Abstract:
This invention provides a solder ball loading apparatus which enables fine solder balls to be loaded on pads while void is blocked from being caught into bump upon reflow. Inactive gas is supplied and the inactive gas is sucked from a loading cylinder located above a ball arrangement mask so as to gather solder balls. The gathered solder balls are rolled on the ball arrangement mask by moving the loading cylinder horizontally and the solder balls are dropped onto connecting pads on a multilayer printed wiring board through openings in the ball arrangement mask. Oxidation of the solder balls and mixture of voids upon reflow are prevented by loading the solder balls in the atmosphere of inactive gas.
Abstract:
A printed wiring board comprises a wiring substrate provided with at least one conductor circuit, a solder resist layer provided on the surface of the wiring substrate, at least one conductor pad formed from a part of the conductor circuit exposed from an opening provided in the solder resist layer, and at least one solder bump for mounting electronic parts on the conductor pad. In the printed wiring board, since the at least one conductor pad is aligned at a pitch of 200 µm or less, and a ratio (W/D) of a diameter W of the solder bump to an opening diameter D of the opening formed in the solder resist layer is within a range of 1.05 to 1.7, connection reliability and insulation reliability can be easily improved.
Abstract:
A printed wiring board in which an opening existing around a pad which is a photovia land is arranged so that it is not overlapped with the pad, the area of an opening existing around a pad and that of another opening are equalized, the quantity of resin which is filled in each opening or is equalized throughout a printed wiring board and the quantity of resin overflowing from each opening or when resin is filled in each opening or is uniformed is provided. According to such a printed wiring board, a reliable printed wiring board wherein secure connection is enabled without causing disconnection can be realized when a circuit pattern provided on an interlayer insulating board formed on the printed wiring board and a conductor pad are connected by arranging an opening existing around a conductor pad so that it is not overlapped with the conductor pad and substantially equalizing the quantity of resin which is filled in an opening around a conductor pad and that of resin which is filled in another opening.
Abstract:
It is to provide a multilayer printed circuit board having excellent resolution, interlaminar insulation property and resistance to cool-heat shock without forming unevenness on the surface and lowering peel strength even if the thickness of the resin insulating layer is thin. The invention proposes a multilayer printed circuit board comprising an upper conductor circuit layer, a lower conductor circuit layer and a resin insulating layer electrically insulating both the conductor circuit layers, in which the resin insulating layer is a composite layer comprised of an insulating layer made from a heat-resistant resin hardly soluble in acid or oxidizing agent as a lower layer and an adhesive layer for electroless plating made from a heat-resistant resin as an upper layer, and if necessary, a resin is filled in a concave portion created between conductor circuits of the lower layer so as to render the surface into the same plane as the surface of the conductor circuit.
Abstract:
A multilayered printed wiring board having a smooth surface, which can be improved in resolution, interlayer insulating property, or thermal shock resistance without lowering its peel strength even if its insulating resin layer is thin. In the printed wiring board in which the conductor circuits of upper and lower layers are electrically insulated from each other by means of the insulating resin layer, the insulating layer is constituted of a composite layer composed of a lower layer made of a heat-resistant resin which is hardly soluble in an acid or oxidizing agent and an upper layer made of a bonding agent for electroless plating composed of a heat-resistant resin and, as necessary, a recessed section formed between conductor circuits of the lower layer is filled with a resin to the level corresponding to the surfaces of the conductor circuits.
Abstract:
A circuit board for mounting electronic parts, which includes first connecting terminal groups (12A and 12B) composed of a plurality of connecting terminals densely formed on the front surface (S1) of a base substrate (2) having through holes (6) and a second connecting terminal group (13) composed of a plurality of connecting terminals formed in at least outer peripheral section on the rear surface (S2) of the substrate (2). The first groups (12A and 12B) are connected to the second group (13) through the holes (6). On the front surface of the substrate (2), build-up multilayered wiring layers (B1 and B2) having via holes (11) are formed and the first groups (12A and 12B) are connected to the second group (13) through the wiring layers (B1 and B2) and through holes (6). In another example, each signal line (52) on the surfaces of the wiring layers (B1 and B2) is composed of a plurality of wiring patterns (58 and 59) having different line widths and a tapered pattern (60) which connects the wiring patterns (58 and 59) to each other and the width of which continuously varies. The line width of the signal line (52) in an area where the wiring density is relatively high is made narrower than that in another area where the wiring density is relatively low.
Abstract:
As an object of proposing a resin filler a resin filler suitable for filling in the concave portion created on the surface of the wiring substrate or the through-hole formed in the substrate and a construction of a build-up multilayer printed circuit board having an excellent reliability obtained by smoothening the surface of the substrate filled with the resin filler, this invention proposes a solvent-free resin filler filled in the concave portion created on the surface of the wiring substrate or in the through-holes formed in the substrate, which comprises a bisphenol type epoxy resin as a resin component and an imidazole curing agent as a curing agent, and if necessary, inorganic particles as an additive component, and a build-up multilayer printed circuit board using this resin filler.
Abstract:
A printed wiring board (1) such that openings (8L) formed around a pad (12L) which is a photo-via land do not overlap a pad (12L) and the area of each of the openings (8L) around the pad (12L) is equal to that of each of the other openings (8), the amount of resin (13) with which each of the openings (8, 8L) is filled is equal to that with which each of the openings (8L) is filled over the whole wiring board (1), and the amounts of resin (13) overflowing from the openings (8, 8L) are equal to each other. The circuit pattern provided on the upper surface of an interlayer insulating layer formed on the printed wiring board can be connected to a conductor pad area without causing any defective connection, providing a highly-reliable printed wiring board.
Abstract:
A board for mounting electronic circuit parts includes a first connection terminal group including a plurality of connection terminals densely formed on the top surface of a substrate having through holes formed therein, and a second connection terminal group including a plurality of connection terminals formed at at least the peripheral portion of a back surface of the substrate. The first connection terminal group is connected to the second connection terminal group by way of the through holes. A build-up multilayer interconnection layer having via holes is formed on the top surface of the substrate, so that the first connection terminal group is connected to the second connection terminal group through the build-up multilayer interconnection layer and the through holes. According to another aspect, each signal line on the top surface of the build-up multilayer interconnection layer comprises a plurality of wiring patterns having different widths and a taper-shaped pattern that connects those wiring patterns together and whose width continuously changes. Each signal line has a smaller width at an area having a relatively high wiring density than at an area having a relatively low wiring density.