A nanoimprint metal mold and its assembly method

Abstract

This invention discloses a nano-imprint metal mold and its assembly method, comprising a mold frame, a mold core, and a pressing block. The mold frame is made of metal, and its top surface has multiple through holes, each of which is a stepped hole. The holes closer to the top surface are of smaller diameter, and those closer to the bottom surface are of larger diameter. The mold core is a cylinder with a top diameter smaller than its bottom diameter, and a stepped surface between the top and bottom. An imprinting lens is mounted on the top surface of the mold core. The number of mold cores is the same as the number of through holes, with one mold core located within one through hole. The top of the mold core is interference-fitted with the small-diameter hole, and the bottom of the mold core is located within the large-diameter hole. The height of the top of the mold core is greater than the height of the small-diameter hole, and the height of the bottom of the mold core is less than the height of the large-diameter hole. The pressing block is located on top of the mold frame, and its diameter is greater than the top diameter of the mold core. The flatness of the bottom surface of the pressing block is <1μm. This method enables the arrangement and processing of a lens array, and the height error between the lens and the mold frame surface can be controlled within 5μm.

Description

Technical Field

[0001] This invention belongs to the field of WLO wafer processing and relates to a nanoimprint metal mold and assembly method. Background Technology

[0002] WLO (Wafer-Level Optical Components) refers to wafer-level lens manufacturing technology and processes. Unlike traditional optical component processing techniques, the WLO process uses semiconductor technology to mass-produce lenses on a single glass wafer. Multiple lens wafers are laminated together and then diced into individual lenses, resulting in small size, low height, and good consistency. Existing molds include glass molds and silicon substrate molds. These molds are generally expensive, have short lifespans, and are limited by the process, making them unsuitable for lenses with a height greater than 100μm. This limits their ability to meet certain optical design requirements and concave lens processing schemes, and they are prone to fragmentation or surface instability during demolding. Metal molds can process lenses larger than 100μm using lathe tools, achieving a mold surface quality PV < 0.05μm, but they cannot be used for full-plate array processing. If full-plate array processing is used, the mold surface processing accuracy PV cannot be achieved below 0.1μm, ultimately affecting the lens surface quality and product imaging performance. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a nano-imprint metal mold and assembly method that can arrange and process lens arrays and control the height error between the lens and the mold base surface to within 5μm.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] A nanoimprint metal mold includes a mold frame, a mold core, and a pressing block;

[0006] The mold frame is made of metal, and the top surface of the mold frame has multiple through holes. Each through hole is a stepped hole, with small diameter holes near the top surface and large diameter holes near the bottom surface.

[0007] The mold core is cylindrical, with a top diameter smaller than a bottom diameter. A stepped surface is provided between the top and bottom, and an imprinting lens is provided on the top surface of the mold core.

[0008] The number of mold cores is the same as the number of through holes. One mold core is located in one through hole. The top of the mold core is interference-fitted with the small-diameter hole, and the bottom of the mold core is located in the large-diameter hole. The height of the top of the mold core is greater than the height of the small-diameter hole, and the height of the bottom of the mold core is less than the height of the large-diameter hole.

[0009] The pressure block is located at the top of the mold frame, and the diameter of the pressure block is larger than the top diameter of the mold core. The flatness of the bottom surface of the pressure block is <1μm.

[0010] Preferably, the bottom center of the pressing block has an opening, the size of which is smaller than the top diameter of the mold core and greater than 3mm.

[0011] Preferably, the material for the pressing block is bakelite.

[0012] Preferably, there are 25 through holes arranged in a 5×5 pattern.

[0013] Preferably, the bottom of the mold core is provided with an axial threaded hole.

[0014] Furthermore, the diameter of the threaded hole is 3mm.

[0015] Preferably, the height of the through hole is greater than or equal to the height of the mold core.

[0016] Preferably, the diameter of the small-diameter hole is 9mm, and the diameter of the large-diameter hole is 12mm.

[0017] Preferably, the height of the small-diameter hole is 8mm, and the height of the large-diameter hole is 3mm.

[0018] An assembly method for the nano-imprint metal mold involves inserting the mold core from the bottom of the mold frame into a through hole, inserting the top of the mold core into a small-diameter hole, and having the top surface of the mold core extend beyond the top surface of the mold frame. A pressure block is used to press down on the top surface of the mold core to make the top surface of the mold core and the top surface of the mold frame flush. The mold core is then assembled in each through hole according to the above method.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention can press the imprinting lens on the top of the mold core down to be flush with the top surface of the mold frame by pressing the pressure block, and the top of the mold core is interference-fitted with the small diameter hole to prevent the mold core from moving downward. Since the flatness of the bottom surface of the pressure block is <1μm, the height error between the lens and the surface of the mold frame can be controlled within 5μm, thereby realizing the whole plate array arrangement processing on the metal mold frame. Furthermore, by using a metal mold frame, the phenomenon of fragmentation or unstable surface shape during demolding can be avoided. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the top surface of the mold frame of the present invention;

[0022] Figure 2 This is a schematic diagram of the through-hole structure of the mold frame of the present invention;

[0023] Figure 3 This is a side perspective view of the mold core of the present invention;

[0024] Figure 4 This is a bottom view of the mold core of the present invention;

[0025] Figure 5 This is a schematic diagram showing the dimensional relationship between the mold frame and the mold core of the present invention;

[0026] Figure 6 This is an assembly diagram of the present invention.

[0027] Wherein: 1-mold frame; 2-through hole; 3-mold core; 4-pressure block. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] It should be noted that the terms “front,” “back,” “left,” “right,” “up,” and “down” used in the following description refer to the directions shown in the attached diagram, while the terms “inside” and “outside” refer to the directions toward or away from the geometric center of a specific component, respectively.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] The nano-imprint metal mold of the present invention includes a mold frame 1, a mold core 3 and a pressing block 4.

[0032] like Figure 1 As shown, the material of the mold frame 1 is metal. The mold frame 1 is a circular plate structure with a diameter of 200mm and a thickness of 11mm. Multiple through holes 2 are arranged on the top surface of the mold frame 1. In this embodiment, the preferred number of through holes 2 is 25, arranged in a 5×5 arrangement. The overall size after the arrangement is less than 90mm×90mm.

[0033] like Figure 2 As shown, each through hole 2 is a stepped hole with an inverted T-shaped cross-section. The hole near the top of the mold frame 1 is a small diameter hole, and the hole near the bottom of the mold frame 1 is a large diameter hole. The diameter of the small diameter hole is 9mm, the tolerance is positive, and the height is 8mm. The diameter of the large diameter hole is 12mm and the height is 3mm.

[0034] like Figure 3As shown, the number of mold cores 3 is the same as the number of through holes 2. One mold core 3 is located in one through hole 2. The mold core 3 is a cylinder with a top diameter smaller than the bottom diameter. A stepped surface is provided between the top and bottom. An embossing lens is provided on the top surface of the mold core 3. The embossing lens is used for embossing pattern reproduction. The cross-section of the embossing part has a wavy structure with the center protruding from the top surface.

[0035] The bottom of mold core 3 is a circular structure with a height of less than 3mm and a diameter of 11mm. The top is a cylinder with a height of more than 8mm and a diameter of 9mm, and the tolerance of the top diameter is negative.

[0036] like Figure 4 As shown, the bottom of mold core 3 is a circle with a diameter of 11mm and a flat opening. The shortest line segment length between the flat opening and the bottom of mold core 3 is 4.7mm. An M3 threaded hole is axially opened at the center of the bottom of mold core 3 for subsequent fixing of mold core 3 and surface machining.

[0037] like Figure 5 As shown, the top of the mold core 3 is interference-fitted with the small-diameter hole, and the bottom of the mold core 3 is located in the large-diameter hole. The height H1 of the top of the mold core 3 is greater than the height H2 of the small-diameter hole, and the height H4 of the bottom of the mold core 3 is less than the height H3 of the large-diameter hole.

[0038] The height of through hole 2 is greater than or equal to the height of mold core 3.

[0039] like Figure 6 As shown, the pressure block 4 is located on the top of the mold frame 1. There is one pressure block 4. The diameter of the pressure block 4 is larger than the top diameter of the mold core 3. The flatness of the bottom surface of the pressure block 4 is <1μm. The material of the pressure block 4 is bakelite. A circular opening is provided at the center of the bottom of the pressure block 4. The opening size is smaller than the top diameter of the mold core 3 and larger than 3mm.

[0040] During assembly, the mold core 3 is inserted into the through hole 2 from the bottom of the mold frame 1, and the top of the mold core 3 is inserted into the small diameter hole, with the top surface of the mold core 3 extending out of the top surface of the mold frame 1. The pressure block 4 is used to press down the top surface of the mold core 3. The opening of the pressure block 4 is located within the top range of the mold core 3, and the outer circle of the pressure block 4 is located outside the mold core 3, making the top surface of the mold core 3 and the top surface of the mold frame 1 level. The bottom of the mold core 3 must not be lower than the bottom of the mold frame 1. The pressure block 4 is used to press down the imprinting lens on the top of the mold core 3 until it is level with the top surface of the mold frame 1. The top of the mold core 3 is also interference-fitted with the small diameter hole to prevent the mold core 3 from moving downward. 25 mold cores 3 are assembled in the above manner. Since the flatness of the bottom surface of the pressure block 4 is <1μm, the height difference between the surface of the mold core 3 and the surface of the mold frame 1 can be controlled within 5μm, which meets the imprinting requirements. This enables the whole-plate array arrangement processing on the metal mold frame 1. Furthermore, by using the metal mold frame 1, the phenomenon of fragmentation or unstable surface shape during demolding can be avoided.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0042] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this teaching should not be determined by reference to the above description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed inventive subject matter.

Claims

1. A nano-imprint metal mold, characterized in that, It includes a mold frame (1), a mold core (3), and a pressure block (4); The mold frame (1) is made of metal. The top surface of the mold frame (1) is provided with multiple through holes (2). Each through hole (2) is a stepped hole. The hole near the top surface of the mold frame (1) is a small diameter hole, and the hole near the bottom surface of the mold frame (1) is a large diameter hole. The mold core (3) is a cylinder with a top diameter smaller than the bottom diameter. A stepped surface is provided between the top and bottom. An imprinting lens is provided on the top surface of the mold core (3). The number of mold cores (3) is the same as the number of through holes (2). One mold core (3) is located in one through hole (2). The top of the mold core (3) is interference-fitted with the small diameter hole, and the bottom of the mold core (3) is located in the large diameter hole. The height of the top of the mold core (3) is greater than the height of the small diameter hole, and the height of the bottom of the mold core (3) is less than the height of the large diameter hole. The pressure block (4) is located at the top of the mold frame (1). The diameter of the pressure block (4) is larger than the top diameter of the mold core (3). The flatness of the bottom surface of the pressure block (4) is <1μm.

2. The nanoimprint metal mold according to claim 1, characterized in that, The bottom center of the pressure block (4) has an opening, the size of which is smaller than the top diameter of the mold core (3) and greater than 3mm.

3. The nanoimprint metal mold according to claim 1, characterized in that, The material of the pressing block (4) is bakelite.

4. The nanoimprint metal mold according to claim 1, characterized in that, There are 25 through holes (2), arranged in a 5×5 array.

5. The nanoimprint metal mold according to claim 1, characterized in that, The bottom of the mold core (3) is provided with an axial threaded hole.

6. The nanoimprint metal mold according to claim 5, characterized in that, The diameter of the threaded hole is 3mm.

7. The nanoimprint metal mold according to claim 1, characterized in that, The height of the through hole (2) is greater than or equal to the height of the mold core (3).

8. The nanoimprint metal mold according to claim 1, characterized in that, The small-diameter hole has a diameter of 9mm, and the large-diameter hole has a diameter of 12mm.

9. The nanoimprint metal mold according to claim 1, characterized in that, The height of the small-diameter hole is 8mm, and the height of the large-diameter hole is 3mm.

10. An assembly method based on the nanoimprint metal mold according to any one of claims 1-9, characterized in that, Insert the mold core (3) into the through hole (2) from the bottom of the mold frame (1), insert the top of the mold core (3) into the small diameter hole, and extend the top surface of the mold core (3) out of the top surface of the mold frame (1). Use the pressure block (4) to press down the top surface of the mold core (3) to make the top surface of the mold core (3) and the top surface of the mold frame (1) level. Assemble the mold core (3) in each through hole (2) according to the above method.

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