JP6057685B2 - Pulse heat type soldering management method and management apparatus - Google Patents

Description

  The present invention relates to a soldering management method applied to pulse heat type soldering, and a management apparatus.

  In a reflow soldering apparatus that has been widely used conventionally, a heater chip is heated while being pressed against a work (target to be soldered) through a spring to melt the solder. Then, when the predetermined heating end time is reached, the heating is stopped (or the temperature is lowered) and the heater chip is raised after the solder is solidified (Patent Document 1).

  Here, when heating ends, the heating time is measured from the time when the heater chip temperature rises to a predetermined temperature (starting point) lower than the solder melting temperature. When this time reaches the set value, heating of the heater chip is stopped and cooling is performed. (Patent Document 1).

  Also, the solder is rapidly heated up to the melting temperature, and after the detection of the lowering of the heater chip accompanying the melting of the solder, the bonding temperature is set to a temperature lower than the melting temperature for a set time. There is also one that raises the heater chip when the soldering reaches a solidification temperature after cooling starts after elapse of the holding time (Patent Document 2).

Japanese Patent Laid-Open No. 11-54905 JP 2010-167450 A

  However, in the case of controlling the end of heating according to time in this way, there is a problem that soldering may be inappropriate due to differences in workpiece characteristics (size, temperature, heat dissipation, deformation of workpiece due to heating), etc. There is. For example, the heating time may be insufficient compared to the size of the workpiece to be soldered at one time, and soldering may be insufficient, or the heating time may be excessive when the workpiece is small, causing thermal damage to the workpiece. There can be. Also, when soldering continuously while sequentially moving the heater chips to different soldering sites, it is conceivable that the heater chip temperature at the start of soldering becomes uneven and the soldering quality becomes unstable.

  The present invention has been made in view of such circumstances, and soldering can be made appropriate even if there are variations in the characteristics of the soldering site, such as size, temperature, heat dissipation, and deformation of the workpiece. A first object is to provide a soldering management (monitoring and monitoring) method of a pulse heat system that can stabilize the soldering quality. It is a second object of the present invention to provide a soldering management (monitoring, monitoring) device that is directly used for carrying out this method.

According to the present invention, a first object is to provide a soldering management method of a pulse heat method in which soldering is performed while performing temperature management of a heater chip by a pulse current.
When the heater chip reaches the workpiece and the pressing force reaches a predetermined pressure, heating of the heater chip is started, and the tip temperature of the heater chip is controlled based on predetermined heating characteristics by controlling the pulse current of the heater chip. On the other hand, the time integrated value of the heater chip temperature is continuously obtained from a predetermined temperature lower than the solder melting temperature as a starting point until the predetermined heating end time, and the time integrated value of the heater chip temperature is compared with a set value. This is achieved by a pulse heat type soldering management method characterized by performing soldering management.

A second object is a pulse heat type soldering management apparatus that performs soldering while controlling the temperature of the heater chip with a pulse current ;
A spring pressurizing joining device that presses the heater chip against the workpiece via a spring ;
Elevating control means for elevating and controlling the heater chip ;
A temperature sensor for detecting the heater chip temperature ;
Temperature control means for controlling the heating current supplied to the heater chip to control the tip temperature of the heater chip based on predetermined heating characteristics ;
Starting point setting means for setting a predetermined temperature lower than the solder melting temperature ;
And integrating means for obtaining continuously a time integral value of the heater tip temperature to a predetermined heating end as a starting point the set temperature of the start point setting means;
When the heater chip reaches the workpiece and the pressing force reaches a predetermined pressure, the heater chip is controlled to move up and down and the heater chip temperature so as to start heating the heater chip, and the integrated value obtained by the integrating means is set as a set value. A main control means for managing the soldering by comparing ;
This is achieved by a pulse heat type soldering management device.

According to the first invention, the predetermined time (θ ₀ ) lower than the solder melting temperature during heating of the heater chip is a starting point (the time is t ₀ ), and the time of the heater chip temperature (θ) that is a function of time t Since the integral value S is calculated and the integral value S reaches the set value, the soldering management (monitoring and monitoring) is performed. Therefore, the heating amount of the workpiece can be set to the integral value S. Since the heating amount has a certain correlation with the integral value S, this method is considered appropriate.

  For this reason, even if there are differences in the characteristics (size, temperature, heat dissipation, workpiece deformation, etc.) of the soldering parts, the heating amount can be made constant and soldering can be made appropriate. For this reason, soldering quality can be stabilized. Further, according to the second invention, a soldering management apparatus used directly for carrying out the first invention can be obtained.

Block diagram of a soldering management apparatus showing an embodiment of the present invention Operation flow chart showing the soldering management process Diagram showing this solder joint process Block diagram of a soldering management apparatus showing another embodiment Operation flow chart showing the soldering management process

  Here, the set value to be compared with the integral value can be an integral value up to the end of heating of the cheetah chip (claim 2). That is, in this management method, the heating end point (soldering end point) is determined based on the integral value. Moreover, this management method may determine whether or not this soldering is appropriate when the soldering is terminated by other appropriate means.

  When determining whether soldering is appropriate or not, the set value is set as a predetermined range including an integral value corresponding to the end of proper heating of the heater chip, and the integrated value at the end of heating of the heater chip is within this predetermined range. If it is out of this predetermined range, soldering is inappropriate (Claim 3).

In this case, the heating end point indicating the end of soldering is determined by another method, but this heating end point can be set by the heating time as shown in Patent Document 1 ( Claim 4). Since the head (heater chip) descends as the solder melts, this heating end time may be set when the descending is detected .

  7. The management apparatus according to claim 6, wherein the set value is an integral value up to the end of heating of the cheetah chip, and the main control means stops heating the heater chip when the time integral value of the heater chip temperature matches the set value. (Claim 7).

  However, it is also possible to determine the quality of soldering based on the integral value. In this case, the set value is set as a predetermined range including the integral value corresponding to the appropriate heating end. The main control means determines that the soldering is appropriate if the time integral value of the heater chip temperature is within a predetermined range of the set value, and that the soldering is inappropriate if it is outside the predetermined range. ).

  In FIG. 1, reference numeral 10 denotes a pressure bonding apparatus, which presses the heater chip 12 against the work 14 via a coil spring 16 and supplies the pulse current to the heater chip 12 to generate heat, thereby soldering the work 14. It is a thing to attach. This pressurizing type joining apparatus 10 has a base part 18, a horizontal work holding base 20 provided on the upper surface thereof, and a column part 22 standing upward. A substantially inverted L-shaped holding portion 24 that is bent upward on the workpiece holding base 20 side is fixed to the support portion 22. The upper portion of the holding portion 24 extends above the work 14 held on the work holding base 20.

  An air cylinder 26 as an actuator is fixed to the upper portion of the holding portion 24. The air cylinder 26 is fixed to the upper surface of the holding portion 24 with a piston shaft 28 serving as an output shaft thereof being vertical. The piston shaft 28 protrudes downward from an opening 30 provided in the holding portion 24. The central axis of the piston shaft 28 is vertical and passes through the workpiece 14.

  An upper end of the piston shaft 28 protrudes upward from the cylinder 26, and a stroke setting dial 32 is screwed therein. The dial 32 sets the pressing stroke of the piston shaft 28. The inside of the cylinder 26 is divided into an upper air chamber and a lower air chamber by a piston 34 fixed to a piston shaft 28. The air pressure of the air pump 34 is supplied to one of the upper and lower air chambers by being controlled by an elevation control means 36. Air is exhausted from the other time. By switching the air chamber that supplies air, the piston shaft 28 can be moved up and down.

  Below the air cylinder 26, a pair of upper and lower spring cases 38 and 40 are held by the support portion 22 so as to be slidable up and down. That is, slide blocks 38 a and 40 a are fixed to the spring cases 38 and 40, and these are held by a slide rail 42 fixed to the support portion 22 so as to be movable up and down independently of each other. The opposite sides of the spring cases 38 and 40 are open, and the coil spring 16 positioned on the central axis of the piston shaft 28 is accommodated in these openings.

  The length of the coil spring 16 is set so that a gap is formed between the opposing surfaces of the upper and lower spring cases 38 and 40 in a state where the heater chip 12 pressurizes the workpiece 14 as will be described later. The stroke setting dial 32 sets the maximum lowering amount of the piston shaft 28 when the piston shaft 28 pushes down the upper spring case 38.

  A free piston 44 with which the upper end of the coil spring 16 abuts from below is accommodated in the upper spring case 38 so as to be movable up and down, and an eccentric cam 46 is in rolling contact with the upper surface of the free piston 44. The horizontal cam shaft 48 of the eccentric cam 46 is rotatably held by the spring case 38 so that one end thereof protrudes through the spring case 38, and the dial 50 is fixed to the protruding end. The eccentric cam 46 is rotated by the rotation of the dial 50 so that the height of the free piston 44 can be adjusted. As a result, as will be described later, the spring force of the coil spring 16 by which the heater chip 12 presses the workpiece 14 can be adjusted.

  The heater chip 12 is fixed to the lower end of the lower spring case 40 via a shank 52. The heater chip 12 is formed by forming a wide electric resistance material in a substantially U shape, and generates heat by a pulse current supplied from a power supply terminal (not shown). A temperature sensor 54 made of a thermocouple is fixed near the tip of the heater chip 12.

56 in FIG. 1 is a temperature control means, a heater by monitoring the tip temperature theta heater chip 12 where the temperature sensor 54 detects, as the temperature theta is the main control unit 58 becomes instruction temperature theta _t to output The pulse current i supplied to the chip 12 is controlled. That changes the pulse current i to the heater chip temperature theta in instruction temperature theta _t.

Here, the command temperature θ _t has a heating characteristic that changes with time. The main control means 58 also sends a height signal h for controlling the elevation position of the heater chip 12 to the elevation control means 34. The elevation control means 34 switches the air pressure supplied to the upper and lower air chambers of the air cylinder 26 based on the height signal h, and controls the height of the heater chip 12 and the pressing force of the heater chip 12 against the work 14.

The temperature control unit 56 sends the temperature θ of the heater chip 12 to the integration unit 60. Here, the temperature θ is a function of time t that varies with time t. When the heater chip temperature θ reaches a predetermined temperature θ ₀ lower than the solder melting temperature set by the starting point setting means 62, the integrating means 60 calculates the time integrated value S of the heater chip temperature θ from the temperature θ ₀ as a starting point. Continue to seek. In other words, the integral value S is obtained by adding (integrating) the product (θ · dt) of the temperature θ and the minute time lapse dt with respect to time from the time point t ₀ at the start point θ _{0 to} the time point t ₂ at the end of the cheetah chip heating. . This integrated value S corresponds to the area of the hatched portion in FIG.

Here, at the heating end point t ₂ , the integral value set value S ₀ set by the integral value setting means 64 is compared with the integral value S obtained by the integral means 60, and these values coincide (S ₀ = S). Is detected by the main control means 58.

Next, the operation of this embodiment will be described with reference to FIGS. First, the temperature θ ₀ as the starting point is set in the starting point setting means 62, and the integral value setting value S ₀ is set in the integral value setting means 64 (step S100 in FIG. 2). The elevation control means 34 lowers the heater chip (that is, the head) 12 based on the height command h of the main control means 58. When the position (head position) of the heater chip 12 reaches the work 14 and the pressing force reaches a predetermined pressure, the main control means 34 supplies a pulse current to the heater chip 12, and the heater chip 12 is controlled based on predetermined heating characteristics. Heat (step S102).

When the temperature of the heater chip 12, that is, the head temperature θ becomes the starting point temperature θ ₀ (step S104), the integrating means 60 starts time integration of θ from this time t ₀ (step S106). The main control unit 58, when the integrated value S reaches the set value S ₀ (step S108), and stops the pulse current supply to the heater chip 12 to the time t ₂ as a heating end (step S110). For this reason, the temperature θ of the heater chip 12 decreases.

When the solder reaches its melting temperature during the heating of the solder, the heater chip 12 is gradually lowered by the restoring force (pressing force) of the coil spring 16 as the melting proceeds. The head position p is in contact with the workpiece 14 during heating and the lowered position is kept at p ₁ . The head position p is lowered to constant height p ₂ when solder melting begins. In FIG. 3, A indicates a time point when the heater chip 12 starts to descend.

If the time when the heater chip 12 starts to descend from A and reaches the height p ₂ coincides with the heating end time t ₂ of the heater chip 12, there is no shortage of heating amount, and there is no wasted heating time. Soldering is performed. In the conventional apparatus, the end time t ₂ of heating is set by the duration T of the reached temperature θ ₁ during heating so that ideal soldering is performed. Displacement characteristic p ₃ of the head position p in Fig. 3 shows the head position changes when this ideal.

Note that for reference in FIG. 3, the solder has started melting earlier than the ideal case p ₃ shows the case starts lowering of the head is fast at p _4, a case where solder melting start is delayed by p ₅ Show. In the case of p ₄ and p ₅ , for example, it may be caused by the size, temperature, heat dissipation, deformation of the workpiece 14 or the like. In the present invention, since the integral value S is made constant instead of the constant heating time T, it is possible to prevent such variation.

When heated by the solder termination time t ₂ as described above is terminated, the heater chip temperature θ is lowered gradually. When it is detected that the temperature is lower than the solder solidification temperature, the heater chip 12 is raised, and one soldering is finished (step S112).

In the above-described embodiment, the integral value S is compared with the set value S _0, and when both match, the heating of the heater chip 12 is terminated. That is, the supply of the pulse current to the heater chip 12 is stopped. However, in the second embodiment, instead of comparing the integrated value S with the set value S ₀ , the integrated value S falls within a predetermined range including the set value S ₀ after the soldering is finished (after the heating of the heater chip 12 is finished). It is determined whether it is inserted, and it is determined whether or not the soldering is appropriate. In FIG. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will not be repeated.

In this case, the end point of soldering is determined by another method. For example, as shown in FIG. 3 described above, the temperature is set at the time T of the ultimate temperature θ ₁ during heating, or the head is cooled after the set time elapses after detecting the head descending as the solder melts (Patent Document) 2), or a value set by changing the slope (tangential differential value) of the change curve of the temperature θ. In Example 2, when the end of heating is detected by an appropriate method, it is determined whether or not this end point is appropriate.

The second embodiment, as shown in FIG. 4, the comprising a setting means 64A of the integral value range S _l to S _h including the ideal integration value S, the main control unit 58A detects the end of the soldering, It is determined whether or not the integral value S obtained by the integrating means 60 is included in this integral value range. That is, when S ₁ <S <S _h is satisfied, it is determined that the soldering is appropriate, and when it is not satisfied, it is determined as inappropriate. If it is appropriate, the process proceeds to soldering of the next work 14. If inadequate, warning is made by appropriate warning means, or data on the solder defective portion is stored in the main control means 58A or another device.

In FIG. 5 showing the operation of the second embodiment, the same reference numerals are given to the steps corresponding to FIG. Differs from the second embodiment is that of FIG. 2, and setting the range S _l to S _h of the integral value in place of the integrated value S in step S100A, soldering termination detecting an external or main control unit 58A (heating The heating of the heater chip 12 is stopped and cooled by a signal indicating (end) (step S150) (step S152), the heating of the heater chip 12 is stopped, cooled and the head is raised (step S154), and the main control means 58A. In step S156, it is determined whether the integrated value S is within the set range (step S156). If the integrated value S is out of the range, an alarm is given as inappropriate soldering, and the soldered part is stored (step S158). .

10 Pressure Bonding Device 12 Heater Chip (Head)
14 Workpiece 16 Coil spring 18 Heater chip 34 Elevating control means 56 Temperature control means 58, 58A Main control means 60 Integration means 62 Start point setting means 64 Integral value setting means 64A Integral value range setting means

Claims (8)

In the soldering management method of the pulse heat method that performs soldering while performing the temperature management of the heater chip by the pulse current,
When the heater chip reaches the workpiece and the pressing force reaches a predetermined pressure, heating of the heater chip is started, and the tip temperature of the heater chip is controlled based on predetermined heating characteristics by controlling the pulse current of the heater chip. On the other hand, the time integrated value of the heater chip temperature is continuously obtained from a predetermined temperature lower than the solder melting temperature as a starting point until the predetermined heating end time, and the time integrated value of the heater chip temperature is compared with a set value. A soldering management method of a pulse heat system, characterized in that soldering management is performed. Heating the end is the time when the time integral value is equal to the set value, the set value of the pulse heat method of claim 1 wherein said time integral value to heating the end of the heater chip during ideal soldering Soldering management method. The set value is set as a predetermined range including a time integral value of the heater chip temperature corresponding to an appropriate heating end time from a starting point at which the heater chip temperature becomes a predetermined temperature lower than the solder melting temperature. 2. The pulse heat type soldering management method according to claim 1 , wherein the soldering is appropriate if the time integration value at is within the predetermined range, and the soldering is inappropriate if it is outside the predetermined range. 4. The pulse heat type soldering management method according to claim 3, wherein the heating end point is set with a predetermined heating time set starting from a predetermined temperature lower than the solder melting temperature . Heating the end sets when the head due to the solder melting becomes lowered a predetermined height, determining the appropriateness of soldering depending on whether the time integral value up to this point is within a predetermined range The soldering management method of the pulse heat system according to claim 3 . In the soldering management device of the pulse heat type that performs soldering while controlling the temperature of the heater chip with the pulse current ;
A spring pressurizing joining device that presses the heater chip against the workpiece via a spring ;
Elevating control means for elevating and controlling the heater chip ;
A temperature sensor for detecting the heater chip temperature ;
Temperature control means for controlling the heating current supplied to the heater chip to control the tip temperature of the heater chip based on predetermined heating characteristics ;
Starting point setting means for setting a predetermined temperature lower than the solder melting temperature ;
And integrating means for obtaining continuously a time integral value of the heater tip temperature to a predetermined heating end as a starting point the set temperature of the start point setting means;
When the heater chip reaches the workpiece and the pressing force reaches a predetermined pressure, the heater chip is controlled to move up and down and the heater chip temperature so as to start heating the heater chip, and the integrated value obtained by the integrating means is set as a set value. A main control means for managing the soldering by comparing ;
A soldering management apparatus of a pulse heat system characterized by comprising: Set value is set by the time integral value of the heater tip temperature to heating the end of the start point Karahi Tachippu, the heating of the heater chip when the main control means for time integration value of the heater chip temperature matches the set value The soldering management apparatus of the pulse heat system according to claim 6 , which is stopped. The set value is set as a predetermined range including the time integral value corresponding to an appropriate heating end, and the main control means determines the suitability of soldering by comparing the time integral value of the heater chip temperature with the set value. 6 pulse heat type soldering management device.

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