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  1. (Dept. of Mechanical Engineering, Dong-Eui University, Korea )



TO-251, TO-252, Void, Wire diatmeter, Sintered Ag, Die-attach, Thermal resistance

1. ์„œ ๋ก 

์ตœ๊ทผ ๋“ค์–ด ์ „๊ธฐ์ฐจ ์‹œ์žฅ์ด ๋น ๋ฅด๊ฒŒ ์„ฑ์žฅํ•˜๊ณ  ์žˆ๋‹ค. 2010๋…„๋ถ€ํ„ฐ ๊พธ์ค€ํ•œ ์„ฑ์žฅ์„ ์ด์–ด๊ฐ€๊ณ  ์žˆ๋Š” ์ „๊ธฐ์ฐจ๋Š” 2021๋…„ ํ˜„์žฌ ์ž๋™์ฐจ ์‹œ์žฅ ์ „์ฒด์—์„œ ์•ฝ 9%์˜ ์ ์œ ์œจ์„ ์ฐจ์ง€ํ•˜๊ณ  ์žˆ๋‹ค[1]. ์ „๊ธฐ์ฐจ ์‹œ์žฅ์˜ ๊ทœ๋ชจ๊ฐ€ ์ฆ๊ฐ€ํ•จ์— ๋”ฐ๋ผ, ์ „๊ธฐ์ฐจ์˜ ์ „๋ ฅ์„ ํšจ์œจ์ ์œผ๋กœ ์ œ์–ดํ•˜๊ณ  ๊ด€๋ฆฌํ•˜๊ธฐ ์œ„ํ•œ ์ „๋ ฅ๋ฐ˜๋„์ฒด์˜ ์‹œ์žฅ ๋˜ํ•œ ์„ฑ์žฅํ•˜๊ณ  ์žˆ๋‹ค. 2025๋…„์—๋Š” 2019๋…„๊ณผ ๋น„๊ตํ•˜์—ฌ ์ „๋ ฅ๋ฐ˜๋„์ฒด ํŒจํ‚ค์ง• ์‹œ์žฅ์ด 10.7% ์ฆ๊ฐ€ํ•  ๊ฒƒ์œผ๋กœ ์˜ˆ์ƒํ•œ๋‹ค[2]. ์ด์— ๋”ฐ๋ผ ์ „๋ ฅ๋ฐ˜๋„์ฒด ํŒจํ‚ค์ง• ์‹œ์žฅ์˜ ์„ฑ์žฅ๊ณผ ํ•จ๊ป˜, ์ „๊ธฐ์ฐจ ์ „๋ ฅ๋ฐ˜๋„์ฒด ํŒจํ‚ค์ง•์˜ ์‹ ๋ขฐ์„ฑ ๋ฌธ์ œ๊ฐ€ ๋งค์šฐ ์ค‘์š”ํ•˜๊ฒŒ ์ธ์‹๋˜๊ณ  ์žˆ๋‹ค.

์ „๋ ฅ๋ฐ˜๋„์ฒด ํŒจํ‚ค์ง€์˜ ์ œ์กฐ ๊ณต์ •์€ ๋‹ค์–‘ํ•œ ๋‹จ๊ณ„๋กœ ์ด๋ฃจ์–ด์ง€๋Š”๋ฐ, ์ด ์ค‘ ์ผ๋ถ€๋กœ๋Š” Wafer saw, Bonding, Molding, Die-attach ๊ณต์ • ๋“ฑ์ด ํฌํ•จ๋œ๋‹ค. Wafer saw๋Š” Chip์„ ๋ถ„๋ฆฌํ•˜๋Š” ๋‹จ๊ณ„์ธ๋ฐ, ์ด ๊ณผ์ •์—์„œ Chip์ด ์†์ƒ๋  ๊ฐ€๋Šฅ์„ฑ์ด ์žˆ๋‹ค[3]. Bonding ๊ณต์ •์€ Wire bonding (WB), Tape automated bonding (TAB), Flip chip bonding (FCB)์œผ๋กœ ๋‚˜๋‰˜๋ฉฐ, ์ ‘์ฐฉ ๋ฉด์ ์— ๋”ฐ๋ผ ๋ณ€ํ™”๊ฐ€ ์žˆ์–ด ์‹ ๋ขฐ์„ฑ์ด ์ค‘์š”ํ•˜๋‹ค[4]. Molding ๊ณต์ •์€ ์••์ถ•์„ฑํ˜• ๊ณผ์ •์œผ๋กœ ๊ฒฐํ•จ์ด ๋ฐœ์ƒํ•  ์ˆ˜ ์žˆ๋‹ค[5]. Die-attach ๊ณต์ •์€ ์‚ฌ์šฉ๋˜๋Š” ์žฌ๋ฃŒ์— ๋”ฐ๋ผ ๋‹ค๋ฅด๋ฉฐ, Ag sinter pastes๋Š” Sintering ๊ธฐ๋ฒ•, Ag epoxy pastes๋Š” Curing ๊ธฐ๋ฒ•, Solder pastes๋Š” Reflow ๊ธฐ๋ฒ•์„ ์‚ฌ์šฉํ•œ๋‹ค[6]. Sintering ๊ณต์ •์—์„œ๋Š” Paste ๋‚ด์˜ ์ž”๋ฅ˜ ์œ ๊ธฐ๋ฌผ๋กœ ์ธํ•ด Void๊ฐ€ ๋ฐœ์ƒํ•  ์ˆ˜ ์žˆ๋‹ค[7]. ๋˜ํ•œ, Reflow ๊ณต์ •์—์„œ๋Š” Solder์˜ Out-gassing์œผ๋กœ ์ธํ•ด Void๊ฐ€ ํ˜•์„ฑ๋  ์ˆ˜ ์žˆ๋‹ค[8]. ์ด๋Ÿฌํ•œ ๋‹ค์–‘ํ•œ ์›์ธ์œผ๋กœ Void๋Š” ๊ณต์ • ์ค‘์— ๋ฐœ์ƒํ•  ์ˆ˜ ์žˆ์œผ๋ฉฐ, Void๋Š” ์‚ฌ์šฉ ์ค‘์— ์ „๋ ฅ ๋ฐ ์—ด๋กœ ์ธํ•œ Stress๋ฅผ ํ†ตํ•ด ์‹œ๊ฐ„์ด ์ง€๋‚จ์— ๋”ฐ๋ผ ์ฆ๊ฐ€ํ•  ์ˆ˜ ์žˆ๋‹ค[9]. ๋˜ํ•œ, Void๋Š” Heat flow๋ฅผ ๋ฐฉํ•ดํ•˜๊ณ  ๋””๋ฐ”์ด์Šค ์˜จ๋„ ์ƒ์Šน์„ ์œ ๋ฐœํ•  ์ˆ˜ ์žˆ๋‹ค[10].

์ด์™€ ๊ด€๋ จ๋œ ์—ฐ๊ตฌ์—์„œ๋Š” Void์˜ ํ˜•ํƒœ์™€ ์œ„์น˜์— ๋”ฐ๋ผ ์—ด ์ €ํ•ญ ๋ฐ Chip ์˜จ๋„ ์ƒ์Šน์— ์ฐจ์ด๊ฐ€ ์žˆ๋‹ค๋Š” ๊ฒƒ์„ ๋‚˜ํƒ€๋‚ด๋Š” ์—ฐ๊ตฌ๋“ค์ด ์žˆ๋‹ค[11]. Random void์™€ Center ๋˜๋Š” Corner void์˜ Rth-JC์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์€ Center ๋˜๋Š” Corner void์˜ ์˜ํ–ฅ์ด ๋” ์ค‘์š”ํ•˜๋ฉฐ, Corner void๊ฐ€ ๋” ์œ„ํ—˜ํ•˜๋‹ค๋Š” ๊ฒƒ์„ ๋ฐํ˜€๋ƒˆ๋‹ค[12]. ๋˜ํ•œ, Void ๋น„์œจ์ด ์ฆ๊ฐ€ํ•˜๋ฉด ์—ด ์ €ํ•ญ์ด ์ฆ๊ฐ€ํ•˜์ง€๋งŒ 20%๊นŒ์ง€์˜ Random void ํŒจํ„ด๊ณผ ์—ฐ์†๋œ Void ํŒจํ„ด์€ ์—ด ์ €ํ•ญ ์ฆ๊ฐ€์œจ์ด ๋‚ฎ๊ณ  ํฐ ์ฐจ์ด๊ฐ€ ์—†๋‹ค[13].

์ด์™€ ๊ด€๋ จํ•˜์—ฌ Void์˜ ํ˜•ํƒœ์™€ ๋ถ„ํฌ๋ฅผ ์กฐ์‚ฌํ•˜๊ณ  ํ•ด์„ํ•˜๋Š” ๋‹ค์–‘ํ•œ ๋ฐฉ๋ฒ•๋“ค์ด ํ™œ์šฉ๋˜๊ณ  ์žˆ๋‹ค. ์˜ˆ๋ฅผ ๋“ค์–ด, Chen, Liu ๋“ฑ์€ ํ†ต๊ณ„์ ์ธ ์ ‘๊ทผ ๋ฐฉ๋ฒ•์œผ๋กœ Mesh๋ฅผ ์ œ์ž‘ํ•˜์—ฌ ํ•ด์„์„ ์ง„ํ–‰ํ–ˆ๋‹ค[12]. ๋˜ํ•œ, M.A.Dudek ๋“ฑ์€ X-์„  ๋‹จ์ธต ์ดฌ์˜์„ ํ†ตํ•œ Void ๋ถ„์„ํ•˜๊ณ  3Dํ™”๋ฅผ ํ™•์ธํ–ˆ๋‹ค[14]. Zhou Bin ๋“ฑ์€ Global model๊ณผ Sub model์„ ํ™œ์šฉํ•œ FEA ๋ฐฉ๋ฒ•์„ ํ†ตํ•ด ์‘๋ ฅ ๋ฐ ๋ณ€ํ˜•๋ฅ ์„ ๊ณ„์‚ฐํ–ˆ๋‹ค[15]. ๊ทธ๋ฟ๋งŒ ์•„๋‹ˆ๋ผ, Void์™€ ๊ด€๋ จ๋œ ๋‹ค์–‘ํ•œ ์—ฐ๊ตฌ๋“ค์ด ์ง„ํ–‰ ์ค‘์ด๋‹ค.

๋ณธ ๋…ผ๋ฌธ์—์„œ๋Š” ์„ ํ–‰ ์—ฐ๊ตฌ์™€ ๋‹ฌ๋ฆฌ TO-251๊ณผ TO-252๋ผ๋Š” ๋‘ ๊ฐ€์ง€ ํŒจํ‚ค์ง€ ๋ชจ๋ธ์„ ์ฑ„ํƒํ•˜์—ฌ ์—ฐ๊ตฌ๋ฅผ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. "TO"๋Š” Transistor Outline์˜ ์•ฝ์–ด๋กœ, ์ด๋Š” ํŠธ๋žœ์ง€์Šคํ„ฐ์— ์‚ฌ์šฉ๋˜๋Š” ํŒจํ‚ค์ง€๋ฅผ ๊ฐ€๋ฆฌํ‚จ๋‹ค. TO-251๊ณผ TO-252 ํŒจํ‚ค์ง€๋Š” ์ค‘๊ฐ„ ์ •๋„์˜ ์ „๋ ฅ์„ ๋‹ค๋ฃจ๋Š” ํŠธ๋žœ์ง€์Šคํ„ฐ์— ์‚ฌ์šฉ๋œ๋‹ค. ์ค‘๊ฐ„ ์ •๋„์˜ ์ „๋ ฅ์€ ๋ช‡ ์™€ํŠธ์—์„œ ์ˆ˜์‹ญ ์™€ํŠธ ์‚ฌ์ด๋ฅผ ๋งํ•œ๋‹ค. ์„ ํ–‰ ์—ฐ๊ตฌ๋“ค์—์„œ๋Š” Die-attach ๋ถ€๋ถ„์˜ Void์— ๋”ฐ๋ฅธ ์—ด์› ๋ฐ ์—ด ์ €ํ•ญ์„ ์ฃผ๋กœ ๋ถ„์„ํ–ˆ์œผ๋‚˜, ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์ „๋ ฅ๋ฐ˜๋„์ฒด ํŒจํ‚ค์ง€ ๋‚ด Die-attach์— ๋ฐœ์ƒํ•œ Void๋ฅผ ํ†ตํ•ด ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„ (Tj), ์ „๋ ฅ์†์‹ค(Power dissipation), ๋ฐ ์—ด ์ €ํ•ญ(Rth)์˜ ๋ณ€ํ™”๋ฅผ ํ™•์ธํ•˜๊ณ ์ž ํ•œ๋‹ค. ์ด๋ฅผ ์œ„ํ•ด, TO-251๊ณผ TO-252 ํŒจํ‚ค์ง€ ๋ชจ๋ธ์— ๋Œ€ํ•œ 3D CAD ๋ชจ๋ธ๋งํ•˜๊ณ  ์‹œ๋ฎฌ๋ ˆ์ด์…˜์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. ๋”๋ถˆ์–ด, Die-attach void๋กœ ์ธํ•ด ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„์—์„œ Wire ์ง€๋ฆ„์„ ๋ณ€ํ™”ํ•˜๋ฉด์„œ ๋ฐœ์ƒํ•˜๋Š” Chip์˜ ์ตœ๋Œ€ Tj, ์ „๋ ฅ์†์‹ค, ๋ฐ ์—ด ์ €ํ•ญ ๋ณ€ํ™”์— ๊ด€ํ•œ ์—ฐ๊ตฌ๋„ ์ง„ํ–‰ํ•˜์˜€๋‹ค. TO-251๊ณผ TO-252 ๋‘ ํŒจํ‚ค์ง€์˜ Die-attach ๊ณต์ •์œผ๋กœ๋Š” Sintered Ag๋ฅผ ์‚ฌ์šฉํ•˜์˜€๋‹ค.

๋ณธ ์—ฐ๊ตฌ์˜ ๋ชฉ์ ์€ ๋‘ ํŒจํ‚ค์ง€ ๋ชจ๋ธ ๊ฐ„์˜ ๋น„๊ต ๋ถ„์„์„ ํ†ตํ•ด ํŒจํ‚ค์ง€ ์ข…๋ฅ˜์— ๋”ฐ๋ฅธ ์—ด ์„ฑ๋Šฅ์˜ ์ฐจ์ด๋ฅผ ํŒŒ์•…ํ•˜๊ณ ์ž ํ•œ๋‹ค. ๋˜ํ•œ, 3D ๋ชจ๋ธ๋ง๊ณผ ์‹œ๋ฎฌ๋ ˆ์ด์…˜์„ ํ™œ์šฉํ•˜์—ฌ ์ •๋Ÿ‰ํ™”๋œ ๋ฐ์ดํ„ฐ๋ฅผ ์ˆ˜์ง‘ํ•˜๊ณ  ๋ถ„์„ํ•จ์œผ๋กœ์จ, ์ด๋Ÿฌํ•œ ๋ฐฉ๋ฒ•์œผ๋กœ๋„ ํŒจํ‚ค์ง€์˜ ์—ด ์„ฑ๋Šฅ ๋ฐ์ดํ„ฐ๋ฅผ ํšจ๊ณผ์ ์œผ๋กœ ํŒŒ์•…ํ•  ์ˆ˜ ์žˆ์Œ์„ ์ œ์‹œํ•˜๊ณ ์ž ํ•œ๋‹ค.

2. ์—ฐ๊ตฌ ๋ฐฉ๋ฒ•

2.1 TO-251, TO-252 ํŒจํ‚ค์ง€ ๋ชจ๋ธ๋ง ๋ฐ ์žฌ๋ฃŒ ๋ฌผ์„ฑ

TO-251์™€ TO-252 ํŒจํ‚ค์ง€๋ฅผ ๋ชจ๋ธ๋งํ•˜์˜€๋‹ค. ๋ชจ๋ธ๋ง์€ ANSYS workbench 2020์œผ๋กœ ์ง„ํ–‰ํ–ˆ๋‹ค (์œตํ•ฉ๋ถ€ํ’ˆ์†Œ์žฌ ํ•ต์‹ฌ์—ฐ๊ตฌ์ง€์›์„ผํ„ฐ ์žฅ๋น„์ธ ANSYS Workbench 2020 R2). ๊ทธ๋ฆผ 1์€ TO-251์™€ TO-252์˜ ๋ชจ๋ธ๋ง์„ ๋‚˜ํƒ€๋ƒˆ๋‹ค. TO-251๊ณผ TO-252์— ์ ์šฉํ•œ ์žฌ๋ฃŒ๋Š” ๋‹ค์Œ ํ‘œ 1์—์„œ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋‹ค. ์žฌ๋ฃŒ๋Š” Epoxy molding compound (EMC), Leadframe (Copper), Die attach (Ag nano paste), Wire (Aluminum), Void (Air)๋ฅผ ์‚ฌ์šฉํ•˜์˜€๋‹ค.

๊ทธ๋ฆผ 1. TO-251(์ขŒ์ธก)๊ณผ TO-252(์šฐ์ธก) ๋ชจ๋ธ๋ง

Fig. 1. TO-251(Left) and TO-252(Right) modeling

../../Resources/kiee/KIEE.2024.73.8.1344/fig1.png

ํ‘œ 1 TO-251๊ณผ TO-252 ํŒจํ‚ค์ง€ ์žฌ๋ฃŒ ๋ฌผ์„ฑ

Table 1 TO-251, TO-252 Package material properties

Material

Electric resistivity[ohm-m]

Thermal conductivity[W/mยทโ„ƒ]

EMC(EMC)

1ร—1013

3

Lead-frame(Cu)

1.71ร—10-8

401

Die attach(Ag nano paste)

1.6ร—10-8

240

Wire(Al)

2.6548ร—10-8

317

Void(Air)

6ร—1013

0.0263

๊ทธ๋ฆผ 2. ๋‹ค์ด์–ดํƒœ์น˜ ๋ฉ”์‰ฌ 4x4x3

Fig. 2. Die-attach mesh 4x4x3

../../Resources/kiee/KIEE.2024.73.8.1344/fig2.png

2.2 Die-attach void ๋ชจ๋ธ๋ง

Die-attach์—์„œ void๊ฐ€ ๋ฐœ์ƒํ•˜๋ฉด, ์—ด๊ณผ ์ „๋ ฅ์— ์˜ํ•ด stress๊ฐ€ ๋ฐœ์ƒํ•˜๋ฉฐ, ์ด๋Š” chip์— ์˜ํ–ฅ์„ ๋ฏธ์น  ์ˆ˜ ์žˆ๋‹ค. Void์˜ ํ˜•์ƒ์„ ๋ชจ๋ธ๋งํ•˜๊ธฐ ์œ„ํ•ด ์ง์œก๋ฉด์ฒด ํ˜•ํƒœ์˜ Die-attach๋ฅผ ์‚ฌ์šฉํ•˜์˜€๋‹ค. ์ด ์ง์œก๋ฉด์ฒด Void ๋ฐฉ๋ฒ•์€ Chen, Liu ๋“ฑ [12]์—์„œ ์‚ฌ์šฉํ•œ ๋‹จ์œ„ ์…€๋กœ ๊ตฌ์„ฑ๋œ Void Grid๋ฅผ ๋ชจ๋ธ์— ๋„์ž…ํ–ˆ๋‹ค. Die-attach๋Š” ๊ฐ€๋กœ x ์„ธ๋กœ x ๋†’์ด(4x4x3)๋กœ ์ด 48๊ฐœ๋กœ ๋‚˜๋ˆ„์—ˆ๋‹ค. Die-attach๋ฅผ ๋‚˜๋ˆˆ ํ˜•ํƒœ๋Š” Fig.2์— ๋‚˜ํƒ€๋ƒˆ๋‹ค. Fig.2์˜ Mesh ๋ชจ๋ธ์€ TO-251์ด๊ณ  ๊ฐ€๋กœ, ์„ธ๋กœ, ๋†’์ด ๊ธธ์ด๋Š” 0.746mm, 0.6655mm, 0.01mm์ด๋‹ค. ์ด ๋ถ„ํ• ๋œ Die-attach๋ฅผ Void๋กœ ๋งŒ๋“ค๊ธฐ ์œ„ํ•ด ํ•˜๋‚˜์˜ ์…€์„ ๊ธฐ์ค€์œผ๋กœ 4๊ฐœ๋ฅผ ์ œ๊ฑฐํ•˜๋Š” ๋ฐฉ๋ฒ•์„ ์‚ฌ์šฉํ–ˆ๋‹ค. Void์˜ ํ˜•ํƒœ๋Š” ํฌ๊ฒŒ ๋‘ ๊ฐ€์ง€๋กœ ๋‚˜๋ˆ„์—ˆ๋‹ค. ์ฒซ ๋ฒˆ์งธ๋Š” ํ•˜๋‚˜๋กœ ํ•ฉ์ณ์ง„ ํฐ Void ํ•˜๋‚˜, ๋‘ ๋ฒˆ์งธ๋Š” ๋ชจ์„œ๋ฆฌ ์ชฝ ๋ถ€๋ถ„์— ๊ฐ๊ฐ 4๊ฐœ์˜ Void๋ฅผ ๋งŒ๋“ค์—ˆ๋‹ค. ์ด๋•Œ ๊ฒฝ์šฐ๋ฅผ ๊ฐ๊ฐ Center, Corner๋ผ๊ณ  ์ง€์ •ํ•˜๊ณ  ๊ทธ๋ฆผ 5์™€ ๊ทธ๋ฆผ 6์— ํ‘œํ˜„ํ–ˆ๋‹ค. ์ฒซ ๋ฒˆ์งธ๋กœ Center๋ฅผ ๋งŒ๋“ค๊ธฐ ์œ„ํ•ด 6๋ฒˆ, 7๋ฒˆ, 10๋ฒˆ, 1๋ฒˆ ์ด 4๊ฐœ์˜ Void๋ฅผ ์ƒ์„ฑํ–ˆ๋‹ค. ๋‘ ๋ฒˆ์งธ๋กœ Corner๋ฅผ ๋งŒ๋“ค๊ธฐ ์œ„ํ•ด 1๋ฒˆ, 4๋ฒˆ, 13๋ฒˆ, 16๋ฒˆ์„ ๋งŒ๋“ค์—ˆ๋‹ค. Source wire๊ณผ Gate wire ๋ถ€๋ถ„์— ์žˆ๋Š” Void๋„ ๋ณด๊ธฐ ์œ„ํ•ด ๊ฐ™์€ ๋ฐฉ๋ฒ•์œผ๋กœ 4๊ฐœ์˜ Void๋ฅผ ๋งŒ๋“ค์—ˆ๋‹ค. ๋จผ์ € ๊ทธ๋ฆผ 5๋ฅผ ๋ณด๋ฉด TO-251์— ๊ฒฝ์šฐ Source wire์— ๋‹ฟ๋Š” Die-attach ์ค‘ 7๋ฒˆ, 8๋ฒˆ, 11๋ฒˆ, 12๋ฒˆ์„ Void๋กœ ํ•˜์˜€๋‹ค. ์ด๋•Œ ๊ฒฝ์šฐ๋ฅผ V1์ด๋ผ๊ณ  ์ง€์ •ํ•˜์˜€๋‹ค. Gate wire๋Š” 5๋ฒˆ, 6๋ฒˆ, 9๋ฒˆ, 10๋ฒˆ์˜ Void๊ฐ€ ์œ„์น˜ํ•˜๋„๋ก ํ•˜์˜€๋‹ค. ์ด๋•Œ ๊ฒฝ์šฐ๋ฅผ V2๋ผ๊ณ  ์ง€์ •ํ•˜์˜€๋‹ค. ๋‹ค์Œ ๊ทธ๋ฆผ 6์— TO-252์˜ V1์€ 11๋ฒˆ, 12๋ฒˆ, 15๋ฒˆ, 16๋ฒˆ์— ์ƒ์„ฑํ–ˆ๋‹ค. V2๋Š” 1๋ฒˆ, 2๋ฒˆ, 5๋ฒˆ, 6๋ฒˆ์— Void๊ฐ€ ์œ„์น˜ํ•˜๋„๋ก ํ•˜์˜€๋‹ค. ์ฐธ๊ณ ๋กœ Void๋Š” Chip์ด ๋‹ฟ๋Š” ์ œ์ผ ์ƒ๋‹จ๋ถ€์—๋งŒ ์‹ค์‹œํ•˜์˜€๋‹ค. ์ด๋Š” Otiaba, K. C ๋“ฑ [11]์—์„œ Die๋ž‘ ๊ทผ์ ‘ํ•œ Void์ผ์ˆ˜๋ก ์—ด ์ €ํ•ญ๊ณผ Chip ์˜จ๋„๊ฐ€ ์˜ฌ๋ผ๊ฐ„๋‹ค๋Š” ์—ฐ๊ตฌ๋ฅผ ์ฐธ๊ณ ํ•˜์—ฌ Die-attach ์ƒ๋‹จ๋ถ€์—๋งŒ Void๋ฅผ ๋งŒ๋“ค๊ณ  ์ง„ํ–‰ํ•˜์˜€๋‹ค.

๊ทธ๋ฆผ 3. TO-251 ์†Œ์Šค ์™€์ด์–ด์™€ ๊ฒŒ์ดํŠธ ์™€์ด์–ด ๋‹ค์ด ์–ดํƒœ์น˜ ๋ชจ๋ธ๋ง

Fig. 3. Modeling for TO-251 Source wire, Gate wire & Die-attach

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๊ทธ๋ฆผ 4. TO-252 ์†Œ์Šค ์™€์ด์–ด์™€ ๊ฒŒ์ดํŠธ ์™€์ด์–ด ๋‹ค์ด ์–ดํƒœ์น˜ ๋ชจ๋ธ๋ง

Fig. 4. Modeling for TO-252 Source wire, Gate wire & Die-attach

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๊ทธ๋ฆผ 5. TO-251 void ๊ฒฝ์šฐ

Fig. 5. TO-251 void case

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2.3 Wire ์ง€๋ฆ„ ๋ณ€ํ™” ๋ชจ๋ธ๋ง

Wire ์ง€๋ฆ„์˜ ๋ณ€ํ™”์— ๋”ฐ๋ฅธ Void์™€์˜ ๊ด€๊ณ„๋ฅผ ํ™•์ธํ•˜๊ธฐ ์œ„ํ•ด Wire์˜ ์ง€๋ฆ„์„ 3%, 7%, 10%๋กœ ๋ณ€๊ฒฝํ•˜๋ฉด์„œ ๋ณ€ํ™”๋ฅผ ๊ด€์ฐฐํ–ˆ๋‹ค. ์ด ์‹คํ—˜์—์„œ๋Š” Void๋ฅผ Source wire ๋ถ€๋ถ„์— ์ƒ์„ฑํ•˜์—ฌ ์ง„ํ–‰ํ•˜์˜€์œผ๋ฉฐ, ์ด ๊ฒฐ๊ณผ๋Š” ๊ทธ๋ฆผ 5์™€ ๊ทธ๋ฆผ 6์— ๋‚˜ํƒ€๋‚ธ ๊ฒƒ๊ณผ ๋™์ผํ•˜๋‹ค. TO-251๊ณผ TO-252์˜ Wire ์ง€๋ฆ„ ๋ณ€ํ™”๊ฐ€ ์—†์„ ๋•Œ์™€ Wire์˜ ์ง€๋ฆ„์ด 10% ์ฆ๊ฐ€ํ•œ ๊ฒฝ์šฐ์˜ ๋ชจ๋ธ๋ง ๊ฒฐ๊ณผ๋Š” ๊ทธ๋ฆผ 7๊ณผ ๊ทธ๋ฆผ 8์— ํ‘œํ˜„ํ–ˆ๋‹ค. TO-251์˜ ๊ฒฝ์šฐ, Wire ์ง€๋ฆ„์ด ๋ณ€ํ™”๊ฐ€ ์—†์„ ๋•Œ Source wire์˜ ์ง€๋ฆ„์€ 8.5mil์ด๋ฉฐ, Gate wire์˜ ์ง€๋ฆ„์€ 5.5mil์ด๋‹ค. TO-252์˜ ๊ฒฝ์šฐ๋„ Wire ์ง€๋ฆ„ ๋ณ€ํ™”๊ฐ€ ์—†์„ ๋•Œ Source์˜ ์ง€๋ฆ„์€ 11 mil์ด๊ณ , Gate wire์˜ ์ง€๋ฆ„์€ 5.5mil์ด๋‹ค.

๊ทธ๋ฆผ 6. TO-252 void ๊ฒฝ์šฐ

Fig. 6. TO-252 void case

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๊ทธ๋ฆผ 7. TO-251 ์™€์ด์–ด ์ง€๋ฆ„ 10% ๋ณ€ํ™”

Fig. 7. TO-251 Wire diameter change 10%

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๊ทธ๋ฆผ 8. TO-252 ์™€์ด์–ด ์ง€๋ฆ„ 10% ๋ณ€ํ™”

Fig. 8. TO-252 Wire diameter change 10%

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2.4 ๊ฒฝ๊ณ„์กฐ๊ฑด

TO-251๊ณผ TO-252์˜ ๊ฒฝ๊ณ„์กฐ๊ฑด์€ ์˜จ๋„๋ฅผ 25โ„ƒ๋กœ ์„ค์ •ํ•˜๊ณ , 25โ„ƒ์˜ ๊ณต๊ธฐ๋ฅผ ์ด์šฉํ•œ ์ž์—ฐ ๋Œ€๋ฅ˜ ์กฐ๊ฑด์„ ๊ฐ€์ •ํ•˜์˜€๋‹ค. ๋Œ€๋ฅ˜ ๊ณ„์ˆ˜๋Š” 5x10-6 W/mm2ยทโ„ƒ๋กœ ์„ค์ •ํ•˜์˜€๊ณ , ์ด๋Ÿฌํ•œ ๊ฒฝ๊ณ„์กฐ๊ฑด์„ ๊ทธ๋ฆผ 9์— ํ‘œํ˜„ํ–ˆ๋‹ค. ๋˜ํ•œ, TO-251๊ณผ TO-252์— ์žˆ๋Š” Source, Current, Gate ๊ฐ’์„ ์ž…๋ ฅํ•˜์˜€๋‹ค. Source์™€ Gate์— ๊ฐ๊ฐ 0mV, -10mV๋ฅผ ์ธ๊ฐ€ํ•˜์˜€๋‹ค. Constant current source๋กœ ๊ฐ€์ •ํ•˜์˜€๊ณ  Drain current๋ฅผ TO-251์—๋Š” โ€“7.8mA, TO-252์—๋Š” โ€“6.5mA๋กœ ์„ค์ •ํ–ˆ์œผ๋ฉฐ, ์ด๋Ÿฌํ•œ ์กฐ๊ฑด์„ ๊ทธ๋ฆผ 10์— ๋‚˜ํƒ€๋ƒˆ๋‹ค.

๊ทธ๋ฆผ 9. TO-251๊ณผ TO-252์— ์˜จ๋„, ๋Œ€๋ฅ˜ ๊ฒฝ๊ณ„์กฐ๊ฑด

Fig. 9. Temperature, convection boundary conditions for TO-251, TO-252

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๊ทธ๋ฆผ 10. TO-251๊ณผ TO-252 ์†Œ์Šค, ๋“œ๋ ˆ์ธ ์ „๋ฅ˜, ๊ฒŒ์ดํŠธ ๊ฒฝ๊ณ„์กฐ๊ฑด

Fig. 10. Source, Drain current, Gate boundary conditions for TO-251, TO-252

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2.5 Chip์˜ Electric resistivity์™€ Rth-jc์˜จ๋„ ์‚ฐ์ถœ

FEA ๋ฐฉ๋ฒ•์„ ์ด์šฉํ•˜์—ฌ Chip์˜ Electric resistivity๋ฅผ ์‚ฐ์ถœํ•˜๊ธฐ ์œ„ํ•ด ์ดˆ๊ธฐ์—๋Š” ANSYS ํ”„๋กœ๊ทธ๋žจ์„ ํ™œ์šฉํ•˜์—ฌ ํ•ด๋‹น Electric resistivity ๊ฐ’์„ ์ž…๋ ฅํ•˜๊ณ  ๊ณ„์‚ฐ์„ ์™„๋ฃŒํ–ˆ๋‹ค. ์ดํ›„, ๋‚˜์˜จ ๊ฒฐ๊ณผ๊ฐ’์„ ์ „๋ฅ˜์— ๋Œ€ํ•œ ๊ณ„์‚ฐ์„ ํ†ตํ•ด ๋ฐ์ดํ„ฐ ์ „๋ฅ˜์™€ ๋น„๊ตํ•˜์˜€๋‹ค. ์ด ๊ณผ์ •์—์„œ ์˜ค์ฐจ๋ฅผ 0.1% ์ดํ•˜๋กœ ์œ ์ง€ํ•˜๋„๋ก ์œ ํ•œ์š”์†Œ ํ•ด์„์„ ๋ฐ˜๋ณตํ•˜์—ฌ Chip์˜ Electric resistivity๋ฅผ ๊ฒฐ์ •ํ•˜์˜€๋‹ค[16]. ํ•ด๋‹น ๊ฒฐ๊ณผ๊ฐ’์€ ํ‘œ 2์— ์ •๋ฆฌํ–ˆ๋‹ค.

Rth-jc ์˜จ๋„๋Š” Juction์—์„œ Case ์˜จ๋„์™€ Lead frame์˜ ๊ฐ€์žฅ ํ•˜๋‹จ ์œ„์น˜ํ•œ ์˜จ๋„์˜ ์ฐจ์ด๋ฅผ ๊ณ„์‚ฐํ–ˆ๋‹ค. ์ „๋ ฅ์†์‹ค์€ Joule heat์˜ ๊ฐ’๊ณผ ๋ถ€ํ”ผ ๊ฐ’์„ ๊ณฑํ•˜์—ฌ ๊ตฌํ•˜์˜€๋‹ค. ๋˜ํ•œ, Chip์˜ ์†Œ๋ชจ๋œ ์ „๋ ฅ์†์‹ค์„ ํ†ตํ•ด Rth-jc ์˜จ๋„๋ฅผ ํŒŒ์•…ํ•˜์˜€์œผ๋ฉฐ, ์ด๋Ÿฌํ•œ ๊ฐ’์˜ ์ •ํ™•์„ฑ์„ ํ™•์ธํ•˜๊ธฐ ์œ„ํ•ด ์ˆ˜์‹ (1)์— ๋”ฐ๋ผ ๊ณ„์‚ฐ๋œ ๊ฐ’์„ ์‹ค์ œ ๋ฐ์ดํ„ฐ ๊ฐ’๊ณผ ๋น„๊ตํ•˜์˜€๋‹ค.

(1)
Rthโˆ’jc=Tjโˆ’TcPdiss

์ด๋ฅผ ํ‘œํ˜„ํ•˜๊ธฐ ์œ„ํ•ด TO-251์˜ ๋‹จ๋ฉด๋„๋ฅผ ๊ทธ๋ฆผ 11์— ๋‚˜ํƒ€๋ƒˆ๋‹ค.

ํ‘œ 2 TO-251๊ณผ TO-252 ์นฉ ์žฌ๋ฃŒ ๋ฌผ์„ฑ

Table 2 TO-251, TO-252 Chip material properties

Material (Si)

Electric resistivity[ohm-m]

Thermal conductivity[W/mยทโ„ƒ]

TO-251

1.578ร—10-4

342

TO-252

1.75 ร—10-4

45.4

๊ทธ๋ฆผ 11. TO-251 ์—ด ์ €ํ•ญ ๋‹จ๋ฉด๋„

Fig. 11. Cross-section of TO-251 to find Rth-jc

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3. ๊ฒฐ ๊ณผ

3.1 Void์— ๋”ฐ๋ฅธ TO-251, TO-252 ๊ฒฐ๊ณผ

TO-251๊ณผ TO-252 ํŒจํ‚ค์ง€๋ฅผ ๋ชจ๋ธ๋งํ•œ ํ›„, ๋จผ์ € void์˜ ๋ชจ์–‘๊ณผ ์œ„์น˜์— ๋”ฐ๋ฅธ ๊ฒฐ๊ณผ๋ฅผ ๋ถ„์„ํ–ˆ๋‹ค. ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„(Tj)๋ฅผ ์‹œ๋ฎฌ๋ ˆ์ด์…˜ ๊ฒฐ๊ณผ๋กœ ๋‚˜ํƒ€๋‚ธ ๊ทธ๋ฆผ 12์—์„œ๋Š” TO-251๊ณผ TO-252 ํŒจํ‚ค์ง€์˜ Void ๋ชจ์–‘๊ณผ ์œ„์น˜์— ๋”ฐ๋ฅธ ์˜จ๋„ ๋ถ„ํฌ๋ฅผ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋‹ค.

๊ทธ๋ฆผ 12. TO - 251๊ณผ TO -252์— ๊ณต๊ทน์ด ์—†๋Š” ์˜จ๋„ ๋ถ„ํฌ

Fig. 12. Temperature distribution for TO-251, TO-252 without voids

../../Resources/kiee/KIEE.2024.73.8.1344/fig12.png

๊ทธ๋ฆผ 13์—์„œ๋Š” TO-251๊ณผ TO-252 ํŒจํ‚ค์ง€์˜ ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„๋ฅผ ๊ทธ๋ž˜ํ”„๋กœ ํ‘œํ˜„ํ•˜์˜€์œผ๋ฉฐ, TO-251 ํŒจํ‚ค์ง€์—์„œ Void-free์ธ ๊ฒฝ์šฐ์˜ ์˜จ๋„๋Š” 40.34โ„ƒ์ด๋ฉฐ, ์ตœ๋Œ€ ์˜จ๋„๋Š” Center์ผ ๋•Œ 52.87โ„ƒ๋กœ ์ฆ๊ฐ€์œจ์€ 31.06%์ด๋‹ค. TO-252 ํŒจํ‚ค์ง€์—์„œ๋Š” Void-free์ธ ๊ฒฝ์šฐ ์˜จ๋„๊ฐ€ 50.32โ„ƒ์ด๋ฉฐ, ์ตœ๋Œ€ ์˜จ๋„๋Š” V1์ผ ๋•Œ 114.05โ„ƒ๋กœ ์ฆ๊ฐ€์œจ์€ 126.65%์ด๋‹ค.

์ „๋ ฅ์†์‹ค์„ ํ‰๊ฐ€ํ•˜๊ธฐ ์œ„ํ•œ ๊ณ„์‚ฐ์„ ์ˆ˜ํ–‰ํ•˜๊ณ , ์ด๋ฅผ ๋‚˜ํƒ€๋‚ด๊ธฐ ์œ„ํ•ด ๊ทธ๋ฆผ 14๊ณผ ๊ทธ๋ฆผ 15์— ์ „๋ ฅ์†์‹ค ๊ฐ’์„ ์‹œ๋ฎฌ๋ ˆ์ด์…˜ ๊ฒฐ๊ณผํ•˜๊ณ  ๊ทธ๋ž˜ํ”„๋กœ ์‹œ๊ฐํ™”ํ–ˆ๋‹ค. TO-251 ํŒจํ‚ค์ง€์—์„œ Void-free์ธ ๊ฒฝ์šฐ์˜ ์ „๋ ฅ์†์‹ค์€ 8.09W์ด๋ฉฐ, ์ตœ๋Œ€ ์ „๋ ฅ ์†์‹ค์€ Center์ผ ๋•Œ 12.22W์ด๋‹ค. ์ด ๊ฒฝ์šฐ ์ „๋ ฅ์†์‹ค์€ 51.03%๋กœ ์ฆ๊ฐ€ํ–ˆ๋‹ค. TO-252 ํŒจํ‚ค์ง€์—์„œ๋Š” Void-free์ธ ๊ฒฝ์šฐ์˜ ์ „๋ ฅ์†์‹ค์ด 4.05W์ด๊ณ , ์ตœ๋Œ€ ์ „๋ ฅ ์†์‹ค์€ V1์ผ ๋•Œ 8.31W์ด๋‹ค. ์ด๋•Œ ์ „๋ ฅ์†์‹ค์€ 105.19%๋กœ ์ฆ๊ฐ€ํ–ˆ๋‹ค. ์ด๋Ÿฌํ•œ ๊ฒฐ๊ณผ๋Š” ๊ฐ๊ฐ์˜ ํŒจํ‚ค์ง€์—์„œ Void์˜ ์กด์žฌ๊ฐ€ Chip ์ „๋ ฅ์†์‹ค์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์„ ๋ณด์—ฌ์ฃผ๊ณ  ์žˆ๋‹ค.

๊ทธ๋ฆผ 13. ๊ณต๊ทน ๋ชจ์–‘์— ๋”ฐ๋ฅธ ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„ ๊ทธ๋ž˜ํ”„

Fig. 13. Maximum Tj graphs based on void style

../../Resources/kiee/KIEE.2024.73.8.1344/fig13.png

๊ทธ๋ฆผ 14. TO-251๊ณผ TO-252์— ๊ณต๊ทน์ด ์—†๋Š” ์ „๋ ฅ์†์‹ค

Fig. 14. Power dissipation for TO-251, TO-252 without voids

../../Resources/kiee/KIEE.2024.73.8.1344/fig14.png

๊ทธ๋ฆผ 15. ๊ณต๊ทน ๋ชจ์–‘์— ๋”ฐ๋ฅธ ์ „๋ ฅ์†์‹ค ๊ทธ๋ž˜ํ”„

Fig. 15. Power dissipation graphs based on void style

../../Resources/kiee/KIEE.2024.73.8.1344/fig15.png

๊ทธ๋ฆผ 16. ๊ณต๊ทน ๋ชจ์–‘์— ๋”ฐ๋ฅธ ์—ด ์ €ํ•ญ ๊ทธ๋ž˜ํ”„

Fig. 16. Rth-jc graphs based on void style

../../Resources/kiee/KIEE.2024.73.8.1344/fig16.png

์—ด ์ €ํ•ญ์„ ํ‰๊ฐ€ํ•˜๊ธฐ ์œ„ํ•ด ์ˆ˜์‹ (1)์„ ํ™œ์šฉํ•˜์—ฌ ๊ตฌํ•˜๊ณ , ์ด๋ฅผ ์‹œ๊ฐ์ ์œผ๋กœ ๋‚˜ํƒ€๋‚ด๊ธฐ ์œ„ํ•ด ์—ด ์ €ํ•ญ ๋ถ„ํฌ๋ฅผ ๋ณด์—ฌ์ฃผ๋Š” ๊ทธ๋ž˜ํ”„๋ฅผ ๊ทธ๋ฆผ 16์— ์ œ์‹œํ•˜์˜€๋‹ค. TO-251 ํŒจํ‚ค์ง€์—์„œ Void-free์ธ ๊ฒฝ์šฐ์˜ ์—ด ์ €ํ•ญ์€ 1.9โ„ƒ/W์ด๋ฉฐ, ์ตœ๋Œ€ ์—ด ์ €ํ•ญ์€ V1์ผ ๋•Œ 2.3โ„ƒ/W๋กœ 21.05% ์ฆ๊ฐ€ํ•˜์˜€๋‹ค. TO-252 ํŒจํ‚ค์ง€์—์„œ๋Š” Void-free์ธ ๊ฒฝ์šฐ์˜ ์—ด ์ €ํ•ญ์ด 6.25โ„ƒ/W์ด๊ณ , ์ตœ๋Œ€ ์—ด ์ €ํ•ญ์€ V1์ผ ๋•Œ TO-251๊ณผ ๊ฐ™์ด ์ œ์ผ ํฐ ๊ฐ’์ธ 10.71โ„ƒ/W๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ์ด๋•Œ ์—ด ์ €ํ•ญ์€ 71.36%๋กœ ์ฆ๊ฐ€ํ•˜์˜€๋‹ค. ์ด๋Ÿฌํ•œ ๊ฒฐ๊ณผ๋กœ๋ถ€ํ„ฐ V1์ผ ๋•Œ์˜ ์—ด ํŠน์„ฑ์ด ๊ฐ€์žฅ ํฐ ๋ณ€ํ™”๋ฅผ ๋ณด์ด๋Š” ๊ฒƒ์„ ํ™•์ธํ•  ์ˆ˜ ์žˆ์—ˆ๋‹ค. ๋”ฐ๋ผ์„œ V1 ๊ธฐ์ค€์œผ๋กœ Source wire์™€ Gate wire์˜ ์ง€๋ฆ„์„ ๊ฐ๊ฐ 3%, 7%, 10% ์ฆ๊ฐ€์‹œ์ผฐ์„ ๋•Œ์˜ ์˜ํ–ฅ์„ ํ‰๊ฐ€ํ•˜์˜€๋‹ค.

3.2 Wire ์ง€๋ฆ„ ๋ณ€ํ™”์— ๋”ฐ๋ฅธ TO-251, TO-252 ๊ฒฐ๊ณผ

TO-251๊ณผ TO-252 ํŒจํ‚ค์ง€์—์„œ V1์ผ ๋•Œ ์˜จ๋„ ๋ถ„ํฌ์™€ ์™€์ด์–ด ์ง€๋ฆ„ ๋ณ€ํ™”์— ๋”ฐ๋ฅธ ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„๋ฅผ ์‹œ๊ฐ์ ์œผ๋กœ ๋‚˜ํƒ€๋‚ธ ๊ฒฐ๊ณผ๋ฅผ ๊ทธ๋ฆผ 17์— ํ‘œํ˜„ํ–ˆ๋‹ค. TO-251 ํŒจํ‚ค์ง€์˜ ๊ฒฝ์šฐ, V1์ผ ๋•Œ ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„๋Š” 52.83โ„ƒ์—์„œ ์‹œ์ž‘ํ•˜์—ฌ Wire ์ง€๋ฆ„์ด 10% ์ฆ๊ฐ€ํ•˜์˜€์„ ๋•Œ ์˜จ๋„๋Š” 49.12โ„ƒ๋กœ ๊ฐ์†Œํ–ˆ๋‹ค. ์ด๋•Œ ๊ฐ์†Œํ•œ ์˜จ๋„ ๋น„์œจ์€ 7.02%์ด๋‹ค. TO-252 ํŒจํ‚ค์ง€์˜ ๊ฒฝ์šฐ์—๋Š” V1์ผ ๋•Œ ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„๊ฐ€ 114.05โ„ƒ์—์„œ ์‹œ์ž‘ํ•˜์—ฌ wire ์ง€๋ฆ„์ด 10% ์ฆ๊ฐ€ํ•˜์˜€์„ ๋•Œ ์˜จ๋„๋Š” 106.7โ„ƒ๋กœ ๊ฐ์†Œํ–ˆ๋‹ค. ์ด๋•Œ ๊ฐ์†Œํ•œ ์˜จ๋„ ๋น„์œจ์€ 6.44%์ด๋‹ค.

์ „๋ ฅ์†์‹ค์€ ๊ทธ๋ฆผ 18์— ํ‘œํ˜„๋˜์–ด ์žˆ๋‹ค. TO-251 ํŒจํ‚ค์ง€์—์„œ V1์ธ ๊ฒฝ์šฐ ์ „๋ ฅ์†์‹ค์€ 12.12W์ด๋ฉฐ, Wire ์ง€๋ฆ„์ด 10% ์ฆ๊ฐ€ํ•˜์˜€์„ ๋•Œ 11.15W๋กœ ๊ฐ์†Œํ–ˆ๋‹ค. ์ด๋•Œ ์ „๋ ฅ์†์‹ค์ด ๊ฐ์†Œํ•œ ๋น„์œจ์€ 8%์ด๋‹ค. TO-252 ํŒจํ‚ค์ง€์˜ ๊ฒฝ์šฐ, ์ „๋ ฅ์†์‹ค์€ 8.31W์ด๊ณ , Wire ์ง€๋ฆ„์ด 10% ์ฆ๊ฐ€ํ•˜๋ฉด 7.98W๋กœ ๊ฐ์†Œํ–ˆ๋‹ค. ์ด๋•Œ ๊ฐ์†Œํ•œ ๋น„์œจ์€ 3.97%์ด๋‹ค.

TO-251๊ณผ TO-252 ํŒจํ‚ค์ง€์˜ ์—ด ์ €ํ•ญ๊ฐ’์€ ๊ทธ๋ฆผ 19์— ๊ทธ๋ž˜ํ”„๋กœ ๋‚˜ํƒ€๋ƒˆ๋‹ค. TO-251 ํŒจํ‚ค์ง€์—์„œ V1์ผ ๋•Œ์˜ ์—ด ์ €ํ•ญ์€ 2.23โ„ƒ/W์ด๊ณ , ์ง€๋ฆ„์ด 10% ์ฆ๊ฐ€ํ•˜์˜€์„ ๋•Œ๋Š” 2.16โ„ƒ/W๋กœ ๊ฐ์†Œํ•˜์˜€๋‹ค. ์ด๋•Œ ๊ฐ์†Œํ•œ ์—ด ์ €ํ•ญ ๋น„์œจ์€ 3.13%์ด๋‹ค. TO-252 ํŒจํ‚ค์ง€์˜ ๊ฒฝ์šฐ, ์—ด ์ €ํ•ญ์€ 10.71โ„ƒ/W์ด๊ณ , ์™€์ด์–ด ์ง€๋ฆ„์ด 10% ์ฆ๊ฐ€ํ•˜์˜€์„ ๋•Œ๋Š” 10.24โ„ƒ/W์ด๋‹ค. ์ด๋•Œ ๊ฐ์†Œํ•œ ์—ด ์ €ํ•ญ ๋น„์œจ์€ 4.39%์ด๋‹ค.

๊ทธ๋ฆผ 17. ์™€์ด์–ด ์ง€๋ฆ„ ๋ณ€ํ™”๋กœ ์ •์…˜ ์˜จ๋„ ๊ฒฐ๊ณผ

Fig. 17. Tj wire diameter variation result

../../Resources/kiee/KIEE.2024.73.8.1344/fig17.png

๊ทธ๋ฆผ 18. ์™€์ด์–ด ์ง€๋ฆ„ ๋ณ€ํ™”๋กœ ์ „๋ ฅ์†์‹ค ๊ฒฐ๊ณผ

Fig. 18. Power dissipation wire diameter variation result

../../Resources/kiee/KIEE.2024.73.8.1344/fig18.png

๊ทธ๋ฆผ 19. ์™€์ด์–ด ์ง€๋ฆ„ ๋ณ€ํ™”๋กœ ์—ด ์ €ํ•ญ ๊ฒฐ๊ณผ

Fig. 19. Rth-jc wire diameter variation result

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4. ๊ฒฐ ๋ก 

TO-251๊ณผ TO-252 ํŒจํ‚ค์ง€ ๋‘ ๊ฐœ๋ฅผ ํ†ตํ•ด ๋น„๊ต ๋ฐ ๋ถ„์„์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. TO-251๊ณผ TO-252 ํŒจํ‚ค์ง€์˜ Void ๋ชจ์–‘๊ณผ ์œ„์น˜์— ๋”ฐ๋ฅธ ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„ (Tj), ์ „๋ ฅ์†์‹ค(Power dissipation), ๊ทธ๋ฆฌ๊ณ  ์—ด ์ €ํ•ญ(Rth)์„ ์กฐ์‚ฌํ–ˆ๋‹ค.

TO-251๊ณผ TO-252 ํŒจํ‚ค์ง€์— ๋Œ€ํ•œ ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„์˜ ๊ฒฝ์šฐ, Void-free ๊ฒฝ์šฐ๊ฐ€ ๊ฐ€์žฅ ๋‚ฎ์•˜์œผ๋ฉฐ, Center์™€ V1 ๊ฒฝ์šฐ์— ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„๊ฐ€ ๋†’์•˜๋‹ค. ํŠนํžˆ TO-252 ํŒจํ‚ค์ง€๋Š” Void-free์ธ ๊ฒฝ์šฐ๋ณด๋‹ค V1์— ๊ฒฝ์šฐ 126.65% ์˜จ๋„๊ฐ€ ์ฆ๊ฐ€ํ•œ ๊ฒƒ์„ ํ™•์ธํ–ˆ๋‹ค. ์ „๋ ฅ์†์‹ค์˜ ๊ฒฝ์šฐ, Void-free์ผ ๋•Œ๋ณด๋‹ค V1 ์ƒํ™ฉ์ผ ๋•Œ 105.19%๋กœ ์ฆ๊ฐ€ํ•˜์˜€๋‹ค. TO-251 ํŒจํ‚ค์ง€๋Š” Center ๋ถ€๋ถ„ Void์—์„œ๋„ ์ „๋ ฅ์†์‹ค์ด 51.03%๋กœ ์ฆ๊ฐ€ํ•œ ๊ฒƒ์„ ํ™•์ธํ–ˆ๋‹ค. Void-free์ผ ๋•Œ๋ณด๋‹ค V1์˜ ์ „๋ ฅ์†์‹ค์€ TO-251 ํŒจํ‚ค์ง€์˜ ๊ฒฝ์šฐ 49.81%๋กœ ์ฆ๊ฐ€ํ–ˆ๋‹ค. ์—ด ์ €ํ•ญ์˜ ๊ฒฝ์šฐ, ๋‘ ํŒจํ‚ค์ง€ ๋ชจ๋‘ V1 ๊ฒฝ์šฐ ์ฆ๊ฐ€ํ•œ ๊ฒƒ์„ ํ™•์ธํ–ˆ๋‹ค. ํŠนํžˆ TO-252 ํŒจํ‚ค์ง€๋Š” 71.36%๋กœ ์ฆ๊ฐ€ํ–ˆ๋‹ค. ์ตœ๋Œ€ ์˜จ๋„๊ฐ€ ๋ฐœ์ƒํ•œ V1์˜ ๊ฒฝ์šฐ๋ฅผ ๊ธฐ์ค€์œผ๋กœ, Source wire์™€ Gate wire์— ์ง€๋ฆ„์„ 3%, 7%, 10%๋กœ ์ฆ๊ฐ€ํ•˜์˜€์„ ๋•Œ ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„, ์ „๋ ฅ์†์‹ค, ์—ด ์ €ํ•ญ์ด ๊ฐ์†Œํ•จ์„ ํ™•์ธํ–ˆ๋‹ค. TO-251 ํŒจํ‚ค์ง€ ๊ฒฝ์šฐ ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„๊ฐ€ V1์ผ ๋•Œ๋ณด๋‹ค ์™€์ด์–ด ์ง€๋ฆ„์„ 10% ์ฆ๊ฐ€ํ•˜์˜€์„ ๋•Œ 7.02% ๊ฐ์†Œํ•˜์˜€๊ณ , ์ „๋ ฅ์†์‹ค์€ 8%, ์—ด ์ €ํ•ญ์€ 3.13% ๊ฐ์†Œํ•˜์˜€๋‹ค. TO-252 ํŒจํ‚ค์ง€ ๊ฒฝ์šฐ์—๋„ ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„๋Š” 6.44%, ์ „๋ ฅ์†์‹ค์€ 3.97%, ์—ด ์ €ํ•ญ์€ 4.39%๋กœ ๊ฐ์†Œํ•˜์˜€๋‹ค.

์ด ์—ฐ๊ตฌ๋ฅผ ํ†ตํ•ด chip์—์„œ ์ตœ๋Œ€ ์˜จ๋„๊ฐ€ ๋ฐœ์ƒํ•œ ๋ถ€๋ถ„์— void๊ฐ€ ๋ฐœ์ƒํ•˜๋ฉด ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„, ์ „๋ ฅ์†์‹ค, ์—ด ์ €ํ•ญ์ด ์ฆ๊ฐ€ํ•˜๋Š” ๊ฒƒ์„ ํ™•์ธํ•  ์ˆ˜ ์žˆ์—ˆ๋‹ค. ๋˜ํ•œ, TO-252 ํŒจํ‚ค์ง€๊ฐ€ TO-251 ํŒจํ‚ค์ง€๋ณด๋‹ค Void์— ๋Œ€ํ•œ ์˜ํ–ฅ์ด ํฌ๋‹ค๋Š” ๊ฒƒ์„ ํ™•์ธํ•˜์˜€๋‹ค. ๊ทธ๋ฆฌ๊ณ  TO-251 ํŒจํ‚ค์ง€์˜ ๊ฒฝ์šฐ Void๊ฐ€ Center์™€ V1์˜ ๊ฒฝ์šฐ ๊ฑฐ์˜ ๋น„์Šทํ•œ ์ „๋ ฅ์†์‹ค์ด ๊ฐ์†Œํ•˜์˜€๋‹ค. ๋งˆ์ง€๋ง‰์œผ๋กœ ์™€์ด์–ด ์ง€๋ฆ„์ด ์ฆ๊ฐ€ํ• ์ˆ˜๋ก ์ตœ๋Œ€ ์ •์…˜ ์˜จ๋„, ์ „๋ ฅ์†์‹ค, ์—ด ์ €ํ•ญ์ด ๊ฐ์†Œํ•œ๋‹ค๋Š” ๊ฒฐ๋ก ์„ ์–ป์„ ์ˆ˜ ์žˆ์—ˆ๋‹ค.

Acknowledgements

์ด ๋…ผ๋ฌธ์€ ์ •๋ถ€(๊ณผํ•™๊ธฐ์ˆ ์ •๋ณดํ†ต์‹ ๋ถ€)์˜ ์žฌ์›์œผ๋กœ ์ •๋ณดํ†ต์‹ ๊ธฐํšํ‰๊ฐ€์›์˜ ์ง€์—ญ์ง€๋Šฅํ™”ํ˜์‹ ์ธ์žฌ์–‘์„ฑ์‚ฌ์—…(IITP-2024-2020-0-01791)๊ณผ ์ •๋ถ€(์‚ฐ์—…ํ†ต์ƒ์ž์›๋ถ€)์˜ ์žฌ์›์œผ๋กœ ํ•œ๊ตญ์—๋„ˆ์ง€๊ธฐ์ˆ ํ‰๊ฐ€์› (KETEP)์˜ ์ง€์› (No. RS-2023-00281219)๋ฅผ ๋ฐ›์•„ ์ˆ˜ํ–‰ํ•œ ์—ฐ๊ตฌ์ž…๋‹ˆ๋‹ค.

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์ €์ž์†Œ๊ฐœ

๋‚จ์ƒ๋ฏผ (Sangmin Nam)
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Sangmin Nam received his bachelorโ€™s degree in automotive engineering from Dong-Eui University, Busan, South Korea. He is currently a M.S student in Department of Mechanical Engineering and Center for Brain Busan 21 Plus Program at Dong-Eui University, Busan, South Korea. His research interests include microelectronics reliability using finite element analysis and bicycle mechanical analysis.

์žฅ์„ฑ์šฑ (Sung-Uk Zhang)
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Sungโ€‘Uk Zhang received a bachelorโ€™s degree in electrical engineering from Sogang University, Seoul, South Korea; a masterโ€™s degree in biomedical engineering, and a Ph.D. degree in mechanical engineering from the University of Florida, Gainesville, FL, USA. He is an associate professor at the Department of Automotive Engineering, Dong-Eui University, Busan, South Korea. Before joining the university, he was with Samsung Electronics, Giheung-gu, Young-si, Gyeonggi-do, South Korea. He has published extensively in journals and conference proceedings. He is a leader in the Digital twin laboratory, at Dong-Eui University. His current research interests include digital twin technology for microelectronics reliability, artificial intelligence for structural health monitoring, semiconductor process simulation, and, multiphysics and multiscale simulation using finite element analysis.