JP2012183552A - Heater tip, joining device, and joining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform soldering which is high in reliability in strength with respect to an article to be joined (particularly covered wire).SOLUTION: A heater tip 10 has a nearly rectangular-parallelepiped-shaped soldering iron part 12 which is a projecting region at the lowest end in the posture of an ordinary form of use, and is provided with a recess 14 for supplying a solder, which communicates with the tip surface 12b of an iron on one side face 12a of the soldering iron part 12. In a work for joining a lead wire 100 to a terminal 104 on a printed wiring board 102, the insulating coating of the lead wire 100 is peeled and just after a primary solder 105 which is coated beforehand on the surface of the terminal 104 is melted, a second solder 66 composed of a linear solid solder is inserted (supplied) into the recess 14 of the heater tip 10.

Description

  The present invention relates to a heater chip, a bonding apparatus, and a bonding method used for soldering, and more particularly to a heater chip suitable for use in reflow soldering.

  Conventionally, for example, in order to join a lead wire (covered wire) 100 of an external electrical component to a terminal (connection pad or electrode) 104 on a printed wiring board 102 by reflow soldering, as shown in FIG. A heater chip 108 having a portion 106 is used (see, for example, Patent Document 1).

  This type of heater chip 108 is formed as a substantially U-shaped plate body made of a refractory metal such as tungsten or molybdenum, and includes a small piece-like iron portion 106 that protrudes downward from the bottom in a concave direction (posture). The connection terminal portions 110L and 110R at the left and right ends are attached to the heater head 112 in a horizontal manner. The illustrated heater head 112 physically connects the left and right connection terminals 110L and 110R of the heater chip 108 with bolts 116L and 116R on one side of a pair of power supply conductors 114L and 114R that communicate with an output terminal of a heater power source (not shown). They are electrically connected to each other, and have an elevating mechanism for moving the heater chip 108 up and down via the power supply conductors 114L and 114R, and a pressurizing mechanism (not shown) for pressing toward the object to be joined. . An insulator 118 is electrically sandwiched between the power supply conductors 114L and 114R to electrically separate them.

  In FIG. 15, the printed wiring board 102 is horizontally placed on a work table (for example, an XY table) (not shown), and the lead wire 100 is placed on the terminal 104. The surface of the terminal 104 is coated with cream-like solder or plating solder 105 in advance.

  When the heater head 112 lowers the heater chip 108, as shown in FIG. 16, the lower surface of the iron portion 106 of the heater chip 108, that is, the iron tip surface 106a is connected to the bonded portion, that is, the lead wire 100 and the terminal 104 on the printed wiring board 102 side. Contact with moderate pressure. When the heater power supply is turned on and current is supplied to the heater chip 108 with the iron part 106 of the heater chip 108 pressed against the joined parts (100, 104), the iron part 106 of the heater chip 108 is supplied. Generates resistance and heats the bonded parts (100, 104). As a result, the insulating film of the lead wire 100 is melted and peeled off by heat, and the solder 105 around the lead wire 100 is also melted. The melted solder 105 rises somewhat so as to creep up along the peripheral surface of the exposed conductor 100a of the lead wire 100. The heater power supply stops energization after a certain time (energization time) has elapsed from the start of energization, and after a certain time (holding time) has elapsed since the end of energization, the heater head 112 raises the heater chip 108 and separates it from the joined parts (100, 104). . Then, the solder is solidified, and the joined parts (100, 104) are joined by reflow soldering.

JP 2005-66636 A

  However, the conventional coated wire bonding method using reflow soldering as described above has insufficient bonding strength, and may be disconnected when an external force is applied to the lead wire 100. That is, unlike the lead of the surface mount type electrical component in which the main body is mounted on the printed wiring board as in the IC package, the lead wire 100 from the external electric component arranged outside the printed wiring board is exposed to the air. The range or section is indefinitely long, and is likely to receive a large external force (stress) during assembly, for example. However, in the conventional bonding method as described above, since the bonding area of the solder 105 that melts and solidifies between the lead wire 100 and the terminal 104 is small, solder bonding with high strength and reliability cannot be obtained.

  The present invention solves the problems of the prior art as described above, and provides a heater chip, a joining apparatus, and a joining method capable of performing highly reliable soldering on an object to be joined, particularly a coated wire. provide.

  The heater chip of the present invention is a heater chip that has a solder part that generates heat when energized, and that joins the article to be joined by soldering by bringing the tip surface of the iron part into pressure contact with the article to be joined. And a solder supply recess extending from a side surface of the iron portion to the iron tip surface.

  In the heater chip of the present invention, when the tip of the iron part is brought into pressure contact with the object to be joined and the heater chip is energized, the temperature of the iron part rises to a set temperature and the object to be joined is heated. Here, at an appropriate timing, solder is put into the recess. Then, the solder quickly melts in the recess and spreads so that the melted solder covers the object to be joined. If the heater chip is de-energized (or weakened) or the heater chip is moved away from the workpiece and cooled, the solder solidifies and a highly reliable solder joint is obtained. It is done.

  In a preferred aspect of the present invention, a plurality of iron parts are electrically connected in series and physically in one piece, and a depression is individually provided in each iron part. According to such a configuration, a plurality of sets of objects to be bonded can be simultaneously bonded by soldering, and a highly reliable soldering connection can be obtained for each set of objects to be bonded.

  According to a preferred aspect of the present invention, the objects to be joined are a covered wire and a terminal member, and soldering is performed by applying the tip surface of the iron portion to the covered wire placed on the terminal member. In this case, the iron part is preferably formed in a substantially rectangular parallelepiped shape. The solder supply recess may have an inlet on one side of the iron part facing the axial direction of the coated wire to be soldered, or one of the iron parts parallel to the axial direction of the coated wire to be soldered. You may have an entrance in the side.

    According to a preferred aspect of the present invention, in the axial direction of the covered wire, the indentation has a depth dimension (or width dimension) of 0.3 to 0.7 times the iron tip surface, and particularly preferably the iron tip. It has a depth dimension (or width dimension) 0.4 to 0.6 times the surface.

  According to a preferred aspect, the ceiling of the indentation is gradually lowered from the side surface of the iron portion toward the inner depth, and the bottom is notched from the entrance to the inner depth end. According to such a configuration, the linear solid solder can be easily inserted (supplied) toward the inner part of the recess and toward the workpiece.

  The joining apparatus of the present invention includes the heater chip of the present invention, a heater head that supports the heater chip and presses the tip of the iron part into the object to be joined when the object to be joined is joined, and the heater A heater power supply for supplying a current for resistance heating to the chip.

  The joining apparatus of the present invention can perform soldering with high strength and reliability by the above-described configuration, particularly by the configuration including the heater chip of the present invention.

  The joining method of the present invention is a joining method for joining a coated wire to a terminal member by soldering using the soldering apparatus of the present invention, wherein the coating is applied to the terminal member via a first solder. A step of placing a wire, a step of applying a predetermined pressing force by applying a tip surface of the iron portion of the heater chip to the covered wire so that a recess of the iron portion covers the covered wire, and the iron portion The step of raising the temperature of the iron part to a first set temperature higher than the melting point of the first solder by energization, and after raising the temperature of the iron part to the first set temperature, Supplying the second solder therein, melting the second solder in the recess, and combining the second solder with the first solder in a molten state so as to wrap the covered wire And the tip of the iron part Separated from serial coated wire, and a step of solidifying said first and second solder coalesced in the molten state.

  In the bonding method of the present invention, with the above-described configuration, in particular, after the temperature of the iron part is raised to the first set temperature, that is, after the insulation film of the coated wire is removed by heating and the first solder is melted, the iron is melted. Supplying the second solder into the recess of the part, melting the second solder in the recess, and combining the second solder with the first solder in a molten state so as to wrap the coated wire As a result, the solder joint area and joint strength can be increased efficiently, and the reliability of the coated wire joint can be improved.

  According to the heater chip, the bonding apparatus, and the bonding method of the present invention, it is possible to perform highly reliable soldering on an object to be bonded, in particular, a covered wire, by the above configuration and operation.

It is a perspective view which shows the structure of the heater chip in one Embodiment of this invention. It is a front view which shows the structure of the said heater chip. It is sectional drawing about the AA line of FIG. It is a figure which shows the whole structure of the joining apparatus in the said embodiment. It is a figure which shows the process example of one Example which joins a covered wire to the terminal on a printed wiring board by soldering using the said joining apparatus. It is a figure which shows the temperature control characteristic of the heater chip in the said Example. It is a perspective view which shows a mode that a covered wire is mounted and positioned in the terminal on a printed wiring board in the said Example. It is a partial cross section front view which shows the state which made the heater chip press-contact the to-be-joined object in the said Example. It is a partial cross section front view which shows a state when the insulating film of a lead wire peels in the said Example and a primary solder melt | dissolves. It is a partial cross section side view which shows a state when the insulating film of a lead wire peels and the primary solder melt | dissolves in the said Example. It is a perspective view which shows a mode when supplying secondary solder in the hollow of a heater chip | tip in the said Example. It is a partial cross section side view which shows a mode that a secondary solder melt | dissolves in the hollow of a heater chip | tip in the said Example, and its effect | action. It is a partial cross section front view which shows a mode when a heater chip is separated from a to-be-joined object in the said Example, and the state of the to-be-joined object after soldering. In the said Example, it is a partial cross section side view which shows the state when separating a heater chip from a to-be-joined object, and the state of the to-be-joined object after soldering. It is a figure which shows one modification regarding the tip part of a heater chip. It is a figure which shows another modification regarding the tip part of a heater chip. It is the perspective view seen from diagonally upward which shows the structure of the heater chip | tip in another embodiment. It is the perspective view which looked at the heater chip | tip of FIG. 13A from diagonally downward. It is a perspective view which shows the process example which joins two covered wires to a different terminal simultaneously by soldering using the heater chip of FIG. 13A. It is a perspective view which shows the example of the conventional heater chip | tip and soldering using it. FIG. 16 is a front view showing a state where the heater chip of FIG. 15 is energized.

  Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS.

  1 to 3 show a configuration of a heater chip in an embodiment of the present invention. 1 and 2 are a perspective view and a front view of the heater chip, and FIG. 3 is a cross-sectional view taken along line AA of FIG.

  The heater chip 10 in this embodiment is formed of a tungsten plate having a plate thickness of 3 to 5 mm, for example. The heater chip 10 is manufactured by punching and integrally processing this tungsten plate by wire electric discharge machining.

  The heater chip 10 has a substantially rectangular parallelepiped shaped iron part 12 which is a projecting portion at the lowermost end in a posture of a normal use form. Solder supply leading to the bottom surface, that is, the iron tip surface 12b, is provided on one side surface 12a of the iron part 12. The main feature is the configuration in which the recess 14 is provided.

  More specifically, the side surface 12a of the iron portion 12 corresponds to the front surface or the back surface of the base material (tungsten plate), and the recess 14 is formed in the side surface 12a by, for example, cutting and polishing. The illustrated recess 14 extends from the upper end to the bottom (the bottom of the iron 12) while spreading laterally in an inversely tapered manner downward at the center in the width direction of the side surface 12a of the iron 12 and increasing the depth inward. It has a structure that has been scraped off to the front surface 12b). In this hollow structure, the ceiling 14a of the hollow 14 is gradually lowered from the side surface 12a toward the inner depth, and the bottom is notched from the inlet 14b to the inner end 14c. As described later, a linear solid solder is used. 66 is easily inserted toward the inside of the recess 14, that is, toward the welded portion.

  In FIG. 3, the depth (depth) D of the recess 14 is preferably in the range of 0.3T to 0.7T, where T is the thickness of the iron part 12, and is in the vicinity of 0.5T, that is, 0.4T to 0.6T. The range of is most preferable. That is, if the depth D is too small as compared with the thickness T of the iron part 12, the amount of secondary solder supplied through the recess 14 and, as a result, the amount of solder pool generated in the recess 14 will be described later. The amount of secondary solder combined with the primary solder is reduced, and the advantage of having the recess 14 is not fully exhibited. On the other hand, if the depth D of the recess 14 is larger than necessary compared to the thickness T of the iron part 12, even if the amount of secondary solder supplied increases, the contact area of the iron tip surface 12b that directly contacts the object to be joined As a result, the heating power is reduced, so that the insulation coating is hardly peeled off by soldering the coated wire as described later, and as a result, it is difficult to improve the solder joint strength.

  The height H and the width W of the bottom of the recess 14 may be selected to be optimal dimensions in view of the trade-off between ease of supplying solder and ease of melting. As a preferred embodiment, the height H is selected in the range of 0.8T to 1.2T, and the bottom width W is selected in the range of 1.5T to 2.0T.

  The left and right connection terminal portions 18L and 18R are connected to the left and right end portions of the upper surface of the iron portion 12 through bifurcated current passage portions 16L and 16R, respectively, whose cross-sectional area is narrowed to increase the current density. . Each of the connection terminal portions 18L and 18R is provided with one or a plurality (two in the illustrated example) of bolt through holes 20L and 20R at the upper end. A protrusion 24 for attaching a thermocouple 22 (FIG. 5) to be described later is formed at the center of the upper surface of the iron part 12.

  Similarly to the conventional heater chip 108, the heater chip 10 is also attached to the heater head 112 (FIG. 15), and applies a predetermined pressurizing operation and energization to a given object under predetermined procedures and conditions. A heat generation operation is performed.

  In FIG. 4, the whole structure of the joining apparatus 26 in this embodiment is shown. The joining device 26 includes the heater chip 10 having the above-described configuration, and a heater that supports the heater chip 10 and presses and contacts the tip surface 12b of the iron part 12 to the workpiece when the workpiece is joined. A head 112, a heater power supply 28 that supplies a current for resistance heating to the heater chip 10, and a control unit 42 that controls each unit in the apparatus and the overall operation.

  The heater power supply 28 uses an AC waveform inverter type power supply circuit. The inverter 30 in this power supply circuit has four transistor switching elements 32, 34, 36, and 38 made of GTR (giant transistor) or IGBT (insulated gate bipolar transistor).

Among these four switching elements 32 to 38, the first set (positive side) switching elements 32 and 36 are driven at a predetermined inverter frequency by in-phase drive pulses G ₁ and G ₃ from the control unit 42 via the drive circuit 40. Switching (on / off) is controlled at the same time (for example, 4 kHz), and the second set (negative electrode side) of the switching elements 34 and 38 are driven by in-phase drive pulses G ₂ and G ₄ from the control unit 42 via the drive circuit 40. Switching control is performed simultaneously with the inverter frequency.

The input terminals [L ₀ , L ₁ ] of the inverter 30 are connected to the output terminals of the three-phase rectifier circuit 44. The three-phase rectifier circuit 44 is formed by, for example, connecting six diodes in a three-phase bridge, and full-wave rectifying a commercial-frequency three-phase AC voltage input from a three-phase AC power supply terminal (R, S, T) to generate a direct current. Convert to voltage. The DC voltage output from the three-phase rectifier circuit 44 is smoothed by the capacitor 46 and then applied to the input terminals [L ₀ , L ₁ ] of the inverter 30.

Output terminals [M ₀ , M ₁ ] of the inverter 30 are respectively connected to both ends of the primary coil of the welding transformer 48. Both ends of the secondary coil of the welding transformer 48 are connected to the connection terminal portions 18L and 18R of the heater chip 10 via the secondary conductors 114L and 114R, respectively, without passing through the rectifier circuit.

  The control unit 42 includes a microcomputer, and performs all control within the heater power supply 28, such as energization control (particularly inverter control), setting of various heat conditions, display processing, etc., as well as required for the heater head 112. Control.

  In the heater power supply 28, a solder temperature measurement signal output from a thermocouple 22 attached to the protrusion 24 of the heater chip 10 is given to the control unit 42 via the cable 25 in order to perform chip temperature feedback control. When current feedback control is performed, a current sensor 50 made of, for example, a current transformer is attached to the conductor of the primary circuit. A measured value (for example, effective value, average value, or peak value) of the primary current or the secondary current is obtained from the output signal of the current sensor 50 in the current measurement circuit 52, and the current measurement signal is given to the control unit 42.

  Next, with reference to FIGS. 5 to 11, an embodiment will be described in which a coated wire is joined to a terminal member by soldering using the joining device 26 having the above-described configuration.

  As shown in FIG. 5, in this embodiment, the lead (covered wire) 100 of the external electric component (for example, small motor) 60 is placed on the printed wiring board 102 in the same manner as the conventional example (FIGS. 15 and 16) described above. Bonded to terminals (connection pads or electrodes) 104 by soldering. In the drawing, the left lead 100 ′ and the terminal 104 ′ are already soldered, and the right lead 100 and the terminal 104 are not yet connected. The terminals 104 and 104 ′ are electrically connected to a surface mount type electric component (not shown) attached to the back surface through printed wirings 62 and 62 ′ on the printed wiring board 102 and through holes (not shown). It is connected to the. The surface of the terminal 104 is pre-coated with cream-like solder or plated solder 105 as primary solder for reflow in this embodiment.

  The joining device 26 uses the rapid heating / rapid cooling characteristics based on the energization heat generation function of the heater chip 10 and the high-speed and fine energization control function of the inverter heater power supply 28 to increase the temperature of the iron part 12 of the heater chip 10 at high speed. And it can be arbitrarily changed. FIG. 6 shows an example of a sequence for variably controlling the temperature of the iron part 12 of the heater chip 10 in this embodiment.

  First, before starting the joining device 26, as shown in FIG. 7, the lead wire 100 is horizontally placed in a predetermined direction on the terminal 104 of the printed wiring board 102 on a work table (not shown), and the heater Positions (100, 104) to be joined are located directly below the heater chip 10 attached to the head 112. At this time, the side surface 12 a of the iron part 12 provided with the recess 14 of the heater chip 10 faces the axial direction of the lead wire 100.

  When the joining device 26 is activated, the heater head 112 is first activated. The heater head 112 lowers the heater chip 10, applies the lower surface of the iron portion 12, that is, the iron tip surface 12b, to the top of the lead wire 100 as shown in FIG. Thus, at substantially the same time as the heater chip 10 comes into pressure contact with the lead wire 100, the heater power supply 28 is activated to start energization.

When energization is started, as shown in FIG. 6, the temperature of the iron part 12 of the heater chip 10 rapidly rises, and from a normal temperature to a base temperature (200 ° C.) in a short time (0.5 seconds). Reach (S ₁ ). The base temperature is maintained for a certain period (0.5 seconds) to thermally stabilize the heater chip 10 (S ₂ ), and then the current amount of the conduction current I is increased so that the temperature of the iron part 12 is increased from the base temperature. The temperature is rapidly raised to a preheating temperature (500 ° C.) in a short time (1.0 second) (S ₃ ).

  Normal preheating means preheating and is set to a temperature lower than the melting point of solder (for example, 320 ° C.) in order to improve the wettability of the solder. However, the preheating in this embodiment means heating for peeling off the insulating film of the lead wire 100 and is set to a temperature (500 ° C.) much higher than the melting point of the solder. As a result, as shown in FIG. 9A, the insulating film of the lead wire 100 is peeled off and removed immediately below and near the iron part 12. The primary solder 105 on the surface of the terminal 104 is also melted around the lead wire 100 by heating from the iron part 12, and a part of the solder is raised so that a part of the primary solder 105 rises along the peripheral surface of the exposed conductor 100a of the lead wire 100 ( FIG. 9A, FIG. 9B).

  Here, the peeling of the insulating film and the melting of the primary solder 105 in the lead wire 100 occur most intensely and directly below the tip surface 12b, but the inside (below) of the recess 104 is heated to a considerable temperature. Even in this vicinity, peeling of the insulating film and melting of the primary solder 105 occur in a considerable amount.

  Thus, the insulating film of the lead wire 100 is peeled from the top to the lower part of the peripheral surface under the iron part 12 heated at the preheating temperature. Then, when the primary solder 105 on the surface of the terminal 104 is melted, vapor smoke rises and the lead wire 100 falls so as to sink into the melted solder 105, and the heater chip 10 also follows and falls (FIG. 9B).

The joining device 26 maintains the preheating temperature for a certain time (for example, 1.0 second) (S ₄ ), and then decreases the current amount of the energization current I by one step, thereby changing the temperature of the iron part 12 from the preheating temperature to the reflow temperature (320). The reflow temperature is rapidly decreased in a short time (1.0 second) until the temperature reaches (° C.) (S ₅ ), and this reflow temperature is maintained for a certain time (eg, 1 second) (S ₆ ).

  The operator confirms that the smoke has fallen as described above and the lead wire 100 and the heater chip 10 have fallen, and at this timing, preferably the wire is formed in the recess 104 of the heater chip 10 as shown in FIGS. 10A and 10B. The secondary solder 66 made of solid solder is inserted (supplied). The secondary solder 66 is preferably made of the same materials or components as the primary solder 105 and has the same melting point (320 ° C.).

  As described above, the tip of the secondary solder 66 inserted into the recess 104 melts rapidly under the reflow temperature, and a solder pool is generated. Then, the melted secondary solder 66 flows down around the lead wire 100 and joins or merges with the primary solder 105 that has crawled up from below. As a result, the exposed conductor 100 a of the lead wire 100 is encased by the primary solder 105 and the secondary solder 66 in a molten state that are united in the recess 104.

After holding the reflow temperature for a certain period of time as described above, the joining device 26 further reduces the current amount of the energization current I and further reduces the temperature of the iron part 12 from the reflow temperature to the base temperature (200 ° C.) ( rapidly back in 0.5 seconds) (S _7). And as shown to FIG. 11A and FIG. 11B, the heater chip | tip 10 is raised by the heater head 112, and it leaves | separates from a to-be-joined part (100,104). In this way, the joined parts (100, 104) are cooled at a base temperature or room temperature, and the solder, particularly the exposed conductor 100a of the lead wire 100, which melts around the joined parts (100, 104) is integrally wrapped. Solder (66,105) coagulates simultaneously. Thereafter also, when implementing continuing the same soldering process and the repeats the temperature control steps of the S ₃ or later. When the soldering process is finished, the energization is stopped and the heater chip 10 is returned to room temperature.

  Thus, in the covered wire joining method of this embodiment, the conductor 100a of the lead wire 100 is wrapped from the top to the bottom on the terminal 104 using the heater chip 10 having the solder supply recess 104 as described above. Such a good finish soldering is performed. As a result, a significantly larger solder joint area and joint strength can be obtained than before, and a physically and electrically highly reliable covered wire joint can be realized.

  In the embodiment described above, the tip surface 12b of the heater chip 10 is formed on a flat surface. However, as shown in FIG. 12A, the center portion is recessed in an inverted V shape when the tip surface 12b is viewed from the front, or the tip surface 12b is formed in a cylindrical surface that is recessed in the center portion as shown in FIG. 12B. The structure etc. to perform are also possible. Thus, by denting the center portion of the tip surface 12b upward, the contact area or the thermal coupling area between the tip surface 12b and the lead wire 100 is increased, and the heating efficiency of the heater chip 10 is improved. Can be made. 12A and 12B, the left side (a) is a front view of the iron part 12, and the right side (b) is a cross-sectional view taken along the line AA of the front view (a).

  In addition, the heater chip 10 in the above embodiment is a type in which a set of objects (100, 104) are joined by soldering at a time, and has a single iron part 12. However, as another embodiment, as shown in FIGS. 13A and 13B, a configuration in which a plurality of, for example, two iron parts 12 (1) and 12 (2) are connected to the heater chip 10 is also possible. These iron parts 12 (1) and 12 (2) are physically integrally formed between the left and right current passage parts 16L and 16R, and are electrically connected in series. Each of the iron tip surfaces 12b (1) and 12b (2) is formed in a cylindrical surface similar to that shown in FIG. 12B, for example. The solder supply recesses 14 (1), 14 (2) are formed on a pair of opposing side surfaces of the iron parts 12 (1), 12 (2), that is, the side surfaces 12L, 12R parallel to the axial direction of the lead wire 100. Are formed respectively. In this case, in the thickness direction of the heater chip 10, the width W of the recesses 14 (1) and 14 (2) 14 is about 0.3T, where T is the thickness of the iron parts 12 (1) and 12 (2). The range of 0.7T is preferable, and the vicinity of 0.5T, that is, the range of 0.4T to 0.6T is most preferable. The entrance height H of the recesses 14 (1) and 14 (2) may be selected to an optimum dimension in view of the trade-off between the ease of supplying solder and the ease of melting.

  Thus, the heater chip of the present invention can be provided with the solder supply recess not only on the side surface of the iron part facing the axial direction of the lead wire but also on the side surface parallel to the axial direction of the lead wire. . Therefore, although not shown, when the single iron part 12 is provided as shown in FIG. 1, a solder supply recess can be provided on the side surface parallel to the axial direction of the lead wire. In addition, when a plurality of iron parts are provided continuously as shown in FIG. 13A, a solder supply recess can be provided on the side surface of the lead wire facing the axial direction.

  According to the joining device 26 using the heater chip 10 having such a configuration, as shown in FIG. 14, two lead wires 100, 100 are connected to two terminals 104, 104 ′ provided close to the printed wiring board 102. 'Can be joined simultaneously in one soldering process.

  In the above-described embodiment, the primary solder 105 is coated on the surface of the terminal 104 (104 ′) in advance based on the conventional reflow soldering method. However, there is a decrease in the strength and reliability of the solder joint, but the soldering with only the secondary solder 66 supplied through the recess 14 (14 (1), 14 (2)) is omitted without the primary solder 105. Is possible. An object to be processed by soldering joining according to the present invention is not limited to a covered wire, and may be a conductor plate, a conductor bar or the like having an insulation coating, or a metal member without an insulation coating. Also good. Further, the secondary solder 66 is not limited to the linear solid solder as described above, and for example, granular or powder solder can be used.

10 Heater chip 12, 12 (1), 12 (2) Iron part 12a, 12L, 12R Side of iron part 12b, 12b (1), 12b (2) Iron tip face 14, 14 (1), 14 (2) Indentation for supplying solder 18L, 18R Connection terminal 26 Joining device 28 Heater power supply 42 Control unit 112 Heater head

Claims (19)

A heater chip that has a iron part that generates heat when energized, and that joins the object to be joined by soldering by bringing the tip of the iron part into pressure contact with the object to be joined,
A heater chip having a solder supply recess extending from a side surface of the iron portion to the iron tip surface.   2. The heater chip according to claim 1, wherein a plurality of the iron parts are electrically connected in series and physically integrally, and the recesses are individually provided in each of the iron parts.   The said to-be-joined object is a covered wire and a terminal member, and solders by applying the tip surface of the said iron part to the said covered wire placed on the said terminal member. Heater chip. The iron part is formed in a substantially rectangular parallelepiped shape,
The recess has an inlet on one side of the iron part facing the axial direction of the covered wire to be soldered,
The heater chip according to claim 3.   5. The heater chip according to claim 4, wherein the recess has a depth dimension of 0.3 to 0.7 times the tip of the iron tip in the axial direction of the covered wire.   6. The heater chip according to claim 5, wherein the indentation has a depth dimension that is 0.4 to 0.6 times the tip of the iron tip in the axial direction of the covered wire. The iron part is formed in a substantially rectangular parallelepiped shape,
3. The heater chip according to claim 1, wherein the recess has an inlet on one side surface of the iron portion that is parallel to an axial direction of the covered wire to be soldered.   The heater chip according to claim 7, wherein the indentation has a width dimension of 0.3 to 0.7 times the tip end surface in the axial direction of the covered wire.   The heater chip according to claim 8, wherein the recess has a width dimension 0.4 to 0.6 times that of the tip end surface in the axial direction of the covered wire.   The heater chip according to any one of claims 1 to 9, wherein a tip surface of the iron portion is formed as a flat surface.   The heater chip according to any one of claims 1 to 9, wherein the iron tip surface of the iron part has an inverted V-shaped center part.   The heater chip according to any one of claims 1 to 9, wherein the iron tip surface of the iron portion is formed on a cylindrical surface having a recessed central portion.   The heater chip according to any one of claims 1 to 12, wherein a ceiling of the recess gradually decreases from a side surface of the iron portion toward an inner depth.   The heater chip according to any one of claims 1 to 13, wherein a bottom of the recess is cut out from an entrance to an inner end. The heater chip according to any one of claims 1 to 14,
A heater head that supports the heater chip and presses and contacts the tip surface of the iron part to the workpiece when joining the workpiece;
And a heater power supply for supplying a current for resistance heating to the heater chip. A joining method for joining a coated wire to a terminal member by soldering using the soldering apparatus according to claim 15,
Placing the covered wire on the terminal member via a first solder;
A step of applying a predetermined pressing force by applying a tip surface of the iron part of the heater chip to the covered wire so that a recess of the iron part covers the covered wire;
Increasing the temperature of the iron part to a first set temperature higher than the melting point of the first solder by energization;
Supplying the second solder into the recess of the iron part after raising the temperature of the iron part to the first set temperature;
Melting the second solder in the recess and coalescing the second solder into the first solder in a molten state so as to wrap the coated wire;
A step of solidifying the first and second solders which are joined in a molten state by separating a tip surface of the iron part from the covered wire.   The bonding method according to claim 16, wherein the temperature of the iron part is lowered from the first set temperature to a second set temperature near the melting point of the second solder, and the second solder is supplied.   The joining method according to claim 16 or 17, wherein the second solder is made of linear solid solder, and a tip portion thereof is inserted into the recess.   The bonding method according to any one of claims 16 to 18, wherein the first set temperature is a temperature at which the insulating film of the coated wire can be peeled off by heat.

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