Trackpad with capacitive force sensing and haptic feedback
A trackpad includes: a substrate; a circuit board coupled to the substrate for detecting a position of an object adjacent the substrate; a haptic feedback component coupled to the circuit board; a first plate coupled to the circuit board; a second plate including a spring element, a spacer coupling the circuit board and the spring element to each other, the spring element facilitating first movement of the substrate, the circuit board and the first plate relative to the second plate, the spacer facilitating second movement of at least the substrate and the circuit board by the haptic feedback component; and a capacitive force sensor that detects a capacitance of the first plate and the second plate. A trackpad can include a circuit board coupled to the substrate and including the first plate.
1. A trackpad comprising:
a substrate;
a circuit board coupled to the substrate for detecting a position of an object adjacent the substrate;
a haptic feedback component coupled to the circuit board;
a first plate coupled to the circuit board;
a second plate including a spring element, a spacer coupling the circuit board and the spring element to each other; and
a capacitive force sensor that detects a capacitance between the first plate and the second plate, wherein the spring element and the spacer provide decoupling of the haptic feedback component and the capacitive force sensor from each other.
2. The trackpad of claim 1 , wherein the spacer includes a stiffener plate positioned between the circuit board and the second plate, the stiffener plate having a recess, the recess aligned with the first plate.
3. The trackpad of claim 2 , wherein the spacer further comprises an adhesive that attaches the stiffener plate and the circuit board to each other, and a disc that couples the stiffener plate and the second plate to each other.
4. The trackpad of claim 1 , wherein the circuit board comprises a printed circuit board assembly, the printed circuit board assembly comprising a first solder mask layer, a core layer, and a first signal layer between the first solder mask layer and the core layer.
5. The trackpad of claim 4 , wherein the first solder mask layer is assembled to the substrate, the printed circuit board assembly further comprising a second solder mask layer, and a second signal layer between the second solder mask layer and the core layer, the first and second signal layers being on opposite sides of the core layer from each other.
6. The trackpad of claim 5 , further comprising a first pre-preg layer between the core layer and the first signal layer, and a second pre-preg layer between the core layer and the second signal layer.
7. The trackpad of claim 1 , wherein the second plate is part of a housing accommodating the trackpad.
8. The trackpad of claim 7 , wherein the spring element has a U-shape, the U-shape defined by a cutout in the housing.
9. The trackpad of claim 1 , wherein the trackpad comprises a moving part and a static part, and wherein the haptic feedback component includes a first component assembled to the moving part, and a second component assembled to the static part.
10. The trackpad of claim 1 , wherein the first plate comprises a stiffener plate assembled to the circuit board.
11. The trackpad of claim 1 , wherein the haptic feedback component includes a layer that forms a trackpad surface for the trackpad, the layer providing haptic feedback using piezoelectric actuation.
12. The trackpad of claim 1 , wherein the trackpad includes multiple haptic feedback components that provide localized haptic feedback, the multiple haptic feedback components arranged in a rectangular pattern relative to the substrate.
13. The trackpad of claim 1 , wherein the spring element comprises one or more legs.
14. The trackpad of claim 13 , wherein the spring element comprises multiple legs, at least two of the multiple legs connected to each other by a turn.
15. The trackpad of claim 13 , wherein the spring element comprises multiple legs, at least two of the multiple legs having different widths from each other.
16. The trackpad of claim 13 , wherein at least one of the one or more legs has a perpendicular connection to the second plate.
17. The trackpad of claim 13 , wherein at least one of the one or more legs has a linear connection to the second plate.
18. The trackpad of claim 13 , wherein at least one of the one or more legs has an angled connection to the second plate.
19. The trackpad of claim 13 , wherein at least one of the one or more legs comprises an essentially circular portion.
20. A method comprising:
detecting a position of an object adjacent a substrate of a trackpad, the position detected using a circuit board coupled to the substrate, the trackpad including a first plate;
performing a first operation based on detecting the position;
detecting a force applied to the substrate using a capacitive force sensor that detects a capacitance between the first plate and a second plate of the trackpad, the second plate including a spring element, wherein a spacer couples the circuit board and the spring element to each other; and
providing haptic feedback to the substrate based at least in part on detecting the force, the haptic feedback provided using a haptic feedback component coupled to the circuit board, wherein the spring element and the spacer provide decoupling of the haptic feedback component and the capacitive force sensor from each other.