Chip-type particulate matter sensor

A PM (Particulate Matter) sensor apparatus comprising:

• a housing to be coupled to an exhaust pipe;
• and
• a sensor installed in the housing, the sensor having a sensing pattern for sensing particulate matters contained in exhaust gas,
• wherein the housing further comprises a cylindrical wall and a plurality of radial partition walls located inside the cylindrical wall,
• wherein the cylindrical wall comprises a plurality of holes arranged in a predetermined interval along a circumference of the cylindrical wall such that, through the plurality of holes, exhaust gas is introduced into and discharged from the housing,
• wherein the plurality of radial partition walls are arranged in a predetermined angular interval along the circumference of
• the cylindrical wall and meet at the center of the housing to form a plurality of channels extending along a longitudinal direction of the housing such that the exhaust gas flows in the longitudinal direction through the plurality of channels,
• wherein the sensing pattern is formed on a sensing surface of the sensor that is arranged to face in the longitudinal direction toward the plurality of channels such that the exhaust gas flowing through the plurality of channels reaches the sensing pattern,
• wherein the sensing pattern comprises a plurality of electrodes patterned in a line shape on a substrate of the sensor,
• wherein the plurality of electrodes forming the sensing pattern are divided into two or more groups which are not electrically connected to each other, and electrodes of different groups are alternately arranged,
• wherein the plurality of electrodes forming the sensing pattern is patterned in a same substrate of the sensor,
• wherein the sensor is fixed in a state where the sensing pattern is exposed to the bottom of an insulator formed in the housing, and
• wherein the sensing pattern is exposed toward lower end of the housing.