US 12,251,879 B2
Methods of controlling dimensions in projection micro stereolithography
Chunguang Xia, San Diego, CA (US)
Assigned to BMF Nano Material Technology Co., Ltd., Shenzhen (CN)
Appl. No. 17/312,173
Filed by BMF Precision Technology (Wuxi) Inc., Wuxi (CN)
PCT Filed Nov. 6, 2019, PCT No. PCT/IB2019/001214
§ 371(c)(1), (2) Date Jun. 9, 2021,
PCT Pub. No. WO2020/121052, PCT Pub. Date Jun. 18, 2020.
Claims priority of provisional application 62/777,353, filed on Dec. 10, 2018.
Prior Publication US 2022/0048254 A1, Feb. 17, 2022
Int. Cl. B29C 64/393 (2017.01); B29C 64/124 (2017.01); B29C 64/40 (2017.01); B33Y 10/00 (2015.01); B33Y 40/20 (2020.01); B33Y 50/02 (2015.01); B33Y 70/00 (2020.01); B29K 33/00 (2006.01); B29K 71/00 (2006.01)
CPC B29C 64/393 (2017.08) [B29C 64/124 (2017.08); B29C 64/40 (2017.08); B33Y 10/00 (2014.12); B33Y 40/20 (2020.01); B33Y 50/02 (2014.12); B33Y 70/00 (2014.12); B29K 2033/26 (2013.01); B29K 2071/02 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method for positioning a first surface of a first substrate relative to a second surface of a second substrate, wherein the second substrate is a transparent membrane, the method comprising:
positioning the first substrate and a system comprising a lens having an optical axis, a charge-coupled device (CCD) capable of performing or assisting in performing an auto focusing program, and exactly one displacement sensor having an emission vector, in a manner such that the lens is situated between the first surface and the CCD, the optical axis of the lens intersects the first surface, the emission vector is parallel to the optical axis, and the CCD is focusable through the lens along the optical axis,
sequentially aligning each point of a first set of three non-linear points on the first surface with the emission vector by moving the first substrate perpendicular to the optical axis, measuring a distance between the displacement sensor and the first surface at each point of the first set of non-linear points, adjusting the first substrate so that the distances between the displacement sensor and each point of the first set of three non-linear points are equal to establish a level first surface,
placing the second substrate between the first substrate and the displacement sensor, sequentially aligning each point of a second set of three non-linear points on the second surface with the emission vector by moving the second substrate perpendicular to the optical axis, measuring a distance between the displacement sensor and the second surface at each point of the second set of non-linear points, adjusting the second substrate so that the distances between the displacement sensor and each point of the second set of three non-linear points are equal to establish the second surface parallel with the level first surface.