JPS63164232A - Manufacture of temperature sensor integrated circuit - Google Patents

Abstract

PURPOSE:To implement a method of manufacturing the title temperature sensor IC without effects of self-heating and external noises, by bonding a wafer, on which the temperature sensor IC is formed, to a dummy wafer, dividing the wafer of the temperature wafer IC into chips, dividing a substrate for each chip, and thereafter performing trimming. CONSTITUTION:Under the wafer state, the base of the transistor of each integrated circuit is connected to a substrate commonly in a temperature sensor integrated circuit. In this circuit, a wafer 1, on which the temperature sensor integrated circuit is formed, is bonded to a dummy wafer 3 with a fixing agent or by anode bonding. The wafer 1 of the temperature sensor integrated circuit is divided into chips. Said substrate is divided for every chip and trimmed. For example, the product wafer 1 after a wafer process 4 undergoes anode bonding to the rear surface of the dummy wafer 3 through a silicon dioxide film 2. Thereafter half dicing 6 is performed until grooves are formed in the dummy wafer 3. The product wafer 1 is divided into the chips. Under this State, the electric characteristics of each chip are measured and the trimming is performed 7. Thereafter, wafer breaking 8 is carried out, and the wafer is divided into the chips.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a method for manufacturing a temperature sensor integrated circuit (hereinafter referred to as IC).

[Prior Art] There is a method for manufacturing bipolar ICs in which one hub is manufactured in the order of one process → IG characteristic measurement and trimming → dicing → package → R final inspection.

[Problems to be Solved by the Invention] However, since this manufacturing method performs dicing after trimming, the following problems arise when applied to manufacturing the WA degree sensor [C].

■ Mechanical stress generated during dicing may affect the measured values in the trimming process and final inspection, and an rC that was determined to be good in the trimming process may turn out to be a defective product in the Mk final inspection, resulting in a decrease in yield. .

(2) The temperature sensor IC generates heat by itself, but since trimming is performed before being separated into chips, the IG being trimmed is affected by the heat of the surrounding ICs, and proper trimming is not performed.

As a method to solve these shortcomings,
There was a manufacturing method described in 8859@ gazette.

This method involves bonding a semiconductor wafer to a conductive film, dividing the wafer into pellets, stretching the conductive film to create a space between each pellet, and then connecting the electrodes within the pellets and measuring the 1ffi conductive film. The electrical characteristics of the semiconductor device are measured by connecting the device to the device.

However, in this method, the semiconductor element is connected to the terminal of the measuring device through a conductive film, so noise easily enters the semiconductor element through the conductive film, which has a large area, resulting in errors in the electrical characteristic measurement signal. There is a problem in that it tends to occur. Therefore, this method is not suitable for manufacturing temperature sensor ICs that require highly accurate trimming.

The present invention has been made in view of the above-mentioned points, and it is an object of the present invention to realize a method for manufacturing a temperature sensor that is difficult to absorb the effects of self-heating and external noise.

[Means for Solving the Problems] The present invention provides a temperature sensor integrated circuit having transistors, in which the bases of the transistors of each integrated circuit are commonly connected to a substrate in a wafer state. In the circuit, the wafer on which the temperature sensor integrated circuit is formed is bonded to a dummy wafer using a fixative or anodic bonding, the wafer of the temperature sensor integrated circuit is divided into chips, the substrate is divided into chips, and then trimming is performed. 1 is a method of manufacturing a temperature sensor integrated circuit, characterized in that:

[Example] The present invention will be explained below using the drawings.

FIG. 1 is a process diagram of an embodiment of a method for manufacturing a temperature sensor IC according to the present invention.

The product wafer 1 that has undergone the wafer process is transferred to the dummy wafer 3 via silicon dioxide (SjO2) ffQ2 on the back surface [! Joined. Here, the product wafer 1 is one in which a plurality of UU sensors C using transistors are formed. An example of the structure of this transistor is shown in FIG. In the figure,
E is an emitter, C is a collector, and B is a base. The collector and the base are connected, and these are connected to the substrate S. Thereby, the bases of the transistors of each temperature sensor [C are commonly connected to the substrate S. Further, the dummy wafer 3 is a wafer on which no pattern is formed.

After such bonding, half guising is performed until grooves are formed in the dummy wafer 3 to divide the product wafer 1 into digs. As a result, the substrate S is divided into chips. At this time, each chip is held in wafer units by a dummy wafer 3.

In this state, the electrical characteristics of each chip are measured and trimming is performed.

After that, we broke the wafer, separated it into chips, and packaged them! iHiragi test is performed to determine whether the chip is good or bad.

An example of 61 used for trimming is shown in FIG.

In the figure, 4 is the stage on which the diced wafer is placed, 5 is the measurement part that measures the electrical Ji (resistance value, voltage, etc.) of the chip to which the probe P is applied, and 6 is the part to be trimmed in 1C. 7 is a mirror that reflects the emitted light of the radar 8 and applies it to the trimming location; 9 is a CP that controls the driving of the measurement unit 5 and the laser 8, and controls the positions of the stage 4 and the mirror 7; (It is J.

When trimming the resistance value with such a device, the CPU 9 cuts the chip pattern with the emitted light of the laser f8 based on the measurement signal from the measuring section 5, and trims the resistance value to the target value. I'll go.

The schematic configuration of the circuit in the wafer process is shown in FIG.

As shown in the figure, the bases of the transistors Tr provided in each temperature sensor IC are commonly connected to the base plate S. aa' is a terminal to which the probe P is applied.

After dicing, the circuit configuration is such that the substrate S is divided into chips as shown in FIG.

In the state not shown in FIG. 4, the substrate S extends over the entire surface of the wafer, and therefore tends to pick up noise. If measurement is carried out in this state, a noise signal will be introduced in the path b, causing a measurement lA difference, and proper trimming will not be performed.

However, in the method according to the present invention, trimming is performed in the state shown in FIG. In the state shown in Fig. 5, the beam straight S is divided into chips, so b
There is no possibility that external noise will enter through this route.

FIG. 6 is a process diagram of the second embodiment of the JT1 method for temperature sensor (C) according to the present invention.

In this method, after the wafer process, the bottom surface of the product wafer 1 is bonded to the dummy wafer 3 using a resist Im9. Thereafter, the product wafer 1 is divided into chips by dicing. At this time, each chip is held by the resist layer 9. After measuring the electrical characteristics and performing trimming in this state, the resist is removed, packaging is performed, and final inspection is performed. A device similar to that shown in FIG. 3 is also used for trimming.

Also in this method, the electrical characteristics are measured with the substrate S divided, so the influence of noise is reduced.

The fixing agent for fixing the product 1 to the dummy wafer 3 is not limited to Regis E. It may be a general adhesive, low melting point glass, or the like.

[Effects] According to the present invention, the electrical characteristics of the chip are measured with the base of the transistor connected and the syst rate separated, which makes it difficult for external noise to enter the measurement signal and allows for appropriate trimming. It is possible to do this.

In addition, since the temperature sensor IC is separated for each chip when measuring electrical characteristics, the chip being trimmed is less susceptible to the effects of self-heating from the surrounding FF1FF sensor ICs, which also makes it easier to perform appropriate trimming. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a process diagram of an embodiment of the method for manufacturing a temperature sensor IC according to the present invention, FIG. 2 is a diagram showing an example of the configuration of a transistor used in the sensor IC, and FIG. 3 is a method according to the present invention. Figures 4 and 5 are diagrams showing an example of a device used for trimming, Figures 4 and 5 are diagrams showing connection states of transistors used in a temperature sensor IC, and Figure 6 is another embodiment of the method according to the present invention. It is a diagram. DESCRIPTION OF SYMBOLS 1... Product wafer, 2... Silicon dioxide layer, 3 Dummy wafer, 5... Measurement part, 8... Laser, 9...
・CPU5S...Substrate, Tr...Transistor. Figure 1 Figure 2 Figure 3 Figure 3

Claims (1)

[Claims] In the temperature sensor integrated circuit having a transistor, the bases of the transistors of each integrated circuit are commonly connected to a substrate in a wafer state, the wafer on which the temperature sensor integrated circuit is formed is fixed with a fixing agent. Alternatively, a method for manufacturing a temperature sensor integrated circuit, which comprises bonding to a dummy wafer by anodic bonding, dividing the wafer of the temperature sensor integrated circuit into chips, and performing trimming after dividing the substrate into chips.