Multilayer resin substrate and method of manufacturing multilayer resin substrate
A multilayer resin substrate includes a stacked body including first resin layers made of a thermoplastic resin, conductor patterns on the stacked body, and a protective layer including a second resin layer made of a thermosetting resin. The stacked body includes first and second main surfaces, and a bent portion. One of the conductor patterns located at the bent portion is located only inside the stacked body. The protective layer covers at least the bent portion, on the main surface of the stacked body.
1. A multilayer resin substrate comprising:
a stacked body having a main surface and including a plurality of first resin layers that are made of a thermoplastic resin and stacked;
one or more conductor patterns in or on the stacked body; and
a protective layer at a portion of the main surface and including a second resin layer made of a thermosetting resin; wherein
the stacked body includes a bent portion that is bent such that the main surface is on an inside or an outside of the bent portion;
any conductor pattern located at the bent portion, among the one or more conductor patterns, is provided only inside the stacked body; and
the protective layer covers at least the bent portion, on the main surface.
2. The multilayer resin substrate according to claim 1 , wherein
the conductor pattern includes an external connection electrode on the main surface; and
the protective layer is not near the external connection electrode.
3. The multilayer resin substrate according to claim 1 , wherein
the conductor pattern includes an external connection electrode on the stacked body;
the protective layer is not near the external connection electrode; and
the external connection electrode is on a boundary surface between an outermost layer including the main surface, among the plurality of first resin layers, and an adjacent layer adjacent to the outermost layer, and is exposed from the opening portion in the outermost layer, to an outside.
4. The multilayer resin substrate according to claim 1 , wherein the conductor pattern at the bent portion has a mesh shape.
5. The multilayer resin substrate according to claim 1 , wherein
the protective layer is adjacent to the second resin layer, and includes a third resin layer that is more flexible than the second resin layer; and
the third resin layer is bonded to the main surface through the second resin layer.
6. The multilayer resin substrate according to claim 5 , wherein a thickness of the second resin layer is less than a thickness of the third resin layer.
7. The multilayer resin substrate according to claim 5 , wherein
the first resin layer is made of a liquid crystal polymer as a main material; and
the third resin layer is made of polyimide as a main material.
8. The multilayer resin substrate according to claim 5 , wherein a flatness of a surface of the protective layer opposite to a surface in contact with the main surface is higher than a flatness of a portion of the main surface in which the protective layer is provided.
9. The multilayer resin substrate according to claim 1 , wherein the protective layer includes a plurality of protective layers.
10. The multilayer resin substrate according to claim 9 , wherein
the bent portion includes a plurality of bent portions; and
the plurality of protective layers are disposed at different bent portions, respectively, on the main surface.
11. The multilayer resin substrate according to claim 9 , wherein
the main surface includes a first main surface and a second main surface that oppose each other; and
the plurality of protective layers are provided on the first main surface and the second main surface, respectively.
12. The multilayer resin substrate according to claim 1 , wherein
the main surface includes a first main surface and a second main surface that oppose each other;
the conductor pattern at the bent portion is disposed at a position closer to the first main surface than to the second main surface; and
the protective layer is provided only on the first main surface.
13. The multilayer resin substrate according to claim 1 , wherein the conductor pattern includes:
a first ground conductor;
a second ground conductor; and
a first signal conductor between the first ground conductor and the second ground conductor in a stacking direction of the stacked body.
14. An electronic device comprising:
the multilayer resin substrate according to claim 1 ;
a first circuit board connected to a first end of the multilayer resin substrate; and
a second circuit board connected to a second end of the multilayer resin substrate.
15. The electronic device according to claim 14 , wherein each of the first and second circuit boards is made of glass epoxy.
16. The electronic device according to claim 14 , wherein
the first circuit board includes a first surface;
the second circuit board includes a second surface parallel or substantially parallel to the first surface; and
the first surface and the second surface are disposed at different height in a vertical or substantially vertical direction.