JPH0330493A - Reflow soldering device - Google Patents

Abstract

PURPOSE:To make a soldering device of this design small in length and to surely judge the fall of a substrate by a method wherein a pre-heat section is arranged vertical to a reflow section, and a board transfer mechanism is formed into a vertical transfer system. CONSTITUTION:A board 13 transferred from the direction of an arrow is made to ascend by supporting its ends with board pads 21a and 21b fitted to endless chains 18a and 18b and pre-heated by not air devices 25a and 25b, located at the top, and soldered at a reflow section provided with far infrared panel heaters 31a and 31b and a hot air jetting nozzle 32. Thereafter, the board 13 is cooled by a cooling device 33 in a cooling section structured the same as a pre-heat section and carried out by a pusher 30. Sensors 36a and 36b are provided to the lowermost part of a vertical transfer section, and other sensors 37a and 37b are provided to the uppermost of the transfer section to judge the fall of a board by comparing the detected board with the board data stored in a memory section.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a reflow soldering apparatus for soldering electronic components to a printed circuit board (hereinafter abbreviated as the board) by heating the board, and particularly relates to a board transport mechanism thereof. It is something.

BACKGROUND OF THE INVENTION Below, a description will be given of a board transfer mechanism of a conventional reflow soldering apparatus that solders electronic parts to a board by heating the board with electronic parts mounted on cream solder.

FIG. 5 shows the entirety of a conventional reflow soldering apparatus having a groove for a substrate conveyance device, and FIG. 6 shows a schematic diagram of a substrate conveyance section. As shown in FIGS. 6 and 6, in this rice substrate conveyance mechanism, the substrate is conveyed in the direction of the arrow by an endless chain 1, far infrared panel heaters 6 and 7, and hot air blowing nozzles/l. In the first preheating section equipped with a /3, the temperature is slightly heated to a certain constant temperature, and further in the second preheating section equipped with a hot air blowing nozzle /1/4, heating is performed to maintain the temperature at a certain constant temperature. The solder is further equipped with far-infrared panel heaters 8 and 9 and a hot air blowing nozzle/I15, and after being heated to melt the solder in the reflow section, the solder is fixed by the cooling device 1Q and then transported out. A method is being adopted.

Details of the substrate transport method at this time are shown below.

As shown in FIG. 1-12! L and 1
It is rotated by 2b. As shown in FIG. 6C, on one side of the chain 1, a bottle 14 for holding the end of the board 13 protrudes 9, and as the chain 1 moves, the plurality of bottles 14 move, and the upper part of the bottle 14 protrudes. The substrate 13 that has come into contact with the substrate 13 is transported.

Next, details of a method for detecting a falling board during transportation and a method for carrying out a fallen board will be described below.

As shown in FIGS. 5 and 6A, below the substrate transfer surface, a light emitting sensor 2a is located at the substrate loading port, and a light receiving sensor 2a is located at the substrate loading port. -2b is placed, so that when the board falls, the sensor 2
By cutting off the beam emitted to b, it is possible to detect a state in which the board has fallen. When the fallen board is detected by the sensors 2a and 2b and falls onto the upper part of the endless mesh belt 1e, it is attached to the rotating shaft of the drive source 18 and the nine sprocket 1
The endless mensch belt 16 rotates and moves the substrate by the far-infrared panel heater 6.
7.8 and 9, and the structure is such that the hot air blowing nozzles 3.4 and 6 are carried out from inside the high temperature furnace.

Problems to be Solved by the Invention However, in the substrate transport mechanism of this type of reflow soldering apparatus, as the size of the substrate increases, the area of the heating section must be made longer, and therefore the apparatus as a whole must also be made longer. An increase in the overall length of the device is undesirable for installation on the main line.

In addition, the method of detecting a fallen board using light-emitting and light-receiving sensors has problems such as deterioration of the sensitivity of the sensor and the need for accurate sensor installation as the overall length of the device increases. be. Furthermore, in order to remove the fallen board,
Providing a drive source, mesh belt for transporting, etc. separately from the substrate transport section is not preferable in terms of equipment costs.

The technical means of the present invention to solve the above-mentioned problems is to vertically transport the substrate horizontally into the device from the substrate loading port of the device, and to perform a preheating section. It is a good idea to equip it vertically. Specifically, the substrate transport mechanism is such that both ends of the substrate along the substrate transport direction are supported by a chain that rotates vertically and moves vertically. The configuration for detecting the dropping of a substrate is such that sensors for detecting the presence or absence of a substrate are provided at the lower and upper parts of the vertical transport section to detect the dropping of the substrate. The configuration for taking out a fallen substrate is to reverse the direction of substrate movement of the vertical transport section so that the falling substrate can be taken out near the substrate loading port of the apparatus.

action The effect of this technical means is as follows.

That is, the length of the apparatus can be shortened by using a vertical transport method as the substrate transport groove in the preheating section. This method is more reliable than the method of detecting a falling substrate because the detection of a falling substrate is determined based on the presence or absence of a substrate in the transport section. In addition, with the structure for removing fallen substrates that occur in the vertical transfer section, by reversing the direction of substrate movement at the same time as detecting a fall, the substrate can be taken out near the substrate loading port of the device, and it is possible to take out the substrate near the substrate loading port of the device. There is no need to newly provide a mechanism.

Example Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 is an overall view of a reflow soldering apparatus that has a vertical conveyance system as the substrate conveyance mechanism, and Figures 2, 3, and 4 are views of the vertical conveyance section of the preheat section as seen from the arrow direction in Figure 1. FIG.

As shown in FIGS. 1 and 2, the board 13 carried in in the direction of the arrow moves upward with the ends of the board supported by the board supports 21 & 21b attached to the endless chains 1e & 18b. .

The chains 18 and 19 are driven by a shaft 2 to which bevel gears 221L and 22b are attached to the drive source 17.
By rotating 4, the bevel gears 23a and 23b integrated with the pulley are rotated by 90 degrees.
It is provided via belts 20& and 20b. As the board moves upward, the hot air devices 2511L and 25
After being preheated by b and positioned at the extreme end, the pusher 27 sliding along the guide rail 2e activates the far infrared panel heaters 311& and 31b and the hot air blowing nozzle!
It is soldered in a reflow section equipped with v32.

Note that the pusher 27 is connected to the sprockets 2aai and 28.
It is fixed to a chain 29 that is suspended between the time points b and is driven by a drive source 3o to which a sprocket 28b is attached.

After the board is soldered, it is cooled by a cooling device 33 in a cooling section of a vertical conveyance type having the same bulging structure as the preheating section. When the substrate reaches the bottom of the vertical transport section, it is carried out by the pusher 30 attached to the tip of the air cylinder 36.

Next, detection of a fallen board in the preheating section will be described. As shown in FIGS. 2 and 3, the sensor 36 is located at the bottom of the vertical conveyance section! L and 3θb.

Sensors 371L and 37b are provided at the top. At a certain point in time, when a board is carried to the bottom of the vertical conveyance section, the sensors 36 and 3eb detect that there is a board, and when no board is carried in, it is detected that there is no board; The presence or absence of a board is stored in a certain memory section. If the loaded board does not fall while the vertical transport unit is rising, it will rise by 6 pitches, with the interval between vertically adjacent board receivers being 1 pitch, and then move to the sensors 37 & 3.
7b, it is detected that a substrate is present. By comparing the presence or absence of the nine substrates detected here with the presence or absence of the substrate stored in the memory section, it is possible to determine whether the substrate has fallen.

As shown in Figure 3, the states in which a board falls during one transport include a state in which both ends of the board have fallen, as in board (M), and a state in which only one end of the board has fallen, as in board (B). Therefore, it is necessary to provide sensors at both ends.

Next, taking out the fallen board will be explained. As shown in FIG. 4, when a falling substrate is detected by the sensors 36 and 37 and the memory section, the drive source 17 is reversed to reverse the moving direction of the chains 1B& and 18b, and the vertical transport section is moved to the top. The missing board can be taken out through the board loading port of the device at the bottom, and the two boards that have fallen and overlap can be taken out.

In addition to the effects of the invention, the length of the apparatus can be shortened by arranging the preheat section perpendicularly to the reflow section and using a vertical transport method as the substrate transport structure. Regarding a dropped board, since the dropping is determined based on the presence or absence of the board in the transport section, the method of detecting a falling board can also reliably determine whether the board has fallen. In order to remove the fallen substrates that occur in the vertical transport section, it is necessary to provide a mechanism for removing the fallen substrates by reversing the direction of substrate movement so that the substrates can be taken out near the substrate loading port of the device. It is advantageous in terms of cost.

[Brief explanation of drawings]

Fig. 1 is a front view of a reflow soldering apparatus according to an embodiment of the present invention, Fig. 2 is a side view of the vertical conveyance section of the preheating section as viewed from the arrow in Fig. 1, and Fig. 3 is a view of the falling board. Fig. 4 is a side view of the vertical transfer unit showing the state of removal of a dropped board, Fig. 6 is a front view of a reflow≠tolding device with a conventional substrate electric transfer mechanism, Fig. 6 6 are a front view, a side view, and a plan view of a main part of the conveyance section in FIG. 6. 13... Board, 17... Sprocket, 18°19.29... Chain, 21...
... Board holder is part, 24... Shirt l-136
, 37... Sensor 25. 32... Hot air blowing nozzle, 31... Far infrared panel heater.

Claims (4)

[Claims] (1) A preheat section that heats the printed circuit board sent by the transport mechanism to a predetermined temperature, and a reflow section that is provided continuously to the preheat section and melts the solder to solder the electronic components to the printed circuit board. The transport mechanism located in the preheating section is configured to vertically transport the printed circuit board horizontally transported from the board loading port, and the transport mechanism located in the reflow section transports the printed circuit board horizontally. A reflow soldering device with the following configuration. (2) The vertical transport mechanism for printed circuit boards provided in the preheating section includes a board receiving part that supports the edge of the printed circuit board along the board transport direction in order to transport the board in the vertical direction, and a plurality of board receiving parts, etc. Two rows of endless chains provided at intervals, two pairs of sprockets that support the two rows of endless chains at both upper and lower ends, and left and right ends, and the left and right sprockets are fixed to rotate the two rows of chains in synchronization. an endless chain comprising a shaft and a drive source for rotating one end of the sprocket, and the board receiving portion for supporting the printed circuit board at both ends, and the sprocket are symmetrically equipped. A reflow soldering apparatus according to claim 1, characterized in that: (3) A sensor for detecting the presence or absence of a printed circuit board is installed near the board receiving part located at the same height as the board loading entrance, and a sensor for detecting the presence or absence of a printed circuit board is installed above the transport part. A reflow soldering apparatus according to claim 2, characterized in that: (4) The present invention is characterized in that the moving direction of the endless chain is reversed when a fall of the board is detected by a sensor, and the printed circuit board is taken out at the lowest part of the vertical conveyance section. Reflow soldering equipment according to scope 3.