低溫封裝玻璃粉2

產品說明

Low Temperature Sealing Glass 2

Sealing glasses are composite materials made by blending matrix powder with a low softening temperature and specially synthesized ceramic filler powder. The sealing temperature and thermal expansion coefficient of sealing glass can be adjusted by changing the kind and blending ratio of the glass and filler. 

LS-2010 is widely used for DIP and QFP made of alumina (thermal expansion coefficient: approximately 70×10-7/K). 

LS-1401S is low sealing temperature of 380℃ makes it suitable for SMD packages for quartz oscillators.

LS-3051S is used for sealing low-expansion ceramics such as AlN (thermal expansion coefficient: approximately 45×10-7/K).

LS-1301 and BF-0901 are suitable for sealing silicon (thermal expansion coefficient: approximately 35X10-7/K).

 

Properties

Usage Alumina AlN, Mullite ,Silicon
Properties/Glass Code LS-1401S LS-2010 LS-3051S LS-1301 BF-0901
Sealing temperature ℃ 380 435 430 450 560
Dielectric constant 1MHz,25℃   45.0 12.5 16 45.5 11.1
tanδ 1MHz,25℃ ×10-4 38 34 41 60 19
Thermal expansion coefficient 30℃-250℃ ×10-7/K 71* 1 65 51 41 49*2
Transformation point ℃ 258 313 303 315 430
Softening point ℃ 355 400 390 390 528
Density ×103kg/m3 7.02 5.67 5.95 6.77 4.68
Volume resistivity  Log ρ 150℃ Ω•cm 6.2 12.4 12.7 12.0 13.3
Thermal conductivity W/m•K 0.98 1.45 1.24 0.84 1.47
Specific heat ×103J/kg•K 0.34 0.41 0.38 0.35 0.46
Acid durability 20%H2SO4, 70℃1min mg/cm2 － 0.8 1.1 0.1 －
10%H2SO4, 20℃10min mg/cm2 － 0.5 0.9 0.1 －
10%HCI, 20℃10min mg/cm2 － 1.9 2.7 0.5 －
10%HNO3, 20℃10min mg/cm2 － 120 120 123 －
Color Black Dark brown Black Black Green
Glass type PbO•B2O3(COM)*3 Bi2O3•B2O3 (COM)* 3
 
  1. This thermal expansion coefficient was measured at 30 to 200 ℃
  2. This thermal expansion coefficient was measured at 30 to 200 ℃
  3. COM:Composite sealing glass

 

Application Method

1. Printing and Drying (except LS-1401S)

The paste for printing is prepared by adding vehicle to the powder glass and mixing them well. The vehicle is obtained by dissolving a low molecular weight acrylic resin in terpineol at a concentration of 5%. The paste obtained is printed on ceramic parts with an 80-100 mesh stainless screen. Printing and drying are repeated in order to increase the glass thckness of the film layer. Drying is carried out at 120℃ for 10-20 minutes.
 

2. Pre-firing

In order to eliminate the resin in the film layer pre-firing is done in an oxidizing atmosphere such as oxygen or air. Decomposition and firing of the resin takes place most actively at 320-380℃, so gradual heating is necessary in this temperature range. Sintering of the powder glass is also carried out.

Glass Code T1 (℃) T2(℃)
LS-1401S 250 350
LS-2010 320 390
LS-3051S 310 380
LS-1301 310 400
BF-0901 350 530
Fig. 1 Pre-firing profile
 

3. Lead-Frame Attaching

Lead-frame attaching is carried out in the air, and maintain the attaching temperature (T) for 5 to 7 minutes. When a heater block is used, the surface temperature of the block is kept higher than the attaching temperature by 30-50 ℃. Soak time is 1 to 2 minutes. 

Glass Code T (℃)
LS-2010 435
LS-3051S 430
LS-1301 450

Fig. 2 L/A profile

 

4. Sealing

Sealing is carried out in either an air or a nitrogen atmosphere. Soak time is approximately 10 minutes and temperature is the same as lead-frame attaching temperature. Heating up rate is 50 to 100℃/min. and cool down rate is 20 to 40℃/min.
 

5. Tin-Plating

Conventional tin-plating techniques are acceptable. Standard acid-cleaning and tin-plating conditions are as follows:

Acid-cleaning
Steps Solution Temp. (℃) Time (min.)
1. De-scaling 50%H2SO4 75-90 1.0-1.5
2. Acid rinse 10-15% H2SO4 20-25 0.5-1.0
3. Water rinse City water 20-25 1.0
4. Water rinse De-ionized water 20-25 1.0
 
Tin-plating
Method Current density (A/dm2) Time (min.)
Rack 2.5-3.0 10
Barrel 1.0-2.0 15-30
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