JP2839411B2 - Inspection device for defective IC - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for distinguishing non-defective products from non-defective products in an electrical characteristic test of a semiconductor device, and an inspection apparatus for inspecting them.

[0002]

2. Description of the Related Art A semiconductor device (hereinafter, referred to as an IC) that has completed an assembly process is sent to a test process.
In this test process, there is a step of the appearance inspection of electrical characteristics testing step of testing the electrical properties, and the inspection of such bending marks and leads indicating the specification of the device. In each of these steps, the IC is divided into non-defective products and defective products, and only non-defective products are sent to the next process or shipped.

[0003]

Since the conventional method for distinguishing between good and defective ICs in the test process has been performed as described above, ICs which are determined to be defective in the electrical characteristic test are particularly apparent. Above, there is no difference from the IC determined to be non-defective. Therefore, depending on the handling method, defective ICs are classified into non-defective ICs due to human error.
Has occurred, which has caused problems such as a decrease in inspection accuracy and shipment of defective products.

[0004] The present invention has been made to solve the above-mentioned problems, and a non-defective product even after an electrical characteristic test.
It is an object of the present invention to obtain a method of distinguishing defective ICs from which defective products can be determined, and further to obtain an inspection apparatus suitable for inspecting the defective ICs.

[0005]

An inspection apparatus according to the present invention.
Can be visually confirmed in the electrical characteristics test process
Printed on the back of the package of defective IC
An inspection device for detecting a defective mark, comprising:
A predetermined size opening is provided in the area corresponding to the back of the package.
An inspection table having a test table, and irradiating light from below the inspection table to perform inspection
A light source for illuminating the back of the IC package mounted on the base,
CC to capture the image of the back of the IC package
An imaging means such as a D camera is provided, and the back of the IC package is provided.
Of the defective IC
Printed on the backside of the page using paint that can be checked with the naked eye
This is to detect a defective mark.

[0006]

[0007]

[0008]

[0009]

According to the inspection apparatus of the present invention, the package
Large enough to detect bad marks on the surface
A hole is provided in the inspection table, and the bottom of the package
Providing imaging means for capturing images, irradiating light
The image on the back of the package is taken in.
Identify defective marks that could not be identified from the cage surface
it can.

[0010]

[0011]

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a defect I according to a first embodiment of the present invention will be described.
A method of distinguishing C will be described with reference to FIG. FIG. 1 shows a QFP (Quad Flat Package) package (IC to be inspected) applied to the method for distinguishing defective ICs according to the first embodiment of the present invention.
1 is a plan view of a package 1 sealed with a resin.
The lead-out surface of the lead 11 is formed on the four side surfaces.
Reference numeral 12 denotes a mark indicating the direction of the chip, which is used to align the lead 11 and a wiring pattern (not shown) of the mounting board during mounting, and forms a concave portion in the sealing resin. And so on. 13 is on the surface 1a of the IC package determined to be defective in the test process.
This is a defective mark printed using a transparent invisible light paint that cannot be identified by the naked eye.

FIG. 2 shows an example of the configuration of an inspection apparatus for inspecting the defective mark 13. In the figure, reference numeral 32 denotes an inspection table on which the IC package 1 to be inspected is supported by its leads 11. Have been. Reference numeral 3 denotes a light source for irradiating light 31 for raising the defective mark 13 marked on the surface 1a of the IC 1 in the IC package of FIG. 1, and 2 denotes an IC surface 1 on which the defective mark 13 is raised.
This is a CCD camera for capturing the image a.

Hereinafter, a method of determining a defect using the above-described IC to be inspected and the inspection apparatus will be described. The ICs sent to the test process in the same manner as before are subjected to an electrical characteristic test and an appearance inspection. Then, in the electrical characteristic test, non-defective products and defective products are selected. Here, the defective mark 13 is formed on the surface 1a of the IC 1 determined to be defective by using an invisible light paint that cannot be recognized by the naked eye, for example, a transparent fluorescent paint that emits fluorescent light by irradiating ultraviolet rays, as shown in FIG. Is printed as follows. Then, only the non-defective products are sent to the next process, and all the test processes are performed.

After completion of all the test steps, in order to inspect whether or not the ICs 1 which have been determined to be defective are present, a defective mark inspection apparatus for determining defective products shown in FIG. To inspect. That is, the IC 1 to be inspected is placed on the inspection table 32 of FIG. 2, and the defect mark 13 written on the surface 1a of the IC 1 to be inspected by the light source 3 as a defective product.
The light 31 is irradiated so that the paint of the first color emerges. Then, an image of the surface 1a of the IC 1 to be inspected is captured by the CCD camera 2, and the defect mark 13 is inspected.

Here, if the inspected IC 1 is defective,
Since the defect mark 13 was printed during the above test,
The defective mark 13 raised by the light 31 is detected from the image of the CCD camera 2 and is processed as a defective product. Conversely, if it is a non-defective product, the defective mark 13 is not detected,
Shipped as a good product. By doing so, it is possible to prevent a defective product from being mixed into a good product group.

As described above, according to the present embodiment, the surface 1a of the defective IC 1 determined to be defective in the electrical characteristic test.
The defect mark 13 is printed using a paint that cannot be confirmed with the naked eye.
1 and irradiate the image of the package surface 1a at that time with CC
Since the defective camera is read by the D camera 2 and the presence of the defective mark 13 is detected, the defective product can be easily found without giving any change in the appearance of the package.

Next, a defective IC according to a second embodiment of the present invention
Will be described with reference to FIG. In the figure, 1
4 is an IC determined to be defective in the electrical characteristic test process.
This is a defective mark printed on the back surface 1b of the package 1 using a visible paint. Hereinafter, an example of a defect mark inspection apparatus used in the second embodiment will be described with reference to FIG. In the figure, reference numeral 4 denotes an inspection table, which includes a CCD.
A hole 41 is provided to allow the camera 2 to capture an image of the defective mark 14 on the back surface of the IC 1 to be inspected. The light 51 emitted from the light source 5 irradiates the back surface of the IC 1 through the hole 41 to be sharp. To capture the best images.

Next, a method of determining a defect using the above-described IC to be inspected and the inspection apparatus will be described. In the same manner as in the above embodiment, after all of the test steps such as electrical characteristics and appearance inspection have been completed, the inspection table 4 is placed on the inspection table 4 in order to inspect whether or not ICs that have been determined to be defective are present. The IC 1 to be inspected is placed so that the package back surface 1b of the IC 1 to be inspected can be seen through the hole 41 of the inspection table 4 from below. And the light source 5
The light 51 is irradiated on the back surface 1b of the IC 1 to be inspected. Then, the image of the package back surface 1b is captured by the CCD camera 2, and the presence or absence of the defective mark 14 is inspected. Then, based on the presence / absence of the defective mark 14, a defective product mixed in a non-defective product is detected and removed. In this manner, as in the case of the first embodiment, it is possible to distinguish a non-defective product from a defective product without giving any change to the appearance of the package.

Next, a defective IC according to a third embodiment of the present invention
Will be described with reference to FIGS. 5 and 6. As shown in FIG. 5, in this embodiment, the position where a defect mark is marked is changed depending on the defect mode.
a indicates a defective mark when the position of the defective mark is changed downward in the defective mode. FIG. 6 is a plan view of the QFP package when the shape of the defective mark (see FIG. 13B) is changed depending on the defect mode.

By performing an IC inspection using such a package in the same manner as in the first and second embodiments, the type of the failure mode can be easily known, and failure analysis and the like can be easily performed. it can.

Further, in the above embodiment, the Q to be inspected is Q
Although the explanation has been made using the FP (Quad Flat Package) package, the DIP (Dual Inline Package) and the SOP (Small Out Package)
linePackage).

[0023]

According to the inspection apparatus of the present invention, an inspection apparatus for detecting a defective mark printed on the back surface of a package of a defective IC using a paint that can be visually confirmed in an electrical characteristic test process. An inspection table having an opening large enough to capture the image of the defect mark in an area corresponding to the back surface of the IC package, and irradiating light from below the inspection table to be mounted on the inspection table A light source for illuminating the back surface of the package of the IC, and imaging means for capturing an image of the back surface of the IC package,
Since defective ICs are detected from the image obtained by the imaging means, defective marks that could not be identified from the surface of the package can be clearly identified, and non-defective and defective products can be obtained without giving an external change to the package. And distinguish
There is an effect that a defective product can be prevented from being mixed into a good product group.

[Brief description of the drawings]

FIG. 1 is a plan view of a QFP package used in a method for distinguishing defective ICs according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of an inspection device suitable for detecting a defective mark printed on the QFP package.

FIG. 3 is a plan view of a QFP package used in a method for distinguishing defective ICs according to a second embodiment of the present invention.

FIG. 4 is a schematic sectional view of an inspection apparatus suitable for detecting a defective mark printed on the QFP package.

FIG. 5 is a plan view of a QFP package in which a print position of a defective mark used in a method of distinguishing defective ICs according to a third embodiment of the present invention is changed.

FIG. 6 is a plan view of a QFP package in which the shape of a defective mark used in the method for distinguishing defective ICs according to the third embodiment of the present invention is changed.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 QFP package (IC to be inspected) 1 a Package front surface 1 b Package back surface 11 Lead 12 Mark indicating chip orientation 13 Defective mark printed using invisible light paint 13 a Defective mark with changed printing position 13 b Defective mark with changed shape 14 Defect mark printed using visible light paint 2 CCD camera (imaging means) 3 Light source 4 Inspection table 32 Inspection table 41 Hole in inspection table 5 Light source

Claims (1)

(57) [Claims] (1) In the electrical characteristic test step,
On the back of the package of defective IC using paint that can be checked
An inspection device for detecting printed defective marks.
A predetermined size in the area corresponding to the back of the IC package.
An inspection table having an opening, and an IC mounted on the inspection table by irradiating light from below the inspection table
Light source for illuminating the back of the package and imaging for capturing an image of the back of the IC package
Means for detecting a defective IC from an image obtained by the imaging means.
An inspection apparatus characterized in that: