JPS59100594A - Melting was coating controller for waxing processor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molten wax application control section of a wax processing apparatus that sprays molten wax onto a printed circuit board on which electronic components to be mounted are temporarily fixed. It is related to.

Figure 1 is a pull diagram showing an example of conventional soldering equipment. 1 shows the entire equipment, 2 shows the processing equipment for preliminary soldering, 3 shows the cutting equipment, and 4 shows the final soldering equipment. is a processing device. In these devices, 5.9 is a Franks processor, 6°10 is a preheater, 7 is a dip type soldering bath, 8.12 is a cooler, and 11 is a jet type soldering bath.

FIG. 2 is a partial side cross-sectional view showing how electronic components are mounted on a printed circuit board, 13 is a printed circuit board, 14 is an electronic component such as a resistor, capacitor, IC, etc., and 15 is a lead l5P of the electronic component 14 ( (or lead terminal), 16 is a through hole into which the lead (or lead terminal) 15 is inserted.

In this way, with conventional soldering equipment, the printed circuit board 13 is heated and molten solder is adhered to it over a period of 20 minutes, during pre-soldering and final soldering. The components 14 are affected by heat, and when finishing soldering is performed after inserting the lead terminals 15 of the IC components into the through holes 16 of the printed circuit board 13, the force of the jet solder may damage the IC.
There were drawbacks such as parts lifting up. Also, processing device 2 is used for preliminary soldering, and processing device 4 is used for final soldering.
Since the soldering device vi1 has the same equipment as the device 1, the entire device vi1 becomes large, and the soldering device 1 requires a large space and is expensive.

This invention was developed in view of the above points, and is a soldering device that sprays molten wax onto the top surface of a printed circuit board, cools it, covers the electronic components with wax, and temporarily fixes them to the printed circuit board. The waxing method provides the processing apparatus with a molten wax application control section for applying molten wax according to the width of the printed circuit board. The present invention will be explained below based on the drawings.

FIG. 3 is a schematic diagram showing one embodiment of the present invention, and 21 shows the entire processing apparatus for carrier-less soldering. Reference numeral 22A is a fixed-side conveyance chino, 22B is a movable-side conveyance chino, 23 is a processing device with wax, 24 is a wax processing section, and 25 is molten wax that has become liquid by heating. Further, the same reference numerals as in FIGS. 1 and 2 indicate the same parts.

Next, the operation shown in FIG. 3 will be explained.

Mount the electronic component 14 on the printed circuit board 13 and connect the lead wire 1
5 protrudes downward.

Next, molten wax 25 is sprayed onto the top surface of the printed circuit board 13 in the wax processing section 24, and then the sprayed molten wax 25 is solidified in the cooler 8, so that the electronic components 14 are not placed on the printed circuit board 13. It is covered with solidified wax and fixed in place.

Further, in the case of an IC component, the molten wax 25 also penetrates between the lead terminal 15 and the through hole 16 and is fixed.

Next, the lead 15 is cut by the cutting device 3, and the final soldering is done by the processing device 4 by the 7lux processing device 9.
．． Preheater 10. Solder paste 11. The cooler 12 is soldered through various processing steps.

Figures 4(a) and (b) show the wax processing section 2 in Figure 3.
4, FIG. 4(a) is a partially cutaway perspective view, and FIG.
FIG. 4(b) is an enlarged side sectional view taken along the line X--X of FIG. 4(a). In these figures, the same reference numerals as those in FIG. A gear pump provided; 28 is a motor that drives the gear pump 27;
29 is a control valve that adjusts the flow rate and pressure of the molten wax 25; 30 is a passage for the molten wax 250; 31 is a filter for removing dust mixed in the molten wax 25; melted wax 2
33 is a plurality of pipes branched from the passage 32 and connected in parallel; 34 is a flexible tape heater wrapped around the outer circumference of the vibrator 33;
The molten wax 25 passing through 3 is heated so as not to solidify.

35 is a heat insulating material that covers the outer periphery of the tape heater 34;

Reference numeral 36 denotes a spraying device for spraying the molten wax 25, and the sprayer 36 sprays the molten wax 25 into each of the vibrators 33 of the numeral ratio through the connecting fittings 3T.
They are attached one by one, and the soldering shown in Figure 3 is done on device 2.
A plurality of printed circuit boards 130 are arranged in a direction perpendicular to the traveling direction of the printed circuit boards 130 transported by one transport chain 22A, 22B. 3B is a thermostat that detects the temperature of the molten wax 25 within the wax elliptical body 26.

Note that 39 removes dust, etc. from the filter 31 (
40 is a control panel.

In the gear pump 2T, 41 is a drive shaft, and the motor 28
is connected to. 42 is a driven shaft.

In FIG. 4(b), 43 is a guide shaft that serves as a guide for assembling the gear pump 27, and 44 is a semicircular fixture used to fix the gear pump 27 to the wax tank body 26. , 45 is a disk-shaped upper case, and 46 and 47 are a pair of spur gears, which mesh with each other at the shaded area in Fig. 4. The spur gear 46 is connected to the drive shaft 41, and the spur gear 47 is connected to the driven shaft It is fixed to +hl+42. 4
8 is a gear case that surrounds and stores the sides of the spur gears 46 and 47 on the lower surface of the upper case 45; 49 is the gear case 4;
8. An inlet for the molten wax 25 formed in the fixture 44;
45a and 48a are delivery holes for sending out the melted wax 25 eluted from the inlet 44a, 51 are supply holes for feeding the molten wax 25 from the gear pump 27 to the passage 30, and 49b and 52 are the passages 30 and 32. from control valve 2
This is a reflux hole for molten wax 25 to be refluxed through 9.

Next, the operations shown in FIGS. 4(a) and 4(b) will be explained.

The solid wax charged into the wax tank body 26 is heated by a heater (not shown) to become molten wax 25, and the temperature is detected by the thermostat 38, and 1il is heated.
The temperature is maintained at a constant temperature by operating the J control panel 40.

A pair of spur gears 4 of the gear pump 27 are driven by the motor 28.
6.47 rotates, the molten wax 25 in the wax tank main body 26 is sucked into the inlet 44a, and enters the supply hole'.
5a+48a (arrow A) and is pressurized by spur gears 46.
and enter the passageway 3o (arrow B).

The molten wax 25 in the passage 30 enters the inside of the filter 31, and after dust etc. are removed, it passes through the passage 32 (arrow C) and is branched into a plurality of pipes 33 (arrow D), and is ejected from each injection device 36. By spraying the printed circuit board 13,
The entire electronic component 14 mounted on the top surface is sprayed.

On the other hand, the molten wax 25 in the passage 32.30 is
9 controls the flow rate and pressure, and the flow from the passage 32° 30 passes through the control valve 29 as shown by arrows E and F in FIG.
．． It is refluxed to 47.

FIG. 5 is an enlarged perspective view showing the gear pump 27 in an exploded manner. The same parts as in FIGS. The insertion hole 49c is the support hole 44d for the drive shaft 41.
, 45d is an insertion hole through which the driven shaft 42 is rotatably inserted, 49d is a support hole for the driven shaft 42, 46c is a fixing hole for fixing the spur gear 46 to the drive shaft 41, and 47c is the driven shaft a fixing hole for fixing the spur gear 47 to 42;
44e.

45e, 48e, 49e are through holes through which the guide shaft 43 is inserted, and 44f, 45f, 48f, 49f are through holes through which the screws 50 are inserted.

When assembling, the drive shaft 41. The driven shaft 42° and the guide shaft 43 are attached to the base 49, and then the spur gears 46 and 47 are engaged to connect the drive shaft 41. It is fixed to the driven shaft 42. next,
After placing the gear case 48 on the base 49, the spur gear 46.
47 is stored, and then) the upper case 45 is placed over the top of the gear case 48 to form 27, which is attached to the wax tank body 26, and the drive shaft 41
Connect to motor 2B.

Note that the operation of the gear pump 2T shown in FIG. 5 has been explained in FIGS. 4(a) and 4(b), and will therefore be omitted here.

FIG. 6 is an enlarged side sectional view showing details of the control valve 29, and FIG.
The same reference numerals as in FIG. 2B indicate the same parts, and 61 is a valve box of the control valve 29, which is fitted into the wax scoop main body 26. Reference numeral 62 denotes an adjustment valve screwed into the valve box 61, which adjusts the flow rate of the molten wax 25 by rotating. A safety valve 63 automatically adjusts the pressure of the molten wax 25. 64 is a valve seat of the regulating valve 62, 65 is a valve seat of the safety valve 63,
66 is a spring that presses the safety valve 63 against the valve seat 65; 6T;
68 is an introduction hole on the safety valve 63 side provided at the other longitudinal end of the valve box 61; 69 is each introduction hole 67; .6
The discharge hole 70 on the side of the reflux hole 52 provided in the middle of 8 is an O-ring for use on water.

Next, the operation shown in FIG. 6 will be explained.

The molten wax 25 pressurized by the rotation of the spur gears 46 and 47 of the gear pump 270 flows from the supply hole 519 passage 30 to the fourth
Passage 32 through filter 31 in Figure (a). Each pipe 33
If you want to adjust the injection amount, turn the adjustment valve 62 to increase the gap between the adjustment valve 62 and the valve seat 64.
5 is diverted and enters the valve box 61 from the introduction hole 6T,
Further, it is sent to the reflux hole 52 via the valve seat 67 and the discharge hole 69. On the other hand, the flow rate of the molten wax 25 is adjusted.

When the pressure drops below a predetermined level due to stopping of injection, etc., a part of the molten wax 25 in the passage 30 is diverted and flows into the introduction hole 6.
8, the safety valve 63 is pressed against the pressing force of the spring 66, and the valve seat 65 is opened.

FIG. 7 is an enlarged side sectional view showing details of one of the injection devices 36 in FIG. 4(a), where the same reference numerals as in FIG. 4(a) indicate the same parts, 71 is a valve box, and the connection A metal fitting 37 is screwed together by a threaded portion 72.

Reference numeral 73 includes a hole for the molten wax 25 provided on the side of the valve box 11, 74 a valve stem, 75 a valve, T6 a valve seat, and 77 the valve seat 76, which is connected to one end of the valve box 71. 80 is a nozzle, 81 is a fitting for the nozzle 80, 82 is a spring that acts in the direction of pressing the valve γ5 against the valve seat T6, 83 is a gasket, 84 is an F-cylinder, and 85 is a piston fixed integrally with the valve shaft γ4 protruding from the other end of the valve box T1.

Next, the operation shown in FIG. 7 will be explained.

The molten wax 25 pressurized by the gear pump 27 of the wax pot body 26 in FIG. It passes through the filter 319 passage 32, passes through the vibrator 33 shown in FIG. 7, and enters the inside of the valve box T1 through the introduction hole T3 in the valve box γ1.

When the printed circuit board 13 passes below the injection device 36,
Detection by a detector such as a phototube (not shown) causes pressurized air to flow into the F cylinder 84, causing the piston 85 to operate and press the valve stem T4 against the pressing force of the spring 82.
5 is released from the valve seat 76. When the valve seat T6 is opened, the molten wax 25 in the valve box 71 is injected from the nozzle 80 through the nozzle fittings 78 and 79, and is blown onto the printed circuit board 13.

1 (Oh, the nozzle 80 may be inserted directly into the valve seat 76 of the connecting fitting γT.

Figure 8 shows the processing device 2 with wax, which is the base of this invention.
First, an outline of the wax application control section of No. 3 will be explained. In the wax processing section 24 shown in FIG. The injection devices 36 are kept in an operable state by turning on the limit switches corresponding to the required number of injection devices 36 according to If@ of the printed circuit board 13, and after detecting the passage of the printed circuit board 13, The molten wax 25 is sprayed. The details will be explained below based on FIG.

In FIG. 8, the same reference numerals as in FIGS. 2, 3, and 4 (a) indicate the same parts, 22A is a fixed-side conveyor chain, and 22B is movable in a direction perpendicular to the running direction of the printed circuit board 130. Transport ceno on the movable side, 361.36□,・
...,36. indicates each of the injection devices 36.

Reference numeral 91 denotes a holding claw for the printed circuit board 13, which is attached to the conveyor cheno 2
It is fixed integrally with 2A and 22B. 92 is a screw rod for moving the conveyance cheno 22B, and 93 is the conveyance cheno 22B.

An operating contact piece 94 that moves together with the holding claw 91 is a limit switch; ．． 942. . . . , 94 □ indicates each of the limit switches 94, and the injection device 36 . ．． 36. , . . . , 36n, and are arranged in the same direction.

Describe the lack, behavior.

For soldering, a handle (not shown) serving as an adjusting means for adjusting the spacing between the holding claws 91 of the device 21 is turned, the conveying chino 22B is moved, and the printed circuit board 13 is attached to the holding claws 91.

At this time, the actuating contact piece 93 moves 94° from the limit switch 94° in FIG. 8 depending on the width of the printed circuit board 130.
When it comes into contact with the 4 units of
Each of the 64 F cylinders 84 (see FIG. 7) is maintained in an operable state.

Next, the printed circuit board 13 runs and the injection device 360
When it comes to the front, air cylinders 841 to 844 are in a state where they can be activated by detection by a detector such as a phototube (not shown).
is operated to spray the molten wax 25 from the four spray devices 36 to 364 onto the printed circuit board 13.

Note that the above injection device 36. ~36. ．． is limit switch 94. ~94. is not turned on, the air cylinder 84 is not maintained in the operating state even if the printed circuit board 13 passes the detector and is detected, so the air cylinder 84 is not operated and the molten wax 25 is not injected.

As explained above, the present invention includes a wax tank body for storing molten wax, a gear H for sending out the smoothed molten wax, and a flow rate of the molten wax sent from this gear pump. In the wax processing section ~1, the wax processing section comprises a control valve for controlling the pressure, and a plurality of injection devices sequentially arranged in a direction perpendicular to the running direction of the printed circuit board.

In order to operate each injection device, a limit switch is provided corresponding to each injection device, and the required limit switch is linked with a holding claw on the printed circuit board that moves according to the width of the board to which molten wax is applied. The molten wax applicator is equipped with a molten wax application control unit that is equipped with an actuating contact that is turned on, and the soldering process is performed by a soldering device. turns on the required number of limit switches, so the same number of injection devices as the limit switches that are turned on can be maintained in a state where molten wax can be automatically sprayed. It has the advantage that wax can be applied and the labor required for these adjustments can be omitted.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an example of a conventional soldering device, Fig. 2 is a partial side sectional view showing how electronic components are mounted on a printed circuit board, and Fig. 3 shows an embodiment of the present invention. Schematic configuration diagram, FIG. 4(a). 4(b) shows the wax processing section in FIG. 3, FIG. 4(a) is a partially cutaway perspective view, and FIG.
), an enlarged perspective view showing the disassembled No. 51 gear pump, and an enlarged side sectional view showing the details of the control valve, and No. 71ii↓ one injection jet. Fig. 8 is a configuration diagram showing the main part of the present invention, ie, the wax application control section (waxing is the processing device σ). In the figure, 3 is the cutting device, and 4 is the finishing device. For soldering, there is a processing device, 8 a cooler, 9 a Franks processor, 10 a preheater, 11 a soldering head, 13 a printed circuit board, 14
is an electronic component, 154 lead wires (or lead terminals),
16 is a through hole 21 is a soldering device, 22A. 2
2Bk1 sending chinin, 23 is processing equipment with wax, 2
4 is the upper wax processing section, 25 is the melted wax, 261 is the wax oval body, 27 is the gear pump, 28 (the motor, 2
9 is a control valve, 30.32 is a passage, 31 is a fill, 33
is a pipe, 34 is a tape heater, 3 5 tic crack heating material 6 is an injection device, 37 is a connection fitting, 38 is a thermostat, 39 is a lid, 40 is a control panel, 41 & machine drive shaft, 4
2 is a driven shaft, 43 is a guide shaft, 44 is a fixture, 45 is an upper case, 46.47 is a spur gear, 4B is a gear case, 49
is a base, 50 is a fixing screw, 51 is a supply hole, 52 is a return hole, 61 is a valve box, 62 is an adjustment valve, 63 is a safety valve, 64.6
5 is a valve seat, 66 is a spring, 67 and 68 are introduction holes, 69 is a discharge hole, 71 is a valve box, 72 is a threaded portion, 73 is an introduction hole, 74
is a valve shaft, 75 is a valve, 76 is a valve seat, 80 is a nozzle, 82 is a spring, 84 is an F cylinder, 85 is a piston, 91 is a holding claw, 92 is a screw rod, 93 is an operating contact piece, 94 is a limit switch 0 Figure 4 (b) Figure 5 Figure 7 Figure 8 Figure 6

Claims (1)

[Claims] A wax pot body for storing molten wax; a gear pump provided in the wax pot body for sending out the molten wax; a control valve for controlling the flow rate and pressure of the molten wax sent from the gear pump; and a printed circuit board. In a wax processing unit equipped with a plurality of injection devices sequentially disposed in a direction perpendicular to the traveling direction, a limit switch provided corresponding to each injection device to operate each injection device, respectively; The waxing device is characterized by comprising an actuating contact piece that moves in accordance with the width of the printed circuit board to which molten wax is applied and that operates in conjunction with a holding claw of the printed circuit board to turn on a desired one of the limit switches. Melted wax application control section.