Delidding
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Decapping (decapsulation) or delidding of an
integrated circuit An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components a ...
(IC) is the process of removing the protective cover or
integrated heat spreader A heat spreader transfers energy as heat from a hotter source to a colder heat sink or heat exchanger. There are two thermodynamic types, passive and active. The most common sort of passive heat spreader is a plate or block of material having hi ...
(IHS) of an integrated circuit so that the contained die is revealed for
visual inspection Visual inspection is a common method of quality control, data acquisition, and data analysis. Visual Inspection, used in maintenance of facilities, mean inspection of equipment and structures using either or all of raw human senses such as vision, ...
of the micro circuitry imprinted on the die. This process is typically done in order to debug a manufacturing problem with the chip, or possibly to copy information from the device, to check for counterfeit chips or to reverse engineer it. Companies such as TechInsights and ChipRebel decap, take
die shot A die shot or die photography is a photo or recording of the layout of an integrated circuit, showings its design with any packaging removed. A die shot can be compared with the cross-section of an (almost) two-dimensional computer chip, on whic ...
s of, and reverse engineer chips for customers. Modern integrated circuits can be encapsulated in plastic,
ceramic A ceramic is any of the various hard, brittle, heat-resistant, and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcela ...
, or epoxy packages. Delidding may also be done to test the chip for radiation-tolerance with a heavy-ion beam or in an effort to reduce the operating temperatures of an integrated circuit such as a processor, by replacing the thermal interface material (TIM) between the die and the IHS with a higher-quality TIM. With care, it's possible to decap a device and still leave it functional.


Method

Decapping is usually carried out by chemical etching of the covering, laser cutting, laser evaporation of the covering,
plasma etching Plasma etching is a form of plasma processing used to fabricate integrated circuits. It involves a high-speed stream of glow discharge (Plasma (physics), plasma) of an appropriate gas mixture being shot (in pulses) at a sample. The plasma source, ...
or mechanical removal of the cover using a
milling machine Milling is the process of machining using rotary cutters to remove material by advancing a cutter into a workpiece. This may be done by varying directions on one or several axes, cutter head speed, and pressure. Milling covers a wide variety of ...
, saw blade, using hot air or by desoldering and cutting. The process can be either destructive or non-destructive of the internal die. Chemical etching usually involves subjecting the (if made of plastic)
IC package Integrated circuits and certain other electronic components are put into protective packages to allow easy handling and assembly onto printed circuit boards and to protect the devices from damage. A very large number of package types exist. So ...
to concentrated or fuming nitric acid, heated concentrated
sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, ...
, white fuming nitric acid or a mixture of the two for some time, possibly while applying heat externally with a hot plate or hot air gun, which dissolve the package while leaving the die intact. The acids are dangerous, so protective equipment such as appropriate gloves, full face respirator with appropriate acid cartridges, a lab coat and a fume hood are required. Laser decapping scans a high power laser beam across the plastic IC package to vaporize it, while avoiding the actual silicon die. In a common version of non-destructive, mechanical delidding, one removes the IHS of an IC such as a computer processor using an oven to soften the solder (if present) between the IHS and the die(s) and using a knife to cut the adhesive in the periphery of the IHS, which joins the IHS with the processor package substrate, which is often a specialized printed circuit board often only called a substrate or sometimes an interposer. In many processors the dies are also soldered to the IHS which can still be removed by applying heat until the solder melts, and removing the IHS while the solder is still liquid. The die(s) are mounted on the substrate using
flip chip Flip chip, also known as controlled collapse chip connection or its abbreviation, C4, is a method for interconnecting dies such as semiconductor devices, IC chips, integrated passive devices and microelectromechanical systems (MEMS), to exter ...
.


Gallery

AMD@7nm(12nmIOD)@Zen2@Rome@EPYC 7702 ES@2S1404E2VJUG5 BB ES DSCx1.jpg, AMD
Zen 2 Zen 2 is a computer processor microarchitecture by AMD. It is the successor of AMD's Zen and Zen+ microarchitectures, and is fabricated on the 7 nm MOSFET node from TSMC. The microarchitecture powers the third generation of Ryzen processors, kn ...
EPYC 7702 server processor, before delidding AMD@7nm(12nmIOD)@Zen2@Rome@EPYC 7702 ES@2S1404E2VJUG5 BB ES DSCx3.jpg, AMD EPYC 7702 after delidding, with remains of solder thermal interface material (TIM). AMD@7nm(12nmIOD)@Zen2@Rome@EPYC 7702 ES@2S1404E2VJUG5 BB ES DSCx6 IOD top metal@5x.jpg, Removed and flipped over center die before metallization etching; visible are pads for
flip chip Flip chip, also known as controlled collapse chip connection or its abbreviation, C4, is a method for interconnecting dies such as semiconductor devices, IC chips, integrated passive devices and microelectromechanical systems (MEMS), to exter ...
solder balls AMD@7nm(12nmIOD)@Zen2@Rome@EPYC 7702 ES@2S1404E2VJUG5 BB ES DSCx13 IOD polysilicon@5x.jpg, Die shot of the center die, after removal from processor package substrate and metallization etching. AMD@7nm(12nmIOD)@Zen2@Rome@EPYC 7702 ES@2S1404E2VJUG5 BB ES DSCx16 CCD polysilicon@5xLED.jpg, Die shot of one of the 8 other dies on the processor, after metallization etching. AMD@7nm(12nmIOD)@Zen2@Rome@EPYC 7702 ES@2S1404E2VJUG5 BB ES DSCx15 IOD+CCD metalsteps notes.jpg, Copper interconnect (metallization) etching (removal) steps


See also

*
Die shot A die shot or die photography is a photo or recording of the layout of an integrated circuit, showings its design with any packaging removed. A die shot can be compared with the cross-section of an (almost) two-dimensional computer chip, on whic ...
*
Reverse engineering Reverse engineering (also known as backwards engineering or back engineering) is a process or method through which one attempts to understand through deductive reasoning how a previously made device, process, system, or piece of software accompl ...
* Sample preparation equipment


References

{{Reflist Integrated circuits