JPH11251344A - Manufacture of hole sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a hole sensor having a high yield and reliability and an excellent operability. SOLUTION: In a method of manufacturing a hole sensor in which a resin package 16 is formed by mounting a semiconductor chip 13 on a chip mounting section 12 of a lead frame 11 having leads 11a to 11d, connecting electrode portions of the semiconductor chip 13 to the lead portions of the lead frame 11 using respective bonding wires 15a to 15d, and performing resin molding on the semiconductor chip 13 and the lead portions using a mold, the resin molding is carried out in such a way that the direction of the flow of the mold resin becomes approximately parallel to the wiring direction of the bonding wires.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of manufacturing a Hall sensor, and more particularly to a method of manufacturing a Hall sensor used for detecting a rotor position of a brushless motor for driving a CD-ROM, VTR, or the like.

[0002]

2. Description of the Related Art A brushless motor used for a CD-ROM or a VTR is composed of a rotor having a cylindrical permanent magnet.
A stator in which two or more rotors are symmetrically arranged close to the rotor, a drive coil (armature) wound around the stator,
It is composed of a yoke for fixing the stator and the like, and has a feature in a configuration without a brush. A rotating magnetic field is formed by switching the current applied to the driving coil in a commutation circuit configured using an IC, a transistor, and the like, and the rotor is rotated by the permanent magnet. Brushless motors
In order to create a relationship between the permanent magnet and the armature that always generates a rotational force, the excitation of the armature is performed by the magnetic poles (N,
It must be performed in accordance with the position of S). A Hall sensor is generally used for detecting the magnetic pole position of the rotor.

FIG. 3 shows the principle of a Hall sensor. The Hall sensor 30 is configured by providing four ohmic electrodes 32a, 32b, 32c, and 32d on one surface of a semiconductor chip 31. A DC power supply 32 is connected between the electrodes 32a and 32b, and an output is taken out from the electrodes 32c and 32d. With the hole input current I _H flowing between the electrodes 32a and 32b, the magnetic field B is applied in the thickness direction of the semiconductor chip 31.
Is added, the Hall output voltage V according to the magnitude of the magnetic field B
_H is output from the electrodes 32c and 32d.

[0004] In the case of a brushless motor, the Hall sensor 30 is provided at a position facing the rotor at the tip end surface of the stator. Each time a magnetic pole of the rotor passes, a Hall output voltage V _H is generated. Signal. FIG. 4 shows a manufacturing process of the Hall sensor. The lead frame 41 is
As shown in (a), in addition to having a lead 41a (four in total) and a chip mounting portion 41b, it actually has a bridge portion in the periphery (not shown in FIG. 4). The semiconductor chip 42 is mounted on the chip mounting portion 41b by die bonding as shown in FIG. Next, as shown in (c), a predetermined position of the lead 41a and the electrode of the semiconductor chip 42 are wire-bonded by the Au wire 43. Next, as shown in (d), the semi-finished product obtained in the step (c) is positioned in a space between the lower mold 44 and the upper mold 45 (having a shape in which a resin package is formed at the time of completion).
A liquid resin is poured from the gate 46 into the mold. In this state, the resin is cured, and resin sealing (resin molding) is performed. Then, remove the cured product from the mold,
The resin package 47 having the shape (side) of (e) and the shape (top) of (f) is obtained. In this state, since the gate resin portion 47a injected into the gate 46 protrudes from the main body, the gate resin portion 47a is cut by a cutter (not shown), and the lead is read from the resin package 47 as shown in FIG. A resin package 47 having a shape in which the protrusion 41a protrudes is obtained, and the Hall sensor is completed.

FIG. 5 shows a detailed configuration of a conventional Hall sensor. The leads 41a shown in FIG.
b, 51c, and 51d, and are arranged on the same plane in an H shape while being separated from each other. A rectangular chip mounting portion 52 for mounting a semiconductor chip 53 is formed at one of these, the tip inside the lead 51a. The semiconductor chip 53 includes electrode portions 54a, 54b,
The electrodes 54a and 51d, the electrodes 54b and 51b, the electrodes 54c and 51c, and the electrodes 54d and 51d are made of Au wires 55a, 55b, 55c and 55d, respectively. Are connected by

[0006] A dotted line in FIG.
7 and the gate resin portion 57a is the lead 51.
c and 51d are set at intermediate positions between the leads 51c and 51d.
The gate position is set so as to be parallel to d. The reason for providing the gate 46 at this position is to prevent the remaining gate from adversely affecting the mounting of the Hall sensor.

[0007]

However, according to the conventional method of manufacturing a Hall sensor, the gate resin portion 57a is connected to the leads 51c and 51d (or the leads 51a and 51b).
Are arranged in a parallel state in the middle of the wire, but when the resin is injected into the mold in this arrangement state, the Au wires 55a to 55d
Resin flows in such a way that the side of the wire is pressed.
Therefore, as shown by the dashed line in FIG.
5a to 55d are deformed from a desired position on the plane indicated by 60, so that disconnection and short circuit are liable to occur, and a decrease in yield leads to an increase in cost. In addition, the reliability is reduced due to the wire deformation.

The present inventors have manufactured a package having the shape of step (g) according to the manufacturing method of FIG. 4 and then opened the package to discriminate between those having a small deformation of the Au wire and those having a large deformation. The tensile strength of each wire was measured. As a result, the wire strength of the smaller wire deformation is about 6 g, and the wire strength of the larger wire deformation is about 4 g, which indicates that the strength of the wire having the larger deformation is reduced. In addition, when a gate is provided between the leads, there is a problem that the terminal is easily deformed when the remaining gate is removed, resulting in poor workability.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for manufacturing a Hall sensor having a high yield, high reliability, and excellent workability.

[0010]

According to the present invention, as a first feature, a semiconductor chip for a hall sensor is mounted on a chip mounting area of a lead frame, and an electrode portion of the semiconductor chip is provided. And a lead portion of the lead frame are connected by a bonding wire, and the semiconductor chip and the lead portion are mounted on a mold and a resin molding is performed. A method for manufacturing a Hall sensor, wherein the resin mold is applied in a direction substantially parallel to a wiring direction of the bonding wire.

According to a second aspect of the present invention, a semiconductor chip for a hall sensor is mounted on a chip mounting area of a lead frame, and an electrode portion of the semiconductor chip and the lead frame are provided. In a method for manufacturing a Hall sensor, in which the lead portions are connected by a bonding wire, and the semiconductor chip and the lead portions are placed in a mold and resin molding is performed, the molding die is substantially in the wiring direction of the bonding wires. A method for manufacturing a Hall sensor, comprising preparing a mold having a resin injection port in a parallel direction, injecting a resin from the resin injection port, and applying the resin mold.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a Hall sensor manufactured by a method of manufacturing a Hall sensor according to the present invention. The lead frame 11 has leads 11a, 11b, 11c, 1
1d, and the respective leads are arranged on the same plane in an H shape while being separated from each other. A chip mounting portion 12 is formed at the tip of the lead 11a, and the chip mounting portion 12 is arranged at the center of the leads 11a to 11d. The semiconductor chip 13 is mounted on the chip mounting portion 12 by die bonding. Semiconductor chip 13
Have four electrode portions 14a, 14b, 14c, 14
d is provided, and each of the electrode part 14a and the lead part of the lead 11a, the electrode part 14b and the lead part of the lead 11b, the electrode part 14c and the lead part of the lead 11c, and the electrode part 14d and the lead part of the lead 11d, They are connected by Au (gold) wires 15a, 15b, 15c, and 15d, respectively. This state corresponds to the state shown in FIG.

The resin molding is performed by using dies 44 and 45 as shown in FIG. Although the outer shape of the resin package 16 according to the present invention is the same as that of the conventional resin package, the direction of the gate of the mold is changed by 90 degrees and is set in a direction perpendicular to the leads. Therefore, the direction of the gate resin portion 16a of the package 16 is also changed by 90 degrees. FIG. 2 shows the outer shape of the resin package 16 in the Hall sensor having the configuration shown in FIG. This shape corresponds to the processing state of (e) and (f) of FIG. The gate resin portion 16 a of the resin package 16 is provided with a lead 11 on a side surface of the resin package 16.
It protrudes so as to be orthogonal to a to 11d.

With such a configuration, the injection of the molten resin from the gate 46 in FIG. 4D is performed from a direction substantially parallel to each of the Au wires 15a to 15d as shown in FIG. For this reason, the Au wire 15
a to 15d are less likely to receive the pressing force of the injected resin,
Almost the posture at the time of bonding is maintained, and disconnection and short circuit hardly occur, so that yield and reliability can be improved. In addition, since the gate package is on the side, the resin injection operation is facilitated.

[0015]

As is clear from the above, according to the method of manufacturing the Hall sensor of the present invention, the flow direction of the molding resin is made substantially parallel to the wiring direction of the bonding wires, so that the wire is formed at the time of resin molding. Deformation hardly occurs. As a result, disconnection and short-circuit hardly occur, and it is possible to improve the stability of the wire strength and the reliability. In addition, the work of injecting resin from the gate becomes easy.

[Brief description of the drawings]

FIG. 1 is a plan view showing a Hall sensor manufactured by a method of manufacturing a Hall sensor according to the present invention.

FIG. 2 is a perspective view showing an outer shape of a resin package in the Hall sensor having the configuration of FIG. 1;

FIG. 3 is a circuit diagram for explaining the principle of a Hall sensor.

FIG. 4 is a flowchart showing a manufacturing process of the Hall sensor.

FIG. 5 is a plan view showing a detailed configuration of a conventional Hall sensor.

[Description of Signs] 11 Lead frame 11a, 11b, 11c, 11d Lead 12 Chip mounting portion 13 Semiconductor chip 14a, 14b, 14c, 14d Electrode portion 15a, 15b, 15c, 15d Au wire 16 Resin package 16a Gate resin portion 44, 45 mold

Claims (2)

[Claims] 1. A semiconductor chip for a Hall sensor is mounted on a chip mounting area of a lead frame, an electrode portion of the semiconductor chip is connected to a lead portion of the lead frame by a bonding wire, and the semiconductor chip and the semiconductor chip are mounted on a mold. In a method for manufacturing a Hall sensor in which a lead portion is provided and resin molding is performed, the resin molding is performed by setting a flow direction of a resin in the molding die to be substantially parallel to a wiring direction of the bonding wire. Manufacturing method of the Hall sensor. 2. A semiconductor chip for a hall sensor is mounted on a chip mounting area of a lead frame, an electrode portion of the semiconductor chip is connected to a lead portion of the lead frame by a bonding wire, and the semiconductor chip and the semiconductor chip are mounted on a mold. In a method of manufacturing a Hall sensor in which a lead portion is provided and resin molding is performed, a molding die having a resin injection port in a direction substantially parallel to a wiring direction of the bonding wire is prepared as the molding die. A method for manufacturing a Hall sensor, comprising: injecting a resin from an inlet to apply the resin mold.