JPH0342690Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a position detection element that detects the rotational position of a rotor by, for example, providing a position detection element on the surface of a stator. A position detection element is provided.

Prior Art FIG. 2 shows a cross-sectional view of a conventional position detection element. To explain this, numeral 1 is a chip that detects changes in magnetic flux, and is fixed to the upper surface of lead 2, which will be described later. 2 is a lead, 3 is a bonding wire for connecting the chip 1 and the lead 2, and 4 is a package for molding the chip 1, the leads 2, and the bonding wire 3.

Problems that the invention attempts to solve: However, with the above configuration, chip 1
is fixed to the upper end of the lead 2, so the thickness A from the top surface of the package 4 to the bonding wire 3 is approximately 0.3 mm, the thickness B from the bonding wire 3 to the top surface of the lead 2 is approximately 0.2 mm, and the thickness of the lead 2 is approximately 0.3 mm. The thickness C is approximately 0.1 mm, and the thickness D from the bottom surface of the lead 2 to the mounting surface of the motor stator portion of the package 4 is approximately 0.2 mm. Therefore, the thickness (A+B+C+D) from the top surface of the package 4 to the mounting surface of the stator portion of the motor is required to be approximately 0.8 mm.
This thickness has the problem of hindering efforts to make the motor thinner.

In view of the above-mentioned problems, the present invention aims to provide a position detection element in which the thickness from the top surface of the package to the mounting surface of the stator portion of the motor is reduced, and the position detection element can be easily positioned.

Means for Solving the Problems In order to solve the above problems, the position detection element of the present invention includes a lead, a chip provided on the lower surface of the lead, and a bonding wire connecting the lead and the chip. A package is formed by molding, and a round protrusion for positioning with a size smaller than the outer diameter of the package is provided on the bottom surface of the package on the lower surface side of the lead, and the bonding wire is arranged on the side of the round protrusion. The sensitivity center position of the chip is made to coincide with the center position of the round protrusion.

Effect: With the above-described configuration, the present invention makes it possible to reduce the thickness from the top surface of the package to the mounting surface of the stator section of the motor, and to easily position the position detection element at a predetermined position on the stator section. .

Embodiments Hereinafter, position detection elements according to embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a sectional view of a position detection element according to an embodiment of the present invention. In the figure, numeral 5 denotes a chip that detects changes in magnetic flux from a magnetized portion provided on the rotor of a motor, for example, and is fixed to the lower surface of a lead 6, which will be described later. 6 is a lead, 7 is a bonding wire that connects the chip 5 and the lead 6, and 8 is a package in which the chip 5, lead 6, and bonding wire 7 are molded.A round projection for positioning is provided on the bottom surface of the package. The center of the chip is made to coincide with the center of sensitivity of the chip.

The operation of the position detection element of this embodiment configured as described above will be described below. Since the chip 5 is fixed to the lower surface of the lead 6, the chip 5 and the bonding wire 7 are located on the side of the round protrusion of the package 8. Therefore, the thickness E from the top surface of the package cage 8 to the top surface of the lead 6 is approximately 0.2 mm, the thickness F of the lead 6 is approximately 0.1 mm, and the thickness G from the bottom surface of the lead 6 to the motor stator mounting surface is approximately 0.2 mm.
mm and each are required. Therefore, the thickness from the top surface of the package 8 to the stator mounting surface of the motor (E
+F+G) is approximately 0.5mm, making it approximately 0.3mm thinner than before. Also, chip 5
Since the sensitivity center of the motor coincides with the center of the round protrusion of the package cage 8, the motor can be attached to the stator by providing a positioning hole in the stator and inserting the round protrusion into this hole. . Therefore, the mounting accuracy of the position detection element can be determined only by the dimensional accuracy of the hole provided in the stator portion.

Effects of the invention As described above, according to the invention, excellent effects can be obtained in that the thickness of the position detection element can be reduced and the dimensional precision of mounting it on the stator of the motor can be improved. .

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a position detection element according to an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional position detection element. 5... Chip, 6... Lead, 7... Bonding wire, 8... Package.

Claims (1)

[Scope of utility model registration request] A package is formed by molding a lead, a chip provided on the lower surface of the lead, and a bonding wire that connects the lead and the chip, and the bottom surface of the package on the lower surface side of the lead has a dimension smaller than the outer diameter of the package. A position detection device characterized in that a round protrusion for positioning is provided, the bonding wire is arranged on the side of the round protrusion, and the sensitivity center position of the chip and the center position of the round protrusion are aligned. element.