JP3833487B2 - Heating device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an improvement in a heating apparatus that heats a board such as a printed board on which electronic components are mounted to perform reflow soldering.
[0002]
[Prior art]
Conventionally, as disclosed in, for example, Japanese Patent No. 2784789, as a heating device that uniformly heats a surface of a substrate on which an electronic component is mounted, one having a configuration as shown in FIGS. 7 and 8 is known. It has been. In FIG. 7, 51 is a board on which electronic components are mounted, 52 is a nozzle provided with a heater, 53 is a connection to the heater, 54 is a thermocouple, 55 is a hot air temperature controller, and 56 is a temperature analysis within the board by thermal analysis simulation. An analysis unit for analysis.
[0003]
According to this, after the hot air having a constant temperature is blown by the plurality of nozzles 52 on the surface of the substrate 51 stopped at a fixed position, the temperature distribution in the substrate is analyzed by the thermal analysis simulation and generated on the surface of the substrate 51. The hot air temperature blown from each nozzle 52 based on this result is adjusted by the hot air temperature controller 55, and then hot air is blown again from the nozzles 52 onto the substrate surface to obtain the temperature on the substrate 51 surface. Reflow soldering is performed with a uniform distribution. FIG. 8 is a schematic configuration diagram of the heating device.
[0004]
[Problems to be solved by the invention]
By the way, the conventional heating apparatus includes a step of conveying and stopping the substrate 51, a step of blowing hot air at a constant temperature on the stopped substrate, a step of grasping the temperature on the surface of the substrate 51 by analysis, The reflow soldering is completed through a process of adjusting the temperature of hot air blown from each nozzle 52 based on the data (result) and a process of blowing hot air on the substrate surface again.
[0005]
In that case, since a considerable amount of time is required until reflow soldering is completed through a series of steps, the production efficiency is lowered. In addition, since the hot air blown from each nozzle 52 is diffused, it is difficult to practice uniform heating on the substrate surface when electronic components are mounted at a high density on the substrate surface.
[0006]
This invention is made | formed in view of this point, The place made into the objective is to provide the heating apparatus which can practice uniform heating on a substrate surface while improving production efficiency.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is premised on a heating apparatus in which a substrate on which an electronic component is mounted is conveyed by a conveying means, and the substrate is heated to perform reflow soldering. Then, based on the difference between the temperature distribution detecting means for detecting the temperature distribution during heating on the surface of the substrate and the temperature distribution detected by the temperature distribution detecting means and the set temperature on the substrate surface, partially heat replenished rows cormorants beam device with respect to the set temperature insufficient portion of the upper, and a moving device that moves in accordance with the conveying speed of the substrate with the light beam apparatus is engaged to the substrate, the Heat replenishment to the set temperature insufficient portion on the substrate surface by the light beam apparatus is performed while moving according to the substrate transport speed by the transport means.
[0008]
According to this specific matter, the step of transporting the substrate on which the electronic component is mounted by the transporting unit, the step of heating the substrate by hot air or the like, and the step of detecting the temperature distribution on the substrate at the time of heating by the temperature distribution detecting unit And reflow soldering is completed through a process of replenishing heat to the set temperature insufficient portion on the board surface based on the difference between the temperature distribution detected by the temperature distribution detecting means and the set temperature on the board surface It is supposed to be. For this reason, the time required for completing the reflow soldering through a series of steps is shortened, and the production efficiency can be improved. In addition, since heat supplementation is partially performed on the part where the set temperature is insufficient on the board surface, it does not diffuse like hot air blown from the nozzle, and electronic components are mounted on the board surface with high density. In addition, heat replenishment is performed only at necessary portions (locations where the set temperature is insufficient), and uniform heating on the substrate surface can be practiced.
[0009]
In particular, the following configuration is listed as a specific method for performing heat replenishment.
[0010]
In other words, when the temperature detection on the substrate surface by the temperature detection means is performed immediately before the heat replenishment to the place where the set temperature is insufficient, the substrate surface immediately after the temperature distribution detection by the temperature distribution detection means is performed. Based on the difference from the above set temperature, heat replenishment is performed to the place where the set temperature is insufficient, and uniform heating on the substrate surface can be practiced accurately and quickly.
[0011]
In addition, when heat replenishment for a set temperature shortage location on the substrate surface is performed by a plurality of light beams collected from the light source, heat replenishment for the location where the set temperature deficiency is insufficient on the substrate surface is accurately performed. It is possible to practice uniform heating with high accuracy on the substrate surface.
[0012]
Then, when heat replenishment is performed on a place where the set temperature is insufficient on the substrate surface in a state where the substrate is conveyed by the conveying means, heat replenishment is performed without stopping the substrate conveyance, and reflow soldering is performed. The time required to complete the process is further shortened, and the production efficiency can be further improved.
[0013]
In addition, when heat replenishment is performed on a part where the set temperature is insufficient on the substrate surface while moving according to the substrate transport speed by the transport means, the part that requires time for heat replenishment (part where the set temperature is insufficient) Even so, the heat replenishment is performed while following the substrate conveyance speed, and the time required to complete the reflow soldering is effectively shortened, and the production efficiency can be further improved.
[0014]
In addition, when the heat replenishment conditions for locations where the set temperature is insufficient on the substrate surface are set or stored for each different substrate type, the heat replenishment conditions are newly set when switching to a different type of substrate. There is no need to re-set, and the production efficiency can be further improved.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
(First embodiment)
FIG. 1 shows a schematic configuration of a heating apparatus 1 according to the present invention.
[0017]
In FIG. 1, 11 is a substrate, 12 is a transport device as a transport means for transporting the substrate 11, 13 is a light beam device, 14 is a moving device that moves the light beam device 13 in accordance with the transport speed of the substrate 11, and 15 is It is a temperature sensor as temperature distribution detecting means for detecting a temperature distribution on the surface of the substrate 11, and these devices 11 to 15 are provided in the heating device 1.
[0018]
The substrate 11 is a printed circuit board on which a plurality of electronic components 11a,... Are mounted, and each electronic component 11a is mounted via cream solder printed on the surface of the substrate 11. .
[0019]
The conveying device 12 includes a belt conveyor 12a and, as shown in FIG. 2, the substrate is heated by hot air having a constant temperature blown from nozzles 10a,... Protruding from the left and right side surfaces (surfaces orthogonal to the conveying direction) of the heating device body 10. The substrate 11 on the belt conveyor 12a is transported at a constant speed from a preheating zone for preheating (heating) 11 in both the left and right directions to a reflow zone for reflowing the cream solder on the surface of the substrate 11. Yes. The substrate 11 is placed on pallets 12b,... Provided on the belt conveyor 12a at predetermined intervals. In this case, also in the reflow zone, the substrate 11 is heated from both the left and right directions by hot air having a constant temperature blown from the same nozzles 10a,.
[0020]
The light beam device 13 is provided in the reflow zone, and as shown in FIG. 3, a cylindrical nozzle 13b protruding downward (substrate 11 side) from a table 13a having an area substantially coincident with the surface of the substrate 11. There are multiple. A light heat source 13c is provided near the base end (upper end) in each nozzle 13b, and a convex lens 13d is provided at the tip (lower end). Then, the light emitted from the photothermal source 13c is condensed by the convex lens 13d to become a light beam 13e, so that a desired location (location where the set temperature is insufficient) on the surface of the substrate 11 is partially irradiated with a pin point. It has become. The amount of light emitted from the light heat source 13c can be adjusted, and thereby, the light beam 13e having the optimum heating temperature is irradiated onto the portion of the substrate 11 where the set temperature is insufficient.
[0021]
As shown in FIGS. 4A and 4B, the moving device 14 is slidably movable in the conveying direction of the belt conveyor 12a (substrate 11) on the convex piece 13f protruding from the upper surface of the table 13a of the light beam device 13. A telescopic air cylinder that is integrally attached to a rail 14a supported on the front and a front end of the table 13a (a front end in the direction of conveyance of the substrate 11), and the tip of the piston rod 14c is locked to the front end of the pallet 12b when extended. 14b and a drive mechanism (not shown) that slides the table 13a to the rear end (fixed position) of the rail 14a backward (in the opposite direction of the belt conveyor 12a). Then, as shown in FIG. 4A, the table 13a is configured such that the front end of the piston rod 14c is locked to the front end of the pallet 12b by extending the air cylinder 14b at a fixed position at the rear end of the rail 14a. 11 is moved in accordance with the transport speed of 11. Further, as shown in FIG. 4B, the table 13a is slid rearward by the drive mechanism by releasing the locking to the front end of the pallet 12b by contraction of the air cylinder 14b at the front end position of the rail 14a. The rail 14a is returned to the rear end position (fixed position).
[0022]
The temperature sensor 15 detects the temperature distribution on the surface of the substrate 11 by infrared rays. The temperature distribution data on the surface of the substrate 11 detected by the temperature sensor 15 is analyzed by a computer (not shown), and based on the difference between the temperature distribution data and the set temperature on the surface of the substrate 11, the light beam device 13. The amount of light emitted from the photothermal source 13c is adjusted, and the light beam 13e having the optimum temperature is partially irradiated (heat replenishment) at a set point shortage on the surface of the substrate 11 at a pin point. The temperature distribution on the surface of the substrate 11 by the temperature sensor 15 is detected immediately before the light beam 13e is irradiated from the photothermal source 13c of the light beam device 13 in the reflow zone, that is, immediately before the surface of the substrate 11 is replenished with heat. To be done.
[0023]
Here, a procedure for performing reflow soldering by heating the surface of the substrate 11 by the heating device 1 will be described.
[0024]
First, the substrate 11 is placed on each of the pallets 12b,... On the belt conveyor 12a, and the substrate 11 is conveyed to the preheating zone by the belt conveyor 12a. Then, the board | substrate 11 is preheated with the hot air of the fixed temperature which blows off from a nozzle in a preheating zone.
[0025]
Subsequently, the board | substrate 11 is conveyed to the reflow zone by the conveyor 12a.
[0026]
Even in this reflow zone, the substrate 11 is continuously heated by hot air having a constant temperature. The temperature sensor 15 detects the temperature distribution on the surface of the substrate 11 as soon as it is conveyed to the reflow zone. The temperature distribution data on the surface of the substrate 11 detected by the temperature sensor 15 is analyzed by a computer. At this time, the amount of light emitted from the photothermal source 13c of the light beam device 13 is adjusted based on the difference between the temperature distribution data analyzed by the computer and the set temperature on the surface of the substrate 11.
[0027]
Thereafter, when the substrate 11 is conveyed to a position below the rear end of the rail 14a, the tip of the piston rod 14c is locked to the front end of the pallet 12b by extension of the air cylinder 14b, and the table 13a of the light beam device 13 is engaged. Begins to move on the rail 14a in accordance with the conveyance speed of the substrate 11.
[0028]
At this time, the light beam 13e having the optimum temperature adjusted in the amount of light emitted from the light source 13c of the light beam device 13 is partially moved at the pin point while moving in the transport direction with respect to the set temperature shortage portion on the surface of the substrate 11. Irradiation (heat supplementation).
[0029]
Thereby, the process of conveying the board | substrate 11 with which electronic component 11a, ... was mounted | worn by the conveying apparatus 12 (belt conveyor 12a), the process of pre-heating and heating the board | substrate 11 with a hot air, and the board | substrate 11 at the time of this heating A step of detecting the temperature distribution by the temperature sensor 15 and analyzing it by a computer, and a point where the set temperature is insufficient on the surface of the substrate 11 based on the difference between the temperature distribution data analyzed by the computer and the set temperature on the surface of the substrate 11 The reflow soldering is completed through a step of irradiating the light beam 13e and performing heat replenishment. For this reason, the time required for completing the reflow soldering through a series of steps is shortened. In addition, heat replenishment to the place where the set temperature is insufficient on the surface of the substrate 11 is achieved by extending the air cylinder 14b to the front end of the pallet 12b on which the substrate 11 is placed on the belt conveyor 12a and locking the tip of the piston rod 14c. Since the table 13a of the light beam device 13 is moved on the rail 14a in accordance with the conveyance speed of the substrate 11, the substrate 11 can be conveyed even at a place where heat supplementation takes time (a place where the set temperature is insufficient). Heat replenishment is performed while following the speed, and the time required to complete reflow soldering is effectively shortened. As a result, production efficiency can be improved.
[0030]
In addition, since heat replenishment is partially performed on a portion where the set temperature is insufficient on the surface of the substrate 11, the electronic components 11a are mounted on the surface of the substrate 11 with high density without being diffused like hot air blown from the nozzle. Even if it is, heat replenishment is performed only in necessary places (places where the set temperature is insufficient). In addition, the detection of the temperature distribution on the surface of the substrate 11 by the temperature sensor 15 is performed immediately before the surface of the substrate 11 is replenished with heat by irradiation with the light beam 13e from the photothermal source 13c. Based on the difference from the set temperature on the surface of the substrate 11 immediately after detection of the temperature distribution by the temperature sensor 15, the heat replenishment to the set temperature insufficient portion is performed. In addition, based on the difference between the temperature distribution data analyzed by the computer and the set temperature on the surface of the substrate 11, the amount of light emitted from the photothermal source 13c of the light beam device 13 is adjusted, and the light beam 13e having the optimum temperature is formed on the substrate. Irradiation is partially performed at a pin point on a set temperature deficient portion on the 11th surface, so that heat replenishment to the set temperature deficient portion is optimally performed. As a result, effective uniform heating on the surface of the substrate 11 can be practiced.
[0031]
(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG.
[0032]
In this embodiment, the moving speed (following speed) of the table and the temperature adjustment of the light beam by the moving device are individually controlled according to different types of substrates. The other configurations except for the moving device are the same as those in the first embodiment, and the same portions are denoted by the same reference numerals and description thereof is omitted.
[0033]
That is, in this embodiment, as shown in FIG. 5, the computer 21 that sets or stores the control and program data of the heating device 1, the speed adjustment unit 22 that adjusts the moving speed of the table 13a of the moving device 14, and the light And a temperature adjustment unit 23 for adjusting the irradiation temperature of the beam 13e.
[0034]
The computer 21 analyzes temperature distribution data on the surface of the substrate 11 detected by the temperature sensor 15 and also analyzes transport speed data of the belt conveyor 12a of the transport device 12.
[0035]
The speed adjusting unit 22 adjusts the moving speed of the moving device 24 when moving the table 13 a of the light beam device 13 in accordance with the transport speed of the substrate 11. The moving device 24 includes a rail 24a that supports a protruding piece 13f protruding from the upper surface of the table 13a of the light beam device 13 so as to be slidable in the conveying direction of the belt conveyor 12a (substrate 11), and the table 13a is a rear end of the rail 14a. A drive mechanism (not shown) that slides in the front-rear direction between the position (fixed position) and the front end position is provided.
[0036]
Then, the computer 21 determines the adjustment amount of the amount of light emitted from the photothermal source 13 c of the light beam device 13 based on the difference between the analyzed temperature distribution data and the set temperature on the surface of the substrate 11. A command signal is output. Further, the computer 21 determines the forward slide moving speed from the rear end position of the rail 14a to the front end position of the table 13a by the driving mechanism based on the analyzed conveying speed data of the belt conveyor 12a of the conveying apparatus 12, and adjusts the speed. A command signal is output to the unit 22. Further, the computer 21 adjusts the amount of light emitted from the photothermal source 13c of the light beam device 13 based on the difference between the analyzed temperature distribution data and the set temperature on the surface of the substrate 11, and the belt of the analyzed transport device 12 Insufficient set temperature on the surface of the substrate 11 for each different type of substrate 11 such as the forward slide movement speed from the rear end position of the rail 14a to the front end position of the table 13a by the driving mechanism based on the conveyance speed data of the conveyor 12a Program data such as heat replenishment conditions for the location is set or stored.
[0037]
Here, a procedure for performing reflow soldering by heating the surface of the substrate 11 by the heating device 1 will be described.
[0038]
First, the substrate 11 is placed on each of the pallets 12b,... On the belt conveyor 12a, the substrate 11 is transported to the preheating zone by the belt conveyor 12a, and the substrate 11 is preheated by hot air blown from a nozzle in the preheating zone.
[0039]
Subsequently, the board | substrate 11 is conveyed to a reflow zone by the conveyor 12a, and the board | substrate 11 is continuously heated with the hot air of fixed temperature. Then, as soon as the substrate 11 is transported to the reflow zone, the temperature distribution on the surface of the substrate 11 is detected by the temperature sensor 15. The computer analyzes the temperature distribution data on the surface of the substrate 11 detected by the temperature sensor 15 and the conveyance speed data of the belt conveyor 12a.
[0040]
At this time, the amount of light emitted from the photothermal source 13c of the light beam device 13 is determined based on the difference between the temperature distribution data analyzed by the computer 21 and the set temperature on the surface of the substrate 11, and a command signal is sent to the temperature adjustment unit 23. Is output. On the other hand, based on the conveyance speed data of the belt conveyor 12 a analyzed by the computer 21, the slide movement speed of the table 13 a by the drive mechanism is determined and a command signal is output to the speed adjustment unit 22.
[0041]
After that, when the substrate 11 is conveyed to a position below the rear end of the rail 14a, the slide beam speed adjusted by the speed adjusting unit 22, that is, the speed of the light beam device 13 is synchronized with the substrate 11 on the belt conveyor 12a. The table 13a starts to move on the rail 24a.
[0042]
At this time, the light beam 13e having the optimum temperature adjusted in the amount of light emitted from the light source 13c of the light beam device 13 is partially moved at the pin point while moving in the transport direction with respect to the set temperature shortage portion on the surface of the substrate 11. Irradiation (heat supplementation).
[0043]
Thereby, when switching to a different type of substrate 11, the amount of light emitted from the photothermal source 13 c of the light beam device 13 is adjusted based on the difference between the temperature distribution data analyzed by the computer 21 and the set temperature on the surface of the substrate 11. Individually different substrates such as the amount of slide movement speed from the rear end position of the rail 14a to the front end position of the table 13a by the drive mechanism based on the amount and the conveyance speed data of the belt conveyor 12a of the conveyance device 12 analyzed by the computer 21 For each of the 11 types, it is not necessary to newly set program data such as heat replenishment conditions for locations where the set temperature is insufficient on the surface of the substrate 11, and the production efficiency can be further improved.
[0044]
(Other embodiments)
In the first embodiment, when the substrate 11 is conveyed to a position below the rear end of the rail 14a, the tip of the piston rod 14c is locked to the front end of the pallet 12b, and the table of the light beam device 13 is used. 13a is moved on the rail 14a in accordance with the conveyance speed of the substrate 11, and in the second embodiment, the speed adjustment unit 22 is moved when the substrate 11 is conveyed to a position below the rear end of the rail 14a. The table 13a of the light beam device 13 is moved at a slide moving speed adjusted by the above, but as shown in FIG. 6, when the substrate 11 is conveyed to a position below the rear end of the rail 14a, When the detection piece 31 fixed to one end (left side in FIG. 6) of the pallet 12b is detected by the transmission type sensor 32 hanging from the table 13a, the computer To speed control unit 22 outputs a signal to 1 may output the command signal. In this case, the light beam device 13 is adjusted with respect to the conveyance speed of the substrate 11 by finely adjusting a command signal to the speed adjustment unit 22 of the computer 21 by a position shift signal from the transmission sensor 32 that detects the position of the detection piece 31. The (photothermal source 13c) can be moved in a synchronized state.
[0045]
Further, in each of the above embodiments, the heat replenishment for the set temperature shortage portion on the surface of the substrate 11 is performed while moving the light beam device 13 in accordance with the transport speed of the substrate 11 by the transport device 12. The replenishment of heat to the set temperature deficient portion may be performed by transporting only the substrate by the transport device without moving the light beam device. In this case, heat replenishment is performed without stopping the conveyance of the substrate, the time required for completing the reflow soldering is shortened, and the production efficiency can be improved.
[0046]
【The invention's effect】
As described above, according to the present invention, the time required for completing the reflow soldering by partially replenishing heat to the portion where the set temperature is insufficient based on the difference between the temperature distribution on the substrate and the set temperature. The production efficiency can be improved by shortening the temperature of the substrate, and uniform heating on the substrate surface can be practiced by replenishing heat only to the portions where the set temperature is insufficient on the substrate surface.
[0047]
In particular, by detecting the temperature distribution on the substrate surface immediately before heat replenishment to the location where the set temperature is insufficient, the location where the set temperature is insufficient based on the difference from the set temperature on the substrate surface immediately after detecting the temperature distribution. Heat can be replenished, and uniform heating on the substrate surface can be practiced accurately and quickly.
[0048]
In addition, by performing heat supplementation for locations with insufficient set temperatures using multiple light beams collected from the light source, it is possible to accurately perform heat supplementation for locations with insufficient preset temperatures, and practice uniform heating with high accuracy on the substrate surface. be able to.
[0049]
In addition, heat replenishment for locations where the set temperature is insufficient while the substrate is being transported enables heat replenishment without stopping the transport of the substrate, further reducing the time required to complete reflow soldering and improving production efficiency. Can be further improved.
[0050]
In addition, heat replenishment for locations where the set temperature is insufficient is performed while moving according to the board conveyance speed, so that heat replenishment can be performed while following the board conveyance speed, effectively reducing the time required to complete reflow soldering. The production efficiency can be further improved.
[0051]
In addition, by setting or storing heat replenishment conditions for locations where the set temperature is insufficient for each different type of board, no new setting of heat replenishment conditions is required when switching to a different type of board, improving production efficiency. Can be further improved.
[Brief description of the drawings]
FIG. 1 is a side view of a schematic configuration of a heating apparatus according to a first embodiment of the present invention as viewed from a direction orthogonal to a substrate transport direction.
FIG. 2 is a front view of the heating device as viewed from the substrate transport direction.
FIG. 3 is a cross-sectional view showing a schematic configuration of the light beam device.
FIG. 4A is an explanatory view showing a state where the moving device is locked to the pallet front end in the same manner.
(B) is explanatory drawing which shows the latch release state to the pallet front end of the movement apparatus.
FIG. 5 is a side view of a schematic configuration of a heating apparatus according to a second embodiment of the present invention as viewed from a direction orthogonal to a substrate transport direction.
FIG. 6 is a front view of a heating apparatus according to another embodiment as viewed from the substrate transport direction.
FIG. 7 is a perspective view illustrating a configuration of a heating device according to a conventional example.
FIG. 8 is a schematic configuration diagram of the heating apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heating apparatus 11 Board | substrate 12 Conveyance apparatus (conveyance means)
11a Electronic component 13c Photothermal source (light source)
13e Light beam 15 Temperature sensor (temperature distribution detection means)

Claims (4)

In a heating apparatus in which a substrate on which electronic components are mounted is conveyed by a conveying means, and this substrate is heated to perform reflow soldering,
Temperature distribution detecting means for detecting the temperature distribution during heating on the surface of the substrate ;
Based on the difference between the temperature distribution detected by the temperature distribution detection means and the set temperature on the substrate surface, a light beam device that partially replenishes heat at a set temperature shortage location on the substrate surface;
A moving device that locks the light beam device with respect to the substrate and moves the light beam device in accordance with the substrate transport speed
With
The heating apparatus according to claim 1, wherein the light beam device replenishes heat to a portion where the set temperature is insufficient on the substrate surface while moving according to the substrate transport speed by the transport means . In the heating apparatus according to claim 1,
A heating apparatus characterized in that detection of a temperature distribution on a substrate surface by a temperature detection means is performed immediately before replenishing heat to a location where a set temperature is insufficient. In the heating apparatus according to claim 1 or 2,
Thermal supplementation on set temperatures insufficient locations on the substrate surface by the light beam apparatus, heating apparatus, characterized in that adapted to be performed by a plurality of light beam focused from a light source. In the heating apparatus according to any one of claims 1 to 3,
The heating apparatus is characterized in that the conditions for heat replenishment with respect to the set temperature deficient portion on the substrate surface are set or stored for each different type of substrate.

Images