News Column

Researchers Submit Patent Application, "Method for Making Image Sensors Using Wafer-Level Processing and Associated Devices", for Approval

May 6, 2014



By a News Reporter-Staff News Editor at China Weekly News -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors JIN, Yonggang (Singapore, SG); Herard, Laurent (Singapore, SG); Lim, WeeChinJudy (Singapore, SG), filed on October 15, 2012, was made available online on April 24, 2014.

The patent's assignee is Stmicroelectronics Asia Pacific Pte. Ltd.

News editors obtained the following quote from the background information supplied by the inventors: "Typically, electronic devices include one or more optical sensor modules for providing enhanced media functionality. For example, the typical electronic device may utilize the optical sensor modules for photo capturing and video teleconferencing. In the typical electronic device with multiple optical sensor modules, the primary optical sensor module has a high pixel density and an adjustable focus lens system, while the secondary optical sensor module is front-facing and has a lower pixel density. Also, the secondary optical sensor module may have a fixed focus lens system.

"For example, U.S. Patent Application No. 2009/0057544 to Brodie et al, assigned to the present application's assignee, discloses a optical sensor module for a mobile device. The optical sensor module comprises a lens, a housing carrying the lens, and a lens cap over the lens and housing. The optical sensor module includes a barrel mechanism for adjusting the lens. During manufacture of an electronic device including one or more optical sensor modules, there is a desire to manufacture the electronic device as quickly as possible, particularly in mass production runs.

"The typical optical sensor module is manufactured in a multi-step process. The first steps include semiconductor processing to provide the image sensor integrated circuit (IC). The next steps include some form of testing for the image sensor IC and packaging. The image sensor IC may be assembled into the optical sensor module, along with a lens and movable barrel if needed. This assembly of the optical sensor module may be performed manually or via machine. For example, in electronic devices that use surface mounted components, a pick-and-place (PNP) machine may assemble the components onto a printed circuit board (PCB). A drawback to such singular packaging is that it is inefficient and also may require that each device be tested individually, adding to the manufacturing time."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "In view of the foregoing background, it is therefore an object of the present disclosure to provide a method of making image sensor devices that is efficient and robust.

"This and other objects, features, and advantages in accordance with the present disclosure are provided by a method of making a plurality of image sensor devices that may comprise forming a sensor layer comprising a plurality of image sensor integrated circuits (ICs) in an encapsulation material, bonding a spacer layer to the sensor layer. The spacer layer may have a plurality of openings therein and aligned with the plurality of image sensor ICs. The method may further include bonding a lens layer to the spacer layer, with the lens layer comprising a plurality of lenses in an encapsulation material and aligned with the plurality of openings and the plurality of image sensor ICs. The method may include dicing the bonded-together sensor, spacer and lens layers to provide the plurality of image sensor devices. For example, the bonded together layers may comprise wafer sized layers. Advantageously, this wafer-level processing (WLP) method may extend the wafer fabrication process to include device interconnection and device protection processes.

"More specifically, the method may further comprise forming at least one electrically conductive via in the sensor layer, forming first and second electrically conductive layers respectively on first and second sides of the sensor layer, and forming a plurality of electrically conductive contacts on the first side of the sensor layer. The method may further comprise forming an adhesive layer on the second side of the sensor layer. For example, the plurality of electrically conductive contacts may comprise a ball grid array of electrically conductive contacts. The method may further comprise forming a passivation layer on each of the first and second sides of the sensor layer.

"Additionally, the forming of the sensor layer may comprise positioning the plurality of image sensor ICs on a first carrier layer, forming the encapsulation material on the plurality of image sensor ICs and the first carrier layer, and removing the first carrier layer. In some embodiments, the method may further comprise forming the spacer layer by at least positioning a plurality of sacrificial bodies on a second carrier layer, forming encapsulation material on the plurality of sacrificial bodies and the second carrier layer, and removing the second carrier layer. Also, the forming of the spacer layer may comprise thinning the spacer layer so that a thickness of the spacer layer is equal with that of each sacrificial body, forming an adhesive layer on the encapsulation material, forming recesses in the adhesive layer over each of the sacrificial bodies, and etching the plurality of sacrificial bodies to define the plurality of openings.

"Moreover, the method may further comprise forming the lens layer by at least forming a coating layer on a glass layer, dicing the glass layer to define the plurality of lenses, and positioning the plurality of lenses on a third carrier layer. The forming of the lens layer may further comprise forming the encapsulation material on the plurality of lenses and the third carrier layer, thinning the lens layer so that a thickness of the encapsulation material is equal to that of the plurality of lenses, and removing the third carrier layer.

"Another aspect is directed to an image sensor device that may comprise a sensor layer having first and second sides and comprising an encapsulation material layer, and a plurality of image sensor ICs therein, and a spacer layer over the first side of the sensor layer and comprising a plurality of openings therein aligned with the plurality of image sensor ICs. The image sensor device may also include a lens layer over the spacer layer and comprising an encapsulation material layer, and a plurality of lenses therein and aligned with the plurality of openings and the plurality of image sensor ICs.

BRIEF DESCRIPTION OF THE DRAWINGS

"FIG. 1 is a cross-section view of a plurality of image sensor devices, according to the present disclosure.

"FIG. 2 is an exploded view of the lens layer, the spacer layer, and sensor layer from the plurality of image sensor devices of FIG. 1.

"FIGS. 3A-3F are cross-section views of steps for forming the sensor layer of the image sensor devices of FIG. 1.

"FIGS. 4A-4G are cross-section views of steps for forming the spacer layer of the image sensor devices of FIG. 1.

"FIGS. 5A-5H are cross-section views of steps for forming the lens layer of the image sensor devices of FIG. 1."

For additional information on this patent application, see: JIN, Yonggang; Herard, Laurent; Lim, WeeChinJudy. Method for Making Image Sensors Using Wafer-Level Processing and Associated Devices. Filed October 15, 2012 and posted April 24, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=5803&p=117&f=G&l=50&d=PG01&S1=20140417.PD.&OS=PD/20140417&RS=PD/20140417

Keywords for this news article include: Singapore, Stmicroelectronics Asia Pacific Pte. Ltd.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


For more stories covering the world of technology, please see HispanicBusiness' Tech Channel



Source: China Weekly News


Story Tools






HispanicBusiness.com Facebook Linkedin Twitter RSS Feed Email Alerts & Newsletters