JPH09266236A - Semiconductor device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the pickup efficiency of elements divided from a wafer by a hardening resin is coated according to the electric characteristic of a divided element surface, separating those elements not coated with this resin and picking up and die-bonding them. SOLUTION: A wafer 1 is laid on a stage, the electric characteristics of selected elements are measured one after another, the water 1 supported on a resin tape 6 is fully cut like a grid from the surface, an UV-setting resin is spread on the surface of those elements not meeting required characteristics and hardened by an ultraviolet ray, the tape 6 is expanded through the periphery of an expandable ring 9 to separate divided elements from each other and the elements at the coated region are peeled off from the tape 6, the elements are knocked up by knockout pins 10, picked up by a suction collet and moved to lead frame tabs of a work to be bonded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an individual semiconductor device which is divided and formed from a wafer.

[0002]

2. Description of the Related Art An individual semiconductor device such as a diode or an LED is subjected to a process of diffusing and etching impurities and forming a metal electrode film continuously in a wafer state, and then divided into individual elements for die bonding. It is manufactured by carrying out resin sealing or the like. These plural elements are collectively formed in a wafer made of a semiconductor material such as silicon through the above-described common steps. However, the wafer itself has segregation of impurities and defects on a macro level. Since the devices are inevitably intervened, even if the devices to be built are formed by a common process, slight variations in electrical characteristics occur between the devices depending on the area of the wafer.

For this reason, the elements formed on the wafer are
In general, do you satisfy the required characteristic requirements as an element by measuring the electrical characteristics by using a measuring probe or a tester connected to this on the surface of each element before dividing it individually? Whether the quality is good or bad is determined and the characteristics of the elements are classified. In particular, when determining pass / fail, electrical characteristics of certain elements are measured for all the elements in the wafer, and then “not acceptable” is determined for elements that do not satisfy the required characteristics. Where "No"
As shown in FIG. 3, the element judged to be in a state in which the ink resin mixed with the pigment is applied in a dot shape and cured to make a marking, and then the element is attached to a resin tape made of an expandable resin. After dividing into individual elements by cutting with a dicing blade, etc., the presence or absence of marking on the element surface is optically recognized by separating the elements by expanding the resin tape using an expanding device etc. However, a semiconductor device is manufactured by selectively die-bonding only the elements which are determined as “good” and which are not marked, to the tab of the lead frame or to the mounting position of the substrate.

On the other hand, in recent years, various semiconductor elements have been miniaturized with the development of semiconductor manufacturing technology and demands for miniaturization, and in some cases, a huge number of tens of thousands on a single wafer. Element has been formed.

[0005]

However, when a large number of elements are formed on a single wafer, the time required for measuring the electrical characteristics of each element, determining the quality based on the measurement, and marking the element is the number of elements. Increase significantly with increasing. In particular, for dot-shaped marking, usually, relative movement and alignment are performed between the syringe containing the ink resin and the element to be marked in the three directions of X, Y, and Z for each element. However, since dot-shaped ink marking is individually applied, it may take about 7-8 hours depending on the case.

In addition, even after the dot-shaped marking is made in this way, when picking up the elements for die bonding, the camera is applied to all the elements including the elements which are determined as "no" at the measurement stage. The presence or absence of the marking is identified through the, and the pickup or die bonding is selectively performed only on the element recognized as not having the marking, so that wasteful time is required at this stage as well.

Therefore, it is an object of the present invention to obtain a method of manufacturing a semiconductor device in which the efficiency of picking up elements divided from a wafer is improved.

[0008]

According to a first aspect of the present invention, there is provided a method of manufacturing a semiconductor device, wherein electrical characteristics of a selected one of a plurality of elements formed on a semiconductor wafer are measured, and the wafer is divided. A curable resin is continuously applied to the surface of the element according to the measurement result, and after curing the applied curable resin, the elements not coated with the curable resin are picked up and die-bonded in a state of being separated from each other. It is characterized by doing.

For this reason, the application of the curable resin does not perform electrical measurement and marking on all the elements, but selectively determines the elements that have been determined by electrical measurement, for example, "no". Since the curable resin can be continuously applied along the device, the time required for coating can be significantly reduced. According to a second aspect of the present invention, there is provided a method of manufacturing a semiconductor device according to the first aspect, further comprising a step of attaching a stretchable resin tape to the wafer, and separating the elements by stretching the resin tape.

By carrying out the method of the present invention in this manner, the present invention can be easily carried out. According to a third aspect of the present invention, in the method of manufacturing a semiconductor device according to the second aspect, the measurement of the electrical characteristics is performed before the step of attaching the wafer to the resin tape, the step of attaching the wafer to the resin tape and dividing the wafer. Or during the process of dividing the wafer and applying the curable resin.

By carrying out the method of the present invention in this way, the degree of freedom in the process is increased, and it becomes possible to carry out the method according to the type and structure of the element or wafer to be formed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a method of manufacturing a semiconductor device according to the present invention will be described in detail with reference to FIGS. In the manufacturing method of the present invention, first, a semiconductor wafer having a plurality of electronic elements formed on its surface is prepared. As the wafer, for example, a large number of elements having P-type and N-type diffusion regions for diodes and metal electrodes are formed, for example, tens of thousands, and a silicon wafer having a surface of, for example, 4 inches is used. You can

After preparing such a wafer, as shown in FIG.
As shown in (a), a wafer 1 is mounted on a stage 3 which can be moved in the X, Y, and Z directions via a table 2, and a probe 4 for characteristic measurement is used from the upper side in the row and column directions. In the direction, for example, the electrical characteristics of the elements selected every 5 elements are sequentially measured. As the electrical characteristics to be measured, the range of voltage value, current value, etc. required according to the specifications and standards of the element to be manufactured is determined in advance.

Here, since variations in electrical characteristics due to segregation of impurities in the wafer generally occur continuously rather than intermittently, the measurement does not necessarily have to be performed for all elements. As described above, by selectively measuring the elements, it is possible to almost estimate the quality of the electrical characteristics and the like, and it is possible to roughly determine the quality and select the characteristics. The stage 3 and the probe 4 are electrically connected to a control device (not shown) and storage means provided in connection with the control device, for example, a floppy disk, and are based on characteristic values of each element obtained by measurement and based on them. The data regarding "good" (satisfying the required characteristics) and "failure" (not satisfying the required characteristics) as the determination result is the orientation flat (Orientati) shown in FIG. 2 provided on the end surface of the wafer 1 shown in FIG.
It is stored and stored in the storage means in association with the position data of each element based on the (on Flat) surface 1a.

After the characteristic measurement of the device is completed, FIG.
As shown in FIG. 5, the wafer 1 is attached to the flat ring 5 concentrically on the stretchable resin tape 6 attached to the annular flat ring 5 on the back surface thereof. Since the resin tape 6 has an adhesive layer formed on its surface,
The wafer 1 can be easily attached to the tape 6.

Next, the wafer 1 thus supported on the resin tape 6 is divided from the surface side by a dicing blade 7 by a grid-like full cut as best shown in FIG. Depending, for example, one side is about 3m
m, cubic individualized diode elements are obtained. After the wafer 1 is divided in this way, as shown in FIG. 1C, the flat ring 5 is fixed on the table 2 of the stage 3, and the stage 3 is moved in the X and Y directions (horizontal direction) or X, Y ,. And a curable liquid resin, such as a UV curable resin, housed in the syringe 8 while being moved in the Z direction (horizontal and vertical directions) continuously along the surface of the element determined to be “NO” in the above measurement. Apply in a striped pattern. The coating is performed so as to straddle the divided elements, and more specifically, as in the example shown in FIG. 2, a storage unit and a control device for the determination data such as the element position and the quality determined by the above measurement. "No" from the measurement result based on the electrical signal from
The surface of the element which is determined to be the element and which is included in an area (hereinafter referred to as “coating area”) 11 defined by the elements on the wafer surface is mounted on the stage 3 in the X and Y directions with respect to the syringe 3. This is done by aligning and moving.

As the curable resin to be used, instead of the UV curable resin which can be easily cured by irradiation with ultraviolet rays as described above, a thermosetting resin which is cured by heating can be used as well. After the curable resin is applied in this manner, it is cured by irradiating it with ultraviolet rays from above, and then, as shown in FIG.
As shown in (d), the divided elements are separated from each other by extending the resin tape 6 attached to the expander through the outer circumference of the expand ring 9 of the expander as in the ordinary expander. When the resin tape 6 is stretched, the elements judged as “good” at the time of the characteristic measurement, that is, the elements outside the application area, are separated from each other at a constant interval along with the extension, while the elements in the application area are cured. Since they are adhered to each other via the cured resin, they are separated from each other and are separated from the resin tape 6.

At the time of adhering such elements, the resin tape 6 can be prepared by appropriately adjusting the coating thickness of the cured resin.
It can be bonded with a strength such that it can be appropriately broken by stretching. Therefore, the portion joined in a multi-layered manner, for example, the wafer peripheral edge coating region 11a in FIG. 2 is divided at any place between the elements, so that there is no problem in expanding.

The element separated by the expansion of the resin tape 6 is attached to the tape 6 by using, for example, tweezers.
Can be easily removed from. After removing the elements in the application region in this manner, the push-up pin 1 is checked while confirming the position and existence of the elements separated by a camera (not shown).
The element is pushed up by 0, and the element pushed up by a suction collet (not shown) is picked up and sequentially transferred and placed on a tab or the like of a lead frame as an object to be bonded to perform a die bonding process.

The thus die-bonded element is subjected to a necessary assembly process such as a wire bonding process or a resin sealing process to manufacture an individual semiconductor device. In addition, in the method of the present invention, the characteristic determination is presumably performed for the selected element, so that an element that should originally be determined as “not” in terms of characteristics can be subjected to the assembly process together with the element determined as “good”. However, all the elements or devices after the assembly process can be removed by the inspection of the electrical characteristics and the like required in the normal inspection process, and there is almost no problem.

In the above example, the electrical characteristics of the device were measured prior to the attachment of the wafer to the resin tape. However, the measurement was performed on the type and structure of the device formed on the wafer, for example, the presence or absence of the back electrode. It goes without saying that it may be performed between the steps of attaching and dividing the wafer, or between the step of dividing and the curable resin, depending on the material of the wafer substrate.

In the above-mentioned example, the elements to be measured are selected every 5 elements in the row direction and the column direction, but such selection can be appropriately changed according to the specifications and standards of the semiconductor device to be manufactured. There is no end. Further, the method of the present invention is not limited to the above-described selection of the quality of the element, but can be applied to classification according to the characteristic value by measurement.

[0023]

As described above in detail, according to the method of the present invention, the application of the curable resin does not perform electrical measurement and marking on all elements, but selectively performs electrical measurement. Since the curable resin can be continuously applied along the element determined by performing the above, for example, the element determined to be “no”, the time required for coating can be significantly reduced.

Further, after the plurality of elements are formed and before the application of the curable resin, the semiconductor wafer is attached onto the expandable resin tape, and the resin tape is expanded after the curable resin is cured. By separating the elements from each other by the resin tape, the plurality of elements fixed by the hardening of the curable resin as the resin tape is stretched are separated from the resin tape without being separated from each other. Can be removed, and thus by picking up and die bonding the remaining elements after these removal,
The time required for these can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a schematic view showing main steps of a manufacturing method of the present invention.

FIG. 2 is a plan view showing an example of application of a curable resin according to the manufacturing method of the present invention.

FIG. 3 is a plan view showing an example of ink marking by a conventional method.

[Explanation of symbols]

 1 Semiconductor Wafer 2 Table 3 Stage 4 Probe 5 Flat Ring 6 Resin Tape 7 Dicing Blade 8 Syringe 9 Expanding Ring 10 Push-up Pin 11 Application Area

Claims (3)

[Claims] 1. The electrical characteristics of selected ones of a plurality of elements formed on a semiconductor wafer are measured, the wafer is divided, and a curable resin is applied to the surfaces of the divided elements according to the result of the measurement. Is continuously applied, the applied curable resin is cured, and then the elements not coated with the curable resin are picked up and die-bonded in a state of being separated from each other, and a method for manufacturing a semiconductor device. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the manufacturing method further includes a step of adhering the wafer to a stretchable resin tape, and separating the elements by stretching the resin tape. 3. The measurement of the electrical characteristics is performed before the step of attaching the wafer to the resin tape, during the step of attaching the wafer to the resin tape and dividing the wafer, or The method of manufacturing a semiconductor device according to claim 2, wherein the method is performed during any one of the steps of dividing the wafer and applying the curable resin.