JPH05245626A - Device for measuring height of jet stream wave in molten metal - Google Patents

Abstract

PURPOSE:To accurately measure a wave height by positioning a probe within the amplitude of the wave height of the jet stream of a molten metal and measuring the height from the number of times for energizing the probe within a prescribed time. CONSTITUTION:Molten solder C is jetted out of a solder injecting tube 5. If the solder wave height is low, molten solder C is not brought into contact with the probe 28, therefore, the molten solder C and the probe 28 are not energized. If the solder wave height is too high, the probe 28 is completely immersed in the molten solder C, and the molten solder C and the probe 28 are kept energized. When the solder wave height is at the normal value, the molten solder C and the probe 28 are repeatedly in contact and noncontact due to the wave front formed on the solder surface, and the two are repeatedly in a conductive and nonconductive state. The number of times of the conductivity and nonconductivity generated within a fixed time are counted; and when the output of a pump is adjusted so that the number of the count is turned to a prescribed value, the jet stream height of the molten solder C is adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jet wave height measuring device for molten metal, which is set in a jet type automatic soldering device for soldering a printed board and measures the wave height of the jetted molten solder. ..

[0002]

2. Description of the Related Art One of soldering devices for soldering various electronic parts to a printed circuit board is a jet type automatic soldering device.

FIG. 3 shows an example of the jet type automatic soldering device (A).

In the figure, (B) is a printed board on which soldering is performed, and (1) is a conveyor for conveying the printed board (B), which is composed of a pair of cords (1a) (1a). , A pair of cords (1a) (1) of this conveyor (1)
The print board (B) is sandwiched between a) and the conveyor (1) is driven in this state to convey the print board (B).

(2) is a solder bath containing the molten solder (C), (3) is a chamber contained in the solder bath (2),
(4) is a jet hole provided in the upper part of the chamber (3),
(5a) is a solder ejection pipe arranged in the opening of the ejection hole (4) so as to be slidable in the horizontal direction, (5a)
Is a nozzle hole formed at equal intervals in the longitudinal direction of the solder jet pipe (5), and (6) is a pump arranged in the chamber (3).

The solder jet pipe (5) is connected to the cam (8) connected to the motor (7) via the hinge (9), the connecting fitting (10) and the rod (11).
When the motor (7) is driven, the solder jetting pipe (5) makes a linear reciprocating motion in a direction orthogonal to the conveying direction of the print substrate (B) by the conveyor (1).

During the soldering work by the jet type automatic soldering apparatus (A) having the above structure, first, the motor (7)
Is driven to linearly reciprocate the solder ejection pipe (5), and at the same time, the pump (6) is driven so that the molten solder (C) in the solder bath (2) is ejected from the ejection hole (4) of the chamber (3). The molten solder (B) is pressure-fed toward the solder ejection pipe (5) and ejected from the nozzle hole (5a) of the reciprocating solder ejection pipe (5).

When the conveyor (1) is driven in this state, the printed board (B) passes over the solder ejection pipe (5), and at this time, from the nozzle hole (5a) of the solder ejection pipe (5). The molten solder (C) ejected adheres to the lands formed on the printed board (B) and the electrodes of the chip component, and soldering is performed.

[0009]

When soldering an electronic component mounted on a printed board (B) using the above-mentioned jet type automatic soldering device (A), the wave height of the molten solder (C) jetted If it is too high, the upper surface of the printed board (B) is covered with the molten solder (C), and the solder adheres to unnecessary portions, causing various troubles.

On the contrary, if the wave height of the jetted molten solder (C) is too low, the solder does not adhere to the soldering portion, resulting in defective soldering.

In particular, with the recent miniaturization of electronic components, the printed circuit board (B) itself tends to be smaller and thinner, so that the soldering work of electronic components mounted on this type of printed circuit board (B) is required. At times, more rigorous adjustment of the wave height of the molten solder (C) jetted is required.

By the way, in the conventional method of adjusting the wave height of the jet solder, as shown by the chain double-dashed line in FIG.
A steel scale (15) is applied to the surface of the, and the operator visually confirms the steel scale (15), and the wave front of the molten solder (C) is located at a predetermined position on the scale marked on the steel scale (15). As described above, the output of the pump (6) is adjusted.

However, as described above, when the operator adjusts the wave height of the molten solder (C) which is jetted visually by using the steel scale (15), there is a variation in the adjustment by the operator and at the same time. There was a problem that the adjustment work became very complicated.

Further, since the molten solder (C) is naturally high in temperature, an operator manually operates the molten solder (C) on the steel scale (1).
There is a problem that the work of inserting 5) and visually confirming the wave height of the molten solder (C) from this scale is very dangerous.

[0015]

[Means for Solving the Problems] A probe that is energized when it comes into contact with a molten metal having conductivity is positioned between the amplitudes of the jet wave height of the molten metal, and melting is performed based on the number of times the probe is energized within a predetermined time. A measuring device that measures the height of the jet wave of metal,

It comprises a first slider which is slidable in the horizontal direction and an apparatus main body which is slidably supported in the horizontal direction by the first slider.

A second slider, which supports the main body of the apparatus above and below the first slider so as to be movable up and down, by a drive unit fixed below the first slider.

A reference pin for zero point correction of the second slider, which is fixed to the lower end of the second slider, and the above-mentioned probe that is fixed to the lower end of the second slider in an electrically insulated state from the second slider. In order to prevent the molten metal from adhering to the measuring element, it is constituted by a nozzle for blowing hot air on the side of the measuring element.

[0019]

The probe for measuring the height of the jet wave of the molten metal is slidably supported in the horizontal and vertical directions by the first slider and the second slider, and the second slider is provided with a reference pin for zero point correction. By disposing a nozzle for blowing hot air on the side of the measuring element, the height of the jet wave of the molten metal by the measuring element can be measured accurately and reliably.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a jet wave height measuring device (D) for molten metal according to the present invention, and FIG. 2 is a principle diagram for explaining the measuring principle of the present invention. First, the measurement principle will be described.

In FIG. 2, (5) is a solder jet pipe arranged in the solder layer (2) of the jet type automatic soldering device (A), and (C) is a nozzle of the solder jet pipe (5). Hole (5a)
It is molten solder that is ejected from.

Reference numeral (28) is a measuring element arranged at a predetermined position above the solder ejection pipe (5) for ejecting the molten solder (C). The measuring element (28) is connected to the positive electrode and the solder bath ( The molten solder (C) in 2) is connected to the negative electrode, respectively.

In the figure, (22) is an apparatus main body for supporting the tracing stylus (28), and (32) is a control panel for detecting the energization state of the tracing stylus (28) and the molten solder (C). , (3
Reference numeral 1) is an insulator for insulating the probe (28) and the apparatus body (22).

In the above structure, when the molten solder (C) is jetted from the solder jet pipe (5) and the solder wave height is low,
Since the molten solder (C) does not come into contact with the tracing stylus (28) at all, the molten solder (C) and the tracing stylus (28) do not conduct, and if the solder wave height is too high, the tracing stylus (28) It is completely immersed in the molten solder (C), and the molten solder (C) and the measuring element (28) are in complete conduction.

When the solder wave height is a specified value, the wave front formed on the solder surface causes the molten solder (C) and the stylus (28) to repeatedly come into contact with and out of contact with each other, so that they are electrically connected and electrically disconnected. Repeat.

Therefore, the number of conductions and non-conductions occurring within a certain period of time is counted with the probe (28) positioned at a position spaced from the upper surface of the solder ejection pipe (5) by a predetermined distance. If the solder wave height is adjusted so that the number becomes a preset predetermined value, the solder wave height can be set to a desired height.

That is, when the tracing stylus (28) is positioned between the amplitudes of the jet wave heights of the molten solder (C) in the ideal state, the number of energizations that occur within the predetermined time of the tracing stylus (28) is experimentally conducted in advance. If the probe (28) is positioned in advance in the ideal position and the output of the pump (6) is adjusted so that the number of energizations at this time becomes a predetermined value, the molten solder (C ) The jet wave height can be adjusted to the ideal state.

Regarding the above measurement principle, Japanese Patent Application No. 2-
The applicant has already filed an application in Japanese Patent No. 3329913.

FIG. 1 shows a jet wave height measuring device (D) of molten metal for measuring the wave height of the molten solder (C) based on the above principle.

In the figure, (5) is the solder jet tube of the above-mentioned jet type automatic soldering device (A), and (D) is arranged above the jet type automatic soldering device (A). It is a jet wave height measuring device of the molten metal concerning the present invention.

This measuring device (D) comprises a guide rail (20) arranged horizontally above the jet type automatic soldering device (A), and a first slider which slides horizontally on the guide rail (20). (21) and the first slider (2
1) and a device main body (22) which is suspended and supported below.

The apparatus main body (22) is fixed to a first bracket (23) extending below the first slider (21) and serves as a drive unit for driving a second slider (26) which will be described later. 24) and the first bracket (2
3) A second slider (26) slidably supported in the vertical direction by a guide rail (25) arranged below the slider, and vertically moved by a pulse motor (24);
A reference pin (2) fixed to the lower end of the second slider (26)
7) and the tracing stylus (28), and a nozzle (30) for blowing hot air, which is arranged laterally of the tracing stylus (28) via a bracket (29) extending from the second slider (26). As an element.

The tracing stylus (28) has a second slider (2
6) is electrically insulated by an insulator (31) and, as described above, this probe (28)
Is the positive electrode of the control panel (32), and the solder bath (2)
The molten solder (C) therein is connected to the negative electrode.

In the figure, (33) is a pulse motor (2
The feed screw (34) directly connected to 4) is the feed screw (3
3) A feed nut screwed with this feed nut (3
4) is fixed to the second slider (26).

Then, by rotating the feed screw (33) forward or reverse by the pulse motor (24),
Move the slider (26) up and down to move the second slider (26).
The reference pin (27) and the stylus (28) fixed to the above are moved up and down.

Further, the nozzle (30) is connected to a hot air supply device (not shown), and its blowout hole has a measuring element (2).
The hot air which is directed toward the 8) side and is jetted from the nozzle (30) is blown toward the tip of the probe (28).

In the above structure, in order to measure the wave height of the molten solder (C) by the measuring device (D) according to the present invention, first, the second slider (26) is positioned at the rising end. Then, by sliding the first slider (21), the apparatus body (22) is moved from the retracted position (side of the solder bath (2)) to the measurement position (position of FIG. 1).

Next, by driving the pulse motor (24), the tip of the reference pin (27) fixedly mounted on the second slider (26) is abutted at a predetermined position of the solder ejection pipe (5). When the second slider (26) is lowered and the reference pin (27) is placed at a predetermined position of the solder ejection pipe (5),
The lowering of the second slider (26) is stopped, and this position is set as the origin when the second slider (26) moves up and down.

That is, by the above work, the second slider (2
6) Simultaneous vertical correction of the zero point.

When the zero point correction is completed as described above, the pulse motor (24) is then driven so that the tip of the probe (28) is located above the upper surface of the solder ejection pipe (5) by a predetermined amount. , Raise the second slider (26) by a predetermined amount.

Thereafter, in this state, the molten solder (C) is ejected from the solder ejection pipe (5), and based on the above-mentioned principle, the jet type automatic operation is performed so that the wave height of the molten solder (C) becomes a desired height. Adjust the output of the pump (6) of the soldering device (A).

When measuring the solder wave height, the nozzle (3
From 0), hot air is blown toward the tip of the tracing stylus (28) to prevent solder from adhering to the surface of the tracing stylus (28) and deteriorating the measurement accuracy.

When the measurement and adjustment of the wave height of the molten solder (C) are completed in this way, the second slider (26) is raised to the rising end, and then the first slider (21) is slid horizontally. Then, the device body (22) is retracted from the measurement position to the retracted position.

After that, in this state, if the print board (B) is supplied onto the solder jetting pipe (5) and the print board (B) is soldered, the solder wave height is accurately set. Soldering to the printed board (B) can be performed accurately and reliably.

[0045]

As described above, according to the present invention, the measuring element for measuring the jet wave height of the molten solder is movably supported in the horizontal direction and the vertical direction, and in the vicinity of the measuring element.
Since a reference pin is provided for zero point correction when the probe moves up and down,
The measuring element can be accurately positioned at a predetermined distance from the upper surface of the solder ejection pipe, and the wave height of the jet solder can be accurately measured.

Further, hot air is blown to the side of the tracing stylus, and a nozzle for blowing hot air for heating the tracing stylus is arranged. Therefore, molten solder adheres to the tracing stylus and the measurement accuracy is lowered. It can be surely prevented.

[Brief description of drawings]

FIG. 1 is a side view showing a molten metal jet wave height measuring device according to the present invention.

FIG. 2 is a principle diagram for explaining the measurement principle of the present invention.

FIG. 3 is a side view showing a jet type automatic soldering device.

[Explanation of symbols]

 C Molten Solder D Molten Metal Jet Wave Height Measuring Device 21 First Slider 22 Device Main Body 24 Pulse Motor 26 Second Slider 27 Reference Pin 28 Measuring Element 30 Nozzle

Claims (1)

[Claims] 1. A probe head which is energized when it comes into contact with a conductive molten metal is positioned between amplitudes of the jet wave height of the molten metal, and the jet wave height of the molten metal is determined from the number of times the probe is energized within a predetermined time at this time. A measuring device for measuring height is configured by a first slider that is slidable in a horizontal direction and a device body supported by the first slider so as to be slidable in the horizontal direction, and the device body is fixed below the first slider. Second slider supported vertically below the first slider by the driven device, a reference pin fixed to the lower end of the second slider for zero point correction of the second slider, and a lower end of the second slider. In addition, the measuring element fixed in a state of being electrically insulated from the second slider and the nozzle for blowing hot air on the side of the measuring element in order to prevent molten metal from adhering to the measuring element. Jet flow height measuring apparatus for molten metal, characterized by being configured I.