JP2005055394A - Inspection method for semiconductor integrated circuit element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection method for a semiconductor integrated circuit capable of detecting minute foreign matter existing on each of multiple leads easily. <P>SOLUTION: The inspection method for the semiconductor integrated circuit 1 which is provided with multiple leads 3 comprises a step for inserting detection electrodes 5 between each of multiple lead 3, a voltage impress step for impressing voltage on the detection electrodes 5, and a step for inspecting existence of foreign mutter on the multiple leads 3 based on the current flow of the inspection electrodes 5 in the previous step. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for inspecting a semiconductor integrated circuit element, and more particularly to a method for inspecting a semiconductor integrated circuit element for inspecting the presence or absence of foreign matter present in a plurality of leads of a semiconductor integrated circuit element.

  In the manufacturing process of a semiconductor device, an appearance inspection of an IC package that has been assembled is performed. In this IC (Integrated Circuit) package appearance inspection, lead appearance inspection is also performed. In the lead visual inspection, the presence or absence of foreign matter present in the lead is inspected. The foreign matter in this case is, for example, a deposit attached between the leads or a protrusion formed when the lead is molded or the lead is plated. Conventionally, lead visual inspection is performed by the following method. That is, the IC package is photographed by the photographing device. Then, the image information of the photographed lead is subjected to data processing by a predetermined method, and the contrast between the bright part and the dark part of the photographed image is enhanced. Then, by comparing this image with a normal image stored in advance, the presence or absence of foreign matter present in the lead is inspected.

  In addition, in the conventional manufacturing process of a semiconductor device, an electrical characteristic test of an assembled IC package is also performed. In the test of electrical characteristics, an electrode is connected to each of the leads, and the electrical characteristics of the IC package are measured. In the case where a short circuit is caused between the leads due to the foreign matter, an abnormality occurs in the electrical characteristics, so that the presence or absence of the foreign matter existing in the lead can be inspected.

  Although the prior art regarding the present invention has been described based on general technical information obtained by the applicant, information that should be disclosed as prior art document information before filing is filed within the scope of the applicant's memory. The person does not have.

  However, in order to detect fine foreign matters in the above-described conventional lead visual inspection, it is necessary to finely adjust the photographing conditions, such as increasing the resolution of the photographing device or adjusting the state of the light source during photographing. For this reason, there has been a problem that fine foreign substances existing in the leads cannot be easily detected.

  In addition, since the conventional electrical characteristic test does not require fine adjustment of the photographing conditions, foreign substances present in the leads can be easily detected. There is a problem that foreign matter cannot be detected unless it is done. In particular, when the foreign matter is fine, it is unlikely to cause a short circuit between each of the leads, so that it is difficult to detect the fine foreign matter by the conventional electrical characteristic test. However, an IC package in which such fine foreign matter is present in the lead is likely to cause a malfunction such as a short circuit later.

  Accordingly, an object of the present invention is to provide a method for inspecting a semiconductor integrated circuit element that can easily detect fine foreign matter present in each of a plurality of leads.

  The method for inspecting a semiconductor integrated circuit device according to the present invention is a method for inspecting a semiconductor integrated circuit device having a plurality of leads, an insertion step of inserting an electrode between each of the plurality of leads, and applying a voltage to the electrode. And a step of inspecting for the presence or absence of foreign matter present in the plurality of leads based on the presence / absence of energization of the electrodes in the step of applying a voltage.

  According to the method for inspecting a semiconductor integrated circuit element of the present invention, foreign matters are detected based on whether or not the electrodes are energized, so that fine foreign matters can be easily detected without finely adjusting the photographing conditions. In addition, since foreign matter is detected by inserting an electrode between each lead, even if the foreign matter is a minute one that does not cause a short between each lead, the inserted electrode and foreign matter are not The electrode is energized by contact. As a result, fine foreign matter can be detected.

  (Embodiment 1)

  FIG. 1 is a plan view for explaining a method for inspecting a semiconductor integrated circuit device according to the first embodiment of the present invention. FIG. 2 is a side view of FIG.

Referring to FIG. 1, a semiconductor integrated circuit element 1 includes a semiconductor chip 2 and a plurality of leads 3. The semiconductor chip 2 in the present embodiment has a square shape, and each of the leads 3 extends outward so as to be orthogonal to each of the four sides of the square. The lead 3 has a cross-sectional shape bent downward. With such a cross-sectional shape, one end of the lead 3 is grounded. The other end of the lead 3 is electrically connected to an electrode pad (not shown) on the semiconductor chip 2. The pitch d ₁ of the leads 3 is, for example, 0.65 mm, and the width d ₂ of each gap of the leads 3 is, for example, 0.22 mm. Such a semiconductor integrated circuit device 1 is manufactured, for example, by the following method.

  That is, the semiconductor chip 2 is disposed on the island of the lead frame and fixed with an adhesive. Next, each of the plurality of electrode pads on the semiconductor chip 2 and each of the leads 3 of the lead frame are electrically connected by wires. Then, the lead frame on which the semiconductor chip 2 is arranged is set in a mold, and high temperature resin is poured into the mold. Thereby, the semiconductor chip 2 is covered with the resin, and the semiconductor integrated circuit element 1 is manufactured. Subsequently, the semiconductor integrated circuit element 1 is separated from the lead frame. Then, the lead 3 is formed and plated, and the shape of the semiconductor integrated circuit element 1 shown in FIG. 1 is obtained.

  Next, a method for inspecting a semiconductor integrated circuit device in this embodiment will be described.

Referring to FIGS. 1 and 2, semiconductor integrated circuit element 1 is fixed, and a plurality of detection electrodes 5 (electrodes) are inserted between leads 3. The diameter d ₃ of each of the detection electrodes 5 is, for example, 0.1 mm or less. The detection electrode 5 has, for example, an inclined portion 6 inclined on the upper surface 1b of the semiconductor integrated circuit element 1 on the side surface. At this time, the detection electrode 5 is inserted by, for example, the following method so that each of the detection electrodes 5 does not touch each of the leads 3. That is, the lead 3 is photographed, and the position of each lead 3 is measured based on the photographed image. Next, the position for inserting each of the detection electrodes 5 is adjusted from each position of the lead 3, and the detection electrodes 5 are inserted. Here, the detection electrode 5 is preferably inserted from the lower surface 1a of the semiconductor integrated circuit element 1 toward the upper surface 1b.

  FIG. 3 is an enlarged view of a portion surrounded by a dotted line in FIG.

  1 and 3, next, one terminal 5a of the plurality of detection electrodes 5 and the terminal 15 of the current detection device 10 are electrically connected to each other, thereby having a terminal 5a. A voltage is applied to the detection electrode 5. The current detection device 10 has the following circuit, for example. That is, the current detection device 10 has a DC power source 12, an ammeter 11, and a terminal 15. The positive pole of the DC power supply 12 is electrically connected to the terminal 15 via the ammeter 11, and the negative pole of the DC power supply 12 is electrically connected to the ground potential. The terminal 15 is electrically connected to the terminal of the detection electrode 5. At this time, if foreign matter 18 exists between the lead 3a and the lead 3b, or if the protrusion 19 is formed on the lead 3a or the lead 3b, these foreign substances come into contact with the detection electrode 5. As a result, a current flows to the lead 3b or the lead 3a via the deposit 18 and the protrusion 19, and the current is detected by the ammeter 11. On the other hand, if no foreign matter such as the deposit 18 or the protrusion 19 exists between the lead 3a and the lead 3b, no current flows through the ammeter 11. In this way, the presence or absence of foreign matter present in the lead 3a and the lead 3b is inspected based on the presence / absence of energization of the detection electrode 5. Since one end of the lead 3 is grounded, even when a current flows through the lead 3b or the lead 3a, the current flows toward the ground potential, and no current flows inside the semiconductor chip 2. Subsequently, the terminal 5b of another detection electrode 5 and the terminal 15 of the current detection device 10 are electrically connected (the terminal of the detection electrode 5 is switched), and the lead 3b and the lead 3c are connected in the same manner. The presence of foreign objects present is inspected. By repeating this, it is possible to inspect for the presence or absence of foreign matter present in all the leads 3.

  According to the inspection method of the semiconductor integrated circuit device 1 in the present embodiment, since the foreign matter is detected based on whether or not the detection electrode 5 is energized, it is possible to easily detect the fine foreign matter without finely adjusting the photographing conditions. can do. Further, since each of the detection electrodes 5 is inserted between each of the leads 3 to detect the foreign matter, even if the foreign matter is a minute one that does not cause a short circuit between each of the leads 3, it is inserted. The detection electrode 5 is energized when the detected electrode 5 and the foreign matter come into contact with each other. As a result, fine foreign matter can be detected.

  In the inspection method of the semiconductor integrated circuit element 1 in the present embodiment, when the detection electrode 5 is inserted, the detection electrode 5 is inserted from the lower surface 1a of the semiconductor integrated circuit element 1 toward the upper surface 1b.

  Thereby, when the detection electrode 5 is inserted, the foreign matter between the leads 3 is removed to the outside by the detection electrode 5.

  In the inspection method of the semiconductor integrated circuit element 1 in the present embodiment, the side surface of the detection electrode 5 is inclined with respect to the upper surface 1 b of the semiconductor integrated circuit element 1.

  Thereby, when the detection electrode 5 is inserted, the foreign matter between the leads 3 falls along the inclination by gravity. Accordingly, the foreign matter between the leads 3 is further easily removed to the outside.

  (Embodiment 2)

FIG. 4 is a plan view for explaining a method for inspecting a semiconductor integrated circuit device according to the second embodiment of the present invention.
Referring to FIG. 4, current detection device 10 in the present embodiment has a current detection portion 10a and an electrode heating portion 10b. The current detection portion 10a has substantially the same circuit as the current detection device 10 (FIG. 1) in the first embodiment. The electrode heating portion 10b has, for example, the following circuit. That is, the electrode heating portion 10 b has an electrical resistance 13 and a DC power source 14. The positive pole of the DC power supply 14 is electrically connected to the terminal 16 and the ground potential via the electric resistor 13, and the negative pole of the DC power supply 14 is electrically connected to the ground potential. The terminal 16 is electrically connected to the terminal 5a of the detection electrode 5.

  In addition, since it is as substantially the same as the structure of Embodiment 1 shown in FIGS. 1-3, about another structure, the same code | symbol is attached | subjected about the same component and the description is abbreviate | omitted.

  Next, a method for inspecting a semiconductor integrated circuit device in this embodiment will be described.

  In the same manner as in the first embodiment, each of the plurality of detection electrodes 5 is inserted between each of the leads 3, and one terminal 5a of the detection electrodes 5 and the terminal 15 of the current detection portion 10a Are electrically connected, and the presence or absence of foreign matter present in the leads 3a and 3b is inspected. When foreign matter is detected in the lead 3a and the lead 3b, the electrical connection between the terminal 5a and the terminal 15 is cut, and instead, the terminal 5a and the terminal 16 of the electrode heating portion 10b are electrically connected. Is done. Then, an electric current flows through the electric resistance 13 to heat the electric resistance 13, thereby heating the detection electrode 5 having the terminal 5 a. Thereby, the foreign matter is dissolved and removed. Alternatively, the lead 3a and the lead 3b are remolded by dissolving the foreign matter.

  The method for inspecting the semiconductor integrated circuit device 1 according to the present embodiment further includes a step of heating the detection electrode 5.

  The foreign matter present in the lead 3 is often a protrusion formed during lead molding or lead plating, and these protrusions have a property of being easily dissolved by heating. Therefore, by heating the detection electrode 5, it is possible to dissolve and remove foreign substances having a property that is easily dissolved by heating. Alternatively, the lead 3 can be re-molded by dissolving foreign matters that are easily dissolved by heating.

  In the present embodiment, the case where the semiconductor integrated circuit element 1 is fixed and each of the plurality of detection electrodes 5 is inserted between the leads 3 is shown. However, the present invention is not limited to such a case, and each of the detection electrodes 5 is fixed and each of the leads 3 of the semiconductor integrated circuit element 1 is inserted between each of the detection electrodes 5. Good.

  In the present embodiment, the case where a plurality of detection electrodes 5 are used has been described. However, the present invention is not limited to such a case, and only one electrode may be used. Further, in the present embodiment, a case where a voltage is applied to each of the detection electrodes 5 by switching the terminal of the detection electrode 5 connected to the terminal 15 using one current detection device 10. Indicated. However, in the present invention, in addition to such a case, a voltage may be applied to each of the plurality of detection electrodes 5 by each of the plurality of current detection devices using, for example, a plurality of current detection devices.

  Moreover, in this Embodiment, it showed about the case where DC power supplies 12 and 14 are used as a power supply in the current detection apparatus 10. However, in the present invention, besides such a case, for example, an AC power source, a DC current source, a DC voltage source, or the like may be used as a power source. In particular, if a power supply with a current limiting function is used, the amount of current flowing can be limited. Therefore, even if a foreign substance exists in the lead 3 and a current flows, an excessive current does not flow to the lead 3.

  Furthermore, in the present embodiment, the detection electrode 5 has an inclined portion 6 that is inclined with respect to the upper surface 1 b of the semiconductor integrated circuit element 1, and the upper surface from the lower surface 1 a of the semiconductor integrated circuit element 1. Although the case where the detection electrode 5 is inserted toward 1b is shown, the present invention is not limited to such a case, and the shape of the electrode and the direction in which the electrode is inserted are arbitrary.

  The embodiment disclosed above should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above embodiments but by the scope of claims, and is intended to include all modifications and variations within the scope and meaning equivalent to the scope of claims.

It is a top view for demonstrating the test | inspection method of the semiconductor integrated circuit element in Embodiment 1 of this invention. It is a side view of FIG. FIG. 2 is an enlarged view of a portion surrounded by a dotted line in FIG. 1. It is a top view for demonstrating the test | inspection method of the semiconductor integrated circuit element in Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor integrated circuit element, 1a lower surface, 1b upper surface, 2 Semiconductor chip, 3, 3a, 3b, 3c Lead, 5 Detection electrode, 5a, 5b, 15, 16 terminal, 6 Inclination part, 10 Current detection apparatus, 10a Current Detection part, 10b Electrode heating part, 11 Ammeter, 12, 14 DC power supply, 13 Electrical resistance, 18 Deposit, 19 Protrusion.

Claims (4)

A method for inspecting a semiconductor integrated circuit device comprising a plurality of leads,
An insertion step of inserting an electrode between each of the plurality of leads;
Applying a voltage to the electrode;
A method for inspecting the presence or absence of foreign matter present in the plurality of leads based on the presence or absence of energization of the electrodes in the step of applying the voltage.   2. The semiconductor integrated circuit device inspection method according to claim 1, wherein, in the inserting step, the electrode is inserted from a lower surface to an upper surface of the semiconductor integrated circuit device.   The method for inspecting a semiconductor integrated circuit device according to claim 2, wherein a side surface of the electrode is inclined with respect to the upper surface of the semiconductor integrated circuit device.   The method for inspecting a semiconductor integrated circuit device according to claim 1, further comprising a step of heating the electrode.

Images