Welding method of lead frame
A technology of lead frame and welding method, which is applied in the field of lead frame welding, can solve the problems of long welding time, easy welding of solder joints, unreliable welding, etc., and achieve the effects of increasing storage costs, improving quality requirements, and shortening welding time
Active Publication Date: 2013-04-24
MORNSUN GUANGZHOU SCI & TECH
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Problems solved by technology
[0005] (1) The solder joints on the lead frame are easy to drag and weld, that is, there is no metal compound formed between the component pins and the pads, and the soldering is unreliable;
[0006] (2) It is not easy to tin on the surface of the lead frame pad during welding, and the welding time is relatively long
Method used
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Embodiment Construction
[0030] Such as figure 1 Shown, be the welding method of a kind of lead frame of the present invention, comprise the following steps:
[0031] (1) Grinding stage: put the lead frame in the laser marking machine, and then perform laser grinding on the welding pad position 2 on the lead frame 1 under the conditions of the working current of 8.5-9A and the focal length of the laser grinding being 28CM , Grind off the nickel plating at pad position 2 to expose the copper surface of the lead frame, see figure 2 . Since the surface of the pad position 2 after polishing is copper, the component pins are directly welded to copper, and it is easier to form a nugget when solder paste and copper are welded, so that the combination of components and the surface of the pad is stronger and strengthened. Improve welding reliability and meet the quality requirements.
[0032] (2) Solder paste printing stage: Print a layer of solder paste on the copper surface of the pad position on the lea...
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The invention discloses a welding method of a lead frame, comprising the following steps of: (1) grinding stage: grinding away coated nickel at the position of a welding disk on the lead frame, and exposing material copper at the welding disk on the lead frame; (2) tin soldering paste printing stage: printing tin soldering paste at the position of the welding disk on the lead frame; (3) patch stage: laminating components on the tin soldering paste of the welding disk on the lead frame; (4) welding stage: feeding the lead frame into a reflow welding machine for welding; and (5) after the welding is finished, taking out the lead frame, standing to room temperature and then sending the lead frame for inspection. In the welding method, as the coated nickel at the position of the welding disk on the lead frame is removed, the tin soldering paste is directly printed on the copper; and in welding, weld nuggets are easily formed between the tin soldering paste and the copper, drag welding canbe avoided for welding spots, therefore, the combination of the components and the surface of the welding disk is firmer, the welding reliability is enhanced, and further the requirement for improving the quality is met.
Description
technical field [0001] The invention relates to a welding method of a lead frame. Background technique [0002] Welding is a very important process in the machinery manufacturing industry. With the miniaturization, miniaturization and high performance of electronic products, the requirements for welding technology are getting higher and higher. In the manufacturing process of electronic and microelectronic components, the reliability of welding has become the focus of many people's attention. It is the guarantee of the quality of modern electronic products to improve the reliability of welding and reduce the damage to components caused by welding. [0003] At present, considering the comprehensive consideration of hardness, ductility and cost performance, the material of the lead frame in the welding process is generally copper or phosphine copper. However, since copper is a metal material that is easily oxidized, it will greatly affect the welding effect after oxidation, w...
Claims
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IPC IPC(8): B23K1/00B23K1/20
Inventor 刘义成刘伟
Owner MORNSUN GUANGZHOU SCI & TECH