添加界面活性劑之 Sb-Te 薄膜熱傳導係數量測

本實驗之鑄液為 1 公升，陽極使用熱電塊材，陰極為鍍金之試片，並在鑄 液中添加 5 ml 的界面活性劑 MA，通以 2 mA/cm²的電流密度進行電鑄，實驗過 程中同時利用磁石攪拌器，以轉速 300 rpm 進行攪拌動作。以電化學沉積的方 式在鍍金的矽晶片上，進行不同厚度的 Sb-Te 熱電材料薄膜沉積，之後在熱電 薄膜表面塗佈 5 μm 聚合物薄膜，並在聚合物薄膜表面製作相同尺寸的金屬導 線。

另外，在 Sb-Te 鍍液中添加界面活性劑 MA 之原因在於目前電化學沉積熱 電材料時，會遭遇到鑄液濕潤性不佳，造成在小線寬內的沉積並不完整，故藉

由添加界面活性劑來改善鑄液之表面張力，使其在小線寬內可完整沉積。為了

下，添加界面活性劑 MA 的熱電材料本身晶格尺寸改變，圖 4-27 為不同厚度的 Sb-Te 複合薄膜剖面圖，由圖中的晶粒結構可發現，厚度範圍約為 0.133 μm 至 1.736 μm 的 Sb-Te 熱電材料，其鍍層結構之上下層部分的晶格尺寸形貌有明顯 的差異，鍍層底部的晶格尺寸較小，鍍層上部的晶格尺寸結構有變大趨勢；其 二乃熱電鍍層其晶格界面有突起形貌，在以 SEM 量測其剖面的形貌時，鍍層結 構實際的厚度無法確實量出，導致在代入計算時，因厚度的不準確性，影響 Sb-Te 複合薄膜的總熱阻值；最後的原因推猜測是因為熱電材料表面有突起形貌，其 表面並不平坦，當以高旋轉速度將聚合物材料塗佈於熱電材料表面，因高旋轉 速度的運動，連帶推動熱電材料表面的突起材料，導致在聚合物薄膜與熱電材 料在界面處形成一模糊結構層，本研究推測此模糊的結構層內產生聚合物材料 與熱電材料參雜混合的傾向，進而影響此複合薄膜量測出的熱阻值。因上述各 點之故，導致量測出的數據無法呈現一線性斜率，產生數據點跳動現象，故本 研究在添加界面活性劑 MA 的 Sb-Te 複合薄膜之熱傳導係數量測上失敗，需要 發展其他量測方法進行其熱傳導係數量測。

Figure 4-8 Structure of thermal conductivity measurement sample.

Figure 4-9 Thermal resistance of polymer measurement sample.

Figure 4-10 Profile of polymer film measurement sample.

Table 4-5 Measurement result of polymer film.

Thickness (μm) Thermal conductivity (W/m⋅K)

4.853 0.306 5.447 0.320 5.323 0.322 5.730 0.325 6.439 0.226

4.5 5 5.5 6 6.5 7

Thickness, t (10

^-6

m)

18 20 22 24 26

T h ermal res is tance, R (10

-6

m

2

K/W )

Figure 4-11 Different thickness corresponds to thermal resistance of polymer film.

R = 3.5952t + 1.5744×10

^-6

Polymer

Si substrate Bi-Te

Figure 4-12 Structure of Bi-Te compound film sample.

Figure 4-13 Thermal resistance of Bi-Te compound film sample.

Figure 4-14 Profile of Bi-Te compound film sample.

Table 4-6 Measurement result of Bi-Te compound film.

Group Thickness (μm) Thermal conductivity (W/m⋅K)

1

0.487 0.430 0.776 0.394 1.009 0.393 1.100 0.392

2

0.863 0.370 1.208 0.366 1.337 0.372

0 0.5 1 1.5 2

Thickness, t (10

^-6

m)

-2 -1 0 1 2 3

The rmal resista nce, R (10

-6

m

2

K/W)

Figure 4-15 Different thickness corresponds to thermal resistance of Bi-Te compound film without adding MA.

R = 4.37425t–2.85961×10

^-6

R = 4.15768t–3.95232×10

^-6

(a) 0.487 μm (b) 0.776 μm

(c) 1.009 μm (d) 1.100 μm

(e) 0.863 μm (f) 1.208 μm

(g) 1.337 μm

Figure 4-16 SEM morphology of Bi-Te compound film without adding MA under different thickness.

Polymer

Si substrate Sb-Te

Figure 4-17 Structure of Sb-Te compound film sample.

Polymer

Si substrate Sb-Te

Rpoly/ Cr

Rint, poly

Rint, Sb-Te

RSb-Te/ Si

RSb-Te/ poly

Figure 4-18 Thermal resistance of Sb-Te compound film sample.

Figure 4-19 Profile of Sb-Te compound film sample.

Table 4-7 Measurement result of Sb-Te compound film.

Group Thickness (μm) Thermal conductivity (W/m⋅K)

1

0.616 0.381 1.513 0.399 1.955 0.420

2

1.034 0.367 1.596 0.379 1.990 0.405

0 0.5 1 1.5 2 2.5

Thickness, t (10

^-6

m)

-1 0 1 2 3 4

The rmal resistance, R (10

-6

m

2

K/W)

Figure 4-20 Different thickness corresponds to thermal resistance of Sb-Te compound film without adding MA.

R = 2.37804t–8.59275×10

^-7

R = 2.41057t–2.01128×10

^-6

(a) 0.616 μm (b) 1.513 μm

(c) 1.955 μm (d) 1.034 μm

(e) 1.596 μm (f) 1.990 μm

Figure 4-21 SEM morphology of Sb-Te compound film without adding MA under different thickness.

Figure 4-22 Profile of Bi-Te compound film sample with adding MA.

Table 4-8 Measurement result of Bi-Te compound film with adding MA.

Thickness (μm) Thermal conductivity (W/m⋅K)

0.702 0.338 1.462 0.386 1.899 0.383 2.011 0.377 2.628 0.403 2.805 0.404 3.370 0.441

1 2 3 4

Thickness, t (10

^-6

m)

0 1.5 3 4.5 6 7.5 9

The rmal resista nce, R (10

-6

m

2

K/W )

Figure 4-23 Different thickness corresponds to thermal resistance of Bi-Te compound film with adding MA.

R = 2.36076t-2.08274×10

^-7

(a) 2.628 μm (b) 2.805 μm

(c) 1.899 μm (d) 2.011 μm

(e) 0.702 μm (f) 1.462 μm

(g) 3.370 μm

Figure 4-24 SEM morphology of Bi-Te compound film with adding MA under different thickness.

Figure 4-25 Profile of Sb-Te compound film sample with adding MA.

Table 4-9 Measurement result of Sb-Te compound film with adding MA.

Thickness (μm) Thermal conductivity (W/m⋅K)

0.133 0.316 0.231 0.379 0.281 0.362 0.137 0.316 0.343 0.548 0.351 0.346 0.520 0.305 0.798 0.647 1.736 1.466

0 0.5 1 1.5 2

Thickness, t (10

^-6

m)

-1 0 1 2 3

Th erm al res istance, R (10

-6

m

2

K/W)

Figure 4-26 Different thickness corresponds to thermal resistance of Sb-Te compound film with adding MA.

(a) 0.133 μm (b) 0.231 μm

(c) 0.281 μm (d) 0.137 μm

(e) 0.343 μm (f) 0.351 μm

(g) 0.520 μm

(h) 0.798 μm

(i) 1.736 μm

Figure 4-27 SEM morphology of Sb-Te compound film with adding MA under different thickness.

在文檔中 熱電材料應用於散熱微致冷晶片之技術開發 (頁 132-153)