JP2005236001A - Automatic soldering equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide automatic soldering equipment by which an operator does not need to turn a handle of vertical movement equipment arranged in a jet stream solder tank at the time of changing the height of the jet stream solder tank, which is different from conventional automatic soldering equipment, and the height can correctly be decided. <P>SOLUTION: In automatic soldering equipment, a jack which vertically moves by a motor is disposed below the jet stream solder tank, a height measuring instrument is fitted between the jet stream solder tank and a base mount, and the height of the jet stream solder tank is correctly decided by the height measuring instrument. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an automatic soldering apparatus for soldering a printed circuit board.

  Generally, soldering of a printed circuit board is performed by an automatic soldering apparatus. This automatic soldering apparatus is one in which a soldering processing apparatus such as a fluxer, a pre-heater, a jet solder bath, a cooling apparatus, etc. is installed in the apparatus main body. In addition, a pair of transport rails are installed above these processing apparatuses, and an endless transport chain is rotated on the transport rails. The printed circuit board is transported by a number of claws installed in the transport chain facing each other, flux applied by a fluxer, pre-heated by a pre-heater, solder deposited in a jet solder bath, cooled by a cooler, and soldered Is made. The printed circuit board carried into the automatic soldering device enters from the fluxer and exits from the cooler. Henceforth, the side where the fluxer is installed is the entrance side, and the side where the cooler is installed is the exit side. Called.

  By the way, when soldering a printed circuit board with an automatic soldering apparatus, the conveyance rail is inclined so as to increase from the entry side toward the exit side. In other words, the printed circuit board conveyed by the chain is processed by each processing apparatus while traveling along the inclination, but the processing apparatus that performs the processing while inclining the printed circuit board is only a jet solder bath, Other processing equipment does not require tilting. Therefore, it may be possible to carry out the inclined conveyance only in the jet solder bath, but it is structurally impossible to make only the jet solder bath in the inclined conveyance. Processing is performed in the state.

  In a jet solder bath that requires inclined conveyance, a primary jet nozzle that jets rough waves and a secondary jet nozzle that jets gentle waves are installed. The rough wave jetted from the primary jet nozzle penetrates into the inside of the through hole and the corner of the chip part to eliminate unsolder. However, since the waves jetted from the primary jet nozzle are rough, the solder adheres in an uneven state or causes soldering defects such as tsura and bridges. Accordingly, the solder that has become unevenness, wiggle, and bridge is brought into contact with a gentle wave jetted from the secondary jet nozzle to correct these defects.

  In the secondary jet nozzle, the amount of solder attached to the printed circuit board is determined. In the adhesion of solder at the secondary jet nozzle, if the amount of solder adhesion is too large, the bridge cannot be corrected, and the appearance is deteriorated. However, if the amount of solder attached to the printed circuit board is too small, the bonding strength is weakened.

  The amount of solder adhesion at the secondary jet nozzle is determined by the angle at which the printed circuit board contacts the secondary jet nozzle. That is, in order to maximize the amount of solder attached, it is preferable to bring the printed circuit board into contact with the molten solder jetted from the secondary jet nozzle in a horizontal state. This is because the molten solder at the secondary jet nozzle is in a calm state where it is almost horizontal, so when the printed circuit board is placed in a horizontal state and brought into contact with the molten solder jetted from the secondary jet nozzle, the printed circuit board becomes gentle. Exit in parallel with the molten solder. Therefore, when the printed circuit board is detached from the molten solder of the secondary jet nozzle, it hangs at a right angle with respect to the soldering portion and adheres in large quantities because of its large diameter.

  On the other hand, in order to reduce the amount of solder attached, it is preferable that the exit side of the transport rail is raised and the inclination is increased. Then, when the printed circuit board is detached from the wide range of molten solder of the secondary jet nozzle, the molten solder adhering to the soldered portion of the printed circuit board falls obliquely downward with respect to the printed circuit board, and the diameter thereof is thin, so that it is easily cut. As a result, the molten solder adhering to the printed circuit board when pulled away from the molten solder of the secondary jet nozzle is pulled by the molten solder of the secondary jet nozzle, and the amount adhering to the soldering portion is reduced. As the inclination of the printed circuit board withdrawing is larger, the molten solder attached to the soldered portion of the printed circuit board is more likely to be cut and the amount of adhesion is reduced.

  By the way, in the printed circuit board, if too much solder is applied, a bridge is generated, and if it is too low, the bonding strength is weak. Therefore, an appropriate amount of adhesion, that is, a bridge is not formed, but the amount of solder that does not reduce the bonding strength. Is required. For this purpose, the angle at which the printed circuit board separates from the molten solder jetted from the secondary jet nozzle must be appropriately changed depending on the type of the printed circuit board and the solder so as to have an optimum adhesion amount.

  In general, Pb-Sn solder has a low viscosity and easily breaks after being attached to the printed circuit board. Therefore, the transport angle of the printed circuit board is 4 to 5 degrees. Lead-free solder containing Sn as a main component is more viscous than Pb-Sn solder. Therefore, the conveyance angle is suitably 5 to 7 degrees, which is larger than that of the Pb-Sn solder. Therefore, when soldering a printed circuit board, the transport angle of the transport rail must be changed depending on the type of solder and the conditions of the printed circuit board.

  If the conveyance angle of the conveyance rail is changed, the interval between the jet solder bath and the conveyance rail changes, and the interval is too far or too close. For example, in an automatic soldering device that pivots on the exit side and installs a vertical movement device on the entry side, if the conveyance angle is smaller than the current conveyance angle, the entry side is raised with the vertical movement device installed on the entry side. . Then, since the transport rail and the jet solder bath are separated from each other, the printed circuit board transported by the transport rail as it is cannot contact the molten solder jetted from the jet nozzle of the jet solder bath, and naturally the solder does not adhere at all. End up. Moreover, in this automatic soldering apparatus, when making a conveyance angle larger than the present conveyance angle, the entrance side is lowered | hung with the vertical motion apparatus installed in the entrance side. Then, since the conveyance rail and the jet solder bath are too close, the claw that runs along the conveyance rail hits the jet nozzle as it is, and the claw is damaged or the nozzle is damaged. It may be submerged in the molten solder that jets, and the upper surface of the printed circuit board is covered with the molten solder, and the solder is attached to unnecessary portions. Therefore, when changing the transport angle of the transport rail, the molten solder in which the back surface of the printed circuit board that runs while being held by the transport rail claw is jetted from the jet nozzle is preliminarily set between the transport rail and the jet solder bath. It is necessary to adjust the position of the jet solder bath so that the solder can be completely adhered to the soldered portion of the printed circuit board.

Conventionally, there has been proposed an automatic soldering apparatus that enables a jet solder bath to move up and down (see Patent Documents 1 and 2). In the automatic soldering apparatus of Patent Document 1, a plurality of support columns are erected at the lower part of a jet solder bath, and support legs for the solder bath base are provided on the support columns via slide bearings. And a cylinder apparatus is installed in a solder tank base, and a solder tank is moved up and down with this cylinder apparatus. Moreover, the automatic soldering apparatus of patent document 2 attaches four screw rods to the four corners of the lifting frame on which the solder tank is placed, and screwes female screws into the screw rods. An endless chain is hung on these female screw sprockets, and the screw rods are moved up and down by turning the chain with a handle and rotating the sprockets at the four corners.
Japanese Utility Model Publication No. 54-14733 Japanese Utility Model Publication No. 2-44932

  By the way, the automatic soldering apparatus of patent document 1 performs the vertical movement of a solder tank with a cylinder apparatus, but the cylinder apparatus is not suitable for the vertical movement of a heavy solder tank. This is because in a cylinder device, if a pipe that supplies compressed air to the cylinder is disconnected or the pipe is cracked, the piston supporting the heavy object may drop suddenly, which is dangerous. It is. In other words, when the piston supporting the solder bath is rapidly lowered, the high-temperature molten solder that has been put in the solder bath is scattered, and a nearby worker is burned. Moreover, the automatic soldering apparatus of patent document 1 performed the positioning with the operator's feeling when the solder tank was moved up and down. Therefore, if the worker is different when positioning the solder bath, the height is different each time and proper soldering cannot be performed.

  The automatic soldering apparatus of Patent Literature 2 is more stable than the above-mentioned Patent Literature because the lifting platform on which the solder tank is placed is supported by four screw rods. However, in the automatic soldering apparatus of Patent Document 2, since the operator must rotate the four screw rods by rotating the handle, the operator has to make a great effort to move the heavy solder bath up and down. There was a work problem that had to be applied. Moreover, since the automatic soldering apparatus of patent document 1 performed the positioning of the solder tub with the operator's feeling like patent document 1, it was still difficult to perform proper positioning.

  The present inventor has found that a pantograph-type jack can easily move up and down even with heavy heavy objects by simply rotating a screw, and the automatic soldering device and the jet solder bath are measured with an electric signal type measuring device, Thus, the present invention was completed by paying attention to the fact that positioning can be performed easily and accurately if the jack can be moved up and down.

  The present invention relates to an automatic soldering apparatus for performing soldering by bringing a printed circuit board into contact with molten solder jetted from a jet nozzle of a jet solder bath, wherein a pantograph-type jack is installed at a lower portion of the jet solder bath, and the jack A sprocket is attached to the end of the long screw that protrudes from the sprocket, and the sprocket is linked to the sprocket of the motor, and the jet solder bath has a measuring instrument that can electrically measure the height of the jet solder bath. It is an automatic soldering apparatus characterized by being installed.

  In the automatic soldering apparatus of the present invention, the jet solder bath is moved up and down with a pantograph type jack that can easily move up and down even with heavy objects by rotating the long screw, and the jack must rotate the long screw. It is safe because it never descends. In addition, since the long screw of the jack is rotated by a motor, it is excellent in the ease of work that does not require any labor of the operator when the jet solder bath moves up and down. Furthermore, since the automatic soldering apparatus of the present invention can be measured by a measuring device that electrically reads the position of the jet solder bath, if an appropriate position is input to the control device in advance, the jet solder bath can be changed even if the operator changes. Can always be in its proper position.

  A suitable pantograph jack for use in the present invention is a hexagonal jack. The hexagonal jack has a pair of upper arms pivotably attached to both ends of a long upper piece, and a pair of lower arms pivotally attached to both ends of a long base. It is what. The hexagonal jack is suitable for supporting things that are absolutely tilted when moving up and down like a jet solder bath. In other words, the hexagonal jack supports the jet solder tank with a long upper piece, and the upper piece always keeps horizontal because the pair of upper arms always change at the same angle.

  Two pantograph-type jacks are installed below the jet solder bath. If one jack is installed in the jet solder bath, it is difficult to keep the solder bath horizontal, and if there are more than two jacks, all jacks cannot be moved up and down in the same state. In order to move the two jacks up and down in the same state, a sprocket having the same number of teeth is attached to the end of the long screw of each jack, and the sprocket is interlocked with an endless chain of the motor.

  In this invention, in order to grasp | ascertain correctly the position of the jet solder tank moved up and down with the jack, the instrument which measures height is installed. The measuring instrument can change the height into an electrical signal and send it to the control device, and a tall gauge is suitable.

  The automatic soldering apparatus of the present invention will be described below with reference to the drawings. 1 is a front sectional view of the automatic soldering apparatus of the present invention, FIG. 2 is a side view of a jet solder bath, FIG. 3 is a plan view of the jet solder bath, and FIG. 4 is a front view of the jet solder bath.

  In the main body 1 of the automatic soldering apparatus, processing devices such as a fluxer 2, a pre-heater 3, a jet solder bath 4, a cooler 5 and the like are installed, and a pair of transport rails 6 are provided on these processing devices. Has been placed. The fluxer 2, the preheater 3, and the cooler 5 are attached to the transport rail 6, and move up and down together with the transport rail when the end of the transport rail is moved up and down. In addition, an endless transport chain with a large number of claws (not shown) is rotated on each transport rail 6, and the printed circuit board is held between the opposing claws of the pair of transport rails to transport on the processing apparatus. It is supposed to be. A transfer conveyor 7 for transferring the printed circuit board from the other manufacturing process to the transfer rail and a transfer conveyor 7 for transferring to the other manufacturing process are installed at the end portions of the transfer rail 6 on the entry side and the exit side.

  An automobile jack 8 for inclining the rail is attached to the lower part on the entry side of the transport rail. In the automobile jack, the upper two arms and the lower two arms are rotatably connected in a rhombus shape, and the support member is supported at the intersection of the upper two arms. When the automobile is moved up and down with the jack, since the automobile can be supported at a point, there is no problem even if the automobile is slightly inclined forward and backward. That is, it is a jack suitable for supporting an inclined object such as a transport rail. The jack is rotatably attached at one end to a position where the long screw 9 is diagonally opposed to the side, and is screwed to a female screw at the other diagonal position. A worm gear 10 is attached to the end of the long screw 9 outside the jack, and the worm gear meshes with the worm gear 12 of the motor 11. Therefore, when the motor 11 is rotated, the rotation of the motor rotates the long screw 9 from the worm gears 12 and 10 that are interlocked.

  A shaft 13 is pivotally supported by a bearing solidified in the main body 1 at the lower part on the exit side of each transport rail 6, and the shaft is interlocked with an encoder 14 that reads the angle of the transport rail. Accordingly, when the motor 11 is rotated to move the jack 8 up and down, the transport rail 6 rotates about the shaft 13 and the entry side end moves up and down as shown by an arrow A to change the inclination angle.

  A pair of hexagonal jacks 15 and 16 are attached to the lower part of the jet solder bath 4 in parallel positions. In the hexagon jack, a pair of upper arms 17 and 18 are rotatably attached to both ends of a long upper piece 19, and a pair of lower arms 20 and 21 are turned to both ends of a long lower piece 22. It is attached movably. The upper piece 19 is fixed to the lower surface of the jet solder bath, and the lower piece 22 is fixed to the base 23. A long screw 24 is rotatably attached to the intersection of one upper arm 17 and one lower arm 20, and the long screw is a female screw at the intersection of the other upper arm 18 and lower arm 21. Are screwed together. The hexagonal jack is different from the above-described automobile jack in the portion that supports the support member. In other words, the jack for automobiles is point support at the intersection of the upper arms, but the hexagonal jack has a pair of upper arms attached to both ends of the long upper piece, and the long upper piece supports the support member. It is supposed to be. The hexagonal jack that supports the support member with a long upper piece is a suitable jack for supporting an object that must not be inclined, such as a jet solder bath, because the upper piece does not tilt.

  Sprockets 26 and 27 having the same number of teeth and the same diameter are attached to the long screws 24 and 25 of the jacks 15 and 16, respectively. The sprockets 26 and 27 attached to the long screws 24 and 25 have different distances from the jet solder bath 4. That is, the sprockets 26 and 27 are attached at positions that do not overlap when viewed from the side. A motor 28 is fixed to the base 23 at the center of the two long screws 24 and 25, and the shaft 29 of the motor has two teeth at the same diameter and the same diameter as the long screw sprockets 26 and 27. Sprockets 30 and 31 are attached. The sprocket 26 of one long screw 24 and one sprocket 30 of the motor 28 are interlocked by an endless chain 32, and the sprocket 27 of the other long screw 25 and the other sprocket 31 of the motor are also endless. The chain 33 is interlocked. The motor 28 is electrically connected to a control device (not shown).

  A height measuring instrument 34 capable of electrically reading the moving distance is attached to the side wall of the jet solder bath 4 and the base 23. The height measuring instrument 34 measures the distance between the jet solder bath 4 and the base 23 and is, for example, a tall gauge. The height measuring instrument is electrically connected to a control device (not shown).

  A caster 35 is attached to the lower surface of the base 23, and the caster moves laterally on the slide base 36 of the main body 1.

  Next, the operation state in the automatic soldering apparatus of the present invention having the above-described configuration will be described.

  When the inclination angle of the conveyance rail 6 is increased, the conveyance rail 6 hits the jet solder tank 4 if the exit-side automobile jack 8 is lowered as it is. Therefore, the jet solder bath is lowered to a predetermined position before lowering the automobile jack 8. At this time, when the control device (not shown) is used to change the tilt angle of the transport rail to a predetermined position, for example, 5 degrees to 7 degrees, when the tilt angle of the height measuring instrument is 7 degrees, Input to send a signal. Then, the control device gives an instruction to operate the motor 28 for moving up and down the jet solder bath. When the shaft 29 of the motor 28 rotates according to an instruction from the control device, the two sprockets 30 and 31 attached to the shaft rotate, and the endless chains 32 and 33 mounted on these sprockets rotate in the same direction. Move. Then, the sprockets 26 and 27 of the long screws 24 and 25 hung on the endless chains 32 and 33 also rotate in the same direction as the shaft 29 of the motor. With the rotation of these sprockets, the long screws 24 and 25 are also rotated, and the two hexagonal jacks 15 and 16 are driven to lower the jet solder tank 4. When the jet solder bath 4 is lowered to a position suitable for an inclination angle of 7 degrees of the transport rail 6 by driving the hexagonal jack, the tall gauge 34 reads it and sends a signal to the control device. A stop signal is sent. In this way, after the jet solder bath 4 is lowered to the position where the conveyance rail is inclined, an instruction is sent from the control device to the motor 11 of the automobile jack 8 of the conveyance rail 6, and the inclination angle is read by the encoder 14, When the inclination angle becomes 7 degrees, the driving of the automobile jack 8 is stopped.

  Since the automatic soldering device of the present invention can control the height of the jet solder bath and the inclination angle of the transport rail with a control device, when soldering various printed circuit boards, a reading code such as a bar code is applied to the printed circuit board. If attached, it is possible to automatically set the inclination angle suitable for the printed circuit board or the height of the jet solder bath.

It is front sectional drawing of the automatic soldering apparatus of this invention. It is a side view of a jet solder bath. It is a top view of a jet solder bath. It is a front view of a jet solder tank.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body of automatic soldering apparatus 2 Fluxer 3 Pre-heater 4 Jet solder bath 5 Cooling machine 6 Conveying rail 15 Hexagon jack 28 Motor 34 Height measuring instrument

Claims (4)

In an automatic soldering apparatus that performs soldering by bringing a printed circuit board into contact with molten solder jetted from a jet nozzle of a jet solder bath, a pantograph-type jack is installed at the bottom of the jet solder bath, and the length protruding from the jack A sprocket is attached to the end of the screw, and the sprocket is linked to the sprocket of the motor, and the jet solder bath is equipped with a measuring instrument that can electrically measure the height of the jet solder bath. An automatic soldering apparatus characterized by that. 2. The automatic soldering apparatus according to claim 1, wherein the pantograph type jack is a hexagonal jack. Two pantograph-type jacks are installed at the bottom of the jet solder bath, and sprockets of the same number of teeth are attached to the ends of the long screws protruding from the respective jacks. An automatic soldering device that is linked with an endless chain. The automatic soldering apparatus according to claim 1, wherein the measuring instrument for electrically measuring the height of the jet solder bath is a tall gauge.

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