Process Technology

Seal the hat
6 Process requirements
6.1 Requirements for Glass Sealing and Gold Tin Sealing Processes
a) The surface of the cover plate should be clean and shiny, with uniform solder, no cracks, porcelain damage, scratches, imprints, or warping;  
b) The relative displacement between the base (adjustable frame) and the cover plate is ≤ 0.3mm;
c) The displacement of the cover plate of black porcelain glass fusion sealed products in the X direction should be less than 0.4mm, and the displacement in the Y direction should be less than 0.2mm; the displacement of the cover plate of gold tin fusion sealed products in the X and Y directions should be less than 0.15mm
d) The fusion surface is dense, smooth, without breakpoints, pores, oxidation, or solder accumulation;  
e) The visual inspection welding ring should be clean and free of dirt, burrs, defects, and curls around it;  
f) The protective gas inside the furnace should be dry nitrogen, and the gas should be introduced into the furnace 30 minutes ± 5 minutes before operation.
Requirements for parallel seam welding process
a) The cover plate and sealing ring should be aligned accurately without any deviation;  
b) The displacement of the parallel seam welded product cover plate in the X and Y directions should be less than 0.15mm
c) After welding, the surface should be clean and shiny, without dirt, scratches, deformation, or ceramic cracks;  
d) The edges of the two sides of the circuit housing cover plate form two parallel, continuous fish scale shaped welds composed of overlapping solder joints;

bonding
6.6 Bonding Wedge Requirements
6.6.1 Ultrasonic wedge bonding on the PAD bonding area or bonding finger, with a width greater than 1.2 times or less than 3.0 times the diameter of the bonding wire, and a length greater than 1.5 times or less than 6.0 times the diameter of the bonding wire;
6.6.2 Hot pressed wedge bonding on the PAD bonding area or bonding finger, with a width greater than 1.5 times or less than 3.0 times the diameter of the bonding wire, and a length greater than 1.5 times or less than 6.0 times the diameter of the bonding wire;
6.6.3 Silicon aluminum wire with a wire diameter of 50.8 μ m or larger, with a wedge-shaped bonding width greater than the diameter of the bonding wire;
6.6.4 The indentation of the wedge bond should completely cover the width of the entire bond wire.
6.7 Requirements for bonding wire tail wire
The tail wire of the bonding wire shall not extend to or come into contact with any common, non passivated active metal region; The length of the tail wire of the bonding wire in the PAD bonding area shall not exceed twice the wire diameter, and the length of the bonding finger shall not exceed four times the wire diameter.
6.8 Other requirements for bonding
1) The bonding must be carried out on a horizontal surface, and the inclined surface of the side area is not suitable for the bonding process;
2) Overlap areas, welding areas, and through holes should not be designed as bonding areas;
3) Multiple leads can be connected in parallel to improve the current carrying capacity. When multiple leads are bonded and connected, the size of the bonding area should be designed perpendicular to the lead direction by multiplying the required area of a single lead by the number of leads;
4) Requirements for the spacing between leads and other components.

For thick aluminum wires with a wire diameter greater than 76.2 μ m, while meeting the above distance requirements, at least one side along the direction of the extended wire at both ends of the lead should have a 3mm wire breakage distance, and there should be no obstacles such as devices or casings within the wire breakage distance.
5) The projection of the lead on the horizontal plane does not allow for cross overlapping.
Note: A is excluded if either end of the lead is connected to the same metallization area.
B-ultrasound large-scale integrated circuits, except for bonding within multi-layer bonding finger housings.

mounting
6 Process requirements
6.1 Process requirements for conductive adhesive sheets
6.1.1 According to the requirements of different chips and packaging forms, choose a reasonable conductive adhesive (QMI2569 conductive adhesive is suitable for circuits using low-temperature glass fusion sealing, JM7000 conductive adhesive is suitable for circuits using gold tin fusion sealing, parallel seam welding, and does not require electrical connections). According to the requirements of the packaging pressure welding diagram, adjust the direction of the chip so that it is correctly attached to the conductive adhesive at the bottom of the base tube cavity.
QMI2569 conductive adhesive curing conditions (99.99% nitrogen atmosphere)
Curing temperature: 200 ℃± 10 ℃ Curing time: 2h
Nitrogen flow rate: (9 ± 1) L/min Nitrogen water content: ≤ 5PPM
JM7000 conductive adhesive curing conditions (99.99% nitrogen atmosphere)
Temperature: 100 ℃± 10 ℃ (2h) → 150 ℃± 10 ℃ (2h) → 200 ℃± 10 ℃ (2h)
Nitrogen flow rate: (9 ± 1) L/min Nitrogen water content: ≤ 5PPM Nitrogen oxygen content: ≤ 10PPM
6.1.2 The conductive adhesive is evenly distributed around the chip in a spherical shape, without any sharp peaks, and is distributed between 1/3 and 2/3 of the height of the chip. The bonding area covers 100% of the bottom area of the chip, and at least 75% of the circumference around the chip is covered with conductive adhesive. The remaining parts of the base tube cavity and the legs of the tube must not have conductive adhesive.
6.1.3 The surface of the bonded chip should be free of scratches, defects, cracks, and stains; The adhesive material shall not peel off.
6.1.4 The surface of the cured conductive adhesive is dense, without pores or foreign objects.
6.1.5 There are no foreign objects inside the lumen of the base.
6.1.6 According to the requirements of GJB 548B-2005 method 2019.2, the shear strength meets the bottom area requirement of the chip.   Z101

a) When the bonding area of the chip is greater than 4.13mm2, it should withstand a minimum force of 25N or its multiples.
b) When the bonding area of the chip is greater than or equal to 0.32mm2 but not greater than 4.13mm2, the minimum stress that the chip can withstand is determined by Figure 4 of GJB 548B-2005 method 2019.2.
c) When the bonding area of the chip is less than 0.32mm2, the minimum force it should withstand is 6N/mm2 at (0.1 times) or 12N/mm2 at (2 times).
6.1.7 The distance between the chip edge and the inner cavity edge of the base shall not be less than 0.3mm (reference value)
6.2 Welding process requirements
6.2.1 According to the requirements of the packaging pressure welding diagram, adjust the direction of the chip so that it is correctly soldered onto the solder at the bottom of the base tube cavity.
6.2.2 The surface of the chip after welding should be free of scratches, defects, cracks, and stains; The chip soldering material shall not peel off.
6.2.3 There are no foreign objects inside the lumen of the base.
6.2.4 According to the requirements of GJB 548B-2005 method 2019.2, the shear strength meets the bottom area requirement of the chip.     Z101
a) When the bonding area of the chip is greater than 4.13mm2, it should withstand a minimum force of 25N or its multiples.
b) When the bonding area of the chip is greater than or equal to 0.32mm2 but not greater than 4.13mm2, the minimum stress that the chip can withstand is determined by Figure 4 of GJB 548B-2005 method 2019.2.
c) When the bonding area of the chip is less than 0.32mm2, the minimum force it should withstand is 6N/mm2 at (0.1 times) or 12N/mm2 at (2 times).