JPH0621177A - Surface mounted semiconductor device - Google Patents

Abstract

PURPOSE:To provide a semiconductor device, in which the temperature at a semiconductor chip mounted on an island and sealed with a resin can be measured accurately and stably. CONSTITUTION:A semiconductor pellet is mounted on an island 11. A p-n junction provided between a p-type semiconductor 4 and an n-type semiconductor 5 is formed on the rear face of the island 11. These semiconductors 4 and 5 are connected to an outer lead 12a. While a voltage is supplied through the outer lead 12a to the P-n junction, the temperature at the pn-junction or around the pn-junction, namely the temperature at the semiconductor pellet, can be measured from its voltage, current, and so on.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount type semiconductor device mounted by soldering or the like, and more particularly to a semiconductor device having a temperature measuring function for use in a solder heat resistance test.

In order to perform a solder heat resistance test on a surface mount type semiconductor device, a semiconductor device having a thermometer on the surface of the package has been conventionally proposed. FIG. 3 is an example thereof, in which the semiconductor pellets 2 are mounted on the islands 11 of the lead frame 1 and packaged with the resin 7, and the external leads 12 of the lead frame 1 are projected from the resin 7.
Then, the thermocouple 8 is integrally fixed to the upper surface of the resin 7 by the epoxy resin 9 or the like. In this semiconductor device, by measuring the heat treatment temperature at the time of soldering with the thermocouple 8, the heat resistance reliability of the semiconductor device can be measured.

[0003]

In such a semiconductor device, since the thermocouple 8 is disposed outside the resin 7, the temperature of the semiconductor pellet 2 cannot be directly measured.
The outer surface of the resin 7 and the semiconductor pellet 2 sealed in the resin 7
There is a problem that it is difficult to measure the temperature with high reliability because a temperature difference occurs between the two. There is also a problem that the measured temperature varies depending on the position where the thermocouple 8 is fixed. An object of the present invention is to provide a semiconductor device capable of accurately and stably measuring the temperature of a semiconductor pellet.

[0004]

According to the present invention, a PN junction composed of a P-type semiconductor and an N-type semiconductor is provided on the back surface of an island on which a semiconductor pellet is mounted, and each of these P-type and N-type semiconductors is arranged. The semiconductor is connected to external leads, the PN junction is energized through these external leads, and the temperature at the PN junction and its vicinity is measured from the voltage and current at that time.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. 1A and 1B are views showing a first embodiment of the present invention. FIG. 1A is a cross-sectional view of the back surface side of a semiconductor device, and FIGS. 1B and 1C are lines AA and BB thereof. It is an expanded sectional view.
In these figures, island 1 of leadframe 1
A semiconductor pellet (not shown) is mounted on the upper surface of 1 and is electrically connected to the external lead 12. An insulating film 3 is formed on the back surface of the island 11 and between the island 11 and the external leads 12, and a P-type semiconductor film 4 is partially formed on the back surface of the insulating film 3.

An N-type semiconductor layer 5 is formed on a part of the back surface of the P-type semiconductor film 4, and the P-type semiconductor film 4 and the N-type semiconductor element 5 form a PN junction thermometer. . Further, the P-type semiconductor film 4 is formed on the back surface of the insulating film 3.
And conductive patterns 6 electrically connected to the N-type semiconductor layer 5 are formed, respectively, and electrically connected to the portions 12a of the external leads 12, respectively. The P-type semiconductor film 4, the N-type semiconductor layer 5, the conductive pattern 6 and the like are integrally sealed with a resin 7 that seals a semiconductor pellet (not shown) mounted on the island 11.

According to this structure, the conductive pattern 6 is energized through the external lead 12a, and the P-type semiconductor film 4 and N
The PN junction with the type semiconductor layer 5 is energized, and the voltage and current at this time are monitored to determine the temperature at the PN junction,
That is, the temperatures of the island 11 and the semiconductor pellet can be measured. Here, if the voltage applied to the PN junction is X and the current at that time is Y, the temperature t at the PN junction has the following relationship. Y∝e ^{X / Kt}

Therefore, in this semiconductor device, the voltage,
Since the temperature in the vicinity of the island 11 sealed with the resin 7 and the semiconductor pellet mounted thereon can be measured based on the electric current, the temperature of the semiconductor pellet during the heat resistance test can be accurately measured. it can. Also, PN
By setting the junction at the center of the island 11, stable temperature measurement can be performed.

FIG. 2 is a diagram showing a second embodiment of the present invention. FIG. 2 (a) is a sectional view of the back side, and FIGS. 2 (b) and (c) are its CC line and DD line. It is an expanded sectional view. In these figures, the same parts as those in the first embodiment are designated by the same reference numerals. Also in this embodiment, the P-type semiconductor film 4 is formed on the insulating film 3 provided on the back surface of the island 11, and the N-type semiconductor layer 5 is formed by implanting impurities in a part thereof. Then, the P-type semiconductor film 4 and the N-type semiconductor layer 5 are connected to the external leads 12a by the conductive patterns 6, respectively.

Here, by electrically connecting one side of the conductive pattern 6 directly to the island 11, the external lead 12 having a PN junction formed integrally with the island 11,
That is, it can be connected to a GND lead (hanging lead), and only one lead as a thermometer needs to be provided as the other external lead 12a, and the lead in the semiconductor device can be effectively used. P through the external leads 12, 12a
The N-junction is energized and PN is applied depending on the voltage and current at that time.
The measurement of the temperature of the junction or the island 11 is the same as in the first embodiment. Needless to say, the structure of the PN junction and the structure of the conductive pattern connected thereto can be changed as appropriate.

[0011]

As described above, according to the present invention, the PN junction is arranged on the island on which the semiconductor pellet is mounted, and the temperature of the PN junction, the temperature of the PN junction, and the island and It is possible to measure the temperature in the immediate vicinity of the semiconductor pellet mounted on it, and to measure the temperature of the semiconductor pellet, which is the most important for reliability, accurately and stably, and to perform a highly reliable heat resistance test. There is an effect that can be.

[Brief description of drawings]

1A and 1B show a first embodiment of the present invention, in which FIG. 1A is a sectional view of a back surface side, and FIGS. 1B and 1C are enlarged sectional views taken along line AA and BB.

2A and 2B show a second embodiment of the present invention, in which FIG. 2A is a cross-sectional view on the back surface side, and FIGS. 2B and 2C are enlarged cross-sectional views taken along the lines CC and DD.

FIG. 3 is a sectional view of a semiconductor device provided with a conventional thermometer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lead frame 2 Semiconductor pellet 3 Insulating film 4 P-type semiconductor film 5 N-type semiconductor layer 6 Conductive pattern 11 Island 12, 12a External lead

Claims (1)

[Claims] 1. A PN junction composed of a P-type semiconductor and an N-type semiconductor is provided on the back surface of an island on which a semiconductor pellet is mounted, and each of the P-type and N-type semiconductors is connected to an external lead, The PN through these external leads
A surface mount type semiconductor device characterized in that the junction is energized, and the temperature of the PN junction and its vicinity is measured from the voltage and current at that time.