Chipworks reverse engineered Samsung Galaxy Note 3 and found that its 13MP primary camera uses the latest generation of Sony stacked image sensor, the IMX135. Sony moved all the electronics to the bottom logic chip, so that the sensor's area is barely larger than the pixel array:
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| IMX135 Die |
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| IMX135 TSVs |
It's quite similar to
iPhone 5s 8MP Sony ISX014 sensor, too having very little area overhead:
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| iPhone 5s primary sensor die |
Can someone explain me why are TSVs needed here? Metals of the BSI silicon layer seem to face the metals of the logic layer. Isn't it possible to use simple metal to metal contacts like Tezzaron does? Is this a patent related issue?
ReplyDeleteTezzaron's metal-to-metal connection requires that the chips be bonded face-to-face; this looks like a face-to-back scenario. Even so, a face-to-face bonding uses TSVs to get the signals out to the pads.
DeleteThe iPhone 5S uses a 8MP 1.5u-pixel stacked BSI custom-designed by Sony, not the ISX014 (8MP, 1.12u pixel)
ReplyDeleteCorrect. I've misinterpreted the Chipworks' article
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