JP4177308B2 - Electronic components with lead terminals - Google Patents

Description

  The present invention relates to an electronic component with lead terminals.

Japanese Patent Application Laid-Open No. 2004-133826 proposes a chip coil that can be easily bent by punching a lead piece. According to the description of Patent Document 1, the chip-type coil is manufactured by the following procedure. First, the coil is held on the lead frame by locking the base end of the lead extending from both ends of the coil to the locking part formed at the tip of the pair of left and right lead pieces protruding from the lead frame. Let In this held state, solder is applied to the base end portion and the engaging portion of the lead, heated and melted, and then cured to electrically connect the lead and the lead piece. Thereafter, the tip of the lead is cut, and the molding is performed with the coil connected to the lead piece. Finally, the lead frame is punched, the lead piece to be the lead terminal is cut off, and the cut lead terminal is bent to manufacture a chip-shaped coil (see FIG. 1 of Patent Document 1 below).
JP-A-5-152129

  In the manufacturing method described in Patent Document 1, when solder is applied to the base end portion and the engaging portion of the lead and heated and melted, the solder flows along the lead terminal to the lead frame side. Therefore, even if the coil is molded and covered with the mold member, the solder may remain on the lead terminals extending outward from the mold member. Since the lead terminals extending to the outside are portions that are electrically connected to other electronic components, the residual solder may cause connection failure.

  Therefore, an object of the present invention is to provide an electronic component with a lead terminal that can suppress the outflow of solder to a lead terminal connected to another electronic component.

  The electronic component with a lead terminal of the present invention includes an electronic component and a lead terminal connected to the electronic component, and the lead terminal is electrically connected to the electronic component by solder and another electronic component. It has the 2nd area | region electrically connected, and the cutting | disconnection area | region which divides | segments a 1st area | region and a 2nd area | region, The cutting | disconnection area | region is characterized by solder wettability being lower than a 1st area | region.

  According to the electronic component with a lead terminal of the present invention, the solder wettability of the divided region existing between the first region and the second region is lower than the solder wettability of the first region. It is possible to suppress the flow of solder to be stopped in the divided region and to flow out to the second region.

  In the electronic component with a lead terminal of the present invention, it is also preferable that the lead terminal is formed using a material in which a tin film is formed on a base metal, and the dividing region is formed by removing the formed tin film. Since the tin film is made of a material formed on the base metal, and the tin film is removed, the divided area is formed. For example, a separate layer is newly formed to form the divided area. Compared with this, it is possible to easily form the divided region.

  In the electronic component with a lead terminal according to the present invention, it is also preferable that the dividing region is formed by removing the tin film by laser processing. Since the tin film is removed by laser processing, it can be processed accurately even if the dividing region is a small area.

  In the electronic component with a lead terminal according to the present invention, it is also preferable that the dividing region is formed of an alloy of tin and a base metal. Since the solder wettability of the alloy of tin and the base metal is lower than the solder wettability of the base metal alone, it is possible to more effectively suppress the solder from flowing into the second region.

  Moreover, in the electronic component with a lead terminal of the present invention, it is preferable to include a mold member that covers at least the first region of the electronic component and the lead terminal and exposes the second region of the lead terminal to the outside. Since the mold member covers the first region and the second region is exposed, it is possible to prevent the solder that is heated and melted from flowing out of the mold member. Therefore, for example, even when the lead component is contained in the solder, the lead component can be prevented from flowing out of the mold member.

  According to the present invention, since the flow of solder that is heated and melted in the first region is stopped in the divided region, it is possible to prevent the solder from flowing out to the second region that is electrically connected to other electronic components.

  The knowledge of the present invention can be easily understood by considering the following detailed description with reference to the accompanying drawings shown for illustration only. Subsequently, embodiments of the present invention will be described with reference to the accompanying drawings. Where possible, the same parts are denoted by the same reference numerals, and redundant description is omitted.

  A coil component with lead terminals (electronic component with lead terminals) according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a configuration of a coil component 1a with lead terminals, and FIG. 2 is a cross-sectional view in a direction from one lead terminal 20 to the other lead terminal 20 in FIG. In FIG. 1 and FIG. 2, the mold member 40 is indicated by a two-dot chain line for easy understanding. In FIG. 2, hatching is omitted.

  The coil component with lead terminal 1 a includes a coil body 10 (electronic component), a lead terminal 20, an internal connection member 30, and a mold member 40. The coil body 10 is configured by winding a winding 102 around a magnetic core 101. The magnetic core 101 is a substantially cylindrical shape, and is a drum core provided with flanges 101a at both ends in the longitudinal direction. The flange portion 101a protrudes in a hook shape in the radial direction at both ends of the magnetic core 101.

  The winding 102 is wound around the coil body 10 between the two flange portions 101a. Winding end portions 102a, which are both ends of the windings 102, are respectively guided over the two flange portions 101a and into recesses 101b formed on the outer surfaces of the respective flange portions 101a.

  The lead terminal 20 includes an internal connection portion 201 (first region), a mounting portion 202 (second region), a divided portion 203 (divided region), and a receiving portion 204.

  The internal connection portion 201 is bent from the portion rising from the mounting portion 202 toward the concave portion 101b of the magnetic core 101, and is formed so that the tip thereof is accommodated in the concave portion 101b. Solder is heated and melted and poured into the recess 101b in a state where the winding end portion 102a of the winding 102 and the internal connection portion 201 of the lead terminal 20 are accommodated. The poured solder is solidified to form the internal connection member 30.

  The mounting portion 202 extends outward from the position corresponding to both ends of the magnetic core 101 along the outer surface of the mold member 40, and is bent at the ridge line portion of the mold member 40. A portion of the mounting portion along the outer surface of the mold member 40 is a portion placed on another electronic component (such as a mounting substrate).

  The divided portion 203 is provided between the internal connection portion 201 and the mounting portion 202 and is a portion that divides the internal connection portion 201 and the mounting portion 202. The divided portion 203 is formed so that the solder wettability is worse than that of the internal connection portion 201. More specifically, by performing laser processing on a portion corresponding to the divided portion 203 of the lead terminal 20, the tin plated on the surface of the lead terminal 20 is melted, sublimated, evaporated, and vaporized and partially peeled off. Grooves are formed.

  In addition, by performing laser processing on a portion corresponding to the divided portion 203, an alloy of tin plated on the surface of the lead terminal 20 and copper which is the base metal of the lead terminal 20 is generated. The solder wettability of 203 is deteriorated. This is because a diffusion layer is formed by alloying of tin having a melting point of 231.9 ° C. and copper having a melting point of 1084.5 ° C. due to the heat of the laser. This is due to the deterioration in the order of tin, copper, and tin-copper alloy.

  The dividing portion 203 is formed so as to cross a portion from the internal connection portion 201 to the mounting portion 202, and the solder forming the internal connection member 30 travels along the surface of the internal connection portion 201 to the outside of the mold member 40. It is blocked substantially so that it will not flow out. The width of the divided portion 203 in the solder flow direction is preferably 0.3 mm or more. This is because if the width in the solder flow direction is smaller than 0.3 mm, the solder flowing out from the internal connection portion 201 may get over the divided portion 203.

  Since laser processing uses a spot laser having a laser spot diameter of about 50 μm, accurate processing can be performed with a small area. On the other hand, when the groove is formed using a cutter or the like, it is more preferable to employ laser processing because the base metal may be cut during processing.

  The receiving portion 204 is formed by being bent into an inverted L shape from the mounting portion 202. More specifically, the receiving portion 204 includes a portion rising from the mounting portion 202 along the dividing portion 203 and a portion extending from the tip of the rising portion toward the flange portion 101a of the magnetic core 101. It is configured. The portion extending toward the flange portion 101a functions as a portion that supports the magnetic core 101 by contacting the flange portion 101a.

  Then, the manufacturing method of the coil component 1a with a lead terminal is demonstrated, referring FIGS. 3-5. As shown in FIG. 3, the coil body 10 and the lead frame 2 are prepared. The coil body 10 is in a state where a winding 102 is applied to a magnetic core 101.

  The lead frame 2 is a frame member in which portions to be the lead terminals 20 are continuously formed. More specifically, the lead frame 2 is formed with a rising portion that becomes the internal connection portion 201 and the dividing portion 203, and a rising portion that becomes the receiving portion 204 so as to sandwich the rising portion. Tin plating is applied to the back surface of the lead frame 2 in FIG. 3, that is, the surface including the surface on which the divided portion 203 is formed. The base metal of the lead frame 2 is phosphor bronze, and the surface of the lead frame 2 in FIG. 3 is exposed to phosphor bronze as the base metal. The part which becomes the divided part 203 is subjected to laser processing, and the plated tin and the copper component of phosphor bronze as a base metal are alloyed.

  After the state of FIG. 3, the coil body 10 is placed on the lead frame 2 as shown in FIG. 4. The coil body 10 is placed on the lead frame 2 so that the internal connection portion 201 formed on the lead frame 2 is accommodated in the recess 101b formed on the flange portion 101 of the coil body 10.

  After the state of FIG. 4, as shown in FIG. 5, the solder is heated and melted and poured into the recess 101 b formed in the flange portion 101 of the coil body 10. In this state, the internal connection portion 201 formed on the lead frame 2 is immersed in the solder, but the solder does not flow over the divided portion 201. In general, the wettability of solder deteriorates in the order of tin, copper, and tin-copper alloy. Therefore, the solder that contacts the internal connection portion 201 is sufficiently wetted and spreads on the surface of the internal contact portion 201 where the tin plating is applied, but the phosphor bronze is exposed on the opposite surface of the internal contact portion 201. Therefore, the solder wettability is poor, and the solder does not flow along the surface. Moreover, since the divided portion 203 is formed on the surface of the internal contact portion 201 where the tin plating is performed, the flow of solder is stopped here.

  Further, the mold member 40 is formed so as to cover the coil body 10 with a resin material. Thereafter, the lead frame 2 is cut along predetermined cutting lines 2a and 2b. By bending the end portion of the separated lead terminal 20, the coil component 1a with lead terminal as shown in FIGS. 1 and 2 is manufactured. Therefore, the solder does not flow out of the mold member 40. For example, even if the solder contains a lead component, the lead component can be prevented from flowing out.

  Here, the situation where wettability changes by laser processing will be described. FIG. 6 shows a photograph of the vicinity of the divided portion 203 when the laser output is changed. FIG. 6A shows a state of being wetted with solder without performing laser processing for reference. As shown in FIG. 6A, it can be seen that the solder is uniformly wet. 6 (b) shows a laser output of 40 (%) about 1.8 (W), FIG. 6 (c) shows a laser output of 60 (%) about 3.5 (W), and FIG. 6 (d). These are photographs showing the situation in the vicinity of the divided portion 203 when the laser output is 80 (%) approximately 5.5 (W). In (b) to (d) of FIG. 6, the portion that appears white compared to the other portions is the portion where the tin component remains. In the state of FIG. 6B, solder wettability is still ensured even in the divided portion 203. In the states of FIGS. 6C and 6D, the wettability of the solder in the divided portion 203 is lowered, and it can be seen that it is effective to perform laser processing with this output.

  In the present embodiment, the coil is exemplified as the electronic component housed in the mold member 40. However, an electronic component such as a capacitor, a varistor, or a thermistor may be employed.

It is a figure which shows the structure of the coil component with a lead terminal which is embodiment of this invention. It is a figure which shows the cross section along the longitudinal direction of FIG. It is a figure for demonstrating the manufacturing method of the coil component with a lead terminal which is embodiment of this invention. It is a figure for demonstrating the manufacturing method of the coil component with a lead terminal which is embodiment of this invention. It is a figure for demonstrating the manufacturing method of the coil component with a lead terminal which is embodiment of this invention. It is a figure for demonstrating the state of the wettability conversion by laser processing.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1a ... Coil component with lead terminal, 10 ... Coil main body, 20 ... Lead terminal, 30 ... Internal connection member, 40 ... Mold member, 101 ... Magnetic core, 101a ... Gutter, 102 ... Winding, 102a ... Winding end 201, internal connection portion, 202, mounting portion, 204, receiving portion.

Claims (3)

An electronic component with a lead terminal comprising an electronic component and a lead terminal connected to the electronic component,
The lead terminal divides the first region electrically connected to the electronic component by solder, the second region electrically connected to another electronic component, and the first region and the second region. A segmented area, and
The lead terminal is formed using a material in which a tin film is formed on a base metal containing a copper component,
The segmented region is formed of an alloy of a copper component and tin contained in the base metal while removing the tin film by laser processing , and has lower solder wettability than the first region. Electronic components with lead terminals. 2. The electronic component with a lead terminal according to claim 1, wherein a groove extending across the portion from the first region to the second region in the lead terminal is formed in the divided region. . Covering at least the first region of the electronic component and the lead terminals comprise a mold member in which the exposed second region of the lead terminals to the external lead terminals with an electronic component according to claim 1 or 2.

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