TWI742884B - Optical inspection equipment with heating function - Google Patents

Abstract

An optical detection equipment includes a bearing platform, a light receiving device at a position corresponding to an opening of the bearing platform, a transparent heating plate and a point measuring device. The transparent heating plate is arranged with its lower surface facing the light receiving device. One of the carrying table and the light receiving device is used for a wafer to be set on the upper surface of the transparent heating plate, and the transparent heating plate is capable of supplying light to pass through the upper and lower surfaces and being energized to generate heat energy To heat the wafer, the spot measuring device includes a base and a probe protruding from the base toward the upper surface of the transparent heating plate to touch a light-emitting chip of the wafer; Therefore, the optical inspection device can detect the luminous efficiency of the light-emitting chip that has not been cut but is still in the wafer state and heat the light-emitting chip at the same time.

Description

Optical inspection equipment with heating function

The present invention relates to optical inspection equipment for detecting light-emitting wafers, in particular to an optical inspection equipment with heating function.

For light-emitting chips such as light-emitting diode chips, laser chips, etc., for luminous efficacy testing, usually the probe of a probe card touches the conductive contacts of a tested chip to make the tested chip emit light. At the same time, a light receiving device (such as an integrating sphere) receives the light emitted by the tested chip to measure its luminous efficacy. This inspection process may also be performed when the wafer is made with a large number of connected chips (ie, crystals). When the circle has not been cut into a large number of separated wafers). For light-emitting chips (such as flip-chip light-emitting chips) where the conductive contacts and the light-emitting parts are located on two surfaces facing opposite directions, the aforementioned luminous efficiency test is usually performed with the conductive contacts of the light-emitting chip facing upwards, The light-emitting part faces downwards, that is, the probe touches the conductive contact of the chip from the top of the top surface of the wafer downwards, and the light receiving device receives the light from the chip below the bottom surface of the wafer The light emitted from the site downwards.

Although there are spot-testing equipment on the market for optical inspection of light-emitting wafers that have not been cut but are still in wafer state, they cannot heat the tested wafers, so the wafers cannot be tested for luminous efficacy under specific high-temperature conditions.

In view of the above-mentioned deficiencies, the main purpose of the present invention is to provide an optical inspection device with heating function, which can detect the luminous efficiency of the light-emitting chip that has not been cut but is still in the wafer state and heat the light-emitting chip at the same time.

In order to achieve the above objective, the optical inspection equipment with heating function provided by the present invention includes a carrying platform with an opening, a light receiving device with a position corresponding to the opening of the carrying platform, a transparent heating plate, and a one-point measuring device. The transparent heating plate has an upper surface and a lower surface for supporting a wafer, and the transparent heating plate is disposed on one of the carrier table and the light receiving device with its lower surface facing the light receiving device, Used to supply light to pass through its upper and lower surfaces and be energized to generate thermal energy to heat the wafer, the spot measuring device includes a base and a projecting from the base toward the upper surface of the transparent heating plate The probe is used to touch one of the light-emitting chips of the wafer.

Thereby, a light-emitting chip such as a flip-chip chip can be touched by the probe because its conductive contacts are facing upwards, and when the light-emitting chip is touched by the probe, the light-emitting chip emits light downwards, and its light can be heated by the transparent A plate (such as conductive glass) for a light receiving device (such as an integrating sphere) placed under the transparent heating plate to receive the light emitted by the light-emitting chip and detect its luminous efficacy. At the same time, the transparent heating plate can be placed on it The surface of the wafer (including the light-emitting chip under test) is heated.

Preferably, the optical detection device may include a temperature sensing unit and a temperature monitoring unit, the temperature sensing unit is used to sense the temperature of at least one of the transparent heating plate and the wafer, the temperature The monitoring unit controls a power supply to the transparent heating plate according to the temperature feedback sensed by the temperature sensing unit. More preferably, the optical inspection device may further include an auxiliary heating element for heating the wafer and electrically connected to the temperature monitoring unit, and the temperature monitoring unit controls the temperature based on the temperature feedback sensed by the temperature sensing unit. Auxiliary heating element. In this way, the optical inspection equipment can test the luminous efficacy of the light-emitting chip under specific high temperature conditions, for example, it can simulate the temperature reached by the heating and heating of the light-emitting chip in actual use, so as to detect whether the luminous efficiency of the light-emitting chip is Decay when the fever heats up.

The detailed structure, characteristics, assembly or use of the optical detection device with heating function provided by the present invention will be described in the detailed description of the following implementation manners. However, those with ordinary knowledge in the field of the present invention should be able to understand that the detailed description and the specific embodiments listed for implementing the present invention are only used to illustrate the present invention, and are not intended to limit the scope of the patent application of the present invention.

The applicant first explains here that in the following embodiments and the scope of the patent application, when it is mentioned that one element is arranged on another element, it means that the aforementioned element is directly arranged on the other element, or the aforementioned element is It is arranged on the other element indirectly, that is, one or more other elements are also arranged between the two elements. When it is mentioned that one element is "directly" arranged on another element, it means that no other element is arranged between the two elements. In addition, in the drawings of the present invention, each element and structure are for illustrative purposes and are not drawn according to actual proportions and quantities. In the following embodiments and drawings, the same reference numbers indicate the same or similar elements or structural features.

Please refer to FIG. 1, the optical detection device 10 with heating function provided by a first preferred embodiment of the present invention includes a carrying table 20, a transparent heating plate 30, a light receiving device 42, a point measuring device 50, and a temperature A sensing unit (including a first temperature sensor 61 and a second temperature sensor 62), a temperature monitoring unit (including a temperature monitoring device 64) electrically connected to the temperature sensing unit, and a The transparent heating plate 30 and the temperature monitoring unit are electrically connected to a power supply 68.

The optical inspection device 10 is used to perform processing on a plurality of light-emitting chips 71 (for example, Vertical-Cavity Surface-Emitting Laser Array (VCSEL Array) chips) contained in a wafer 70 For luminous efficiency testing, the wafer 70 has thousands or even more tiny light-emitting chips 71, and the light-emitting chips 71 are not yet cut and connected to each other. In other words, the optical inspection device 10 is used to detect The light-emitting chip 71 which is still in the wafer state after being cut. Figures 1 and 2 are schematic cross-sectional views of the optical inspection equipment of the present invention and the wafer 70. To simplify the drawing and facilitate the description, only a block of the wafer 70 is schematically represented in Figures 1 and 2 A light-emitting chip 71.

The optical inspection device 10 of the present invention may (but is not limited to) include a three-axis drive structure (not shown in the figure), and a horizontal movement structure 12 and a vertical movement structure 13 that are driven and displaced by the three-axis drive structure. In detail, the three-axis drive structure includes a base assembly (not shown in the figure), and two horizontal drive devices (not shown in the figure) and a vertical drive device (not shown in the figure) arranged on the base assembly ), the horizontal movement structure 12 can be driven by the two horizontal drive devices to move along two horizontal axes and is arranged on the three axis drive structure, and the vertical movement structure 13 can be driven by the vertical drive device along a vertical axis The movable ground is provided on the three-axis driving structure and above the horizontal moving structure 12. The structure of the aforementioned horizontal and vertical drive device is the same as that of the conventional linear drive device, so the applicant will not describe it in detail here.

The aforementioned horizontal movement structure 12 includes a base (not shown) that is driven by the aforementioned horizontal drive device to move along a horizontal axis, and can be driven by a first rotation drive device (not shown) to be rotatably arranged at The wafer chuck 20 of the susceptor and the transparent heating plate 30 arranged on the supporting platform 20, the wafer 70 is placed on the transparent heating plate 30. The aforementioned vertical movement structure 13 includes a base (not shown in the figure) that is driven by the aforementioned vertical drive device to move along a vertical axis, and is rotatably arranged by being driven by a second rotating drive device (not shown in the figure) The aforementioned spot measuring device 50 on the base. The structure of the aforementioned rotary drive device is the same as that of the conventional rotary drive device, so the applicant will not describe it in detail here.

It can be seen from the foregoing that the carrying table 20, the transparent heating plate 30 and the wafer 70 of this embodiment can be driven by the aforementioned horizontal drive device and the first rotation drive device to move horizontally along the horizontal axis and rotate around the vertical axis. The point measuring device 50 of this embodiment can be driven by the aforementioned vertical drive device and the second rotation drive device to move vertically along the vertical axis and rotate around the vertical axis. However, the arrangement of the carrying platform 20, the transparent heating plate 30 and the spot measuring device 50 of the present invention is not limited to those provided in this embodiment, as long as the spot measuring device 50 can move relative to the carrying platform 20 and the transparent heating plate 30 It is enough to be close to and away from the wafer 70.

The carrying platform 20 has a top surface 21, a bottom surface 22, and an opening 23 penetrating the top surface 21 and the bottom surface 22. The transparent heating plate 30 is a conductive transparent plate body, for example, a conductive glass plated with a conductive layer (such as indium tin oxide (ITO)) for light to pass through the transparent heating plate 30 Upper and lower surfaces 34,35. The transparent heating plate 30 is disposed on the top surface 21 of the carrier 20 with the lower surface 35 facing the opening 23, and the wafer 70 is disposed on the upper surface 34, so that even if the wafer 70 is a Thin wafers can still be supported by the transparent heating plate 30 to avoid bending. In addition, the transparent heating plate 30 is further provided with a plurality of vacuum holes 36, which are used to communicate with a vacuum source (not shown in the figure), so that the wafer 70 is vacuum sucked, so that the wafer 70 is more stably placed on the transparent The upper surface 34 of the heating plate 30. The light-emitting chip 71 included in the wafer 70 may be a light-emitting chip such as a flip chip (for example, a VCSEL chip or a laser chip, etc.), and its conductive contacts (not shown) are facing The upper part is for the point measuring device 50 to touch (detailed below), and the light-emitting chip 71 emits downward when touched by the point measuring device 50, and the light can pass through the transparent heating plate 30 so as to pass through the The light receiving device 42 (such as an integrating sphere) opposite to the lower surface 35 of the transparent heating plate 30 through the opening 23 of the stage 20 can receive the light of the light-emitting chip 71 to detect its luminous efficacy. Furthermore, the transparent heating plate 30 is electrically connected to the power source 68 to generate heat energy to heat the wafer 70 by energizing. In other words, the transparent heating plate 30 of this embodiment has the functions of supporting the wafer 70, adsorbing the wafer 70, heating the wafer 70, and allowing light to pass through the wafer 71.

The point measuring device 50 can be a conventional probe card, which includes a base 53 and at least one probe 55 protruding from the base 53 toward the upper surface 34 of the transparent heating plate 30 for point contact The conductive contacts of the light-emitting chip 71 (not shown in the figure). Thereby, the light-emitting chip 71 can receive the detection signal output by a testing machine (not shown in the figure) above the point-measurement device 50 through the point-measurement device 50 to emit light, and then the light-receiving device 42 can receive and detect light. . It can be seen that the optical inspection equipment of the present invention can detect the luminous efficiency of the light-emitting chip 71 that has not been cut but is still in a wafer state and heat the light-emitting chip 71 at the same time.

In the aforementioned process of detecting the light-emitting chip 71, the first temperature sensor 61 provided on the transparent heating plate 30 can sense the temperature of the transparent heating plate 30 and transmit the sensing signal to the temperature monitoring device 64 to The temperature monitoring device 64 controls the power supply 68 according to the temperature feedback sensed by the first temperature sensor 61, and then controls the power of the transparent heating plate 30 to heat the light-emitting chip 71 to provide the light-emitting chip 71 for testing. The required ambient temperature.

The optical detection equipment of the present invention may (but is not limited to) further includes an auxiliary heating element 66 electrically connected to the temperature monitoring device 64. The auxiliary heating element 66 may (but is not limited to) a laser heating source which emits The laser light passes through a through hole 56 of the point measuring device 50 to heat the wafer 70 without contacting. Moreover, the point measuring device 50 can be provided with a reflector 57 at the bottom end of the through hole 56 to reflect the laser light. To the light-emitting chip 71 under test, directly heat the light-emitting chip 71 under test. In addition, the second temperature sensor 62 is a non-contact thermometer, which is used to sense the temperature of the wafer 70 through the other through hole 58 of the spot measuring device 50 without contacting, even the spot measuring device 50 can be provided with another reflector 59 at the bottom end of the through hole 58 so that the second temperature sensor 62 can sense the temperature of the light-emitting chip 71 under test by the reflection of the reflector 59. Thereby, the temperature monitoring device 64 can control the auxiliary heating element 66 according to the temperature feedback sensed by the second temperature sensor 62, so as to use the auxiliary heating element 66 to appropriately compensate the difference between the wafer 70 or the light-emitting chip 71 The temperature, in this way, the temperature of the wafer 70 or the light-emitting chip 71 can be controlled more accurately.

The auxiliary heating element 66 and/or the transparent heating plate 30 cooperate with the temperature sensing unit and the temperature monitoring unit to control the temperature of the wafer 70 or the light-emitting chip 71 at a specific temperature. Therefore, the present invention The optical inspection device 10 can detect the luminous efficacy of the light-emitting chip 71 of the wafer 70 at a specific temperature. For example, a micro-laser chip easily generates heat when it emits light to increase its own temperature. The optical inspection device 10 of the present invention can simulate the temperature when the micro-laser chip is actually used and generate heat, and detect the micro-laser chip under this temperature condition. The chip is used to eliminate the chips that have luminous efficacy degradation under the temperature conditions, so that the performance of the microlaser chips that pass the inspection can be ensured in actual use. Furthermore, in the present invention, the transparent heating plate 30 heats the wafer 70, and measures the surface temperature of the wafer 70 (or even directly measures the light-emitting chip 71 under test), plus the auxiliary heating element 66 for auxiliary temperature compensation. This not only shortens the measurement time, but also effectively controls the temperature and reduces the error between the actual temperature and the predetermined temperature. In addition, the test conditions (such as temperature, needle drop amount) of each light-emitting chip 71 on the wafer 70 have high consistency, which can be used to accurately determine the received light and electrical properties.

It is worth mentioning that the temperature monitoring unit of this embodiment uses the same temperature monitoring device 64 to receive the sensing signals of the first and second temperature sensors 61 and 62 and feedback and control the power supply 68 and the auxiliary heating element 66, but It is also possible to use two temperature monitoring devices to receive the sensing signals of the first and second temperature sensors 61 and 62 respectively, and to control the power supply 68 and the auxiliary heating element 66 by the two temperature monitoring devices respectively. In addition, the temperature monitoring unit is not limited to using the temperature of the transparent heating plate 30 and the temperature of the wafer 70 to feed back and control the power supply 68 and the auxiliary heating element 66, as long as it can effectively make the tested light-emitting chip 71 reach the required level for testing. The temperature is fine.

Please refer to FIG. 2, the optical inspection device 10' provided by a second preferred embodiment of the present invention is similar to the aforementioned optical inspection device 10, and the main difference lies in the size and arrangement of the transparent heating plate. In detail, the area of the transparent heating plate 30 of the optical inspection device 10 of FIG. 1 is larger than the area of the wafer 70, and the transparent heating plate 30 is arranged on the top surface 21 of the carrier 20 and is provided for the wafer 70 as a whole. On the upper surface 34 of the transparent heating plate 30 to heat the entire wafer 70. The area of the transparent heating plate 30' of the optical inspection device 10' of FIG. 2 is much smaller than that of the wafer 70. The transparent heating plate 30' is disposed on the light receiving device 42 and on the carrier through a support frame 44. In the opening 23 of the 20, the wafer 70 is provided on the top surface 21 of the carrier 20 and the upper surface 34 of the transparent heating plate 30' at the same time, so that the wafer 70 is properly supported to avoid spot measurement. When bending deformation. The wafer 70 is driven to move horizontally through the carrying table 20, the transparent heating plate 30' can be supported at any position of the wafer 70, and can also be supported on the light-emitting chip 71 under test every time it is inspected, and simultaneously The light-emitting chip 71 to be tested is heated. In addition, the first temperature sensor 61 of the optical detection device 10' of FIG. 2 senses the temperature of the transparent heating plate 30' through the opening 23 of the carrier 20 without contact. Furthermore, the temperature monitoring unit of the optical detection device 10' of FIG. 2 includes two temperature monitoring devices 64, 65, and the two temperature monitoring devices 64, 65 receive the sensing of the second and first temperature sensors 62, 61, respectively. The auxiliary heating element 66 and the power source 68 supplying power to the transparent heating plate 30' are respectively fed back to control the auxiliary heating element 66. Such an optical inspection device 10' can also achieve the functions of the aforementioned optical inspection device 10. Furthermore, the advantage of the embodiment of FIG. 2 is that the transparent heating plate 30' can be added to the light receiving device 42 of the original machine for heating measurement in a specific range, and the transparent heating plate 30' can also be provided with a vacuum The hole is used to fix the periphery of the tested light-emitting chip 71 through a vacuum method. This can not only support the spot measurement area, quickly heat and compensate the temperature, but also has a high degree of freedom in the setting method. It can be directly added to the original machine without limitation. It is the size of the stage 20 and facilitates the switching of the light-emitting chip 71 under test.

Finally, it must be explained again that the constituent elements disclosed in the previously disclosed embodiments of the present invention are only examples and are not intended to limit the scope of the case. Alternatives or changes to other equivalent elements should also be the scope of the patent application for this case. Covered.

10,10’: Optical inspection equipment 12: Horizontal mobile structure 13: Vertical movement structure 20: Bearing platform 21: top surface 22: Bottom 23: opening 30,30’: Transparent heating plate 34: upper surface 35: lower surface 36: Vacuum channel 42: Optical receiver 44: support frame 50: Point measuring device 53: Seat 55: Probe 56: Piercing 57: mirror 58: Piercing 59: Mirror 61: The first temperature sensor 62: The second temperature sensor 64, 65: temperature monitoring device 66: auxiliary heating element 68: Power 70: Wafer 71: light-emitting chip

1 is a schematic cross-sectional view of an optical inspection device with heating function and a wafer provided by a first preferred embodiment of the present invention. 2 is a schematic cross-sectional view of an optical inspection device with heating function and a wafer provided by a second preferred embodiment of the present invention.

10: Optical inspection equipment

12: Horizontal mobile structure

13: Vertical movement structure

20: Bearing platform

21: top surface

22: Bottom

23: opening

30: Transparent heating plate

34: upper surface

35: lower surface

36: Vacuum channel

42: Optical receiver

50: Point measuring device

53: Seat

55: Probe

56: Piercing

57: mirror

58: Piercing

59: Mirror

61: The first temperature sensor

62: The second temperature sensor

64: Temperature monitoring device

66: auxiliary heating element

68: Power

70: Wafer

71: light-emitting chip

Claims (12)

A kind of optical inspection equipment with heating function, including: a carrying table with an opening; a light receiving device with a position corresponding to the opening of the carrying table; a transparent heating plate with a support for supporting a wafer On the upper surface and the lower surface, the transparent heating plate is set on one of the bearing platform and the light receiving device with its lower surface facing the light receiving device, so as to allow light to pass through the upper surface and the lower surface and be able to It is energized to generate heat to heat the wafer; and a point measuring device comprising a base body and a probe projecting from the base body toward the upper surface of the transparent heating plate to touch the wafer A light-emitting chip. The optical detection device with heating function according to claim 1, wherein the transparent heating plate is a conductive glass. The optical inspection device with heating function according to claim 1, further comprising a power supply electrically connected to the transparent heating plate, and a power source for sensing the temperature of at least one of the transparent heating plate and the wafer The temperature sensing unit, and a temperature monitoring unit electrically connected to the power supply and the temperature sensing unit, the temperature monitoring unit controls the power supply according to the temperature feedback sensed by the temperature sensing unit. The optical inspection device with heating function as described in claim 3, further comprising an auxiliary heating element for heating the wafer and electrically connected to the temperature monitoring unit, and the temperature monitoring unit senses according to the temperature sensing unit The received temperature feedback controls the auxiliary heating element. The optical inspection device with heating function according to claim 4, wherein the auxiliary heating element heats the wafer without contact through a through hole of the spot measuring device. The optical inspection device with heating function according to claim 5, wherein the auxiliary heating element further heats the light-emitting chip under test through a reflector. The optical inspection device with heating function according to claim 4, wherein the auxiliary heating element emits laser light to heat the wafer without contact. The optical inspection device with heating function according to claim 4, wherein the temperature sensing unit includes a first temperature sensor for sensing the temperature of the transparent heating plate, and a first temperature sensor for sensing the wafer The second temperature sensor of the temperature, the temperature monitoring unit controls the power supply according to the temperature feedback sensed by the first temperature sensor, and controls the auxiliary heating according to the temperature feedback sensed by the second temperature sensor Pieces. The optical detection device with heating function according to claim 3, wherein the temperature sensing unit includes a temperature sensor that senses the temperature of the wafer through a through hole of the spot detection device without contact. The optical detection device with heating function according to claim 9, wherein the temperature sensor further senses the temperature of the light-emitting chip under test through a reflector. The optical detection device with heating function according to claim 1, wherein the transparent heating plate is arranged on the carrying table with its lower surface facing the opening, and the transparent heating plate is provided with a plurality of vacuum channels for vacuum adsorption The wafer. The optical inspection device with heating function according to claim 1, wherein the transparent heating plate is arranged in the light receiving device and located in the opening of the carrier, so that the wafer can be heated by the carrier and the transparent at the same time Board support.

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