SEMICONDUCTOR DEVICE

• US 20160061885A1
• Filed: 08/06/2015
• Published: 03/03/2016
• Est. Priority Date: 08/29/2014
• Status: Abandoned Application

• Current Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Original Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Inventors: TAKEMATSU, Yuji, OKAMOTO, Kenji
• Application Number:
  US14/820,298
• Publication Number:
  US 20160061885A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01R 31/2851 Testing of integrated circuits [IC] G01R31/317 takes precedence; testing individual devices G01R31/26; testing printed circuits G01R31/2801
• CPC Class Codes: G01R 31/2856 Internal circuit aspects, e.g. built-in test features; Test chips; Measuring material aspects, e.g. electro migration [EM]
• CPC Class Codes: G01R 31/2875 related to heating
• CPC Class Codes: G01R 31/2896 Testing of IC packages; Test features related to IC packages containers per se H01L23/02, encapsulations per se H01L23/28
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 23/29 characterised by the material , e.g. carbon interlayer dielectrics H01L23/5329
• CPC Class Codes: H01L 23/3121 a substrate forming part of the encapsulation
• CPC Class Codes: H01L 24/01 Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/181 Encapsulation

Abstract

A semiconductor device including: an insulating substrate; a semiconductor element mounted on the insulating substrate; an internal printed circuit board disposed on the semiconductor element; and a sealing member that seals the semiconductor element, the internal printed circuit board, and at least a portion of the insulating substrate. The sealing member is made of a sealant that includes a resin and a pigment, and that initially has a chromatic, white, or gray color, and the sealing member degrades, thereby causing color of a front surface thereof to change to a degree recognizable by a user after the semiconductor device has been in use under a prescribed condition for a prescribed duration.

Claims

1. A semiconductor device, comprising:

an insulating substrate;

a semiconductor element mounted on said insulating substrate;

an internal printed circuit board disposed on said semiconductor element; and

a sealing member that seals said semiconductor element, said internal printed circuit board, and at least a portion of said insulating substrate;

wherein said sealing member is made of a sealant that includes a resin and a pigment, and that initially has a chromatic, white, or gray color, and

wherein said sealing member degrades, thereby causing color of a front surface thereof to change to a degree recognizable by a user after the semiconductor device has been in use under a prescribed condition for a prescribed duration.

2. The semiconductor device according to claim 1, wherein said pigment has a blue color so that a b* value within a L*a*b* color space of the front surface of said sealing member is −

40 to −

20.

3. The semiconductor device according to claim 2, wherein the b* value of at least a portion of the front surface of said sealing member changes to −

5 or above as a result of degradation of said sealant.

4. The semiconductor device according to claim 1, wherein said pigment has a blue color and the sealant further includes another pigment that has a yellow color, so that an a* value within a L*a*b* color space of the front surface of said sealing member is −

30 to −

15.

5. The semiconductor device according to claim 4, wherein the a* value of at least a portion of the front surface of said sealing member changes to −

5 or above as a result of degradation of said sealant.

6. A device, comprising:

a printed circuit board; and

the semiconductor device according to claim 1 mounted in a plurality on the printed circuit board.

7. A method of estimating remaining life of a semiconductor device that includes a sealing member made of a sealant, the sealant initially having a chromatic, white, or gray color, the method comprising:

heating a test sealant that has the same composition as the sealant in the semiconductor device at prescribed heating temperatures for prescribed durations;

acquiring a relationship among the heating temperatures, heating durations, and resulting changes in color of the test sealant, by observing the color of the test sealant while the test sealant is being heated; and

estimating the remaining life of the semiconductor device that has been operated, by evaluating color of a front surface of the sealing member in accordance with the relationship acquired in the step of acquiring said relationship.

8. The method of estimating remaining life of a semiconductor device according to claim 7, wherein the color of the test sealant is quantified using a L*a*b* color space in the step of acquiring said relationship.

9. The method of estimating remaining life of a semiconductor device according to claim 7, wherein the step of heating includes:

preparing a test semiconductor device having the same structure and composition as the semiconductor device of which the remaining life is to be estimated;

operating the test semiconductor device under a prescribed condition for a prescribed duration;

measuring a temperature of the front surface of the sealing member of the test semiconductor device while the test semiconductor device is being operated; and

observing changes in the color of the front surface of the sealing member of the test semiconductor device while the test semiconductor device is being operated.

10. A method of verifying the quality of semiconductor devices, comprising:

mounting a plurality of semiconductor devices, each including a sealing member formed of a sealant that initially has a chromatic, white, or gray color, on a substrate;

comparing degrees of discoloration of the respective sealing members in the plurality of semiconductor devices to one another; and

determining that the plurality of semiconductor devices are in good working condition when the step of comparing does not show a prescribed degree of variation in the degrees of discoloration among the plurality of semiconductor devices, and determining that the plurality of semiconductor devices are not in good working condition when the step of comparing shows the prescribed degree of variation in the degrees of discoloration among the plurality of semiconductor devices.