JP2521556B2 - Optical beam heating machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a light beam heating machine used for resin processing such as soldering and sealing of a resin case in the fields of semiconductors, electronic components, and electronic devices. .

(Prior Art) Conventionally, light from a light-emitting lamp such as a xenon lamp is focused at one point by using an elliptical mirror, and an object to be heated is installed at this focusing point to perform heating processing such as soldering. .

In addition, a light receiving unit of the bundle optical fiber is installed in the light collecting unit, a light collecting lens is provided at an emitting end of the bundle optical fiber, and heat processing is performed at a light collecting point of the light collecting lens to generate light energy in the bundle optical fiber. It was possible to heat at any desired position by guiding the, so that the range of its use was expanded.

FIG. 4 is a principle view of the light beam heating machine, in which 1 is a light emitting lamp, 2 is an elliptic mirror, and 3 is a first focal point of the elliptic mirror, which is substantially aligned with the highest bright spot of the light emitting arc of the light emitting lamp. .
Reference numeral 4 is the second focal point of the elliptical mirror, and the object to be heated is positioned or the light receiving end 6 of the bundle optical fiber 5 is installed as shown in FIG. 4, and the condenser lens 7 is provided at the output end of the bundle optical fiber 5. The object to be heated is placed on the focal point 8 condensed by the condenser lens 7 to perform the heating process.

(Problems to be solved by the invention) The light energy of a conventional light-emitting lamp utilizes what is radiated at the time of arc discharge between a cathode and an anode provided in the light-emitting lamp. -OFF
The arc generation position between the cathode and the anode changes little by little with respect to the electrode, and it is extremely difficult to hold the arc at exactly the same point. Since the point deviates from the first focal point of the mirror, the point at which the energy of the light focused on the second focal point is highest deviates from the second focal point, and the degree of condensing also becomes poor.

In addition, the light energy emitted from the light-emitting lamp
It gradually decreases due to wear of the electrode due to long-term use and fogging of the lamp glass.

Conventionally, the lamp position is manually readjusted by such a change and the input current to the lamp is reset by such a change so that the light energy output is kept constant and concentrated on the second focal portion. I was doing.

In the above-mentioned conventional example, since the readjustment by hand is always required, the heating cannot be automated and unmanned. Therefore, in the present invention, this is automatically adjusted so that the light energy output is always concentrated at the second focal point. It aims to provide a heating source that can be controlled and easily automated and unmanned.

(Means for Solving the Problem) In the present invention, the light receiving portion of a bundle optical fiber formed by springing dozens to hundreds of thin optical fiber strands is installed at the second focal portion of the elliptic mirror, and At least two of the lines are used for optical output detection, and a light receiving element for converting the detected light into an electric signal is provided corresponding to each optical detection fiber, and the difference between the signals is extracted. And a focus position adjusting means for adjusting the relative position of the light emitting lamp and the elliptic mirror in the direction of reducing the difference signal output from the comparison unit.

Further, the light detection fiber is arranged symmetrically with respect to the center of the bundle fiber in the outer peripheral portion at the light receiving end of the bundle optical fiber, and the relative position between the light emitting lamp and the elliptical mirror corresponding to the arrangement position of the light detection fiber. A position adjustment mechanism was provided.

Further, the focus position adjusting means comprises a control unit which receives an output signal from the comparing unit and outputs an output for driving the relative position adjusting mechanism, and the relative position adjusting mechanism, wherein the relative position adjusting mechanism is an elliptic mirror. The position of the light emitting lamp was fixed relative to the light receiving part of the bundle optical fiber, and the position of the light emitting lamp was moved relative to the elliptical mirror.

In addition, two optical fibers for photodetection are provided on the outer circumference facing each other with the center of the bundled optical fiber in between,
The light from each of the two photo-detecting fibers constituting each pair is arranged as a pair and is arranged as a pair of the other two at a position orthogonal to the photo-detecting fiber thus arranged. Light is received by the light receiving elements of, and the output between each pair of light receiving elements is input to the comparison section, and the two difference outputs of the comparison section are input to the two control sections that are part of the focus position adjusting means.
The two outputs of the control unit drive respective orthogonal relative position adjustments corresponding to the arrangement of the pair of photodetection fibers.

Further, the light from at least one light detecting fiber is received by the light receiving element, and the electric output signal of the light receiving element is set from the outside directly or indirectly through the amplifier and / or the function generator. A reference comparison unit that outputs a difference signal in comparison with a reference signal is provided, and the output of this reference comparison unit is input to the optical output automatic correction unit, and the optical output automatic correction unit emits light according to the signal from the reference comparison unit. The current supplied to the lamp is increased / decreased, thereby increasing / decreasing the light radiant energy of the light emitting lamp and holding it at a constant value corresponding to the reference signal.

(Operation) By adopting the means described in the previous section in order to solve the problem, even if the position of the cathode and the anode in the light emitting lamp and the lamp is unchanged with respect to the elliptical mirror, the arc generation site with respect to both the positive and negative electrodes is A slight change causes a shift in the emission site of the light radiation energy from the first focal point portion of the elliptic mirror, which causes the focal point to be slightly displaced from the second focal point of the elliptic mirror. When this shift occurs, the light incident on the two or more photodetection fibers becomes unequal, and the light incident on each light receiving element also changes accordingly, resulting in a difference between the output signals of the two or more light receiving elements. . This difference is taken out as a difference signal by the comparison unit, and the difference signal is input to the focus position adjusting means to move the position of the light emitting lamp in the direction in which this difference signal becomes smaller, so that the bundle optical fiber light receiving end face due to the deviation of the arc generation position. It is possible to automatically correct the deviation between the center and the light collection center.

Further, two pairs of photodetection fibers in the X-axis direction with respect to the center of the light receiving end surface of the bundle optical fiber are provided on the outer peripheral portion of the bundle optical fiber, and the other two pairs of photodetection fibers are arranged in the X direction. Since it is provided in the Y-axis direction orthogonal to the axis in the same manner as a pair in the X-axis direction, and the relative position adjusting mechanism is provided in each of the X- and Y-axis directions, the arc generation position in the light emitting lamp is displaced. Can be completely corrected in any direction.

With such a correction, the amount of light incident on at least two, preferably four, photodetection fibers becomes almost equal, and the amount of light incident on the photodetection fiber is equal to that of any one bundle optical fiber. The value has a substantially constant relationship with the amount of light incident on the whole.

Even if the input current value to the amplifier is kept constant, the light-emitting lamp has a reduced light emission output due to various causes such as fogging of the glass bulb due to long-term use. Even if such a decrease in optical output occurs, the light incident on at least one photodetection fiber and emitted is received by the photodetector, and the output signal of the photodetector is compared directly or indirectly with the reference signal. However, since the light output correction means operates so as to make them substantially coincident with each other and the input current to the light emitting lamp is adjusted,
The amount of light incident on the entire bundle optical fiber can be maintained at a constant value.

(Embodiment) FIG. 1 is a schematic view of a bundle optical fiber light receiving end surface of a light receiving end of a bundle optical fiber of a light beam heater according to the present invention as seen from a light irradiation side. A bundle optical fiber light receiving end face composed of the optical fiber strands 10, 11a and 11b are a pair of optical detection fibers provided in the outer peripheral portion in the X-axis direction, and 12a and 12b are outer peripheral portions in the Y-axis direction. It is a pair of optical detection fibers provided. The fiber strand 10 and the detection fiber may have the same thickness or different diameters, but from the viewpoint of industrial production, the same diameter is easier to manufacture.

FIG. 2 is a structural structural diagram of the present invention, in which 1 is a light emitting lamp, 2 is an elliptic mirror, 3 is a first focal point of the elliptic mirror 2, 4 is a second focal point, and the light receiving end 6 of the bundle optical fiber 5 is shown. Is provided. Reference numeral 13 denotes a fixed plate of the elliptic mirror 2, which is fixedly assembled and coupled to the light receiving end support 14 of the bundle optical fiber 5. Reference numeral 15 is a lamp support of the light-emitting lamp 1, 16 is a relative position adjusting mechanism in the X-axis direction, 17 is a relative position adjusting mechanism in the Y-axis direction, and each of the X-axis direction and the Y-axis direction is a bundle optical fiber. Is provided in a direction coinciding with the X-axis and the Y-axis provided in the above, and each has a slide guide mechanism and a drive motor / drive mechanism. Reference numeral 18 denotes a position adjusting mechanism support, which is fixedly attached to the elliptic mirror fixing plate 13 and holds the Y-axis direction relative position adjusting mechanism 17. The lamp support 15 is attached to the movable portion of the X-axis direction relative position adjusting mechanism, the fixed portion of the relative position adjusting mechanism 16 is supported by the movable portion of the relative position adjusting mechanism 17, and the fixed portion of the relative position adjusting mechanism 17 is supported. Each is attached to body 18.

The conductors 19 and 20 for supplying an electric current are connected to the lamp 1, and the other ends of the conductors 19 and 20 are connected to a lamp power source (not shown).

The light detecting fibers 11a, 11b, 12a, 12b arranged on the light receiving end face 6'as shown in FIG. 1 are branched by a branching portion 21 provided between the light receiving end and the emitting end of the bundle optical fiber, and It has emitting ends 11a ', 11b', 12a ', 12b'.

FIG. 3 is a block diagram showing the signal flow of the present invention, and 22a, 22b, 23a and 23b are optical detection fibers 11 respectively.
The light is emitted from a, 11b, 12a, 12b, and is applied to the corresponding light receiving elements 24a, 24b, 25a, 25b. Light receiving element 2
4a, 24b, 25a, 25b may be any one capable of converting a light input into an electric output such as a photodiode, a phototransistor, a photoconductive cell. Especially since this machine is used as a heating machine,
The one that outputs an electrical signal according to the optical input in the wavelength range of 600 nm to 2500 nm is adopted. Reference numeral 26 is an X-axis comparison unit, 27 is a Y-axis comparison unit, and the comparison unit 26 is a light receiving element 24.
Compare the output signals from a and 24b, when the output signal from the light receiving element 24a is larger than the output signal from the light receiving element 24b,
Set the drive motor Mx28 in the X-axis direction relative position adjustment mechanism 16 to the third position.
A signal is sent to the control unit 30 in order to drive the focus 4 of FIG. 2 so as to move in the (+) direction of the arrow A in the figure, and the control unit 30 keeps the signal from the comparison unit 26 below a certain fixed value. Drive motor
Drive the Mx28. The signal from the light receiving element 24b is the light receiving element 24a.
Is larger than the signal from (the amount of received light of 11b 'is large in relation to the amount of received light), the drive motor Mx28 indicates the arrow (-) of arrow A.
X-axis relative position adjustment mechanism 16 so that the focus moves in the direction
To correct the light emitting lamp position. The Y-axis direction is controlled similarly to the X-axis direction according to the signals from the light receiving elements 25a and 25b.

Reference numeral 32 is one of the light receiving elements, for example, an amplifier connected to 25b or an amplifier including an amplifier and a function generating device, 33 is a reference signal holding unit input from an external terminal 34, and 35 is an output of the amplifier 32. The signal is compared with the reference signal held by the reference signal holding unit 33, and is a reference comparing unit that outputs a difference signal corresponding to the difference, and the output difference signal is input to the optical output automatic correction means 36, The optical output automatic correction means 36,
When the output signal of the amplifier 32 is smaller than the signal from the reference signal holding section 33 by a certain difference or more (when the emitted light from the light emitting lamp 1 is smaller than the set value), the current supplied to the light emitting lamp 1 is changed. When the output signal of the amplifier 32 is increased, the supply current to the light emitting lamp 1 is decreased.

(Effects of the Invention) According to the present invention, it is no longer necessary to manually perform focusing by trial and error as to the defocus at the heating point due to the deviation of the light emitting point in a light emitting lamp such as a xenon lamp. , The light beam heater can now be used stably as a means for automatic soldering by incorporating it into an automated line.

In addition, the life of the light emitting lamp is about 800 hours in the past,
After this, the light emitting points were frequently displaced, the total amount of light emission was decreased, and the heating capacity was decreased. According to the present invention, it is possible to automatically correct the deviation of the light emitting point of the light emitting lamp and also to correct the decrease of the light amount, so that the life of the light emitting lamp can be significantly increased.

As described above, the contribution and effect of providing a stable non-contact heating source to the industrial world at low running cost (low lamp replacement cost) has become extremely large.

[Brief description of drawings]

FIG. 1 is a main part view of a light receiving end surface of a bundle optical fiber of a light beam heater according to the present invention, FIG. 2 is a mechanical structural configuration diagram of an embodiment of the present invention, FIG. 3 is an electric block diagram thereof, and FIG. It is a principle view of a light beam heating machine. 1 ... Light emitting lamp, 2 ... Elliptical mirror, 3 ... First of elliptical mirror
Focus, 4 ... Second focus of elliptical mirror, 5 ... Bundled optical fiber, 6 ... Light receiving end, 7 ... Condensing lens, 8 ... Focus, 10 ... Optical fiber wire, 11a, 11b ... X axis Directional light detection fiber, 12a, 12b ... Y-axis direction light detection fiber.

Claims (6)

(57) [Claims] 1. A light-emitting point of a light-emitting lamp such as a xenon lamp is located at a first focal point of an elliptical mirror, light is condensed at a second focal point of the elliptic mirror, and a plurality of optical fiber strands are arranged at the condensing portion. In a light beam heating machine with a fiber, which is provided with a light receiving part of an optical fiber and a heating target is installed at the emitting part of the optical fiber, and at least two or more optical fiber strands are used for optical output detection. A light beam heating machine characterized by being used as. 2. An electric resistance, voltage, current, etc. of detected light from at least two or more optical output detecting optical fiber wires depending on the amount of light received by a phototransistor, a photodiode, a photoelectric cell, or the like. In order to reduce the error signal, there is provided a comparison unit that receives light individually by the light receiving elements of varying amounts, compares the electrical outputs of two or more light receiving elements, and outputs a difference signal according to the difference. The light beam heating machine according to claim 1, further comprising a focus position adjusting unit that adjusts a relative position between the light emitting lamp and the elliptical mirror. 3. A light receiving end of a bundle optical fiber,
Detecting optical fiber on the outer circumference of the bundle fiber,
The light according to claim (1) or (2), wherein the bundle fibers are arranged symmetrically with respect to the center, and a relative position adjusting mechanism for the light emitting lamp and the elliptic mirror corresponding to this arrangement position is provided. Beam heating machine. 4. The focal position adjusting means adjusts the relative position of the light emitting lamp and the elliptic mirror by fixing the positional relationship between the elliptical mirror and the bundle optical fiber light receiving unit and moving the position of the light emitting lamp. The light beam heater according to claim (2). 5. A light receiving end of a bundle optical fiber,
Four fiber strands for optical output detection are provided on the outer peripheral portion of the bundle optical fiber at positions that divide the outer periphery into four equal parts, and two pairs facing each other with the center of the bundle optical fiber as one pair are formed. 3. The light beam heating machine according to claim 1, wherein the light beam heating apparatus is arranged so as to be orthogonal to the other pair, and compares the detected light amount between each pair of the optical output detecting fiber wires. . 6. The detection light from at least two or more optical output detecting fiber wires is received by a light receiving element for converting the light quantity into an electric quantity, and the electric output of one of the light receiving elements is directly output. In addition, or indirectly via an amplifier and / or a function generator, it has a reference comparison unit that outputs a difference signal by comparing with a reference signal set from the outside, and directly or indirectly from the reference signal and the light receiving element. The optical output automatic correction means for adjusting the current value supplied to the light emitting lamp so that the difference between the signals is reduced, (1),
The light beam heater according to (2), (3), (4) or (5).