JP2935344B2 - Equipment for testing temperature characteristics of optical semiconductor elements - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for testing the temperature characteristics of an optical semiconductor, and more particularly to an apparatus for testing the temperature characteristics of an optical semiconductor element capable of performing precise temperature control over a wide temperature range.

[0002]

2. Description of the Related Art Conventionally, an optical semiconductor temperature characteristic test apparatus of this type performs a temperature characteristic test of an optical semiconductor element such as a laser diode as disclosed in Japanese Patent Application Laid-Open No. 63-247676. The purpose is to sort out good and bad.

FIGS. 6 and 7 are diagrams for explaining an example of a conventional optical semiconductor temperature characteristic testing apparatus.

A flat heat equalizing block 101 is provided with refrigerant passing means 102 penetrated in the upper and lower parts in a horizontal direction, and the refrigerant passing means 102 is connected by a connecting pipe 102a.
A heater 103 is provided on the back surface of the heat equalizing block 101, and a plurality of insertion holes 104 are provided through the heat equalizing block 101, and a printed board 106 having a light receiving element 105 provided in the insertion hole 104 is provided. It is provided on the back side of the heater 103 side. In addition, the heat equalizing block 101
An auxiliary heat equalizing block 108 having various insertion holes 107 having different inner diameters is attached to the surface of the optical semiconductor device such as a laser diode provided on a printed circuit board 109 in the insertion hole 107 of the auxiliary heat equalization block 108. 110 is inserted.

[0005] Heat equalizing block 101, auxiliary heat equalizing block 1
08, the light receiving element 105 and the optical semiconductor element 110 are positioned in the insertion holes 104 and 107, the refrigerant is passed through the refrigerant passing means 102, and the heater 103 is heated by the control means (not shown). Is a predetermined temperature. Then, the optical semiconductor element 101 emits light, and the light receiving element 105
Is measured, and the temperature characteristic of the optical semiconductor element 101 is measured. Since the size of the refrigerator for supplying the refrigerant becomes large, it takes time to change the temperature of the refrigerant. Therefore, in this test apparatus, the temperature of the refrigerant is kept constant regardless of the test temperature, and the temperature control is performed by the heater 103.

[0006]

The first problem is that the temperature accuracy when the temperature is changed from room temperature is poor. In addition, it is conceivable to improve the temperature accuracy by further adding a temperature control using a Peltier element to the above-described conventional example, but in that case, since the life of the Peltier element is short, it is necessary to frequently maintain the apparatus. And running costs increase.

[0007] The reason is that the temperature control is performed by installing the soaking block in a normal temperature atmosphere. When the test temperature is high or low, the temperature inside the heat equalizing block becomes non-uniform due to the heat transfer between the heat equalizing block and the atmosphere and the thermal resistance inside the heat equalizing block. Have difficulty. When a Peltier element is used, there is a possibility that the Peltier element may be deteriorated or damaged due to thermal distortion due to non-uniform temperature in the heat equalizing block. In order to prevent heat radiation from the soaking block, it is necessary to strictly insulate the soaking block from the atmosphere, but this increases the manufacturing cost of the soaking block.

The second problem is that since the light receiving element for measurement is also heated and cooled to the test temperature, it must be corrected in consideration of the temperature characteristics of the light receiving element during measurement. Such corrections not only complicate the equipment, but also
This may cause a decrease in measurement accuracy.

The reason is that the light receiving element is exposed to the test temperature similarly to the optical semiconductor element because the light receiving element is in the insertion hole of the heat equalizing block.

A third problem is that when the optical semiconductor device to be tested is a laser diode, the far field pattern (FFP) of the laser diode cannot be measured. Further, when the optical semiconductor element to be tested is a light receiving element, it can be realized by placing a light emitting element such as a laser diode instead of the light receiving element of the above-described conventional example, but in this case, the sensitivity distribution of the light receiving surface cannot be measured. .

The reason is that the light emitting element and the light receiving element are fixed to the heat equalizing block or the auxiliary heat equalizing block. In order to measure the FFP of a laser diode or to measure the light receiving surface sensitivity distribution of a light receiving element, it is necessary to change the relative position of the light emitting element and the light receiving element and measure the two-dimensional distribution of laser intensity or light receiving sensitivity.

A fourth problem is that when the test temperature is low,
Dew in the insertion hole causes frost to adhere to the windows of the optical semiconductor element and the light receiving element, preventing accurate measurement.

The reason is that, since the optical semiconductor element is inserted in a normal temperature atmosphere, the dew point of air in the insertion hole is higher than the low-temperature test temperature. This is because the water vapor contained in the air becomes frost.

[0014]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a temperature characteristic test apparatus having a high set temperature accuracy and a high measurement accuracy for various characteristics of an optical semiconductor device.

It is another object of the present invention to provide a temperature characteristic test apparatus which realizes various measurements such as FFP measurement and light-receiving sensitivity distribution even in high-temperature and low-temperature environments.

[0016] Therefore, (1) Temperature characteristic test apparatus for an optical semiconductor device of the present invention, the
Temperature adjustment means to keep the optical semiconductor device to be inspected at the test temperature
And a step for measuring opto-electrical characteristics of the optical semiconductor device.
A temperature characteristic testing apparatus having
The conductor element is a light emitting element, and the temperature adjusting means is
And soaking jig for mounting the light emitting element, it can be stored a Peltier element for controlling the temperature of the soaking jig and the light-emitting element in contact with the soaking jig, the soaking jig and the Peltier element temperature tea <br/> down bar having a transmission window on the optical axis of the light emitting element, wherein and a air conditioner for supplying temperature controlled air to the temperature inside the chamber, wherein the measuring means, the temperature chamber An external Fourier transform lens and the Fourier
The light emission distance of the light emitting element formed by the conversion lens
An imaging device for imaging a field pattern, and adjusting the position of the Fourier transform lens to form the far field pattern
And a optical axis alignment Organization for adjusting the position, configured to include a closing mechanism that opens and closes the temperature chamber. (2) Temperature characteristic test apparatus for an optical semiconductor device of the present invention, the
Temperature adjustment means to keep the optical semiconductor device to be inspected at the test temperature
And a step for measuring opto-electrical characteristics of the optical semiconductor device.
A temperature characteristic testing apparatus having
The conductor element is a light receiving element, and the temperature adjusting means is the light receiving element.
A heat equalizing jig for mounting an optical element, and
Peltier for controlling the temperature of the soaking jig and the light receiving element
The element, the heat equalizing jig and the Peltier element can be stored.
A temperature chip having a transmission window on the optical axis of the optical semiconductor element.
Chamber and temperature-controlled air in the temperature chamber.
A supply air conditioner, and the measuring means
Illuminates the light receiving surface of the light receiving element placed outside the chamber
A reference light source that emits light and light that guides light emitted by the reference light source
Fiber, the light receiving element
A lens for forming a condensed spot on a light receiving surface, and the lens
And adjust the position of
Optical axis alignment mechanism for scanning two-dimensionally on the surface
An opening and closing mechanism for opening and closing the temperature chamber.
You. (3) Temperature characteristic test apparatus for an optical semiconductor device of the present invention, the upper
Test near the transmission window of the temperature chamber described in (1) or (2).
Dry air supply apparatus for supplying a gas of lower test temperature dew point
It is characterized by having . (4) Temperature characteristic test apparatus for an optical semiconductor device of the present invention, the upper
The temperature chamber of (1) or (2) and the Fourier transformation
Care about the interchangeable lens or the lens forming the focused spot.
Place in a closed room, and place a gas with a dew point lower than the test temperature in the closed room.
It is characterized by being filled with the body .

The vicinity of the optical semiconductor element is surrounded by a temperature chamber, and in addition to controlling the atmosphere in the temperature chamber to the test temperature, a heat equalizing jig on which the optical semiconductor element is mounted is precisely controlled by a Peltier element. Therefore, highly accurate temperature control can be realized without imposing a load on the Peltier element.

All of the components other than the optical semiconductor device to be subjected to the temperature characteristic test are placed in a normal temperature atmosphere outside the temperature chamber, so that highly accurate measurement can be performed regardless of the temperature characteristics of measuring instruments. In addition, since a mechanism for aligning the optical axis of the optical semiconductor element with the optical fiber connected to the optical power meter or the reference light source is also placed in a room temperature atmosphere, a precise optical axis alignment mechanism can be easily realized.

[0019]

Next, a first embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram for explaining a first embodiment of the present invention.

The apparatus for testing temperature characteristics of an optical semiconductor device according to the first embodiment is a soaking jig made of a material having good thermal conductivity for mounting an optical semiconductor device 1 which is a light emitting device such as a laser diode. 2, a Peltier element 3 installed in contact with the heat equalizing jig 2 and controlling the temperature of the heat equalizing jig 2, and a Peltier element 3
, A temperature chamber 5 accommodating the heat equalizing jig 2 and the Peltier element 3, and an air conditioner 6 for supplying air controlled at a test temperature to the temperature chamber 5. . A temperature sensor (not shown) is installed in the soaking jig 2, and the temperature control device 4 and the air conditioner 6 feed back the temperature measured by the temperature sensor 7 to control the temperature of the soaking jig 2. Do.

The temperature chamber 5 has a minimum volume capable of accommodating the heat equalizing jig 2 on which the optical semiconductor element 1 is mounted and the Peltier element 3, and the amount of air to be controlled by the air conditioner 6 is minimized. deep. Further, on the wall of the temperature chamber 5 in the optical axis direction of the optical semiconductor element 1, a transmission window 7 for transmitting the wavelength of the light of the optical semiconductor element 1 is provided. Take out outside. Light taken out of the temperature chamber 5 is condensed by a lens 8 and introduced into an optical fiber 9. At this time, in order to efficiently introduce the light output from the optical semiconductor element 1 into the optical fiber 9, the lens 8 and the optical fiber 9 are mounted on an optical axis alignment mechanism 10 composed of XYZ axes. Optical axis alignment is performed so that the intensity of the introduced light is maximized. The output end of the optical fiber 9 is connected to an optical measuring device 11 such as an optical power meter or an optical spectrum analyzer, and measures the power, wavelength, and the like of light transmitted through the optical fiber.

Transmission window 7 provided in temperature chamber 5
Is made of a glass material such as quartz excellent in light transmittance of the optical semiconductor element 1, and is optically polished so that both surfaces are precisely parallel planes in order to narrow out the emitted light to minute spots.

In order to prevent attenuation due to reflection on the front and back surfaces, an anti-reflection coating suitable for the wavelength of light of the optical semiconductor device 1 is applied. Also, the optical semiconductor device 1
It is necessary to condense the light emitted from through the transmission window 7 with the lens 8, so that the lens 8 must have the transmission window 7 whose glass thickness has been corrected. Specifically, the front lens 8a that converts the spread light emitted from the optical semiconductor element 1 into parallel light is provided on the glass thickness correction objective lens GP.
A lens such as lan Apo20 × (manufactured by Mitutoyo Corporation) or the like can be used, and a normal bright-field objective lens or LD is provided on the rear lens 8b for condensing the light collimated by the front lens 8a into a minute spot. Aspherical molded glass lens (manufactured by HOYA CORPORATION) can be used.
When selecting a lens, it is preferable to select a lens having a divergence angle of the optical semiconductor element 1 and an NA equal to the numerical aperture (NA) of the optical fiber 9.

The temperature chamber 5 can be moved up and down by an opening / closing mechanism 12 driven by a cylinder or the like, and exchange and maintenance of the optical semiconductor element 1 to be tested are performed. Therefore, air whose temperature is controlled is sent from the air conditioner 6 to the temperature chamber 5 through the flexible duct 13.

Since the temperature inside the temperature chamber 5 becomes low, the transmission window 7 is prevented from deteriorating in transmittance due to dew condensation on the transmission window 7.
Is provided in the vicinity of the nozzle 14 for supplying dry air having a dew point equal to or lower than the test temperature.

Next, the operation of the temperature characteristic test apparatus of FIG. 1 will be described with reference to the drawings.

The optical semiconductor device 1 to be tested is previously mounted on the heat equalizing jig 2. The temperature chamber 5 is opened by the opening / closing mechanism 12, and the heat equalizing jig 2 is set on the Peltier element 3. At this time, the temperature control device 4 and the air conditioner 6 are both stopped, and the temperature chamber 5 is at room temperature. After setting the soaking jig 2, the temperature chamber 5 is closed, and the temperature chamber 5 is
The temperature controlled device 4 drives the Peltier element 3 to control the temperature of the heat equalizing jig 2 to the test temperature. When the test temperature is lower than the normal temperature, dry air is flowed from the nozzle 14 so that the transmission window 7 of the temperature chamber 5 does not dew. For example, when the test temperature is −40 ° C., the dew point of the dry air supplied to the transmission window 7 should be −50 to 60 ° C.

The heat equalizing jig 2 is provided with a socket into which the optical semiconductor element 1 is inserted, and this socket is electrically connected to a drive circuit of the optical semiconductor element 1. Therefore, after setting the heat equalizing jig 2 in the temperature chamber 5, a drive current is applied to the optical semiconductor element 1 to cause the optical semiconductor element 1 to emit light.

When the temperature equalizing jig 2 reaches the test temperature, the position of the lens 8 is adjusted by the optical axis aligning mechanism 10 to introduce the light emitted from the optical semiconductor element 1 into the optical fiber 9.
And fine adjustment is performed so that the light intensity entering the optical fiber 9 is maximized. When the light intensity transmitted through the optical fiber 9 becomes maximum, the light measuring device 11 measures the light intensity and wavelength.

When the measurement is completed, the air conditioner 6 and the Peltier element 3 gradually return the temperature of the heat equalizing jig 2 to room temperature so as not to cause dew condensation. And take out the optical semiconductor element 1 for which measurement has been completed together with the heat equalizing jig 2.

FIG. 2 is a diagram for explaining a state of the FFP measurement of the optical semiconductor device 1 according to the first embodiment.

The lens 8 and the optical fiber 9 shown in FIG.
Instead, a Fourier transform lens 15 and an imaging device 16 having sensitivity to light emitted from the optical semiconductor element 1 are provided on the optical axis of the optical semiconductor element 1. Here, the imaging surface 17 of the imaging device 16 is placed so as to be a Fourier transform surface of the Fourier transform lens 15. When the optical semiconductor element 1 emits light in this way, the Fourier transform lens 15
Since the FFP of the optical semiconductor element 1 is projected on the Fourier transform surface of the optical device 1, the imaging device 16 captures the FFP as a two-dimensional image, and outputs the FF output from the imaging device 16.
The P video signal is recorded in the image recording device 18.

Next, effects of the first embodiment will be described.

In the first embodiment, only the optical semiconductor element 1 to be inspected placed in the temperature chamber 5 and the heat equalizing jig 2 and the Peltier element 3 mounted thereon are exposed to the test temperature. Since all the measurement and mechanical systems such as the lens 8, the optical axis alignment mechanism 10, the optical measuring device 11, and the imaging device 16 are placed in a normal temperature atmosphere outside the temperature chamber 5, the optical semiconductors in various temperature environments The light output, wavelength, light emission pattern and the like of the element 1 can be measured with high accuracy.

Next, a second embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 3 is a diagram for explaining a second embodiment of the present invention.

The optical semiconductor device temperature characteristic test apparatus shown in FIG. 3 performs a temperature characteristic test of a light receiving element 20 such as a photodiode instead of the optical semiconductor element 1 which is a light emitting element such as a laser diode shown in FIG. The light output from the reference light source 21 passes through the optical fiber 9 and is condensed on the light receiving surface of the light receiving element 20 by the lens 8. The heat equalizing jig 2 has a socket into which the light receiving element 20 is inserted. A bias voltage is applied to the light receiving element 20 via the socket, and a current value flowing through the light receiving element 20 is measured by an ammeter.

FIG. 4 is a graph showing the relationship between the position of the spot focused by the lens 8 and the value of the current flowing through the light receiving element 20.

In the case of the light receiving element 20, since the light receiving surface has a size of several tens to several hundreds of μm, the position of the spot where the value of the current flowing through the light receiving element 20 is maximum has a range similar to that of the light receiving surface. Therefore, the light receiving element 2 is
0 and the lens 8 are aligned when the light receiving element 20
From the maximum value of the current value of FIG.
%), The position of the edge where the current value decreases is detected, and the spot position is adjusted to the middle position between the edges on both sides thereof. By performing the optical axis alignment in this manner, the spot focused by the lens 8 can be accurately aligned with the center of the light receiving surface of the light receiving element 20. By scanning the spot two-dimensionally by the optical axis alignment mechanism 10, the sensitivity distribution in the light receiving surface of the light receiving element 20 can also be measured.

The second embodiment shows that not only the temperature test of the optical semiconductor element 1 as the light emitting element shown in the first embodiment but also the temperature test of the light receiving element 20 can be realized. Also in the temperature test of the light receiving element 20 in the second embodiment, since the lens 8, the optical axis alignment mechanism 10, the reference light source 11, and the like can all be placed in the normal temperature atmosphere outside the temperature chamber 5, Various measurements including the sensitivity distribution can be performed with high accuracy under various temperature environments.

Next, a third embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 5 is a diagram for explaining a third embodiment of the present invention.

The temperature characteristic testing apparatus for an optical semiconductor device according to the third embodiment includes a temperature chamber 5 instead of the nozzle 14 for supplying dry air near the transmission window 7 shown in FIG. Is covered with an airtight chamber 22, a piping system 23 for supplying dry air into the airtight chamber 22 is provided, and the atmosphere in the airtight chamber 22 is replaced with dry air to perform a temperature characteristic test. FIG.
When the dry air is supplied to the vicinity of the transmission window 7 through the nozzle 14 as shown in FIG.
It was necessary to open the temperature chamber 5 after returning to room temperature. However, in the third embodiment shown in FIG. 5, the entire apparatus is placed in the hermetic chamber 22 and the dew point in the hermetic chamber 22 is lowered, so that the temperature chamber 5 is opened while the optical semiconductor element 1 is cold. Even if the dew does not form, the optical semiconductor element 1
There is no need to wait for the temperature to return to room temperature, so that the index of the apparatus is improved.

[0045]

The first effect is that precise temperature control of the optical semiconductor device can be performed.

The reason is that not only the temperature of the heat equalizing jig on which the optical semiconductor element is mounted is precisely controlled by the Peltier element, but also the atmosphere around the heat equalizing jig is brought close to the test temperature by an air conditioner. This is because the temperature gradient in the heat equalizing jig can be reduced and the temperature uniformity in the heat equalizing jig can be improved.

The second effect is that various characteristic tests can be performed with high accuracy not only at room temperature but also at high and low temperatures. In addition, various characteristic tests such as measurement of FFP of a laser diode and in-plane sensitivity distribution of a light receiving element can be performed.

The reason is that only the optical semiconductor element, the heat equalizing jig and the Peltier element in the temperature chamber are exposed to various test temperatures, and other lenses, optical axis alignment mechanisms, optical measuring instruments and reference This is because the measurement system / mechanism system such as the light source is in an ambient temperature atmosphere, so that precise optical axis alignment and precise measurement independent of temperature characteristics can be realized. Further, even at the time of a test at a low temperature, the dew point in the vicinity of the transmission window of the temperature chamber is lowered by dry air, thereby preventing dew condensation on the transmission window.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of an optical semiconductor element temperature characteristic test apparatus of the present invention.

FIG. 2 is a diagram for explaining a state of FFP measurement of the optical semiconductor device according to the first embodiment of FIG.

FIG. 3 is a configuration diagram showing a second embodiment of the temperature characteristic testing apparatus for an optical semiconductor element of the present invention.

FIG. 4 is a graph showing a relationship between a spot position and a current value flowing through a light receiving element according to the present embodiment.

FIG. 5 is a configuration diagram showing a third embodiment of the temperature characteristic testing device for an optical semiconductor element of the present invention.

FIG. 6 is a plan view showing an example of a conventional optical semiconductor element temperature characteristic test apparatus.

7 is a cross-sectional view of the optical semiconductor device temperature characteristic test apparatus shown in FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical semiconductor element 2 Heat equalizing jig 3 Peltier element 4 Temperature controller 5 Temperature chamber 6 Air conditioner 7 Transmission window 8 Lens 8a Front lens 8b Rear lens 9 Optical fiber 10 Optical axis alignment mechanism 11 Optical measuring instrument 12 Opening / closing Mechanism 13 Duct 14 Nozzle 15 Fourier transform lens 16 Imaging device 17 Imaging surface 18 Image recording device 20 Light receiving element 21 Reference light source 22 Airtight room 23 Piping system 101 Heat equalizing block 102 Refrigerant passing means 103 Heater 104, 107 Insertion hole 105 Light receiving Device 106, 109 Printed circuit board 108 Auxiliary heat equalizing block 110 Optical semiconductor device

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01R 31/26 H01L 21/66

Claims (4)

(57) [Claims] 1. A temperature characteristic testing apparatus comprising: a temperature adjusting means for maintaining an optical semiconductor device to be inspected at a test temperature; and a measuring means for measuring optical-electrical characteristics of the optical semiconductor device. The element is a light emitting element, and the temperature
Adjusting means for mounting the light emitting element, a heat equalizing jig, a Peltier element in contact with the heat equalizing jig and controlling the temperature of the heat equalizing jig and the light emitting element, the heat equalizing jig and the Peltier element the includes a temperature chamber having a transparent window on an optical axis of possible light emitting element housing, and a temperature-controlled air supply air conditioner in the temperature chamber, the measuring means
The onset but a Fourier transform lens <br/>'s placed outside the temperature chamber, which is formed by the Fourier transform lens
An imaging device for imaging a far-field pattern of light emission of the optical element;
The position of the Fourier transform lens is adjusted and the far-field pattern is adjusted.
Including the optical axis alignment mechanism for adjusting the position over down is formed
And a switching mechanism for opening and closing the temperature chamber. 2. A temperature characteristic testing apparatus, comprising: a temperature adjusting means for keeping an optical semiconductor device to be inspected at a test temperature; and a measuring means for measuring optical-electrical characteristics of the optical semiconductor device. The element is a light receiving element, and the temperature
Adjusting means for mounting the light receiving element, a Peltier element in contact with the heat equalizing jig and controlling the temperature of the heat equalizing jig and the light receiving element, and the heat equalizing jig and the Peltier element. temperature chamber having a retractable transparent windows on the optical axis of said optical semiconductor element, and a for supplying air conditioner temperature controlled air to the temperature inside the chamber, the measuring hand
A step, a reference light source for emitting light for irradiating a light-receiving surface of the light-receiving element placed outside the temperature chamber, an optical fiber for guiding light emitted from the reference light source, and a light-receiving element from light emitted from the optical fiber. a lens for forming a focused spot on the light receiving surface of the focusing spot by adjusting the position of said lens comprises an optical axis alignment mechanism for two-dimensionally scanned on the light receiving surface of the light receiving element, the temperature chamber An apparatus for testing the temperature characteristics of an optical semiconductor device, comprising: an opening / closing mechanism for opening and closing. 3. A temperature characteristic test apparatus for an optical semiconductor device according to claim 1 or 2 Claims characterized by having a dry air-supplying apparatus for supplying a gas of lower dew point than the test temperature transmission window near the temperature chamber . 4. The temperature chamber and the Fourier transform laser.
3. The temperature characteristic of the optical semiconductor device according to claim 1, wherein the lens or the lens forming the condensing spot is placed in an airtight chamber, and the airtight chamber is filled with a gas having a dew point lower than a test temperature. Testing equipment.