A conductive ball includes a copper ball, a nickel layer formed with being patterned on an outer surface of the copper ball, and a tin-based solder covering each outer surface of the copper ball and the nickel layer.

Embodiments include a microelectronic package structure having a substrate with one or more substrate pads on a first side of the package substrate. A ball interconnect structure is on the substrate pad, the ball interconnect structure comprising at least 99.0 percent gold. A discrete component having two or more component terminals is on the ball interconnect structure.

A circuit adapter board has a film circuit board, a spring probe assembly, a space, and a filler. The film circuit board has a film body and multiple conductors. The film body has multiple first contacts and multiple second contacts. A density of distribution of the second contacts is higher than a density of distribution of the first contacts. The conductors are respectively connected to the first contacts. The spring probe assembly is disposed out of the first outer layer and has a plate and multiple spring probes. The spring probes are respectively disposed in the plate. Each spring probe has a base, a connecting portion, and a contacting portion being retractable. The space is formed between the film body of the film circuit board and the plate. The filler is disposed between the film body and the plate.

There is provided a conductive particle including a core particle containing a resin material, and a surface layer that covers a surface of the core particle and contains a solder material, in which a melting point of the solder material is equal to or lower than a softening point of the resin material.

A display apparatus including a display panel including a base substrate and a first pad electrode on a first pad portion of the base substrate, a flexible substrate connected to the first pad portion, and a driving chip electrically connected to the flexible substrate. The flexible substrate includes a first film layer, a first wiring layer on the first film layer and comprising a plurality of wirings, a second film layer on the first wiring layer, and a second wiring layer on the second film layer and comprising a plurality of wirings. The wirings of the second wiring layer include a first_first wiring and a first_second wiring, the first_first wiring and the first_second wiring extend in a same direction along a same line and are spaced from each other by a gap therebetween. The gap is at an edge of the base substrate in a plan view.

A display apparatus including a display panel including a base substrate and a first pad electrode on a first pad portion of the base substrate, a flexible substrate connected to the first pad portion, and a driving chip electrically connected to the flexible substrate. The flexible substrate includes a first film layer, a first wiring layer on the first film layer and comprising a plurality of wirings, a second film layer on the first wiring layer, and a second wiring layer on the second film layer and comprising a plurality of wirings. The wirings of the second wiring layer include a first_first wiring and a first_second wiring, the first_first wiring and the first_second wiring extend in a same direction along a same line and are spaced from each other by a gap therebetween. The gap is at an edge of the base substrate in a plan view.

A circuit adapter board has a film circuit board, a spring probe assembly, a space, and a filler. The film circuit board has a film body and multiple conductors. The film body has multiple first contacts and multiple second contacts. A density of distribution of the second contacts is higher than a density of distribution of the first contacts. The conductors are respectively connected to the first contacts. The spring probe assembly is disposed out of the first outer layer and has a plate and multiple spring probes. The spring probes are respectively disposed in the plate. Each spring probe has a base, a connecting portion, and a contacting portion being retractable. The space is formed between the film body of the film circuit board and the plate. The filler is disposed between the film body and the plate.

Provided is a method for manufacturing a multilayer substrate capable of suppressing short circuits between bumps and the warpage of substrates. This method includes: providing a first substrate being a rigid substrate including first bumps, and a second substrate or semiconductor device including second bumps, the first bumps and the second bumps being composed of a metal or alloy having a melting point of 600? C. or more, and having a height of 0.3 ?m or more; performing cleaning treatment on bonding surfaces of the first bumps and the second bumps under a pressure of 1?10.sup.?3 Pa or less, and subsequently stacking the first substrate and the second substrate or semiconductor device so that the bonding surfaces of the first bumps and the second bumps abut each other, and pressure-welding the first bumps and the second bumps at a temperature of 90? C. or less to form a multilayer substrate.

A manufacturing method of an electronic device including the following steps is provided. First, a first conductive layer is formed on a substrate. Next, a first insulating layer and a second conductive layer are formed on the first conductive layer. The first insulating layer is disposed between the second conductive layer and the first conductive layer, and the first insulating layer has a via exposing a part of the first conductive layer. An aspect ratio of the via of the first insulating layer is greater than 1, and at least part of a sidewall of the first insulating layer is covered by the second conductive layer.

A circuit module includes an upper circuit board, a lower circuit board, a first conductor member, a second conductor member, and a first component. The upper circuit board has a first upper main surface and a first lower main surface. The lower circuit board has a second upper main surface and a second lower main surface, is disposed below the upper circuit board, and overlaps the upper circuit board as viewed in the downward direction. The first component is mounted on the first lower main surface or the second upper main surface. The first conductor member is a metal pin and is connected to the first lower main surface. The second conductor member is a metal pin and is connected to the second upper main surface. The second conductor member is electrically connected to the first conductor member.