Abstract: A vertical stack type multi-chip package is provided having improved reliability by increasing the grounding performance and preventing the decrease in reliability of the multi-chip package from moisture penetration into a lower semiconductor chip. The vertical stack type multi-chip package comprises an organic substrate having a printed circuit pattern on which a semiconductor chip is mounted. A first semiconductor chip is mounted on a die bonding region of the organic substrate and is electrically connected to the organic substrate through a first wire. A metal stiffener is formed on the first semiconductor chip and connected to the organic substrate by a first ground unit around the first semiconductor chip. An encapsulant is used to seal the first semiconductor chip below the metal stiffener. A second semiconductor chip, which is larger in size than that the first semiconductor chip, is mounted on the metal stiffener and connected by a second ground unit.

Abstract: Disclosed in a semiconductor device including a semiconductor chip including an electrode, a projection electrode, an sealing film for encapsulating the semiconductor chip and the projection electrode, a first wiring lines provided on one surface of the sealing film, which is electrically connected with the electrode and the projection electrode, a second wiring lines provided on the other surface of the sealing film, which is electrically connected with the projection electrode and at least one of a first via hole conductor for electrically connecting the first wiring lines and the projection electrode or a second via hole conductor for electrically connecting the second wiring lines and the projection electrode, and an area of the projection electrode in an interface where the projection electrode and the first via hole conductor contact each other is greater than an area of the first via hole conductor in the interface and an area of the projection electrode in an interface where the projection electrode a

Abstract: An integrated circuit (IC) die includes two bonding pads, that share a common logical function, such as signal input or signal output, separated by the width of the die, and preferably on opposite sides of the die. System-in-package devices are produced by steps including directly electrically connecting one or the other bonding pad to bonding pads of other, functionally different IC dies, with the bonding pads of the other IC dies, to which are connected bonding pads of common logical function of the IC dies of the present invention, being functionally identical but geometrically different. Multichip package devices are produced by stacking the IC dies of the present invention with other IC dies and directly electrically connecting one or the other bonding pad to different bonding pads of the other IC dies.

Abstract: A method is disclosed for packaging semiconductor chips on a flexible substrate employing thin film transfer. The semiconductor chips are placed on a temporary adhesive substrate, then covered by a permanent flexible substrate with a casting layer for planarizingly embedding the chips on the permanent substrate before removing the temporary substrate. With the surface of the chips coplanar with the surface of the complete structure without any gaps, interconnect metal lines can be easily placed on the uninterrupted surface, connecting the chips and other components.

Abstract: A package-on-package system includes: providing an interposer substrate; mounting a base substrate under the interposer substrate and having a first integrated circuit die connected thereto; forming an encapsulant between the interposer substrate and the base substrate, the encapsulant encapsulating the first integrated circuit die; and forming a via z-interconnection extending through the encapsulant and one of the substrates to the other of the substrates.

Abstract: An integrated circuit package system comprising: providing a substrate; attaching an integrated circuit die over the substrate; attaching a connector to the integrated circuit die and the substrate; and forming an encapsulant over the substrate, the integrated circuit die, and the connector and minimizing ambient gas deformation of the substrate to keep the connector from touching another connector.

Abstract: An electronic device includes a packaged integrated circuit having an integrated circuit die having an active surface, and a molding compound overlaying the active surface of the integrated circuit die. In a particular embodiment, the packaged integrated circuit includes at least approximately five weight percent (5 wt %) zinc relative to the molding compound. In another embodiment, the packaged integrated circuit includes approximately 0.3 ?mol/cm2 of zinc in an area parallel to the active surface of the integrated circuit die.

Abstract: A method of manufacture of an integrated circuit packaging system includes: providing a base circuit assembly having an integrated circuit device; mounting a pre-formed conductive frame having an outer interconnect and an inner interconnect shorter than the outer interconnect over the base circuit assembly, the inner interconnect over the integrated circuit device and the outer interconnect around the integrated circuit device; applying an encapsulant over the inner interconnect and the outer interconnect; and removing a portion of the pre-formed conductive frame exposing an end of the inner interconnect and an end of the outer interconnect.

Abstract: A method of manufacture of an integrated circuit packaging system includes: providing a base strip having a base top side; forming a terminal body with a substantially spherical shape partially in the base strip; attaching a device adjacent the terminal body and over the base top side, a device mount side of the device below a top portion of the terminal body; attaching a device connector to the device and the top portion of the terminal body; applying an encapsulant over the device connector, the device, and the top portion of the terminal body; and removing the base strip providing the terminal body partially exposed from the encapsulant.

Abstract: Disclosed herein is a die package including an encapsulated die, including: a die including pads on one side thereof; an encapsulation layer covering lateral sides of the die; a support layer covering the encapsulation layer and one side of the die; a passivation layer formed on the other side of the die such that the pads are exposed therethrough; and a redistribution layer formed on the passivation layer such that one part thereof is connected with the pad. Here, since one side of the die is supported by the support layer and the encapsulation layer is formed on only the lateral side of the die, the warpage of the die package due to the difference in thermal expansion coefficient can be minimized.

Abstract: A method of manufacture of an integrated circuit packaging system includes: providing a structure having a via filled with conductive material completely through the structure, a recess, and a pedestal portion bordering the recess; mounting a semiconductor device inside the recess in the structure; and encapsulating the structure and the semiconductor device in an encapsulation.

Abstract: A semiconductor device is made by forming a first conductive layer over a first temporary carrier having rounded indentations. The first conductive layer has a non-linear portion due to the rounded indentations. A bump is formed over the non-linear portion of the first conductive layer. A semiconductor die is mounted over the carrier. A second conductive layer is formed over a second temporary carrier having rounded indentations. The second conductive layer has a non-linear portion due to the rounded indentations. The second carrier is mounted over the bump. An encapsulant is deposited between the first and second temporary carriers around the first semiconductor die. The first and second carriers are removed to leave the first and second conductive layers. A conductive via is formed through the first conductive layer and encapsulant to electrically connect to a contact pad on the first semiconductor die.

Abstract: A semiconductor including a selectively plated lead frame is disclosed. The lead frame contains a die pad and a plurality of lead fingers, where each lead finger is formed with a bonding pad on the center portion of the lead finger by selective plating. The surface area of the lead finger material is increased so the adhesion to molding material is improved. The edges of the lead finger tips are half etched to further increase the surface area of lead finger material. A method of manufacturing the lead frame is also provided.

Abstract: Organic anti-stiction coatings such as, for example, hydrocarbon and fluorocarbon based self-assembled organosilanes and siloxanes applied either in solvent or via chemical vapor deposition, are selectively etched using a UV-Ozone (UVO) dry etching technique in which the portions of the organic anti-stiction coating to be etched are exposed simultaneously to multiple wavelengths of ultraviolet light that excite and dissociate organic molecules from the anti-stiction coating and generate atomic oxygen from molecular oxygen and ozone so that the organic molecules react with atomic oxygen to form volatile products that are dissipated, resulting in removal of the exposed portions of the anti-stiction coating. A hybrid etching process using heat followed by UVO exposure may be used. A shadow mask (e.g., of glass or quartz), a protective material layer, or other mechanism may be used to selective expose the portions of the anti-stiction coating to be UVO etched.

Abstract: A semiconductor package has a first substrate having a plurality of metal traces. At least one die is electrically coupled to the first surface of the first substrate. A plurality of land pads is formed on the first surface of the first substrate. A mold compound encapsulates portions of the die and portions of the first surface of the first substrate. A conductive coating is applied to the mold compound and electrically coupled to at least one metal trace. A non-conductive coating is formed over the conductive coating and portions of the mold compound. A plurality of vias is formed through the non-conductive coating and the mold compound to expose the land pads.

Abstract: In a semiconductor device made of a plurality of materials, if the device is fabricated through a step of cutting the bonded plurality of materials, a boundary line of the plurality of materials is exposed on a cutting plane. Internal stress in the cutting remains at this boundary line to allow moisture and corrosive gas to easily enter into the device. In order to reduce the entrance of the moisture, the gas, and the like, the boundary appearing on the cutting plane is covered by a covering layer. At this time, partial cutting exposing the boundary line and not separating semiconductor devices are performed so that the covering layer can be formed with the plurality of semiconductor devices attached to the substrate.

Abstract: The size of a semiconductor device is reduced. A semiconductor chip in which a power MOSFET is placed above a semiconductor chip in which another power MOSFET is formed and they are sealed with an encapsulation resin portion. The semiconductor chips are so arranged that the upper semiconductor chip does not overlap with the area positioned directly above a gate pad electrode of the lower semiconductor chip. The semiconductor chips are identical in size and the respective source pad electrodes and gate pad electrodes of the lower semiconductor chip and the upper semiconductor chip are identical in shape and arrangement. The lower semiconductor chip and the upper semiconductor chip are arranged with their respective centers displaced from each other.

Abstract: An adhesive tape 101 electrically connecting conductive components includes a resin layer 132 containing a thermosetting resin, a solder powder 103 and a curing agent. The solder powder 103 and the curing agent reside in the resin layer 132, the curing temperature T1 of the resin layer 132 and the melting point T2 of the solder powder 103 satisfy T1?T2+20° C., wherein the resin layer 132 shows a melt viscosity of 50 Pa·s or above and 5000 Pa·s or below, at the melting point T2 of the solder powder 103.

Abstract: A semiconductor package comprises a conduction member, a semiconductor chip mounted on and electrically connected to the conduction member, and a sealing body configured to seal the conduction member and the semiconductor chip. The conduction member comprises a power supply section configured to supply a power voltage to said semiconductor chip, a ground section configured to supply a ground voltage to the semiconductor chip, and a signal section connected to a signal terminal of the semiconductor chip. The power supply section, the ground section, and the signal section are arranged so as not to overlap each other. At least a part of said ground section is exposed on an under surface of the sealing body. The power supply section comprises an exposed region of which bottom surface is exposed on the under surface, and a plurality of power hanging-pin region configured to extend to a side of the sealing body from the exposed region.

Abstract: A semiconductor chip package is disclosed. One embodiment provides at least one semiconductor chip including contact elements on a first surface of the chip. An encapsulation layer covers the semiconductor chip. A metallization layer is applied above the first surface of the chip and the encapsulation layer. The metallization layer includes contact areas connected with the contact elements of the chip. External pins are connected with the contact areas.

Abstract: A method of manufacture of an integrated circuit packaging system includes: providing a substrate; attaching an interconnect to the substrate; encapsulating the interconnect with an encapsulation leaving a portion of the interconnect not encapsulated; attaching a joint to the interconnect and simultaneously creating a coined-surface of the interconnect contacting the joint; and attaching an integrated circuit to the substrate.

Abstract: In an embodiment, the invention provides a SLCC package comprising first and second electrically conductive terminals, a polysiloxane and glass fiber structural body, a light source and a polysiloxane encapsulant. The first and second electrically conductive terminals are attached to the polysiloxane and glass fiber structural body. The light source is electrically connected to the first and second electrically conductive terminals. The polysiloxane and glass fiber structural body has a cavity that contains at least a portion of the polysiloxane encapsulant.

Abstract: A method for producing a nitride semiconductor laser light source is provided. The nitride semiconductor laser light source has a nitride semiconductor laser chip, a stem for mounting the laser chip thereon, and a cap for covering the laser chip. The laser chip is encapsulated in a sealed container composed of the stem and the cap. The method for producing this nitride semiconductor laser light source has a cleaning step of cleaning the surface of the laser chip, the stem, or the cap. In the cleaning step, the laser chip, the stem, or the cap is exposed with ozone or an excited oxygen atom, or baked by heat. The method also has, after the cleaning step, a capping step of encapsulating the laser chip in the sealed container composed of the stem and the cap. During the capping step, the cleaned surface of the laser chip, the stem, or the cap is kept clean.

Abstract: A semiconductor device with plastic housing composition includes an internal wiring that is electrically insulated from the plastic housing composition by an insulation layer. The plastic housing composition has a high thermal conductivity and a low coefficient of expansion, the coefficient of expansion being adapted to the semiconductor chip of the semiconductor device. This is achieved by forming the plastic housing composition with electrically semiconducting and/or electrically conducting filler particles. In particular, this plastic housing composition is advantageously used for semiconductor devices with flip-chip contacts and/or for semiconductor devices which are constructed according to the “universal packaging concept”.

Abstract: A MEMS microphone package includes a carrier, an application specific IC, an encapsulant and a microphone chip. The application specific IC and the microphone chip are respectively disposed on first and second surfaces of the carrier, and the application specific IC and the microphone chip are electrically connected to the carrier. The encapsulant includes first and second encapsulants, the first encapsulant is formed on the first surface to seal the application specific IC, the second encapsulant is formed on the second surface to become a cavity and the microphone chip is located at the cavity. Because the application specific IC and the microphone chip are disposed on the first and second surfaces of the carrier, respectively, the second encapsulant surrounds the microphone chip, and the first and second encapsulants are formed at the same time, it can increase the structural strength of package and reduce the process.

Abstract: A semiconductor device has a substrate containing a conductive layer. An interconnect structure is formed over the substrate and electrically connected to the conductive layer. A semiconductor component is mounted to the substrate. An encapsulant is deposited over the semiconductor component and interconnect structure. A channel is formed in the encapsulant to expose the interconnect structure. Solder paste is deposited in the channel prior to forming the shielding layer. A shielding layer is formed over the encapsulant and semiconductor component. The shielding layer can be conformally applied over the encapsulant and semiconductor die and into the channel. The shielding layer extends into the channel and electrically connects to the interconnect structure. A docking pin is formed on the shielding layer, which extends into the channel and electrically connects to the interconnect structure. A chamfer area is formed around a perimeter of the shielding layer.

Abstract: The device includes at least one optoelectronic component positioned on a substrate and at least one transparent face. The component is covered by a packaging layer which includes at least one barrier layer and a moisture-reactive layer. The reactive layer includes a moisture-reactive material chosen from alkaline-earth metals, alkali metals and organo-metallic derivatives. The material can be positioned in the moisture-reactive layer in the form of a continuous layer or in the form of a plurality of nodules dispersed in an organic matrix.

Abstract: Flip chip ball grid array semiconductor devices and methods for fabricating the same. In one example, a near chip scale method of semiconductor die packaging may comprise adhering the die to a substrate in a flip chip configuration, coating the die with a first polymer layer, selectively removing the first polymer layer to provide at least one opening to expose a portion of the die, and depositing a first metal layer over the first polymer layer, the first metal layer at least partially filling the at least one opening to provide an electrical contact to the die, and including a portion that substantially surrounds the die in a plane of an upper surface of the first metal layer to provide an electromagnetic shield around the die.

Abstract: An epoxy resin composition for encapsulating a semiconductor device, the epoxy resin composition including an epoxy resin, a curing agent, and one or more inorganic fillers, the one or more inorganic fillers including prismatic cristobalite, the prismatic cristobalite being present in the epoxy resin composition in an amount of about 1 to about 50% by weight, based on the total weight of the epoxy resin composition.

Abstract: A method includes: mounting a plurality of semiconductor elements on a substrate having wirings; connecting electrically electrodes of the semiconductor elements and the wirings; sealing the semiconductor elements with a resin, which is carried out by bringing a thermal conductor having a concavity and the substrate to be in contact with each other so that the semiconductor elements are positioned within the concavity and by filling the concavity with the resin; and separating respective semiconductor elements 1. In the resin-sealing step, in a state where the thermal conductor is arranged with its concavity facing up and the concavity of the thermal conductor is filled with a liquid resin, the semiconductor elements are dipped in the liquid resin in the concavity and the liquid resin is solidified.

Abstract: A semiconductor device includes a semiconductor chip, a plurality of bumps and at least one electrically conductive component. The semiconductor chip includes an active area having electronic circuits formed therein and a plurality of pads. The plurality of bumps is placed on the semiconductor chip, wherein a location where at least one of the bumps is located on the semiconductor chip does not overlap a location where a specific pad of the pads is located on the semiconductor chip. The electrically conductive component connects a top surface of at least the bump and the specific pad.

Abstract: The advanced quad flat non-leaded package structure includes a carrier having a die pad and a plurality of leads, at least a chip, a plurality of wires, and a molding compound. The rough surface of the carrier enhances the adhesion between the carrier and the surrounding molding compound.

Abstract: Semiconductor die packages are disclosed. An exemplary semiconductor die package includes a premolded substrate. The premolded substrate can have a semiconductor die attached to it, and an encapsulating material may be disposed over the semiconductor die.

Abstract: The present invention provides a semiconductor device having a coating film of a predetermined thickness provided along the circumference of a semiconductor light emitting element, and provide a method for easily manufacturing the semiconductor device. A semiconductor light emitting element 2 that emits blue light is mounted face down on the top face of a pedestal 1, and a coating film 3 containing a YAG fluorescent material 6 that emits yellow light is placed so as to cover the top face and side face of the semiconductor light emitting element 2 and the top face of the pedestal 1. With the semiconductor light emitting element 2 and other elements placed between a first film 8 and a second film 9, the films are laminated in vacuum, thereby to fasten the coating film 3 onto the semiconductor light emitting element 2.

Abstract: A polyimide shield includes a base film layer that is made from polyimide, and a colored film layer that overlies the base film layer and that contains a coloring agent dispersed in a polymer. A method of making the polyimide shield includes forming the base film layer from polyimide and applying a liquid composition onto the base film layer. The liquid composition contains a polymer and the coloring agent that is dispersed in the polymer. An integrated circuit structure includes a circuitry substrate and the polyimide shield that covers the circuitry substrate.

Abstract: A silicon polymer material, which has a silicon polymer backbone with chromophore groups attached directly to at least a part of the silicon atoms, the polymer further exhibiting carbosilane bonds. The film forming composition and resulting coating properties can be tailored to suit the specific exposure wavelength and device fabrication and design requirements. By using two different chromophores the refractive index and the absorption co-efficient can be efficiently tuned. By varying the proportion of carbosilane bonds, and a desired Si-content of the anti-reflective coating composition can be obtained.

Abstract: The present invention discloses a multi-die package which facilitates heat dissipation for a high power consumption die. In the package, part of the lead frame is bent so as to be exposed at the surface of the package. On the opposite side of the exposed surface, a high power consumption die is attached. The other die with lower power consumption is not at the surface of the multi-die package.

Abstract: According to one embodiment, a semiconductor chip mounting body, with an enhanced shock-resistance at portions of the bonding member corresponding to the corners of a semiconductor chip, is provided. The semiconductor chip mounting body includes a circuit board having a circuit pattern formed on a mounting surface thereof, a semiconductor chip mounted on the circuit pattern of the circuit board, and a bonding member arranged at least between the circuit board and the semiconductor chip, and on the sides of the semiconductor chip to fix the semiconductor chip on the circuit board. The bonding member contains thermosetting resin and magnetic powder dispersed in the thermosetting resin. The magnetic powder is locally disposed in portions of the bonding member which is located the corners of the semiconductor chip.

Abstract: Nanoparticles (<100 nm) and submicron particles (<400 nm) can be used as filler material to form a nanocomposite that can be used as an encapsulant for optoelectronic devices. These nanocomposites can function to reduce light scattering and increase thermal, mechanical and dimensional stability of the optoelectronic device. Such nanocomposites can also improve moisture barrier characteristics, lower the dielectric constant and increase resistivity of the optoelectronic device.

Abstract: A method of manufacture of an integrated circuit packaging system includes: providing a sacrificial carrier assembly having a stack interconnector thereover; mounting an integrated circuit having a connector over the sacrificial carrier assembly with the connector over the stack interconnector; dispensing an underfill material between the sacrificial carrier assembly and the integrated circuit with the underfill material substantially free of a void; encapsulating the integrated circuit over the sacrificial carrier assembly and the underfill material; exposing the stack interconnector by removing the sacrificial carrier assembly; and forming a base array over the underfill material and the stack interconnector.

Abstract: A method of manufacture of an integrated circuit packaging system includes: providing a first stack layer including a first device over a first substrate, the first device including a through silicon via; configuring a second stack layer over the first stack layer, the second stack layer including an analog device; configuring a third stack layer over the second stack layer; and encapsulating the integrated circuit packaging system.

Abstract: A method for manufacturing an integrated circuit package system includes: forming a first device unit, having first external interconnects arranged along a perimeter of the first device unit, and a second device unit, having second external interconnects arranged along a perimeter of the second device unit, in an array configuration; mounting an integrated circuit die over the first device unit; connecting the integrated circuit die and the first external interconnects; encapsulating with an encapsulation covering the integrated circuit die, the first device unit, and the second device unit with both the first external interconnects and the second external interconnects partially exposed; and forming a partial encapsulation cut in the encapsulation electrically isolating the first external interconnects and the second electrical interconnects.

Abstract: A substrate is provided with electrical connection pads on a front face and on a rear face, the front pads and rear pads being selectively connected via a network passing through the substrate. A peripheral edge of the substrate is mounted on a rigid annular frame and the rearm face secured to a suction table. A layer of a dielectric sealant containing electrically conductive particles is deposited on the front face and front pads of the substrate. Integrated-circuit chips are positioned on the front face to flatten the layer of dielectric sealant, the included electrically conductive particles making electrical connection between pads of the integrated-circuit and the front pads of the substrate. The resulting assembly in then encapsulated in a block of encapsulating material positioned on top of the front face of the substrate. The block is then diced in order to obtain a plurality of semiconductor packages.

Abstract: Dummy electrodes (15) are disposed on wiring connected to first electrodes (2) of the substrate (1), outside a junction region containing all of the first electrodes (2) and second electrodes (6) and in bonding resin (4), the dummy electrodes (15) not being involved in electrical connection between the substrate (1) and the component (5). When conductive particles (3) in the bonding resin (4) are melted by heating, molten solder self-assembles and solidifies between the first electrodes (2) and the second electrodes (6) and on the dummy electrodes (15). With this configuration, the solder self-assembles between the adjacent dummy electrodes (15) and causes a solder short circuit. Thus it is possible to eliminate excessive solder supply between the adjacent first electrodes (2) and the adjacent second electrodes (6), thereby preventing short circuits between the adjacent first electrodes (2) and the adjacent second electrodes (6).

Abstract: A method of manufacture of an integrated circuit packaging system includes: providing a carrier; mounting an integrated circuit on the carrier; mounting a z-interconnect on the carrier, the z-interconnect for supporting a trace cantilevered over the integrated circuit; encapsulating the integrated circuit with an encapsulation; removing the carrier; and depositing a substrate below the integrated circuit.

Abstract: In a semiconductor device, corner portions of a inner insulating film are chamfered, and hence a damage is less likely to reach the corner portion of the inner insulating film, though the corner portion of an outer insulating film is damaged. Therefore, a hermeticity of a semiconductor element can be effectively maintained, and the yield of semiconductor pellets can be improved. Moreover, since it is not necessary to chamfer the corner portion of the outer insulating film, the structure remains simple and the productivity can be improved.

Abstract: A stacked multichip package comprises a first chip having a first active surface and a first rear surface, a first chip carrier having a first opening and being configured to carrier the first active surface, a plurality of first conductive leads passing through the first opening and being configured to electrically connect the first active surface and the first chip carrier, a second chip having a second active surface and a second rear surface, an adhesive layer configured to enclose the first conductive leads and to electrically couple the first chip carrier to the second rear surface, a second chip carrier having a second opening and being electrically connected to the second active surface, and a plurality of conductive leads passing through the second opening and being configured to electrically connect the second active surface and the second chip carrier.

Abstract: A method for thin wafer handling and processing is provided. In one embodiment, the method comprises providing a wafer having a plurality of semiconductor chips, the wafer having a first side and a second side. A plurality of dies are attached to the first side of the wafer, at least one of the dies are bonded to at least one of the plurality of semiconductor chips. A wafer carrier is provided, wherein the wafer carrier is attached to the second side of the wafer. The first side of the wafer and the plurality of dies are encapsulated with a planar support layer. A first adhesion tape is attached to the planar support layer. The wafer carrier is then removed from the wafer and the wafer is diced into individual semiconductor packages.

Abstract: Glass frits, conductive inks and articles having conductive inks applied thereto are described. According to one or more embodiments, glass frits with no intentionally added lead comprise TeO2 and one or more of Bi2O3, SiO2 and combinations thereof. One embodiment of the glass frit includes B2O3, and can further include ZnO, Al2O3 and/or combinations thereof. One embodiment provides for conductive inks which include a glass frit with no intentionally added lead and comprising TeO2 and one or more of Bi2O3, SiO2 and combinations thereof. Another embodiment includes articles with substrates such as semiconductors or glass sheets, having conductive inks disposed thereto, wherein the conductive ink includes glass frits having no intentionally added lead.

Abstract: Manufacturing a semiconductor device involves forming (200) a sacrificial layer where a micro cavity is to be located, forming (210) a metal layer of thickness greater than 1 micron over the sacrificial layer, forming (220) a porous layer from the metal layer, the porous layer having pores of length greater than ten times their breadth, and having a breadth in the range 10 nm-500 nanometers. The pores can be created by anodising, electrodeposition or dealloying. Then the sacrificial layer can be removed (230) through the porous layer, to form the micro cavity, and pores can be sealed (240). Encapsulating MEMS devices with a porous layer can reduce costs by avoiding using photolithography for shaping the access holes since the sacrificial layer is removed through the porous membrane.