Wafer substrate suction cup

Abstract

The invention discloses a wafer substrate sucker, comprising a sucker body, wherein the sucker body has a sucker working surface for adsorbing and fixing a wafer substrate and a reflective structure layer for reflecting light, wherein the reflective structure layer is arranged on the backlight surface of the sucker working surface and is parallel to the sucker working surface, and when light is transmitted through the sucker working surface from the light-facing surface of the sucker working surface, it is reflected at the reflective structure layer, and the light reflected from the reflective structure layer is emitted from the wafer substrate sucker through the sucker working surface again, or is emitted from the wafer substrate sucker from the lateral end surface between the sucker working surface and the reflective structure layer. The wafer substrate sucker of the invention blocks light energy from being absorbed by the sucker by reflection, thereby avoiding temperature fluctuations of the sucker.

Description

Technical Field

[0001] The present invention relates to a WLO (Wafer Level Optics) manufacturing technology, and in particular to a wafer substrate suction cup for adsorbing and fixing a wafer substrate when a UV curing injection molding process is performed on the surface of the wafer substrate. Background Art

[0002] WLO refers to a micro-nano structure optical element made by using semiconductor technology to produce micro-nano structures on a substrate wafer. Different from the processing technology of traditional optical elements, the WLO process uses semiconductor technology to batch replicate and process lens unit arrays on a whole transparent wafer substrate. Multiple transparent wafer substrates are pressed together and then cut into single lenses. It has the characteristics of small size, low height, and good consistency. The position accuracy of wafer-level optical lenses reaches the nm level, which is the best choice for future standardized optical lens combinations.

[0003] UV curing injection molding is a key step in processing a lens array on a transparent wafer substrate. In the UV curing injection molding process, a suction cup is required to adsorb and fix the wafer substrate. When ultraviolet light is irradiated on the wafer substrate adsorbed on the suction cup, due to the light transmittance of the wafer substrate, the light will be transmitted through the wafer substrate to the surface of the suction cup, and the surface temperature of the suction cup will increase. The heat on the suction cup surface will be transferred to the processed wafer substrate in the form of conduction, causing the temperature of the processed wafer substrate to increase, resulting in thermal expansion and contraction effects, thereby changing the scale and spacing of the marking points and lens structure on the wafer substrate, making it impossible to align the marking points and lens structure on the wafer substrate with the marking points and lens structure on the mask, mold or another wafer one by one, seriously affecting the production accuracy and production yield.

[0004] Usually, a coolant circulation device is provided inside the suction cup to prevent the suction cup temperature from being too high due to continuous exposure to light. The existing coolant circulation device arranges cooling pipes inside the suction cup to take away the heat energy converted from light energy on the surface of the system suction cup through the cooling pipes. This cooling solution has a certain hysteresis, so the temperature fluctuation of the suction cup surface will be large. Summary of the invention

[0005] Purpose of the invention: The purpose of the present invention is to provide a wafer substrate suction cup, which blocks light energy from being absorbed by the suction cup by reflection, thereby avoiding fluctuations in the suction cup temperature.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A wafer substrate suction cup comprises a suction cup body, characterized in that: the suction cup body has a suction cup working surface for adsorbing and fixing the wafer substrate and a reflective structure layer for reflecting light, the reflective structure layer is arranged on the backlight surface of the suction cup working surface and is parallel to the suction cup working surface, when the light is transmitted from the light-facing surface of the suction cup working surface through the suction cup working surface, it is reflected at the reflective structure layer, and the light reflected from the reflective structure layer passes through the suction cup working surface again to emit out of the wafer substrate suction cup, or emits out of the wafer substrate suction cup from the lateral end surface between the suction cup working surface and the reflective structure layer.

[0008] Furthermore, the reflective structure layer is a single-layer dielectric film, a multi-layer dielectric film, a metal film or a grating structure capable of reflecting illumination or exposure light sources.

[0009] Furthermore, the reflective structure layer consists of at least two layers, which are parallel to each other.

[0010] Furthermore, a light-transmitting structure layer is arranged between two adjacent light-reflecting structure layers.

[0011] Furthermore, the suction cup working surface is provided with a vacuum adsorption area and a distance sensor detection area, the vacuum adsorption area and the distance sensor detection area are arranged on the same plane, the vacuum adsorption area is used to place and adsorb the wafer substrate, and the distance sensor detection area is arranged as the detection surface of the distance sensor.

[0012] Furthermore, the detection surface is a contact plane suitable for a contact sensor or a measurement light reflection surface suitable for a non-contact sensor.

[0013] Furthermore, the detection area of ​​the distance sensor surrounds the vacuum adsorption area.

[0014] Furthermore, a metal structure layer is arranged on the bottom surface of the reflective structure layer.

[0015] Furthermore, the wafer substrate is a single silicon wafer, a glass wafer or an organic material sheet wafer, or a stacked combination of at least two of the above three types of wafers.

[0016] Furthermore, the illumination or exposure light source is an ultraviolet light source.

[0017] Beneficial effects:

[0018] 1) The wafer substrate suction cup structure of the present invention is adopted, and a reflective structure layer is provided on the inner side of the suction cup working surface to reflect the light energy of the illumination or exposure light source to prevent the light energy from continuously irradiating the suction cup and causing the suction cup temperature to be too high.

[0019] 2) Reflecting the light that has passed through the wafer substrate through the reflective structure helps to achieve a more uniform light intensity distribution on the surface of the wafer substrate, which is more conducive to UV curing injection molding. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the present invention;

[0021] Figure 2 It is a schematic diagram of the arrangement of the multi-layer reflective structure layers;

[0022] Figure 3 It is a schematic diagram of a reflective structure with a metal structure layer;

[0023] In the figure: 1-suction cup working surface; 1-1-vacuum adsorption area; 1-2-distance sensor detection area; 2-reflective structure layer; 3-suction cup body; 4-light-transmitting structure layer; 5-metal structure layer. DETAILED DESCRIPTION

[0024] The present invention will be further explained below in conjunction with the accompanying drawings.

[0025] like Figure 1 As shown, a wafer substrate suction cup of the present invention includes a suction cup body 3, the suction cup body 3 has a suction cup working surface 1 for adsorbing and fixing the wafer substrate and a reflective structure layer 2 for reflecting light, the reflective structure layer 2 is arranged on the backlight side of the suction cup working surface 1 and is parallel to the suction cup working surface 1, when the light is transmitted from the light-facing side of the suction cup working surface 1 through the suction cup working surface 1, it is reflected at the reflective structure layer 2, and the light reflected from the reflective structure layer 2 passes through the suction cup working surface 1 again to emit out of the wafer substrate suction cup, or emits out of the wafer substrate suction cup from the lateral end surface between the suction cup working surface 1 and the reflective structure layer 2.

[0026] The reflective structure layer 2 can be adapted with through holes according to the type of suction cup. If the external vacuum of the suction cup is input from the vacuum pipeline inside the suction cup body 3, it is necessary to arrange through holes corresponding to the vacuum pipeline of the suction cup body 3 on the reflective structure layer 2. If the external vacuum of the suction cup is introduced from the side between the suction cup working surface 1 and the wafer substrate, no through holes are required.

[0027] The reflective structure layer 2 can be a single-layer dielectric film, a multi-layer dielectric film, a metal film, or a grating structure capable of reflecting illumination or exposure light sources.

[0028] like Figure 1 and 2 As shown, the reflective structure layer 2 can be set as a single layer, or at least two layers. When the reflective structure layer 2 adopts a structure of more than two layers, the layers are parallel to each other, and each layer of the reflective structure layer 2 can be configured with different parameters, so that some layers meet the reflection conditions for certain spectra, and some layers meet the reflection conditions for incident light at certain angles.

[0029] When the reflective structure layer 2 is at least two layers, a light-transmitting structure layer 4 can be disposed between two adjacent reflective structure layers 2. The light-transmitting structure layer 4 defines the distance between two adjacent reflective structure layers 2 and serves as a light transmission channel. The light-transmitting structure layer 4 can be a single-layer dielectric film or a multi-layer dielectric film.

[0030] The suction cup working surface 1 is provided with a vacuum adsorption area 1-1 and a distance sensor detection area 1-2, and the vacuum adsorption area 1-1 and the distance sensor detection area 1-2 are arranged on the same plane. The vacuum adsorption area 1-1 is used to place and adsorb the wafer, and the distance sensor detection area 1-2 is arranged as the detection surface of the distance sensor.

[0031] The distance sensor detection area 1-2 is a contact plane suitable for a contact sensor or a measurement light reflection surface suitable for a non-contact sensor. The matching sensor can be installed on a photolithography machine, and the specific installation position depends on the design structure of the photolithography machine, for example, it can be installed on the mask suction cup of the photolithography machine.

[0032] according to Figure 2 As shown, the distance sensor detection area 1-2 can be arranged around the vacuum adsorption area 1-1. Three or more distance sensors are evenly distributed above the distance sensor detection area 1-2, which is convenient for detecting the position direction of the wafer substrate, that is, the normal direction of the wafer substrate surface can be adjusted to coincide with the axial direction of the illumination light source. For the design of the reflective structure layer 2, when the wafer direction is configured in the above direction, the reflection effect is best.

[0033] like Figure 3 As shown, a metal structure layer 5 is disposed on the bottom surface of the reflective structure layer 2. The metal structure layer 5 plays a protective role, so that the reflective structure layer 2 is not easily damaged.

[0034] The wafer substrate used in the present invention is a single silicon wafer, a glass wafer or an organic material sheet wafer, or a stacked combination of at least two of the above three wafers.

[0035] The illumination or exposure light source used in the present invention is an ultraviolet light source.

[0036] On the basis of the suction cup structure, a light-guiding structure can be arranged around the reflective structure layer 2 and between the suction cup working surface 1. For the reflective structure with a through hole, when the light energy passes through the through hole area, refraction will occur. This part of the light energy will be emitted from the side of the reflective structure layer 2, and will be reflected multiple times in the light-guiding structure, and finally be guided out to a place far away from the wafer substrate suction cup, or be absorbed by the light energy absorbing structure (light trap) and converted into heat energy, which will then be transferred to the heat dissipation system.

[0037] The light-guiding structure may be made of ultraviolet-transmitting materials such as glass, crystal, polymer, or a cavity structure composed of reflective materials.

[0038] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A wafer substrate suction cup, comprising a suction cup body, characterized in that: The suction cup body has a suction cup working surface for adsorbing and fixing the wafer substrate and a reflective structure layer for reflecting light. The suction cup working surface is provided with a vacuum adsorption area, and the vacuum adsorption area is used to place and adsorb the wafer substrate. The reflective structure layer is arranged on the backlight surface of the suction cup working surface and is parallel to the suction cup working surface. When the light is transmitted from the light-facing surface of the suction cup working surface through the suction cup working surface, it is reflected at the reflective structure layer. The light reflected from the reflective structure layer passes through the suction cup working surface again and emits out of the wafer substrate suction cup, or emits out of the wafer substrate suction cup from the lateral end surface between the suction cup working surface and the reflective structure layer. The reflective structure layer comprises at least two layers, which are parallel to each other, and a light-transmitting structure layer is arranged between two adjacent reflective structure layers; It also includes a light-guiding structure and a light-energy absorbing structure. The light-guiding structure is arranged around the reflective structure layer and between the working surface of the suction cup. For the reflective structure with a through hole, when the light energy passes through the through hole area, refraction will occur, and this part of the light energy will be emitted from the side of the reflective structure layer. The light energy emitted from the side of the reflective structure layer will be reflected multiple times in the light-guiding structure, and finally be emitted to a place far away from the wafer substrate suction cup, or be absorbed by the light-energy absorbing structure.

2. The wafer substrate suction cup according to claim 1, characterized in that: The reflective structure layer is a single-layer dielectric film, a multi-layer dielectric film, a metal film or a grating structure capable of reflecting illumination or exposure light sources.

3. The wafer substrate suction cup according to claim 1, characterized in that: The distance sensor detection area is arranged on the working surface of the suction cup, the vacuum adsorption area and the distance sensor detection area are arranged on the same plane, and the distance sensor detection area is arranged as the detection surface of the distance sensor.

4. The wafer substrate suction cup according to claim 3, characterized in that: The detection surface is a contact plane suitable for a contact sensor or a measurement light reflection surface suitable for a non-contact sensor.

5. The wafer substrate suction cup according to claim 4, characterized in that: The distance sensor detection area surrounds the vacuum adsorption area.

6. The wafer substrate suction cup according to claim 1, characterized in that: A metal structure layer is arranged on the bottom surface of the reflective structure layer.

7. The wafer substrate suction cup according to claim 1, characterized in that: The wafer substrate is a single silicon wafer, a glass wafer or an organic material sheet wafer, or a stacked combination of at least two of the above three types of wafers.

8. The wafer substrate suction cup according to claim 1, characterized in that: The illumination or exposure light source is an ultraviolet light source.

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