JPS5946868A - Non-destructive inspection of semiconductor device - Google Patents

Abstract

PURPOSE:To make an inspection device small in size and compact in the stage of subjecting a semiconductor device wherein a semiconductor chip is sealed with an insulator from above the leads connected to the electrodes on the surface of said chip and part of the leads are exposed to the outside to a non- destructive inspection by putting the semiconductor device in a high frequency electromagnetic field and subjecting the same to the inspection. CONSTITUTION:The entire part of a semiconductor device produced by bonding one end of a wire 3 of Au or Al to an electrode 2 consisting of Al formed on the surface of a semiconductor element 1, connecting the other end of the wire to an external lead 4 consisting of Cu, etc., sealing the surface thereof with a resin molded body 5, and exposing part of the lead 4 on the outside is exposed to a high frequency electromagnetic field in a high frequency current heater 6. Thermal impact is thus applied to the conductive parts such as the Al electrodes, Au wires, Cu leads, etc. and the junctures thereof, whereby the semiconductor device is inspected. The metallic parts of the electrodes, etc. sealed in the resin body are heated instantaneously without breaking down the resin body by making use of the high frequency current heating and the partial disconnection defect, etc. are discovered in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for non-destructive testing of semiconductor devices under different temperature conditions.

Methods for non-destructive screening (called screening) of semiconductor devices such as transistors and ICs (semiconductor integrated circuits) include (1) temperature cycling, (2) high temperature storage, and (3)
) At present, it is possible to leave it at a low temperature. Among these (1)
In the temperature cycle, the elements to be tested are placed alternately in several constant temperature baths with different temperatures, for example, at a low temperature of -55C for 30 minutes.
It is used to inspect the electrical characteristics of semiconductor devices and defects such as disconnections by changing the temperature for 10 minutes at room temperature and 30 minutes at a high temperature of 150C for 5 to 10 cycles, depending on the screening conditions. , the content of defects discovered differs. (2) High-temperature leaving requires leaving at a maximum temperature of 150 C or higher for 1 to 5 hours, which is difficult to take and is difficult to automate. (3) Low-temperature storage involves leaving the product at the lowest temperature of -55C or less for 1 to 5 hours, so it cannot be incorporated into the regular inspection process because the equipment is large and the cost is high. Have difficulty.

In this way, traditional screening is time-consuming and costly.
In addition, it is difficult to automate inspection when produced on a line. Particularly in the case of digital ICs, bonding wire breakage failures occur frequently during or after the resin molding process.
However, conventional temperature cycling alone has limited testing ability.

The present invention has been made to solve the above-mentioned problems. Therefore, one objective of the present invention is to shorten screening time and increase testing efficiency, and another objective is to reduce testing costs with simple equipment.

The present invention will be described in detail below with reference to Examples.

One embodiment of the present invention is an AA formed on the surface of a semiconductor element (St chip) 1 as shown in FIG.
One end of a wire 3 made of Au or An is bonded (connected) to a different electrode 2, and the other end of this wire is connected to an external lead 4 made of Cu or the like, and the top is placed in a resin (synthetic resin) molded body 5. By exposing the entire semiconductor device, which is formed by sealing the resin well and exposing a portion of the leads 4 to the outside of the resin, to a high frequency electromagnetic field in a high frequency current heating device 6, the A electrode + Au wire Cu lead is heated. The test is performed by applying temperature shock to the conductor parts and their connection parts.

In addition, in the figure, 7 is an electrode for high frequency heating, and 8 is a terminal for measuring characteristics.

By using high-frequency current heating, metal parts such as electrodes sealed inside the resin body can be heated instantly without destroying the resin body, and the AA
Half-disconnection defects caused by incomplete crimping of bonding wires to N poles and leads can be discovered in a short time. According to experiments conducted on resin-sealed transistors, when a high-frequency current is applied, the resin (epoxy resin) is heated to 50C in a short period of time, and an induced current flows from the chip to the wires and leads, causing high temperatures at the thin joints. It turned out that it heats up and the resistance increases, causing it to burn out.

In the conventional method, since air or resin is interposed as a heat medium between the external heating body and the element, it takes a long time to heat up to the electrode part, but in the present invention, it takes a long time to heat up to the electrode part. Screening efficiency is extremely high because metal parts can be heated intensively and instantaneously.

In addition, according to the present invention, there is no need to use a constant temperature bath like in the past, and all that is required is a high-frequency current heating means, so the inspection device can be made smaller and more compact, and the equipment cost can be lowered.
Therefore, it can be adapted to mass production.

Further, according to the present invention, the temperature cycle test can be performed while the semiconductor device to be tested is kept stationary, and the test can be performed in a short time, so that automation of the test can be realized. An example is a marking machine for semiconductor products.

System cleaning efficiency can be increased by installing an inspection device having a high-frequency current heating means according to the present invention in a sorter, handler, or the like.

The nondestructive testing method according to the present invention can be applied to resin-sealed ICs in addition to the resin-sealed transistors described in the embodiments.

It is extremely effective when applied to all semiconductor products, such as ceramic-sealed ICs and hybrid ICs in which various elements are mounted on a printed wiring board.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a semiconductor device and a schematic diagram of an inspection apparatus for explaining an embodiment of the non-destructive inspection method according to the present invention. DESCRIPTION OF SYMBOLS 1... Semiconductor chip, 2... A2 electrode, 3... Wire, 4... Lead, 5... Resin sealing body, 6...
High frequency current heating device, 7... electrode, 8... terminal. Ku Agent Patent Attorney Bo 1) Interest! 'Flower Figure 1

Claims (1)

[Claims] 1. When conducting a non-destructive test against temperature changes on a semiconductor device in which the soil to which the leads are connected to the electrodes on the surface of the semiconductor chip is sealed with an insulating material and a portion of the leads are exposed to the outside, the semiconductor device is A non-destructive testing method for semiconductor devices, characterized in that the above-mentioned testing is performed in a high-frequency electromagnetic field.