Underfill flow management in electronic assemblies
Disclosed herein are structures and techniques for underfill flow management in electronic assemblies. For example, in some embodiments, an electronic assembly may include a first component, a second component, an underfill on the first component and at least partially between the first component and the second component, and a material at a surface of the first component, wherein the material is outside a footprint of the second component, and the underfill contacts the material with a contact angle greater than 50 degrees.
1. An electronic assembly, comprising:
a first component;
a second component;
an underfill on the first component and at least partially between the first component and the second component; and
a material at a surface of the first component, wherein the material is outside a footprint of the second component, and the underfill contacts the material with a contact angle greater than 50 degrees;
wherein the material includes a silicone, a polyurethane, a polyolefin, or an elastomer.
2. The electronic assembly of claim 1 , wherein the contact angle is greater than or equal to 60 degrees.
3. The electronic assembly of claim 1 , wherein the material includes fluorine.
4. The electronic assembly of claim 1 , wherein the underfill includes an epoxy.
5. An electronic assembly, comprising:
a first component;
a second component;
an underfill on the first component and at least partially between the first component and the second component; and
a material at a surface of the first component, wherein the material is outside a footprint of the second component, and the underfill contacts the material with a contact angle greater than 50 degrees;
wherein the material has a surface energy that is less than 40 dynes per centimeter.
6. The electronic assembly of claim 5 , wherein the material has a surface energy that is less than 30 dynes per centimeter.
7. An electronic assembly, comprising:
a first component;
a second component;
an underfill on the first component and at least partially between the first component and the second component; and
a material at a surface of the first component, wherein the material is outside a footprint of the second component, the material does not surround the footprint of the second component, and the underfill contacts the material, wherein:
the second component has a side surface and the material is proximate to the side surface;
the material is arranged in a line that is parallel to at least some of the side surface; and
the line has a length that is a less than a length of the side surface.
8. The electronic assembly of claim 7 , wherein the length of the line is less than or equal to one-half the length of the side surface.
9. An electronic assembly, comprising:
a first component;
a second component;
an underfill on the first component and at least partially between the first component and the second component; and
a material at a surface of the first component, wherein the material is outside a footprint of the second component, the material does not surround the footprint of the second component, and the underfill contacts the material, wherein:
the second component has a side surface and the material is proximate to the side surface;
the material is arranged in a line that is parallel to at least some of the side surface; and
the line is spaced away from a footprint of the side surface by a distance between 0.5 millimeters and 1 millimeter.
10. An electronic assembly, comprising:
a first component;
a second component;
an underfill on the first component and at least partially between the first component and the second component; and
a material at a surface of the first component, wherein the material is outside a footprint of the second component, a line of the material is parallel and proximate to a side surface of the second component, and a length of the line is less than a length of the side surface.
11. The electronic assembly of claim 10 , wherein the side surface is a first side surface, the line is a first line, the second component has a second side surface opposite to the first side surface, and the material includes a second line that is parallel and proximate to the second side surface.
12. The electronic assembly of claim 11 , wherein the first line and the second line are parallel.
13. The electronic assembly of claim 10 , wherein the material does not surround the footprint of the second component.
14. The electronic assembly of claim 10 , wherein the underfill includes a tongue portion outside a footprint of the second component.
15. The electronic assembly of claim 14 , wherein the line is a first line, the material includes a second line of the material, an end of the first line is proximate to a first side of the tongue portion, and an end of the second line is proximate to a second side of the tongue portion.
16. The electronic assembly of claim 14 , wherein the tongue portion is a first tongue portion, and the underfill includes a second tongue portion opposite to the first tongue portion.