1

00:00:03,233 --> 00:00:06,366

Use curved tweezers to stabilize the stencil

2

00:00:06,766 --> 00:00:08,500

Must be curved tweezers

3

00:00:08,500 --> 00:00:11,866

The contact surface of the straight tweezers is too small

4

00:00:11,933 --> 00:00:17,833

For example, if we press this area on the left, the right side will easily lift up

5

00:00:18,033 --> 00:00:22,166

When pressing the right side, the left side is easy to lift up

6

00:00:22,333 --> 00:00:27,000

And because of the small contact area, the stencil is easy to move

7

00:00:27,800 --> 00:00:33,400

So we use the curved legs of the curved tweezers, all pressed onto the stencil

8

00:00:33,633 --> 00:00:35,200

It will be more stable

9

00:00:35,933 --> 00:00:37,200

Flattened the stencil

10

00:00:38,500 --> 00:00:46,333

When tinning with the blade, keep the blade 2-3mm away from the solder balls in the first row on the far left

11

00:00:46,466 --> 00:00:48,900

Push the blade down and flatten it back

12

00:00:50,333 --> 00:00:54,366

In this way, most of the solder on the top has been flattened

13

00:00:54,400 --> 00:00:55,900

Then turn the blade back

14

00:00:56,466 --> 00:00:58,000

Flatten it on the bottom

15

00:01:00,100 --> 00:01:02,066

So the solder has been flattened

16

00:01:03,333 --> 00:01:07,866

If the size is small enough, some chips will be flattened once

17

00:01:08,133 --> 00:01:10,033

Then shovel off the excess solder

18

00:01:10,600 --> 00:01:11,733

After shoveling

19

00:01:13,133 --> 00:01:15,900

Wipe off excess with a dust-free cloth

20

00:01:16,933 --> 00:01:18,900

We use rotary-air hot gun

21

00:01:19,866 --> 00:01:22,400

The temperature is about 230 degrees

22

00:01:22,600 --> 00:01:24,900

Air volume to level 3 or 4

23

00:01:25,466 --> 00:01:26,400

Blow the solder

24

00:01:27,300 --> 00:01:29,733

Sweep blowing on a large area first

25

00:01:30,500 --> 00:01:33,600

Such an area about 5 cm in diameter

26

00:01:34,300 --> 00:01:35,866

Heating the surrounding area

27

00:01:36,700 --> 00:01:40,500

In this way, the stencil is not easily deformed

28

00:01:42,233 --> 00:01:43,900

Blow for about a minute

29

00:01:44,500 --> 00:01:47,766

Stop the nozzle to a corner of the chip to blow the solder

30

00:01:50,666 --> 00:01:54,066

Don't rush to loosen the tweezers after the solder melts

31

00:01:54,366 --> 00:01:57,733

Wait 5-10 seconds for the solder to solidify

32

00:01:57,900 --> 00:01:59,266

Release the tweezers

33

00:02:00,000 --> 00:02:01,600

Bending steel stencil

34

00:02:01,866 --> 00:02:03,366

Pick the chip from the back

35

00:02:04,466 --> 00:02:05,766

Reballing is done