Soldering device including pulsed light irradiator, soldering method using pulsed light irradiation, and method of manufacturing semiconductor package
A soldering device includes a control unit to predict a final rise temperature of an electronic device, based on power of a light pulse from at least one pulsed light irradiator, a weight of the electronic device, a real-time temperature of the electronic device, the quantity of exposures of the light pulse, and an irradiation period of the light pulse, and change a condition of the light pulse, based on a predicted result. A soldering method includes calculating power of the light pulse based on a time width of the light pulse, measuring a temperature of the electronic device, and predicting a final rise temperature of the electronic device, based on the calculated power, a weight of the electronic device, the measured temperature, the quantity of exposures of the light pulse, and the irradiation period.
1 . A soldering method, comprising:
loading a workpiece into a soldering chamber comprising at least one pulsed light irradiator, the workpiece comprising a main substrate, an electronic device on the main substrate, and a solder material layer between the main substrate and the electronic device;
setting a time width of a light pulse from the at least one pulsed light irradiator and an irradiation period of the light pulse;
calculating a power of the light pulse based on the time width of the light pulse to determine a calculated power;
measuring a temperature of the electronic device in the soldering chamber to determine a measured temperature;
predicting a final rise temperature of the electronic device, based on the calculated power of the light pulse, a weight of the electronic device, the measured temperature of the electronic device, a quantity of exposures of the light pulse to the electronic device, and the irradiation period of the light pulse to determine a predicted final rise temperature; and
changing at least one of the power of the light pulse, the time width of the light pulse, or the irradiation period of the light pulse in response to a determination that the predicted final rise temperature of the electronic device deviates from a particular temperature range.
2 . The soldering method of claim 1 , wherein the solder material layer comprises solder paste, solder balls, solder bumps, flux, or any combination thereof.
3 . The soldering method of claim 1 , further comprising applying a single light pulse to the workpiece under setting conditions used to predict the final rise temperature of the electronic device, by using the at least one pulsed light irradiator, in response to a determination that the predicted final rise temperature of the electronic device is within the particular temperature range.
4 . The soldering method of claim 1 , wherein the calculating of the power of the light pulse comprises calculating a power Ep of the light pulse according to Equation 1:
E
P
=
V
3
t
P
K
0
2
[
Equation
1
]
wherein, in Equation 1,
V denotes a charging voltage of the at least one pulsed light irradiator,
tp denotes the time width of the light pulse, and
K 0 denotes an impedance of the at least one pulsed light irradiator,
wherein the predicting the final rise temperature of the electronic device comprises predicting a final rise temperature ΔT of the electronic device according to Equation 2:
Δ
T
=
∑
n
=
1
N
E
P
cM
-
(
aT
+
b
)
(
1
/
f
)
[
Equation
2
]
wherein, in Equation 2,
c denotes a specific heat of the electronic device,
M denotes the weight of the electronic device,
T denotes the temperature of the electronic device, which is measured in real time in the soldering chamber immediately before subsequent irradiation of pulsed light,
f denotes the irradiation period of the light pulse,
each of a and b denotes a particular constant that determines a temperature attenuation function represented by “aT+b,” and
N denotes the quantity of exposures of light pulses to the electronic device.
5 . The soldering method of claim 1 , wherein the at least one pulsed light irradiator irradiates intense pulsed light (IPL).
6 . A method of manufacturing a semiconductor package, the method comprising:
forming a plurality of workpieces based on arranging a plurality of electronic devices on the main substrate; and
bonding the plurality of electronic devices onto the main substrate based on using the soldering method of claim 5 .
7 . The soldering method of claim 1 , further comprising, in response to a determination that the predicted final rise temperature of the electronic device is within the particular temperature range, applying a single light pulse to the workpiece under setting conditions used to predict the final rise temperature of the electronic device by using the at least one pulsed light irradiator and repeating the applying of the single light pulse to the workpiece a plurality of times,
wherein the measuring of the temperature of the electronic device is performed each time the single light pulse is applied to the workpiece.
8 . The soldering method of claim 7 , wherein the solder material layer comprises solder paste comprising tin (Sn) and silver (Ag).
9 . The soldering method of claim 1 , further comprising:
applying a single first light pulse to the workpiece under setting conditions used to predict the final rise temperature of the electronic device, by using the at least one pulsed light irradiator, in response to a determination that the predicted final rise temperature of the electronic device is within the particular temperature range;
re-measuring the temperature of the electronic device in the soldering chamber after the single first light pulse is applied to the workpiece to determine a re-measured temperature;
re-predicting the final rise temperature of the electronic device, based on the re-measured temperature of the electronic device to determine a re-predicted final rise temperature; and
applying a single second light pulse to the workpiece under setting conditions used to re-predict the final rise temperature of the electronic device, by using the at least one pulsed light irradiator, in response to a determination that the re-predicted final rise temperature of the electronic device is within the particular temperature range.
10 . The soldering method of claim 9 , wherein the single first light pulse and the single second light pulse are applied to the workpiece under a condition that at least one selected from a power of the single second light pulse and a time width of the single second light pulse has a same value as a corresponding at least one of a power of the single first light pulse and a time width of the single first light pulse.
11 . The soldering method of claim 9 , wherein the single first light pulse and the single second light pulse are applied to the workpiece under a condition that at least one selected from a power of the single second light pulse and a time width of the single second light pulse has a different value than a corresponding at least one of a power of the single first light pulse and a time width of the single first light pulse.
12 . The soldering method of claim 9 , wherein:
the soldering chamber comprises a plurality of soldering zones arranged in a line in a direction in which a transfer device is configured to move, and a plurality of pulsed light irradiators in separate, respective soldering zones of the plurality of soldering zones, and
the soldering method further comprises:
a first operation of applying a single light pulse to the workpiece under setting conditions used to predict the final rise temperature of the electronic device, by using a selected one pulsed light irradiator of the plurality of pulsed light irradiators in a selected one soldering zone of the plurality of soldering zones, in response to a determination that the predicted final rise temperature of the electronic device is within the particular temperature range,
a second operation of re-measuring the temperature of the electronic device in the soldering chamber after the single light pulse is applied to the workpiece;
a third operation of re-predicting the final rise temperature of the electronic device, based on the re-measured temperature of the electronic device; and
sequentially repeating the first operation, the second operation, and the third operation.
13 . A soldering method, comprising:
sequentially loading a plurality of workpieces into a soldering member comprising at least one pulsed light irradiator in a linear movement scheme, each workpiece of the plurality of workpieces including
a main substrate,
an electronic device on the main substrate, and
a solder material layer between the main substrate and the electronic device;
setting a time width of a light pulse irradiated from the at least one pulsed light irradiator and an irradiation period of the light pulse;
calculating a power Ep of the light pulse according to Equation 1:
E
P
=
V
3
t
P
K
0
2
[
Equation
1
]
wherein, in Equation 1,
V denotes a charging voltage of the at least one pulsed light irradiator,
tp denotes the time width of the light pulse, and
K 0 denotes an impedance of the at least one pulsed light irradiator;
measuring a temperature of the electronic device comprised in each of the plurality of workpieces in a soldering chamber;
predicting a final rise temperature ΔT of the electronic device to determine a predicted final rise temperature ΔT of the electronic device according to Equation 2:
Δ
T
=
∑
n
=
1
N
E
P
cM
-
(
aT
+
b
)
(
1
/
f
)
[
Equation
2
]
wherein, in Equation 2,
c denotes a specific heat of the electronic device,
M denotes a weight of the electronic device,
T denotes the temperature of the electronic device, which is measured in real time in the soldering chamber immediately before subsequent irradiation of pulsed light,
f denotes the irradiation period of the light pulse,
each of a and b denotes a particular constant that determines a temperature attenuation function represented by “aT+b,” and
N denotes a quantity of exposures of light pulses to the electronic device;
changing at least one of the power Ep of the light pulse, the time width tp of the light pulse, or the irradiation period f of the light pulse in response to a determination that the predicted final rise temperature ΔT of the electronic device deviates from a particular temperature range to produce at least one changed value; and
applying a single light pulse to each of the plurality of workpieces by using the at least one pulsed light irradiator under setting conditions used to predict the final rise temperature ΔT of the electronic device, in response to a determination that the predicted final rise temperature ΔT of the electronic device is within the particular temperature range.
14 . The soldering method of claim 13 , wherein the at least one pulsed light irradiator is configured to irradiate intense pulsed light (IPL).
15 . The soldering method of claim 13 , further comprising:
changing at least one value of the power Ep of the light pulse, the time width tp of the light pulse, and the irradiation period f of the light pulse in response to a determination that characteristics of the electronic device in a selected one workpiece of the plurality of workpieces are different from characteristics of the electronic device to which the light pulse is applied immediately before;
measuring a temperature of the electronic device in the selected one workpiece;
re-predicting the final rise temperature ΔT of the electronic device comprised in the selected one workpiece according to Equation 2, based on the at least one changed value and the temperature of the electronic device comprised in the selected one workpiece; and
applying another single light pulse to the selected one workpiece by the at least one pulsed light irradiator under setting conditions used to re-predict the final rise temperature ΔT of the electronic device in the selected one workpiece, when the final rise temperature ΔT of the electronic device comprised in the selected one workpiece is within the particular temperature range.