Image pickup unit, endoscope, and method for manufacturing image pickup unit

An endoscope comprising:

• an image pickup unit at a distal end of an insertion portion, the image pickup unit including:
• a three-dimensional wiring board including a recess;
• an image sensor and one or more optical lenses disposed in the recess;
• and
• resin disposed in a gap between an inner surface of the recess and an outer surface of the image sensor and the one or more optical lenses, wherein
• in the resin:
• a transmittance of light having a wavelength of 380 to 780 nm is equal to or lower than 0.5%;
• and
• a reflectance of the light having the wavelength of 380 to 780 nm is equal to or lower than 5%, and
• when a value of a bidirectional reflectance distribution function in a direction in which an azimuth angle from an incident surface is ϕr and a polar angle is θr, with a polar angle in an incident direction as θi is BRDF (θi, ϕr, θr), in a case where θi is 45 to 75 degrees, or is −60 to 60 degrees, and θr is −85 to 85 degrees, the value of the bidirectional reflectance distribution function is equal to or lower than 0.1 of incident light, wherein, ϕr≠0 and θi≠θr.

A method for manufacturing an image pickup unit, the method comprising:

• housing an image sensor and one or more optical lenses in a recess of a three-dimensional wiring board;
• connecting wiring of the three-dimensional wiring board and the image sensor via an external electrode;
• filling a first resin within a first portion of a gap between the recess and the image sensor and the one or more optical lenses, from a bottom surface of the recess to a first position of an aperture of the one or more optical lenses;
• and
• filling a second resin within a second portion of the gap, from the first position of the aperture to a second position adjacent to an outermost surface of the one or more optical lenses,
• wherein the first resin having a greater dielectric breakdown resistance value and a smaller viscosity than the second resin.