JPH07130771A - Assembly method for discrete device - Google Patents

Abstract

PURPOSE:To provide a method of assembling discrete devices with identical characteristics from semiconductor chips. CONSTITUTION:When pellets having different characteristics are used, their characteristics are measured for classification. The pellets classified into different groups are mounted on different lead frames.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembling method for manufacturing individual devices having uniform characteristics in a final inspection from semiconductor pellets having characteristics of two or more types.

[0002]

As is well known, individual elements such as transistors and Hall elements are made from a semiconductor wafer. Patterning including electrode formation is performed on a semiconductor wafer and diced into individual pellets. Generally, a wafer is attached to an elastic film having an adhesive and then diced, and the film is expanded into individual pellets. These pellets are picked up one by one using a die bonder and transferred to a lead frame having an adhesive resin at a predetermined position.

However, the electromagnetic characteristics at the pellet stage that define the characteristics of these elements are not only within the range, but also have a certain distribution and extend over at least two types of characteristics. When semiconductor pellets having mixed electromagnetic characteristics are transferred to the same lead frame as described above, the individual elements assembled through the steps after the bonding step must be sorted out in some way.

Conventionally, it is the final inspection step that the characteristics are made uniform. In this step, the lead frame is cut into individual elements, boxes are prepared according to the characteristics, and the pieces are placed in the boxes in discrete states. Then, except when it is packed in a bag immediately, elements with the same characteristics are once gathered, rearranged, and marks according to the characteristics are marked on the elements with a means such as a laser, and then formed or taped to form the product. Is normal. Further, with the miniaturization of the element, these final inspection steps become more and more difficult, and there is a problem in productivity such that the operation rate of the equipment is lowered. As described above, there are many steps after the final inspection, and in order to ensure reliability, all of them are inspected every time the above work is completed. Therefore, it has been a problem that much labor is required. Particularly, as individual devices become cheaper and smaller, rationalization of these processes is becoming an urgent issue.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an assembling method capable of solving the above problems when manufacturing individual elements having uniform characteristic ranges after element formation.

[0006]

As a result of repeated studies to solve the above problems, the present inventors have measured the characteristics of individual semiconductor pellets (elements) before die-bonding them onto a lead frame. The present invention has been completed by finding that an assembly method for manufacturing individual elements having uniform characteristics can be realized in a final inspection after element formation by individually mounting the lead frames specified in advance by the characteristic range. Came to.

That is, according to the present invention, in the method of assembling an individual element having characteristics of two or more ranges, the step of individually measuring the characteristics of the pellet and two or more ranges of measured values are designated in advance. Then, each pellet within the range is transferred to another lead frame, and the individual element is assembled.

A method of assembling the individual elements according to the present invention will be described by taking a magnetoelectric conversion element as an example. First, the structure of the pellet of the magnetoelectric conversion element will be described. FIG. 1 is a diagram showing the structure of a pellet. In the figure, 1 is a substrate such as silicon or ferrite, and 2 is a semiconductor. The semiconductor 2 is composed of a magnetic sensing part, two input terminals, and two output terminals.
This is the output voltage when a constant DC voltage is supplied to the resistance of the input / output terminal and the input terminal, and when a constant magnetic field is applied to the magnetic sensitive section and when it is not applied. The lead frame has an island portion on which a semiconductor pellet is mounted, a lead portion that serves as an external terminal,
It consists of the parts that fix them. The surface is entirely or partially plated.

Next, the assembling method will be described. Figure 2
FIG. 4 is a flow chart showing a process line of an assembling method of individual elements according to the present invention.

The operation of the assembling method according to the above-mentioned steps will be described below.

First, the electromagnetic characteristics of each pellet are measured. In this step, since the input / output terminals are formed at the four corners of the pellet, a probe or the like is brought into contact with the input / output terminals to apply the input voltage, and the output voltage in the magnetic field and in the non-magnetic field is measured. If the characteristic value is a non-defective product, it will belong to any of two or more types of characteristic ranges designated in advance. In this way, by individually measuring the pellets one after another, a group of pellets having the same characteristic range is completed. Next, pellets having the same characteristic range are die-bonded to the same lead frame and fixed by adhesion. An apparatus generally known as a die bonder can be used in this step. That is, an adhesive is applied in advance to the island portion of the lead frame by various methods, and pellets are placed thereon. Further, the pellet is integrated with the lead frame by putting it in an oven or the like to cure the adhesive. Die-bonded lead frames having the same characteristic range are stored in the same magazine. The die-bonded lead frame is wire-bonded,
Connect the pellet terminals to the lead frame leads. For this step, a device generally known as a wire bonder can be used. That is, both ends of the wire are crimped to the input / output terminal side and the lead portion of the lead frame using ultrasonic waves and heat.

[0012]

According to the above construction, individual elements having a uniform characteristic range can be selected after being made into elements, and individual elements having a single characteristic range will flow to the process after the final inspection. Can be produced efficiently.

Hereinafter, the present invention will be described in more detail with reference to Examples.

[0014]

[Embodiment] The surface is insulated and has a diameter of 4 inches and a thickness of 0.2.
Electron mobility 20000 cm2 on a 5 mm silicon substrate
/ V ・ S characteristics (measured by van der Pau method) In
A semiconductor of Sb (indium antimony) is formed and patterned by wet processing. The patterned wafer is cut by a dicing machine to form 0.8 mm square pellets.

The input / output resistance of each of these pellets is individually measured by an electromagnetic characteristic tester, a DC voltage of 1 V is applied to the input terminal, and a magnetic field of 200 Gauss and a magnetic field-free output voltage are measured. The non-magnetic field output voltage is determined to be non-defective in the range of -5 mV to 5 mV. Regarding the output voltage of the magnetic field, the three ranges as the characteristic range are determined as non-defective products. The range is 10 mV to 12.4 mV as the first range and 12.5 mV as the second range.
mV to 15.3 mV, and the third range is 15.4 mV to 18 mV. According to the measured output voltage of the magnetic field of the pellet, it is classified into each of the three ranges. The distributions in each range were 5%, 63%, and 32%, excluding the defects.

The pellet group in the first range, the pellet group in the second range and the pellet group in the third range were each made to have a thickness of 0.1 m.
An island measuring 1 mm x 1.2 mm in size is 4.6
Die-bonded to a lead frame having a size of 15 mm × 92 mm arranged in 20 pieces at a mm pitch, housed in a magazine and cured. This separated into three groups of leadframes.

This lead frame group was connected to the input / output terminals and the lead frame with a gold wire by a wire bonding device. After that, resin encapsulation is performed to form an element. The Hall element groups in the respective characteristic ranges thus formed are finally inspected with a magnetic field of 500 Gauss, and the output voltage is 2.times the output voltage of the 200 Gauss magnetic field, excluding bonding defects, and the distribution is It was confirmed that the product was good without any change in the range of characteristics.

[0018]

As described above, according to the present invention,
The individual elements within a single characteristic range will flow to the process after the final inspection, and the individual elements can be systematically and efficiently produced.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a structure of a pellet of an individual element according to the present invention.

FIG. 2 is a flow chart showing a process line of an assembling method of individual elements according to the present invention.

[Explanation of symbols]

 1 substrate 2 semiconductor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiaki Fukunaka 6-4100 Asahi-cho, Nobeoka, Miyazaki Prefecture Asahi Kasei Denshi Co., Ltd. (72) Yuuki Matsui 6-4100 Asahi-cho, Nobeoka, Miyazaki Prefecture Asahi Kasei Denshi Within the corporation

Claims (1)

[Claims] 1. A method of assembling individual devices having characteristics in a range of two or more, wherein a step of dicing a semiconductor wafer to obtain pellets, and then individually measuring the characteristics of the pellets, A method of assembling an individual element, comprising the steps of: specifying two or more ranges of measured values in advance and sorting, and transferring each pellet within the sorted range to a different lead frame.