to be soldered 101 and / or replenish the solder. Specifically, the preset length is, for example, 0.1 to 1 mm. When the distance between the molten solder and the end of the wire to be soldered 101 exceeds the preset length, the excess wire to be soldered 101 can be directly cut off along the lower end face of the solder using pliers; or flux and solder can be reapplied, both of which can form an ellipsoidal solder ball 102 at the end of the wire to be soldered 101. During the process of cutting off the excess wire, there may be solder loss. In this case, flux and solder can be reapplied for replenishment. Figure 5 A schematic diagram is shown showing that the lower end of the molten solder is higher than the end of the wire 101 to be soldered, that is, there is an excess part below the wire 101 to be soldered; Figure 6 A schematic diagram is shown showing the cutting off of the excess portion below the wire 101 to be soldered.
[0063] As the flux and solder move toward the end of the wire 101 to be soldered under the influence of gravity, the flow of flux and solder may be obstructed due to factors such as the roughness of the wire wall. This may result in no solder or only a small amount of solder at the end of the wire 101 to be soldered. This not only affects the reliability of the subsequent connection between the wire 101 and the pin to be soldered, but also may cause the wire 101 to cross the pin and occupy space when it approaches the pin. This makes it easy for the solder to connect with adjacent or more pins, causing a short circuit. It is also not conducive to achieving precise docking between the wire 101 and the pin to be soldered. The preferred welding method in this embodiment, by cutting off the excess portion at the end of the wire 101 to be welded and / or adding solder, can ensure that the ellipsoidal solder ball 102 is located at the end of the wire 101 to be welded, and can also ensure that the end 1011 of the wire to be welded has sufficient solder. This has the advantages of enhancing the reliability of the connection between the wire 101 to be welded and the pin to be welded, avoiding the solder from connecting with adjacent pins, and facilitating the precise docking of the wire 101 to be welded and the pin to be welded.
[0064] Preferably, the formulation used for replenishing the solder includes flux and solder, and the weight ratio of flux to solder is 1:1 to 1:2. Similar to the flux and solder initially applied, the flux also reduces the surface tension of the solder. If the proportion of flux is too small, its effect of reducing the surface tension of the solder is weakened, which is not conducive to the flow of solder to the end 1011 of the conductor to be soldered. Since flux has a lower melting point than solder, if the proportion of flux is too large, the flux that melts first will coat the solder, which is not conducive to the melting of the solder and also not conducive to the formation of ellipsoidal solder balls 102.
[0065] According to a preferred embodiment, in step S200, a hot air source is used to intermittently heat the solder, causing it to melt under the heat. Preferably, the hot air source operates at a minimum wind speed. Specifically, the solder melts after approximately 10 seconds of heating by the hot air source operating at minimum wind speed. Intermittent heating of the solder can be achieved by continuously shaking the handle of the hot air source, causing hot air to blow intermittently onto the solder. For example, the hot air source is shaken 5 to 15 times during the solder heating period. The welding method of this preferred embodiment, by intermittently heating the solder and maintaining the hot air source at minimum wind speed, avoids the problem of solder accumulating on the leeward side of the conductor while having too little solder on the windward side, which is detrimental to the formation of uniform ellipsoidal solder balls 102. At the same time, intermittent heating also prevents the flux from drying out or evaporating due to excessive heat, leading to flux failure.
[0066] Preferably, the angle between the outlet direction of the hot air source and the wire 101 to be welded is 30-60°. When the angle between the outlet direction of the hot air source and the wire 101 to be welded is too large, for example, 90°, the solder tends to accumulate on the leeward side of the conductor, while there is too little solder on the windward side of the conductor, which is not conducive to forming a uniform ellipsoidal solder ball 102. When the angle between the outlet direction of the hot air source and the wire 101 to be welded is too small, that is, the hot air source is too close to the wire 101 to be welded, which is inconvenient for operation. The welding method of the preferred technical solution in this embodiment, with an angle between the outlet direction of the hot air source and the wire 101 to be welded of 30-60°, not only facilitates the formation of a uniform ellipsoidal solder ball 102, but also provides a downward driving force for the solder, thereby driving the solder to move towards the lower end of the wire 101 to be welded.
[0067] According to a preferred embodiment, in step S300, when the wire 101 to be soldered is brought closer to the pin to be soldered, the wire 101 to be soldered is located above the pin to be soldered, or the wire 101 to be soldered is located to the side of the pin to be soldered, and the wire 101 to be soldered is parallel to the pin to be soldered, or the angle between the wire 101 to be soldered and the pin to be soldered is less than 10°. For the first type of chip pin, its pin structure diagram is as follows... Figure 7 As shown, this type of pin 201 is fixed to the chip body 202. The pin 201 has a vertical structure and includes a side pin 2011 and a front pin 2012. Taking the side pin 2011 as the pin to be soldered as an example, it is easy to place the wire to be soldered 101 on the side or on top of the pin. Preferably, when the pin 201 has a vertical structure, placing the wire to be soldered 101 on the side of the pin not only enhances the reliability of the connection but also avoids the problem of solder being blown onto adjacent pins when the solder ball is remelted by hot air if the wire to be soldered 101 is placed on top of the pin. For the second type of chip pin, the pin 201 is fixed to the chip body 202, and the structural diagram of the pin 201 is shown below. Figure 8 As shown, this type of pin 201 has a pin tilting portion 201a and a pin horizontal portion 201b. When the wire to be soldered 101 is placed on the side of the pin tilting portion 201a, it is not only convenient to place the wire to be soldered 101, but also to solder the wire to be soldered to the side of the pin to be soldered, which can also enhance the reliability of the connection between the two.
[0068] Preferably, the vertical distance between the end of the wire 101 to be soldered and the pin to be soldered is 3-5 mm. Specifically, when the wire 101 to be soldered approaches the pin, the pin is first positioned and accurately located. Then, hot air is blown to melt the ellipsoidal solder ball 102, and then the wire 101 to be soldered is brought closer to the pin to complete the soldering. In this preferred embodiment, if the vertical distance between the end of the wire 101 to be soldered and the pin to be soldered is too large, there is a risk that solder will drip onto other pins (when the wire 101 to be soldered is above the pin to be soldered). Alternatively, if the distance between the wire 101 to be soldered and the pin adjacent to the pin to be soldered is too small, there is a risk that the molten solder will easily connect with other pins. If the vertical distance between the end of the wire 101 to be soldered and the pin to be soldered is too small, it is difficult to keep the wire 101 in the same position during the heating process, otherwise the molten solder will easily connect with other pins, and it will also easily cause hand and eye fatigue. In the preferred embodiment of the welding method, the vertical distance between the end of the wire 101 to be welded and the pin to be welded is 3-5mm. This not only facilitates the precise connection between the wire 101 to be welded and the pin to be welded, but also provides a better field of vision for the welding operation.
[0069] According to a preferred embodiment, in step S300, based on at least one of the molten state of the ellipsoidal solder ball 102, the molten state of the lead to be soldered, the air velocity of the hot air gun, and the air velocity of the soldering station, the ellipsoidal solder ball 102 is intermittently or continuously heated using a hot air source, causing the ellipsoidal solder ball 102 to remelt under the influence of heat. Specifically, when heating the ellipsoidal solder ball 102, the molten state of the ellipsoidal solder ball 102 and the molten state of the lead to be soldered can be observed, and intermittent or continuous heating can be selected in combination with the air velocity of the hot air gun and / or the air velocity of the soldering station, with the aim of remelting the ellipsoidal solder ball 102.
[0070] According to a preferred embodiment, the angle between the outlet direction of the hot air source and the wire 101 to be welded is 30° to 90°. The angle between the outlet direction of the hot air source and the wire 101 to be welded is also the angle between the central axis of the outlet 301 of the hot air source and the wire 101 to be welded, specifically as follows: Figure 7 and Figure 8As shown by α and β in the figure. If the angle between the outlet direction of the hot air source and the wire 101 to be welded is too small, it is not convenient for operation and the pin to be welded is not heated evenly. It may also pose a risk of blowing the ellipsoidal solder ball 102 off the wire. If the angle between the outlet direction of the hot air source and the wire 101 to be welded is too large, it is also not convenient for the pin to be welded to be heated evenly. At the same time, it may blow the ellipsoidal solder ball 102 upward, resulting in an excessive distance between the ellipsoidal solder ball 102 and the pin to be welded, which is not conducive to subsequent welding. In the preferred welding method of this embodiment, the angle between the outlet direction of the hot air source and the wire 101 to be welded is 30-90°. This allows the hot air to be blown onto both the ellipsoidal solder ball 102 and the pin to be welded at the same time. This ensures that both the ellipsoidal solder ball 102 and the pin to be welded are heated evenly, and it is also conducive to the welding between the wire 101 and the pin to be welded.
[0071] It should be noted that, in this document, 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 that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.
[0072] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for soldering high-density pins, characterized in that, Includes the following steps: Step S100: Apply flux to one end of the wire to be soldered, and use the flux to adhere the solder to the wire to be soldered; Step S200: Heat the solder to make it molten, place the wire to be soldered vertically, and make the molten solder form an ellipsoidal solder ball at the end of the wire to be soldered. Then cool the ellipsoidal solder ball for 1 to 3 seconds and let the ellipsoidal solder ball solidify. Step S300: Bring the wire to be soldered close to the pin to be soldered, heat the ellipsoidal solder ball to melt it, and use the melted ellipsoidal solder ball to solder the wire to be soldered to the pin. Before step S100, there is also a step of preparing solder, and the preparation of solder includes the following steps: The solder is thinned and shortened based on the density of the pins to be soldered, and the thickness and length of the solder after the treatment are both less than or equal to the distance between the pin to be soldered and the adjacent pins. The solder is thinned and shortened based on the length of the exposed portion of the pin to be soldered, and the thickness and length of the solder after the treatment are both less than or equal to the length of the exposed portion of the pin to be soldered. The solder is thinned and shortened based on the diameter of the pin to be soldered, so that the thickness and length of the solder after the process are both less than or equal to the diameter of the pin to be soldered.
2. The high-density pin soldering method according to claim 1, characterized in that, In step S100, the flux is a paste; the weight ratio of flux to solder is 1:1 to 1:
2.
3. The high-density pin soldering method according to claim 1, characterized in that, Step S200 also includes the following steps: placing the wire to be welded vertically and observing whether the molten solder is located at the end of the wire to be welded. When the lower end of the molten solder is located above the end of the wire to be welded and the distance between the lower end of the molten solder and the end of the wire to be welded exceeds a preset length, the excess part of the end of the wire to be welded is cut off and / or replenished.
4. The high-density pin soldering method according to claim 3, characterized in that, The formulation used for patching includes flux and solder, and the weight ratio of flux to solder is 1:1 to 1:
2.
5. The high-density pin soldering method according to claim 1, characterized in that, In step S200, hot air is used to intermittently heat the solder, causing it to melt under the heat. The hot air source should be operated at minimum wind speed. The angle between the outlet direction of the hot air source and the wire to be welded is 30~60°.
6. The high-density pin soldering method according to claim 1, characterized in that, In step S300, when the wire to be soldered is brought close to the pin to be soldered, the wire to be soldered is located above the pin to be soldered, or the wire to be soldered is located to the side of the pin to be soldered, and The vertical distance between the end of the wire to be soldered and the pin to be soldered is 3~5mm. The wire to be soldered should be parallel to the pin to be soldered, or the angle between the wire to be soldered and the pin to be soldered should be less than 10°.
7. The high-density pin soldering method according to claim 1, characterized in that, In step S300, based on at least one of the molten state of the ellipsoidal solder ball, the molten state of the pin to be soldered, the wind speed of the hot air gun, and the wind speed of the soldering station, the ellipsoidal solder ball is intermittently or continuously heated using a hot air source, and the ellipsoidal solder ball melts again under the action of heat.
8. The high-density pin soldering method according to claim 7, characterized in that, The angle between the outlet direction of the hot air source and the wire to be welded is 30~90°.