Thin-frame touch panel
In an analog resistive-film touch panel, a lower electrode member has a transparent electrode on a top face of a transparent insulating base member, a pair of bus bars on parallel sides of the transparent electrode, and routing circuits connected to the bus bars for external connection on a portion other than the transparent electrode. Further, an upper electrode member has a transparent electrode on a bottom face of a flexible transparent insulating base, a pair of bus bars on parallel sides of the transparent electrode, and routing circuits connected to the bus bars for external connection on a portion other than the transparent electrode. The lower and upper electrode members face each other in a square pattern via an insulative spacer and are bonded at peripheral portions. The bus bars and the routing circuits are formed from metal thin wires with a diameter of 30 to 100 μm.
1. An analog resistive-film type thin-frame touch panel, comprising:
a lower-side electrode member having
a lower-side transparent insulating base member,
a lower-side transparent electrode on a part of a top face of the lower-side transparent insulating base member,
a pair of lower-side bus bars disposed on two parallel sides of the lower-side transparent electrode, and
lower-side external terminal connection portions disposed on a portion other than the lower-side transparent electrode and connected to the lower-side bus bars;
an upper-side electrode member having
a flexible upper-side transparent insulating base member,
an upper-side transparent electrode on a part of a bottom face of the flexible upper-side transparent insulating base member,
a pair of upper-side bus bars disposed on two parallel sides of the upper-side transparent electrode, and
upper-side external terminal connection portions disposed on a portion other than the upper-side transparent electrode and connected to the upper-side bus bars; and
an insulative spacer, wherein
the lower-side electrode member and the upper-side electrode member are disposed facing each other via the insulative spacers such that the upper-side bus bars and the lower-side bus bars are arranged in a square pattern, and the lower-side electrode member and the upper-side electrode member are bonded at peripheral portions,
the lower-side bus bars are formed by metal thin wires having a circular cross section and a wire diameter of 30 to 100 μm,
the upper-side bus bars are formed by metal thin wires having a circular cross section and a wire diameter of 30 to 100 μm, and
the metal thin wires and a portion of each of the upper-side and lower-side transparent insulating base members around the metal thin wires are covered with a conductive paste so that the metal thin wires are respectively fixed onto the upper-side transparent insulating base member and the lower-side transparent insulating base member.
2. The thin-frame touch panel as defined in claim 1 , wherein
the lower-side electrode member further has lower-side routing circuits disposed on the portion other than the lower-side transparent electrode, for connecting the lower-side bus bars and the lower-side external terminal connection portions,
the upper-side electrode member further has upper-side routing circuits disposed on the portion other than the upper-side transparent electrode, for connecting the upper-side bus bars and the upper-side external terminal connection portions, and
the lower-side routing circuits are formed from metal thin wires having a circular cross section and a wire diameter of 30 to 100 μm and the upper-side routing circuits are formed from metal thin wires having a circular cross section and a wire diameter of 30 to 100 μm.
3. The thin-frame touch panel as defined in claim 2 , wherein the metal thin wires constituting each of the lower-side routing circuits and the upper-side routing circuits are extended to outside of the lower-side electrode member and the upper-side electrode member to constitute the lower-side external terminal connection portions and the upper-side external terminal connection portions.
4. The thin-frame touch panel as defined in claim 2 , wherein a part of each of the metal thin wires is respectively embedded in one of the upper-side and lower-side transparent insulating base members by melting and solidification of the upper-side and lower-side transparent insulating base members.
5. The thin-frame touch panel as defined in claim 4 , wherein
at least one of bend portions of the lower-side routing circuits and the lower-side bus bars of the lower-side electrode member are covered with the conductive paste to form a lower-side covering layer that has a width 2 to 5 times larger than the wire diameter of the metal thin wires of the lower-side electrode member,
other portions of the lower-side electrode member are covered with the conductive paste to form a lower-side covering layer that has a width 1 to 5 times larger than the wire diameter of the metal thin wires of the lower-side electrode member,
at least one of bend portions of the upper-side routing circuits and the upper-side bus bars of the upper-side electrode member are covered with the conductive paste to form an upper-side covering layer that has a width 3 to 5 times larger than the wire diameter of the metal thin wires of the upper-side electrode member, and
other portions of the upper-side electrode member are covered with the conductive paste to form an upper-side covering layer that has a width 2 to 5 times larger than the wire diameter of the metal thin wires of the upper-side electrode member.
6. The thin-frame touch panel as defined in claim 2 , wherein the lower-side and upper-side bus bars, the lower-side and upper-side routing circuits, and the lower-side and upper-side external terminal connection portions are formed at peripheries of the lower-side and upper-side transparent insulating base members and form an interconnection region of the upper-side and lower-side transparent insulating base members, the innerconnection region being formed such that its thin-frame width size as seen from an external form thereof is 2 mm or lower at least on three sides.
7. The thin-frame touch panel as defined in claim 1 , wherein
the lower-side bus bars and the lower-side external terminal connection portions are directly connected, and the lower-side external terminal connection portions are also formed by metal thin wires having a circular cross section and a wire diameter of 30 to 100 μm,
the upper-side bus bars and the upper-side external terminal connection portions are directly connected, and the upper-side external terminal connection portions are also formed by metal thin wires having a circular cross section and a wire diameter of 30 to 100 μm, and
the metal thin wires of the upper-side external terminal connection portions and the metal thin wires of the lower-side external terminal connection portions are extended to outside of a region where the lower-side electrode member and the upper-side electrode member are bonded to each other.
8. The thin-frame touch panel as defined in claim 1 , wherein the metal thin wires have a specific resistance value of 20×10 −6 Ω·cm or less.
9. The thin-frame touch panel as defined in claim 8 , wherein the with a conductive paste has a specific resistance value of 1×10 −4 Ω·cm or less.