Abstract:
Disclosed herein are a printed circuit board having metal bumps which have uniform diameter and are formed at fine pitch, and a method of manufacturing the printed circuit board.
Abstract:
A circuit structure suitable for being disposed on a carrier board. The circuit structure comprises a first patterned conductive layer, a second patterned conductive layer, and a solder mask. The first patterned conductive layer is disposed on the carrier board. The second patterned conductive layer is disposed on a part of the first patterned conductive layer. A part of the edge of the second patterned conductive layer and a part of the edge of the first patterned conductive layer are substantially coplanar. The patterned solder mask covers a part of the first patterned conductive layer and has at least one opening for exposing the second patterned conductive layer and a part of the first patterned conductive layer adjacent to the second patterned conductive layer.
Abstract:
A method of manufacturing a printed circuit board having a metal bump, including: forming a recess for creation of the metal bump on a first carrier, forming a first barrier layer on the first carrier, and forming an upper circuit layer on the first barrier layer, the upper circuit layer including a metal bump charged in the recess and a circuit pattern; forming a second barrier layer on a second carrier, and forming a lower circuit layer on the second barrier layer; preparing an insulating layer, and transferring the upper and lower circuit layers to the insulating layer; removing the first and second carriers; and removing the first and second barrier layers.
Abstract:
A QFN package with improved joint solder thickness for improved second level attachment fatigue life. The copper leadframe of a QFN chip carrier is provided with rounded protrusions in both the chip attach pad region and the surrounding lead regions before second level attachment. The rounded stand-off protrusions are formed from the copper itself of the copper of the leadframe. This may be achieved by punching dimples into one surface of the copper plate of the leadframe before plating to form protrusions on the opposing surface. This method of forming the rounded protrusions simplifies the process of forming stand-offs. The protrusions provide a structure that increases wetting area and allows the use of a larger quantity of solder for increased solder joint thickness and better die paddle solder joint area coverage. As a result of the increased solder joint thickness, second level fatigue life is significantly improved. As a result of the improved die paddle solder joint area coverage, improved thermal performance of the chip carrier is also significantly improved.
Abstract:
A method for forming a bump structure and a bump structure for conductive interconnection with another element having at least one of microelectronic devices or wiring thereon, used as an electric connection in an electronic circuit, includes the steps of forming a mandrel by steps including forming at least one opening extending through a bump-forming die body in the thickness direction thereof and positioning a bump-forming die lid on a surface of the bump-forming die body so as to cover one end of the opening and to thereby define a bump-forming recess. The bump-forming die body may be comprised of a metal sheet. A metal layer is formed at least on an inner surface of the bump-forming die lid exposed within the bump-forming recess. The mandrel is removed so as to expose the metal layer and form a bump structure.
Abstract:
A plurality of semiconductor devices having different thicknesses from each other and having respective electrode terminals are fixed on a surface of the support plate through a resin layer in such a manner that terminal surfaces of the electrode terminals are on the level with each other. An insulating layer covers terminal forming surfaces of the semiconductor devices. At least one tapered bump having a tip surface formed in a smaller area than an area of the terminal surface of the electrode terminal of the semiconductor device is formed on one of the terminal surfaces of the electrode terminals and penetrates the insulating layer in such a manner that the tip surface of the tapered bump is exposed to a surface of the insulating layer. A wiring pattern is formed on the surface of the insulating layer and connected to the tip surface of the tapered bump.
Abstract:
Disclosed is a method for forming post bumps, the method including the steps of: forming a seed layer for metal plating on a substrate; forming a resist layer having openings provided as positions where the seed layer is subjected to metal plating; forming a dummy sheet, exposing the openings, on the resist layer; forming a post by performing metal plating of the openings; forming solder balls on the post; and removing the dummy sheet and the resist layer.
Abstract:
A method of manufacturing a functionally gradient material having a gradient from a first material to a second material different to the first material by ejecting inks onto a base material from a plurality of inkjet heads, includes the steps of: supplying a first functional ink containing the first material to a first inkjet head; supplying a second functional ink containing the second material to a second inkjet head; specifying a ratio between a volume of the first functional ink ejected from the first inkjet head and a volume of the second functional ink ejected from the second inkjet head; causing the first inkjet head to eject the first functional ink and/or causing the second inkjet head to eject the second functional ink, in accordance with the specified ratio, so as to form one layer; and stacking a plurality of layers onto the base material by repeating the forming step, so as to obtain a laminated body, wherein in the control step, the ratio between the first functional ink and the second functional ink is specified in such a manner that respective layers of the plurality of layers progressively have a smaller ratio of the first functional ink and a larger ratio of the second functional ink, toward an upper layer.
Abstract:
A packaged microelectronic element includes connection component incorporating a dielectric layer (22) carrying traces (58) remote from an outer surface (26), posts (48) extending from the traces and projecting beyond the outer surface of the dielectric, and pads (30) exposed at the outer surface of the dielectric layer, the pads being connected to the posts by the traces. The dielectric element overlies the front surface of a microelectronic element, and contacts (74) exposed on the front surface of the microelectronic element are connected to the pads by elongated leads (76) such as wire bonds. Methods of making the connection component are also disclosed.
Abstract:
A printed circuit board includes a core layer, an insulation layer formed on the core layer and having a cavity formed on a part of the insulation layer, and a circuit pattern formed on the insulation layer, wherein the circuit pattern comprises one or more external terminals positioned above the cavity.