The present invention generally relates to microelectronic imagers including stacked lens assemblies, and more particularly, to an integrated lens stack used in an imager.
Microelectronic imagers are used in digital cameras, wireless devices with picture capabilities, products with IR or UV sensors, and many other applications. Cell phones and Personal Digital Assistants (PDAs), for example, often have microelectronic imagers for capturing and sending pictures. The growth rate of microelectronic imagers has been steadily increasing as they become smaller and produce better images with higher pixel counts.
Manufacture of optical elements by replication techniques, such as embossing or molding, is known. Of special interest for a cost effective mass production are wafer-scale manufacturing processes where an array of optical elements, e.g. lenses, is fabricated on a disk-like wafer by means of replication. In most cases, two or more wafers with optical elements attached thereto are stacked in order to form a wafer scale package where optical elements attached to different substrates are aligned. Subsequent to replication, this wafer structure can be separated into individual optical devices (dicing).
A wafer or substrate in the meaning used is a disc or a rectangular plate or a plate of any other shape of any dimensionally stable, often transparent material. The diameter of a wafer disk is typically between 5 cm and 40 cm, for example between 10 cm and 31 cm. Often it is cylindrical with a diameter of either 2, 4, 6, 8 or 12 inches, one inch being about 2.54 cm. The wafer thickness is for example between 0.2 mm and 10 mm, typically between 0.4 mm and 6 mm. The subsequent dicing step of the wafer then yields many individual optical devices.
Typically, an integrated optical device includes at least two optical elements stacked together along the general direction of light propagation. The light travelling through the optical elements from one side of the optical element to the other side of the optical element is substantially parallel to the optical axis, such that an optical boundary of the side is nearly as large as an optical boundary of the other side of the optical element. While the optical device is diced to fit with an array camera image sensor, an aperture will be provided at a side of the optical device. As the dicing process of the optical device is a process that generates dust and chip, the dust enables penetrating the aperture. It will need an extra process to clean the optical device, which limits the structure of the optical device, and leads to increased cost.
Many aspects of the exemplary embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiments.
Reference will now be made to describe the exemplary embodiments of the present disclosure in detail.
Referring to
The image sensor 110 is used for collecting light from the corresponding lens module 120. The image sensor is a necessary component to manufacture a finished integrated lens stack. The image sensor can be obtained in the public-known arts. The shapes, forms, engaging relationships, and sizes of the element of the image sensor do not affect the engagement of the lens module.
A second embodiment of the present disclosure is shown in
While the present invention has been described with reference to the specific embodiments, the description of the invention is illustrative and is not to be construed as limiting the invention. Various of modifications to the present invention can be made to the exemplary embodiments by those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims.
Number | Date | Country | Kind |
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201310272320.8 | Jun 2013 | CN | national |