Abstract: A semiconductor die has a conductive layer including a plurality of trace lines formed over a carrier. The conductive layer includes a plurality of contact pads electrically continuous with the trace lines. A semiconductor die has a plurality of contact pads and bumps formed over the contact pads. A plurality of conductive pillars can be formed over the contact pads of the semiconductor die. The bumps are formed over the conductive pillars. The semiconductor die is mounted to the conductive layer with the bumps directly bonded to an end portion of the trace lines to provide a fine pitch interconnect. An encapsulant is deposited over the semiconductor die and conductive layer. The conductive layer contains wettable material to reduce die shifting during encapsulation. The carrier is removed. An interconnect structure is formed over the encapsulant and semiconductor die. An insulating layer can be formed over the conductive layer.

Abstract: Described herein is a stacked package using laser direct structuring. The stacked package includes a die attached to a substrate. The die is encapsulated with a laser direct structuring mold material. The laser direct structuring mold material is laser activated to form circuit traces on the top and side surfaces of the laser direct structuring mold material. The circuit traces then undergo metallization. A package is then attached to the metalized circuit traces and is electrically connected to the substrate via the metalized circuit traces.

Abstract: An embodiment is directed to an IC mounting assembly that comprises an IC device having a first planar surface, wherein multiple electrically conductive first terminals are located at the first surface. The assembly further comprises an IC device mounting platform having a second planar surface in closely spaced relationship with the first surface, wherein multiple electrically conductive second terminals are located at the second surface, each second terminal corresponding to one of the first terminals. A solder element extends between each first terminal and its corresponding second terminal, and a constraining element is fixably joined to the second surface, wherein the constraining element has a CTE which is selectively less than the CTE of the mounting platform at the second surface. The constraining element is provided with a number of holes or apertures, and each hole is traversed by a solder element that extends between a first terminal and its corresponding second terminal.

Abstract: At least one metal adhesion layer is formed on at least a Cu surface of a first device wafer. A second device wafer having another Cu surface is positioned atop the Cu surface of the first device wafer and on the at least one metal adhesion layer. The first and second device wafers are then bonded together. The bonding includes heating the devices wafers to a temperature of less than 400° C., with or without, application of an external applied pressure. During the heating, the two Cu surfaces are bonded together and the at least one metal adhesion layer gets oxygen atoms from the two Cu surfaces and forms at least one metal oxide bonding layer between the Cu surfaces.

Abstract: A packaging method is disclosed that comprises attaching a plurality of dice, each having a plurality of bonding pads disposed on an active surface, to an adhesive layer on a substrate. A polymer material is formed over at least a portion of both the substrate and the plurality of dice and a molding apparatus is used on the substrate to force the polymer material to substantially fill around the plurality of dice. The molding apparatus is removed to expose a surface of the polymer material and a plurality of cutting streets is formed on an exposed surface of the polymer material. The substrate is removed to expose the active surface of the plurality of dice.

Abstract: The film for back surface of flip-chip semiconductor according to the present invention is a film for back surface of flip-chip semiconductor to be formed on a back surface of a semiconductor element having been flip-chip connected onto an adherend, wherein a tensile storage elastic modulus at 23° C. after thermal curing is 10 GPa or more and not more than 50 GPa. According to the film for back surface of flip-chip semiconductor of the present invention, since it is formed on the back surface of a semiconductor element having been flip-chip connected onto an adherend, it fulfills a function to protect the semiconductor element. In addition, since the film for back surface of flip-chip semiconductor according to the present invention has a tensile storage elastic modulus at 23° C. after thermal curing of 10 GPa or more, a warp of the semiconductor element generated at the time of flip-chip connection of a semiconductor element onto an adherend can be effectively suppressed or prevented.

Abstract: A stack that includes non-volatile memory devices is disclosed. One of the non-volatile memory devices in the stack is a master device, and the remaining memory device or devices is a slave device(s).

Abstract: A method of manufacturing a semiconductor device includes providing a carrier and attaching a plurality of semiconductor chips to the carrier. The semiconductor chips have a first electrode pad on a first main face and at least a second electrode pad on a second main face opposite to the first main face, whereby the first electrode pad is electrically connected to the carrier. A plurality of first bumps are formed on the carrier, the first bumps being made of a conductive material. The carrier is then singulated into a plurality of semiconductor devices, wherein each semiconductor device includes at least one semiconductor chip and one first bump.

Abstract: A bonded device structure including a first substrate having a first set of metallic bonding pads, preferably connected to a device or circuit, and having a first non-metallic region adjacent to the metallic bonding pads on the first substrate, a second substrate having a second set of metallic bonding pads aligned with the first set of metallic bonding pads, preferably connected to a device or circuit, and having a second non-metallic region adjacent to the metallic bonding pads on the second substrate, and a contact-bonded interface between the first and second set of metallic bonding pads formed by contact bonding of the first non-metallic region to the second non-metallic region. At least one of the first and second substrates may be elastically deformed.

Abstract: A method of connecting chips to chip carriers, ceramic packages, etc. (package substrates) forms smaller than usual first solder balls and polymer pillars on the surface of a semiconductor chip and applies adhesive to the distal ends of the polymer pillars. The method also forms second solder balls, which are similar in size to the first solder balls, on the corresponding surface of the package substrate to which the chip will be attached. Then, the method positions the surface of the semiconductor chip next to the corresponding surface of the package substrate. The adhesive bonds the distal ends of the polymer pillars to the corresponding surface of the package substrate. The method heats the first solder balls and the second solder balls to join the first solder balls and the second solder balls into solder pillars.

Abstract: A packaging method is disclosed that comprises attaching a plurality of dice, each having a plurality of bonding pads disposed on an active surface, to an adhesive layer on a substrate. A polymer material is formed over at least a portion of both the substrate and the plurality of dice and a molding apparatus is used on the substrate to force the polymer material to substantially fill around the plurality of dice. The molding apparatus is removed to expose a surface of the polymer material and a plurality of cutting streets is formed on an exposed surface of the polymer material. The substrate is removed to expose the active surface of the plurality of dice.

Abstract: A die that includes a substrate having a first and second major surface is disclosed. The die has at least one unfilled through via passing through the major surfaces of the substrate. The unfilled through via serves as a vent to release pressure generated during assembly.

Abstract: A method of molding a semiconductor package includes coating liquid molding resin or disposing solid molding resin on a top surface of a semiconductor chip arranged on a substrate. The solid molding resin may include powdered molding resin or sheet-type molding resin. In a case where liquid molding resin is coated on the top surface of the semiconductor chip, the substrate is mounted between a lower molding and an upper molding, and then melted molding resin is filled in a space between the lower molding and the upper molding. In a case where the solid molding resin is disposed on the top surface of the semiconductor chip, the substrate is mounted on a lower mold and then the solid molding resin is heated and melts into liquid molding resin having flowability. An upper mold is mounted on the lower mold, and melted molding resin is filled in a space between the lower molding and the upper molding.

Abstract: A method of assembling chips. A first chip and a second chip are provided. At least one conductive pillar is formed on the first chip, and a conductive connecting material is formed on the conductive pillar. The second chip also comprises at least one conductive pillar. The first chip is connected to the second chip via the conductive pillars and the conductive connecting material.

Abstract: A semiconductor integrated circuit device is made by stacking a plurality of semiconductor chips. The semiconductor integrated circuit device includes: a penetrating electrode formed to penetrate the plurality of semiconductor chips; a plurality of electrodes formed in respective layers constituting each of the plurality of semiconductor chips and having respective openings within which the penetrating electrode penetrates; and a plurality of vias each of which electrically connects electrodes of the plurality of electrodes located in adjacent layers. The vias are each formed so that the side face thereof is in contact with the penetrating electrode.

Abstract: A vacuum hermetic organic packaging carrier is provided. The organic packaging carrier includes an organic substrate, a conductive circuit layer, and an inorganic hermetic insulation film. The organic substrate has a first surface. The conductive circuit layer is located on the first surface and exposes a portion of the first surface. The inorganic hermetic insulation film at least covers the exposed first surface to achieve an effect of completely hermetically sealing the organic packaging carrier.

Abstract: A semiconductor device includes a first bump that is located over a surface of a semiconductor element, and is formed on a first bump formation face distanced from a back surface of the semiconductor element at a first distance, and a second bump that is located over the surface of the semiconductor element, and is formed on a second bump formation face distanced from the back surface of the semiconductor element at a second distance being longer than the first distance, the second bump having a diameter larger than a diameter of the first bump.

Abstract: A semiconductor device includes a semiconductor element having a plurality of element electrodes formed thereon, a circuit board having board electrodes respectively corresponding to the element electrodes formed thereon and having the semiconductor element mounted thereon, and bumps each of which is provided on at least one of the element electrode and the board electrode, and connects together the element electrode and the board electrode corresponding to each other when the semiconductor element is mounted on the circuit board. Furthermore, at least one of a dielectric layer and a resistive layer is provided between at least one of the bumps and the element or board electrode on which the at least one of the bumps is provided, so that the element or board electrode, the dielectric layer or the resistive layer, and the bump form a parallel-plate capacitor or electrical resistance.

Abstract: The present invention provides a dicing tape-integrated film for semiconductor back surface, including: a dicing tape including a base material and a pressure-sensitive adhesive layer provided on the base material; and a film for flip chip type semiconductor back surface provided on the pressure-sensitive adhesive layer, in which the film for flip chip type semiconductor back surface has a storage elastic modulus (at 60° C.) of from 0.9 MPa to 15 MPa.

Abstract: An electronic apparatus and method of fabrication of the apparatus, the apparatus including a first electronic device having an interconnection surface with a first plurality of interconnection pads extending from the surface by a first distance and a second plurality of alignment posts extending from the surface by a second distance greater than the first distance, and a second electrical device having an interconnection surface with a first plurality of electrical interconnection pads, each pad arranged to contact a corresponding first electronic device interconnection surface pad upon assembly of the first electronic device interconnection surface upon the second electronic device interconnection surface, the second electronic device interconnection surface including a third plurality of alignment posts, each located to be adjacent to at least one of the first electronic device alignment posts upon assembly.

Abstract: An integrated circuit (IC) package having a packaging substrate, an IC disposed onto the packaging substrate, and a rigid support member attached to the substrate layer through an adhesive spacer is provided. The packaging substrate includes multiple decoupling capacitors positioned thereon around the IC. A heat sink is placed over the IC. The rigid support member provides enhanced structural support for the IC packaging and there is ample space between a bottom surface of the rigid support member and the packaging substrate to allow the placement of the decoupling capacitors underneath the rigid support member.

Abstract: An electronic component including a wiring board having a power-source pattern and a signal pattern, a semiconductor element mounted on the wiring board and having a power-source electrode pad and a signal electrode pad, a first connection portion being made of a conductive material and connecting the signal pattern of the wiring board and the signal electrode pad of the semiconductor element, and a second connection portion being made of a conductive material and connecting the power-source pattern of the wiring board and the power-source electrode pad of the semiconductor element. The conductive material of the first connection portion and the conductive material of the second connection portion are selected such that the conductive material of the second connection portion has an electrical resistance which is lower than an electrical resistance of the conductive material of the first connection portion.

Abstract: A microelectronic device structure including increased thermal dissipation capabilities. The structure including a three-dimensional (3D) integrated chip assembly that is flip chip bonded to a substrate. The chip assembly including a device substrate including an active device disposed thereon. A cap layer is phsyically bonded to the device substrate to at least partially define a hermetic seal about the active device. The microelectronic device structure provides a plurality of heat dissipation paths therethrough to dissipate heat generated therein.

Abstract: A method for producing a two-chip assembly includes: providing a wafer having a first thickness, which wafer has a front side and a back side, a first plurality of first chips being provided on the front side of the wafer; attaching a second plurality of second chips on the front side of the wafer, so that every first chip is joined in each instance to a second chip and forms a corresponding two-chip pair; forming a cohesive mold package on the front side of the wafer, so that the second chips are packaged; thinning the wafer from the back side to a second thickness which is less than the first thickness; forming vias from the back side to the second chips; and separating the two-chip pairs into corresponding two-chip assemblies.

Abstract: A method of manufacturing package-on-packages (POPs) includes: forming a plurality of internal connection members that are separated from each other on a first circuit substrate; forming a first package by attaching a plurality of first chips between the internal connection members on the first circuit substrate; forming a second package by attaching a plurality of second chips that are separated from each other on a second circuit substrate; electrically connecting the first circuit substrate and the second circuit substrate by stacking the internal connection members onto the second circuit substrate; forming an encapsulant to encapsulate the first package and the second package; and forming the POPs in which the first chips and the second chips are respectively formed by cutting the first circuit substrate, the second circuit substrate, and the encapsulant.

Abstract: According to a manufacturing method of one embodiment, a first solder bump and a second solder bump are aligned and placed in contact with each other, and thereafter, the first and second solder bumps are heated to a temperature equal or higher than a melting point of the solder bumps and melted, whereby a partially connection body of the first solder bump and the second solder bump is formed. The partially connection body is cooled. The cooled partially connection body is heated to a temperature equal to or higher than the melting point of the solder bump in a reducing atmosphere, thereby to form a permanent connection body by melting the partially connection body while removing an oxide film existing on a surface of the partially connection body.

Abstract: A semiconductor device has a substrate and first conductive pads formed over the substrate. An interconnect surface area of the first conductive pads is expanded by forming a plurality of recesses into the first conductive pads. The recesses can be an arrangement of concentric rings, arrangement of circular recesses, or arrangement of parallel linear trenches. Alternatively, the interconnect surface area of the first conductive pads is expanded by forming a second conductive pad over the first conductive pad. A semiconductor die has a plurality of interconnect structures formed over a surface of the semiconductor die. The semiconductor die is mounted to the substrate with the interconnect structures contacting the expanded interconnect surface area of the first conductive pads to increase bonding strength of the interconnect structure to the first conductive pads. A mold underfill material is deposited between the semiconductor die and substrate.

Abstract: A semiconductor device includes a vertical transistor and an external contact plane. The transistor includes: a first side with a first load electrode and a control electrode, and an opposite second side with a second load electrode. The first side of the transistor faces the external contact plane. A dielectric layer extends from at least one edge side of the transistor as far as the second load terminal. An electrically conductive deposited layer is arranged on the dielectric layer and electrically connects the second load electrode to the second load terminal.

Abstract: The present invention relates to a semiconductor device structure and a method for manufacturing the same; the structure comprises: a semiconductor substrate on which a device structure is formed thereon; an interlayer dielectric layer formed on the device structure, wherein a trench is formed in the interlayer dielectric layer, the trench comprises an incorporated via trench and a conductive wiring trench, and the conductive wiring trench is positioned on the via trench; and a conductive layer filled in the trench, wherein the conductive layer is electrically connected with the device structure; wherein the conductive layer comprises a conductive material and a nanotube/wire layer surrounded by the conductive material. Wherein, the conductive layer comprises a conductive material and a nanotube/wire layer surrounded by the conductive material.

Abstract: A semiconductor device includes a semiconductor die and a plurality of lead-free solder bumps disposed on a surface of the semiconductor die. A substrate includes a plurality of metal layers and a plurality of dielectric layers. One of the metal layers includes a plurality of contact pads corresponding to the plurality of lead-free solder bumps, and one of the dielectric layers is an exterior dielectric layer having a plurality of respective openings for the contact pad. A plurality of respective copper posts is disposed on the contact pads. The respective copper post for each contact pad extends from the contact pad through the respective opening for the contact pad. The semiconductor die is mounted on the substrate with connections between the plurality of lead-free solder bumps and the plurality of copper posts.

Abstract: A BGA substrate which has a back surface to which a heat radiating plate is attached and an opening for accommodating a relay wiring substrate therein, which is provided in the center of its surface, is used. The relay wiring substrate to which an ASIC chip and a memory chip are flip-chip connected, is bonded to the heat radiating plate in the opening with a thermal conductive bonding material. Further, each of the back surfaces of the ASIC chip and the memory chip is connected to a metal cap for sealing the opening through a thermal conductive material interposed therebetween.

Abstract: A method of manufacture of an integrated circuit packaging system includes: providing a substrate with a projection formed along a perimeter of a first surface of the substrate; mounting an integrated circuit over the first surface; forming a protruding interconnect over the first surface between the projection and the integrated circuit; and forming an underfill between the integrated circuit and the projection with a uniform height, the uniform height of the underfill less than a height of the projection.

Abstract: An electronic device with integrated discrete components, including a wafer including cavities that can receive the components, an active face of the components being in a same plane as a face of the receiving wafer, and a material for laterally coating the components in the cavities.

Abstract: A method of manufacture of an integrated circuit packaging system includes: providing a substrate having a substrate first side and a substrate second side opposite the substrate first side; attaching a base integrated circuit to the substrate first side; attaching a mountable integrated circuit to the substrate second side; attaching a via base to the substrate second side adjacent the mountable integrated circuit; forming a device encapsulation surrounding the via base and the mountable integrated circuit; and forming a via extension through the device encapsulation and attached to the via base, the via extension exposed from the device encapsulation.

Abstract: This invention reveals a flip-chip type full-wave rectification semiconductor device which includes at least a PNNP type and/or NPPN type flip-chip, and a sheet stuff or substrate including a plurality pins, and which is characterized in that: all the soldering points (bumps) of the PNNP type and/or the NPPN type flip-chip are on an identical surface, this can make easy connecting of the pins with the bumps of the flip-chips by soldering in pursuance of circuit arrangement of the full-wave rectification device, and complete manufacturing product after the steps of shaping/packing and cutting; such product has a function of making full-wave rectifying, and can simplify the manufacturing process, reduce the manufacturing cost, and get an effect of reducing the size of the product with better heat dissipation, being different from traditional full wave rectification semiconductor devices composed of two/four grains.

Abstract: A semiconductor package method for co-packaging high-side (HS) and low-side (LS) semiconductor chips is disclosed. The HS and LS semiconductor chips are attached to two opposite sides of a lead frame, with a bottom drain electrode of the LS chip connected to a top side of the lead frame and a top source electrode of the HS chip connected to a bottom side of the lead frame through a solder ball. The stacking configuration of HS chip, lead frame and LS chip reduces the package size. A bottom metal layer covering the bottom of HS chip exposed outside of the package body provides both electrical connection and thermal conduction.

Abstract: A carrier substrate has a mounting location with a number of electrical connection pads on a top side and external contacts connected thereto on an underside. A metal frame encloses the connection pads of the mounting location. A MEMS chip has electrical contacts on an underside. The MEMS chip is placed on the mounting location of the carrier substrate in such a way that the MEMS chip is seated with an edge region of its underside on the metal frame. Using a flip-chip process, the electrical contacts of the MEMS chip are connected to the connection pads of the carrier substrate by means of bumps the metal frame is connected to the MEMS chip such that a closed cavity is formed between MEMS chip and carrier substrate.

Abstract: A method of manufacturing a semiconductor device, includes mounting a semiconductor chip on a wiring substrate such that one surface of the semiconductor chip is faced to one surface of the wiring substrate, and filling a first resin in a gap between the surface of the wiring substrate and the surface of the semiconductor chip such that part of the first resin protrudes from the gap. In the filling of the first resin, the first resin is injected into the gap by use of a first resin injection nozzle while the first resin injection nozzle is being moved along any one of sides of the semiconductor chip or along two sides of the semiconductor chip which are adjacent to each other.

Abstract: A manufacturing method for a semiconductor device includes: the step of preparing a semiconductor chip which is provided with a functional element formed on a front surface side of a semiconductor substrate, a feedthrough electrode which is placed within a through hole that penetrates the semiconductor substrate, a front surface side connection member which protrudes from the front surface, and a rear surface side connection member which has a joining surface within a recess that is formed in a rear surface; the step of preparing a solid state device where a solid state device side connection member for connection to the front surface side connection member is formed on one surface; and the joining step of making the front surface of the semiconductor chip face the first surface of the solid state device by holding the rear surface of the semiconductor chip, and of joining the front surface side connection member to the solid state device side connection member.

Abstract: A surface mount type semiconductor device is disclosed. The semiconductor device has testing lands on a lower surface of a wiring substrate with a semiconductor chip mounted thereon. Lower surface-side lands with solder balls coupled thereto respectively and testing lands with solder balls not coupled thereto are formed on a lower surface of a wiring substrate. To suppress the occurrence of contact imperfection between the testing lands and land contacting contact pins provided in a probe socket, the diameter of each testing land is set larger than the diameter of each lower surface-side land. Even when the wiring substrate is reduced in size, electrical characteristic tests using the testing lands can be done with high accuracy.

Abstract: A flip-chip package structure comprising a substrate, a chip, a bump structure and a solder resist is provided. The substrate has a circuit layer disposed on the surface thereof. The chip comprises a central region and two edge regions disposed on the two sides of the central region. The bump structure is disposed on the central region of the chip and faces the substrate. The solder resist is disposed on the substrate to partially cover the circuit layer. The chip is electrically connected to the substrate by the bump structure, and the solder resist is adapted to come into contact with the two edge regions of the chip to support the chip with the bump structure when the chip is disposed on the substrate.

Abstract: Fabricating a semiconductor chip with backside optical vias is provided. A silicon wafer is received for processing. The silicon wafer includes an optically transparent oxide layer on a frontside of the silicon wafer. A complementary metal-oxide-semiconductor layer is formed on top of the optically transparent oxide layer. A backside of the silicon wafer is etched to form optical vias in a silicon substrate using the optically transparent oxide layer as an etch-stop.

Abstract: An underfill device and method have been are provided. Advantages of devices and methods shown include dissipation of stresses at an interface between components such as a chip package and an adjacent circuit board. Another advantage includes faster manufacturing time and ease of manufacture using underfill devices and methods shown. An underfill assembly can be pre made with conductive structures included within the underfill assembly. Steps such as flowing epoxy and curing can be eliminated or performed concurrently with other manufacturing steps.

Abstract: A wiring electronic component of the present invention is incorporated into an electronic device package in which a circuit element including a semiconductor chip is disposed and in which the circuit element is connected to a wiring pattern on the back face and also connected, via vertical wiring, to external electrodes located on the front face opposite the wiring pattern. The wiring electronic component is composed of an electrically conductive support portion, which serves as an electroforming mother die, and a plurality of vertical wiring portions formed through electroforming such that they are integrally connected to the support portion.

Abstract: A preassembly semiconductor device comprises substrate soldering structures extending toward chip soldering structures for forming solder connections with the chip soldering structures, i.e., the chip and the substrate are in preassembly positions relative to one another. The height of the substrate soldering structures is greater than the height of the chip soldering structures. A pre-applied underfill is contiguous with the substrate and is sufficiently thick so as to extend substantially no further than the full height of the substrate soldering structures. In another embodiment the height of the chip soldering structures is greater than the height of the substrate soldering structures and the pre-applied underfill is contiguous with the semiconductor chip and sufficiently thick so as to extend substantially no further than the full height of the chip soldering structures.

Abstract: The present invention relates to an under-fill dam with high detection probability that is composed of a dry film solder resist and provided in the form of a fence around a chip device in order to prevent leaks of an under-fill material filled in a gap between a substrate and the chip device.

Abstract: A semiconductor chip device includes a first semiconductor chip adapted to be stacked with a second semiconductor chip wherein the second semiconductor chip includes a side and first and second conductor structures projecting from the side. The first semiconductor chip includes a first edge, a first conductor pad, a first conductor pillar positioned on but laterally offset from the first conductor pad toward the first edge and that has a first lateral dimension and is adapted to couple to one of the first and second conductor structures, a second conductor pad positioned nearer the first edge than the first conductor pad, and a second conductor pillar positioned on but laterally offset from the second conductor pad and that has a second lateral dimension larger than the first lateral dimension and is adapted to couple to the other of the first and second conductor structures.

Abstract: A method of manufacturing a semiconductor device is disclosed. One embodiment includes placing multiple semiconductor chips onto a carrier, each of the semiconductor chips having a first face and a second face opposite to the first face. An encapsulation material is applied over the multiple semiconductor chips and the carrier to form an encapsulating body having a first face facing the carrier and a second face opposite to the first face. A redistribution layer is applied over the multiple semiconductor chips and the first face of the encapsulating body. An array of external contact elements are applied to the second face of the encapsulating body.

Abstract: A method of manufacturing a semiconductor device includes forming an interconnect member, mounting a first semiconductor chip having a semiconductor substrate in a face-down manner on the interconnect member, forming a resin layer on the interconnect member to cover a side surface of the first semiconductor chip, thinning the first semiconductor chip and the resin layer, forming an inorganic insulating layer on a back surface of the first semiconductor chip so as to be in contact with the back surface and to extend over the resin layer, and forming a through electrode so as to penetrate the inorganic insulating layer and the semiconductor substrate.

Abstract: A semiconductor device comprising a semiconductor pellet mounted on a pellet mounting area of the main surface of a base substrate, in which first electrode pads arranged on the back of the base substrate are electrically connected to bonding pads arranged on the main surface of the semiconductor pellet. The base substrate is formed of a rigid substrate, and its first electrode pads are electrically connected to the second electrode pads arranged on its reverse side. The semiconductor pellet is mounted on the pellet mounting area of the main surface of the base substrate, with its main surface downward, and its bonding pads are connected electrically with the second electrode pads of the base substrate through bonding wires passing through slits formed in the base substrate.