Contact force sensor package, blood pressure meter with the same, and method for fabricating the contact force sensor package

A blood pressure meter comprising:

• a blood pressure measuring block having at least one contact force sensor package detecting a sphygmus wave of a human body and measuring blood pressure based on the detected sphygmus wave;
• and
• a contact maintaining device maintaining a state in which the blood pressure measuring block contacts the human body,
• wherein the contact force sensor package comprises:
• a substrate layer formed of silicon and having a vibration detection unit that includes a shape deformation element which changes shape by a contact force and a pair of first junction pads that are electrical connection ports which are provided on an upper surface of the substrate layer;
• a flexible circuit substrate layer formed of an elastic material and having a pair of second junction pads provided at a position corresponding to the first junction pads and electrically connected to the first junction pads, via a pair of metal bumps;
• a vibration transfer unit having one side contacting the shape deformation element of the vibration detection unit and the other side contacting a human body to detect a sphygmus wave and transferring the sphygmus wave to the vibration detection unit;
• and
• an adhesion layer formed between the substrate layer and the flexible circuit substrate layer to reinforce a junction force between the substrate layer and the flexible circuit substrate layer, the adhesion layer being not formed in an area overlapping at least the vibration transfer unit, and
• wherein the elastic material of the flexible circuit substrate layer has an elastic coefficient which is less than an elastic coefficient of the shape deformation element.

A method for fabricating a contact force sensor package, the method comprising:

• preparing a substrate layer formed of silicon and having a vibration detection unit that includes a shape deformation element which changes shape by a contact force and a pair of first junction pads that are electrical connection ports which are provided on an upper surface of the substrate layer;
• providing a flexible circuit substrate layer formed of an elastic material and having a pair of second junction pads at a position overlapping the first junction pads;
• forming a pair of metal bumps which electrically connect the first and second junction pads;
• forming a vibration transfer unit having one side contacting the shape deformation element of the vibration detection unit and the other side contacting a human body to detect a sphygmus wave and transferring the sphygmus wave of the human body to the vibration detection unit;
• and
• forming an adhesion layer by implanting and curing a liquid material between the substrate layer and the flexible circuit substrate layer to reinforce a junction force between the substrate layer and the flexible circuit substrate layer, wherein the liquid material is not implanted in an area overlapping the vibration detection unit, and
• wherein the elastic material of the flexible circuit substrate layer has an elastic coefficient which is less than an elastic coefficient of the shape deformation element.