Application Note
rev1.0
(New : 4. July. 2014)
Samsung Electronics
LH351B (3535)
Index
1. Introduction
Page
1.1 Prologue …………………………………………………………………………………
3
1.2 Application ………………………………………………………………………………
4
1.3 Dimension
………………………………………………………………………………
5
1.4 Feature ……………………………………………………………………………………
6
1.5 Estimation of system performance ………………………………………………
7
2. Characteristics
2.1 Structure …………………………………………………………………………………
10
2.2 Thermal resistance ……………………………………………………………………
11
2.3 Electrical characteristics ……………………………………………………………
12
2.4 Luminous flux characteristics
……………………………………………………
13
…………………………………………………………
14
2.6 Optic characteristics …………………………………………………………………
16
2.5 Color shift characteristics
3. Module performance
3.1 Current sweep comparison …………………………………………………………
17
3.2 Temperature sweep comparison …………………………………………………
18
3.3 Derating curve …………………………………………………………………………
19
4. Mechanical guidance
4.1 SMT guidance
…………………………………………………………………………
2
20
1.1 Prologue
Traditional lighting source have several properties like as inexpensive, light, wide viewing
angle, high color rendering index(CRI) and simple structure of space. Due to low efficiency
of energy conversion, new light source is start to come out and among them LED is the
most popular lighting source of next generation. To meet these market needs, Samsung has
made full line-up of LED for illumination.
Product family of middle power LED is consist of LM561A/B, LM231A/B, LM362A which is
adjust to diffuser optic solution lighting - T8 retrofit tube, flat-panel, lamp. And high power
product family of large single chip solution based on ceramic substrate is consist of
LH351A/B and LH351Z which is powerful solution at directional illumination - MR, PAR,
Torch, Street light – linked with 2nd optic Lens solution. Especially Samsung has system
merging solution like as LH934A(AC-LED) merged with power supply unit and LC013B,
LC026B, LC040B merged with metal PCB board(COB – Chip on Board) making single
LES(light emission size) light source.
This application note is focused on LH351B which is very powerful solution for directional
illumination and adopted advanced techniques such as hot temperature sorting process
and robust chip and white package technology. Detail information, characteristics,
performances and useful guidance of LH351B are written on this note. Please be careful
these all data and graphs are made for designer reference only, not for any guarantee. Thus
it could be changeable without any pre-notification.
[ Samsung LED Line-up for illumination ]
3
1.2 Application
LH351B is most optimal solution for directional application which require small form factor
making easy design to target beam angle and high luminous output including robust
reliability. Hot binning technique will help designer to match datasheet value with final
results of illumination at real operating condition.
• Consumer – Torch light
LH351B is convenient light source to collect beam to spot area through reflector.
LED structure is suitable for reducing yellow ring effect.
• Indoor – MR, PAR, Down light, Spot light
One of the major market trend of LED is low-cost. Middle power LED is advantageous
in these needs. But there are some barriers to design target beam angle due to large
amount of LEDs rather than high power LED. For these reason, LH351Z is optimal solution
for low-cost and easy to design directional illumination.
• Outdoor – Street Light, Security light, Tunnel light, Parking light, Canopy
LH351B has wide operation range(~5Watt) and outstanding reliability performance.
With optimum 2nd lens, it is easy to make required beam pattern for street lighting
standard. High flux and efficacy help designer to make superior outdoor illumination.
• Industry – High bay, Low bay
[ Optimal illuminations of LH351Z ]
4
1.3 Dimension
Anode (+)
LED
Zener
Diode
Cathode (-)
[ Electrical circuit diagram ]
[ Dimension]
5
1.4 Feature
• 3.5 x 3.5 x 1.93 ㎜
• Ceramic substrate LED package
• 120˚ viewing angle
• JEDEC Level 2a (Precondition)
• Up to ±5kV (HBM – ESD)
• Hot temperature sorting (Tj 85℃)
• Max forward current 1500mA
Typical forward current 350mA
• Max junction temperature 150℃
• Reliability Test : IES-LM-80-08 qualified
Light
Phosphor
Lens
Reflector
material
Flip - LED chip
Zener Diode
Wire
Cu pad
Ceramic
substrate
[ structure of cross section]
LH351B is built of high technology manufacturing process and consists of cutting edge
material. To simplify manufacturing process and reduce forward voltage level, LH351B
consists of flip-chip solution and to increase ability of color binning supply (MacAdam3step yield), film phosphor technology is adopted. Package structure using reflection
material could help to reduce yellow ring phenomenon.
The optimum material having fast heat transfer characteristic, reliability, design freedom of
electrical pad space and dielectric behavior at once is ceramic material. LH351B also
mounted on this ceramic substrate and could have small form factor with 1~5watt
operation.
To progress optic design (lens, reflector etc,.), designer could get optic raw-file of LH351B
from webpage http://www.samsung.com/global/business/led/lighting/component/highpower/overview/259 (ASAP,FRED,LightTools,Photopia,SimuLux,Speos,TracePro,Zemax,RS8).
6
1.5 Estimation of System performance
1.5.1 Flux rank & color binning supply
LH351B Luminous Flux Rank
160
P1
150
N1
140
M1
130
K1
120
J3
110
100
J3
J3
J3
J3
J3
0.46
0.44
3500K
0.42
4000K
4500K
UM
5000K TM
5700K
0.40
0.38
6500K
T0
0.34
0.32
PT
U0
V0
3000K
2700K
WM
VM
W0
RT
QT
0.28
0.28 0.30 0.32 0.34 0.36 0.38 0.40 0.42 0.44 0.46 0.48 0.50
[ Binning of chromaticity coordinate]
7
6500K (70Ra)
5700K (75Ra)
5700K (70Ra)
5000K (75Ra)
5000K (70Ra)
4000K (80Ra)
4000K (70Ra)
E1
Nominal CCT [K}
0.30
H1
F1
F3
0.36
J1
G1
G3
G3
3500K (80Ra)
80
3000K (80Ra)
90
G3
2700K (80Ra)
Luminous Flux [lm]
170
1.5.2 Estimation of system performance
1400
140
1200
120
1200
120
1000
100
1000
100
800
80
800
80
600
60
600
60
400
Case1-1 (80%/80%)
Case1-2 (85%/85%)
Case1-3 (90%/90%)
200
0
40
20
400
200
Typical
Case1-1
(80%/80%)
80%
80%
0.6
7
Case1-2
(85%/85%)
85%
85%
0.6
7
Case1-3
(90%/90%)
90%
90%
0.6
7
Range
Worst
Typical
Best
Worst
Typical
Best
Worst
Typical
Best
20
Typical
Best
lm(H1) / Vf(max) lm(J1) / Vf(typ) lm(K1) / Vf(min)
[ Estimation of set output
@5000K(70Ra) – 600mA, 7LEDs]
PSU
Optic current # of
efficiency efficiency
[A]
LEDs
40
0
Worst
Best
lm(H1) / Vf(max) lm(J1) / Vf(typ) lm(K1) / Vf(min)
351Z
Case2-2 (85%/85%)
0
0
Worst
Case2-1 (80%/80%)
Set efficiency [lm/W]
140
Total flux output [lm]
1400
Set efficiency [lm/W]
Total flux output [lm]
When designer start to consider illumination, important thing is to choice LED which
specification is characteristics, reliability and then performance estimation of final
illumination output is important design steps. Indeed estimation of system performance is
quite necessary to forecast the range of mass production and these kinds of estimation are
closely related with the ability of LED supplying which consist of luminous flux rank,
forward voltage bin and chromaticity bin.
For example, in case of a certain system condition such as 80% power supply conversion
efficiency and 80% optic transmission efficiency, the output performance of illumination
could be estimated by the number of LEDs and driven forward current. The expected
performance range of mass production is depends on the combination of fine flux rank and
voltage binning. Worst case of poor performance could be made by the combination of
high voltage bin and low flux rank. At 5000K CCT, 7 LEDs and 600mA driving current per LED,
the combination of H1 flux rank and highest voltage could be expected to make 917lm
luminous output, 16.7W total power consumption and 54.8lm/W set efficiency. Otherwise
best performance could be made by K1 rank and minimum voltage bin at same CCT and
operating condition. It could be expected 1083lm luminous output, 18.1W total power
consumption and 71.8lm/W set efficiency. Depends on which rank and which binning is
used, the output performance could vary. Designer should consider these relations to
expect product yield of final set.
[ Estimation of set output
@5000K(70ra) – 700mA, 6LEDs]
Flux
Vf
lm
W lm/W
rank rank
H1 max 917 16.7 54.8
J1
typ 1000 16.2 61.8
K1
min 1083 15.1 71.8
H1 max 974 15.8 61.8
J1
typ 1063 15.2 69.8
K1
min 1151 14.2 81.1
H1 max 1031 14.9 69.3
J1
typ 1125 14.4 78.2
K1
min 1219 13.4 90.9
351Z
[ Case1 - 1,2,3 @600mA, 7LEDs]
PSU
Optic
Current # of
efficiency efficiency
[A]
LEDs
Case2-1
(80%/80%)
80%
80%
0.7
6
Case2-2
(85%/85%)
85%
85%
0.7
6
Case2-3
(90%/90%)
90%
90%
0.7
6
Range
Worst
Typical
Best
Worst
Typical
Best
Worst
Typical
Best
Flux
Vf
lm
W lm/W
rank rank
H1 max 883 17 51.9
J1
typ 964 16.5 58.6
K1
min 1044 15.3 73.5
H1 max 939 16 58.6
J1
typ 1024 15.5 66.1
K1
min 1109 144 76.8
H1 max 994 15.1 65.7
J1
typ 1084 14.6 74.1
K1
min 1174 13.6 86.2
[ Case2 - 1,2,3 @700mA, 6LEDs ]
8
1.5.3 Design support Tool
In order to expect set performance, through the graph of characteristics, designer needs to
find estimated luminous flux and forward voltage of each LED matching with real operating
current and solder temperature(Ts). Actually this job does not need high techniques but
somewhat inefficient action. In order that designer save development time and get more
accuracy expectation, samsung provide design support tool. One is ‘system estimation &
compare tool (circle-B)’ and another is ‘color mixing tool (circle-C)’.
Circle-B could help designer to
estimate LED and system performance
at each various operating conditions.
Especially in mechanical and reliability
aspect, dynamic derating curve and
expected lifetime could be shown in
accordance with real input current and
Ts value.
[ circle-B ]
Circle-C could help designer to estimate color shift
characteristics of LED relating with given driving
current, Ts information and also expect final
coordinate of color mixing result among several
different chromaticity bins. Especially circle-C could
be used for manufacturing steps of mass production.
Some examples are presented as follows.
Center At 25℃, Shifted At 85℃, Shifted
Coordinate
coordinate
coordinate
[ color shift on circle-C ]
[ color mixing on circle-C ]
In case of 5000K R4 bin, center coordinate could be shifted depends on input current and
Ts condition. In LH351B, hot bin sorting technique is adopted, therefore coordinate of
original bin could be almost same as coordinate of real operating condition, Ts 85℃.
In case of 5000K R1, R3 and R4 bin, the expected color mixing coordinate could be shown
relating with input number of LEDs , driving current and Ts condition.
9
le
ho
N-type
el
ec
tro
n
2.1 Structure
P-type
LH351B
Lighting
Thermal
Solder
Cu pad
(-)
Thermal
pad
Cathod
(+)
Anode
Insulator
Metal
PCB
Al substrate
Electrical
resistance
Thermal
resistance
Ts
(solder temperature point)
TJ
(junction temperature point)
[ Cross section of LED on McPCB]
Ts
[ Test McPCB of LH351B]
Dynamic operating relations with thermal, optical and
electrical properties which parameters are forward current,
voltage, thermal resistance, solder temperature, phosphor
performance and other’s is major unique characteristics of LED.
From these complex relation, LED sweep curves doesn’t have
simple linear properties. In this application note, more detail
sweep curves which have 2nd or 3rd polynomial properties are
presented. And surely main curves are based on datasheet.
Datasheet of sorting LH351B adopt hot binning condition to be
referenced by LED junction temperature (Tj). But actually
designer can easily measure Ts which is solder temperature on
PCB instead of Tj. Between Tj and Ts surely some differences of
electrical and thermal characteristics could be happened due
to electrical and thermal resistance. For example, let’s assume
100lm at Tj 85 ℃ on datasheet. Then 100lm should be
recognized as same as lower Ts temperature including thermal
resistance (Rth j-s).
In this application note, Ts temperature is criterion of every
information such as graphs and data.
10
2.2 Thermal resistance
Normally thermal resistance (Rth) of LED package could be variable depending on
temperature and current like as following graph. Especially high power LED (normally over
1watt power consumption) has wider deviation range of thermal resistance rather than
middle power or small power LED. This effect is caused by the difference of thermal density
and current density versus fixed physical dimension.
Thermal resistance (Rth) could be defined variously as like Rth(j-s), Rth(j-a), Rth(s-c) etc,.
Rth(j-s) is Rth from LED chip juction to solder point on PCB, Rth(j-a) is junction to ambient.
Normally Rth(j-a) is called as thermal resistance of system.
Tj (temperature of LED junction)
= Ts (temperature of solder) + Rth(j-s) X Power consumption of LED
TJ : Junction Temp.
PLED : Thermal Source
Ceramic (substrate)
Solder to PCB
PCB Solder Pads
PCB Dielectric layer
Copper thermal pad
RJS : Junction-Solder
TS : Solder Temp.
RSB : Solder to Board
Aluminium Plate
TB : Board Temp.
Classical TIM
to heat-sink
RBC : Board to Case
TC : Case Temp.
RCA : Case to Air
Heat Sink
TA : Ambient Temp.
Tambient : Thermal Ground
K factor
[ Thermal resistance of LH351B]
4.0 K/W
(@350㎃, 25℃)
6.0 K/W
(@700㎃, 85℃)
Rth (K/W)
[ Thermal resistance (Rth j-s) of LH351B]
11
2.3 Electrical characteristics
Forward Current (mA)
measuring time
Even if same measuring time, measured data
could be different according to test condition.
Data of LH351B datasheet is measured and
sorted by pulse testing signal.
Testing current
Normally illumination development engineer
signal wave
is interested in data which is measured under
continuous wave driving current condition. In [ Pulse measuring (pulse)] [ Continuous wave (CW)]
this application note, ‘CW’ means measuring
condition under continuous current wave and
‘pulse’ means pulsed signal test condition.
78℃-pulse
1400
LH351B is very powerful
25℃-CW
1200
LED component allowing
50℃-CW
Vf
driving
current
until
78℃-CW
Solder
1000
1500mA. Due to electrical
100℃-CW
Resistance
resistance
generated
800
from SMT process, IVAluminium Plate
curve measured by CW
Vf on PCB Board
600
has somewhat incline
400
properties rather than
pulse testing.
200
From IV-curve, power consumption could be
2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4
calculated and the reason why constant
Forward Voltage (V)
current (C.C) operation is recommended in
LED driving could be understood easily. If
[Forward current vs. Typical
driven by constant voltage(C.V), output
forward voltage @Ts]
variation versus solder temperature becomes
larger than C.C.
3.5
Forward Voltage (V)
Forward Current (mA)
1400
1200
1000
800
25℃
50℃
78℃
100℃
600
400
200
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
3.3
3.1
2.9
25℃
50℃
78℃
100℃
2.7
2.5
0.0
Power Consumption (W)
1.0
2.0
3.0
4.0
Power Consumption (W)
[Forward current vs.
Power consumption @Ts]
[Forward voltage vs.
Power consumption @Ts]
12
5.0
2.4 Luminous flux characteristics (for illumination CCT)
Luminous flux is shown as following graphs. Luminous flux at 5000K is higher than 3000K at
same power consumption, but relative ratio is similar between each CCT – WM, VM, UM,
TM, RJ. From referenced by 25℃ room temperature, relative ratio also presented.
550
400
350
450
300
250
200
150
400
350
300
250
200
150
100
100
50
50
0
200
400
600
800 1000 1200
Forward Current (mA)
0
200
1400
[Luminous flux vs. Forward current
@3000K(85Ra) J1 rank]
600
800 1000 1200
Forward Current (mA)
1400
130%
78℃-pulse
25℃-CW
50℃-CW
78℃-CW
100℃-CW
300%
250%
78℃-pulse
Normalized Luminous Flux Ratio (%)
Relative Luminous Flux Ratio (%)
400
[Luminous flux vs. Forward current
@5000K(70Ra) M1 rank]
350%
200%
150%
100%
50%
200
78℃-pulse
25℃-CW
50℃-CW
78℃-CW
100℃-CW
500
Luminous Flux [lm]
450
Luminous Flux [lm]
550
78℃-pulse
25℃-CW
50℃-CW
78℃-CW
100℃-CW
500
400
600
800 1000 1200
Forward Current (mA)
[Relative luminous flux ratio
vs. Forward current]
50℃-CW
78℃-CW
110%
100℃-CW
100%
90%
80%
70%
200
1400
25℃-CW
120%
400
600
800 1000
Forward Current (mA)
1200
[Relative luminous flux ratio
referenced by Ts 25℃]
13
1400
2.5 Color shift characteristics (for illumination CCT)
0.020
0.020
350mA
700mA
0.010
1000mA
0.005
350mA
0.015
Relative chromaticity (△Cy)
Relative chromaticity (△Cx)
0.015
0.000
-0.005
-0.010
-0.015
-0.020
700mA
0.010
1000mA
0.005
0.000
-0.005
-0.010
-0.015
-0.020
0
25
50
Ts (℃)
75
100
0
[ Relative chromaticity (△Cx)
Vs. Ts @VM 3000K ]
50
Ts (℃)
75
100
[ Relative chromaticity (△Cy)
Vs. Ts @VM 3000K ]
0.43
0.42
25
0.414
0.412
V0
0.410
Cy
Cy
0.41
25℃
350mA
0.408
50℃
0.406
0.40
0.402
1000mA
75℃
0.404
0.39
700mA
100℃
0.400
0.38
0.41
0.42
0.43
0.44
Cx
0.45
0.46
[ Color shift @VM 3000K ]
0.424
0.428
Cx
0.432
0.436
[ Color shift @VM 3000K ]
14
2.5 Color shift characteristics (for illumination CCT)
0.020
0.015
350mA
0.010
700mA
1000mA
0.005
0.000
-0.005
-0.010
-0.015
-0.020
0
25
50
75
350mA
0.015
Relative chromaticity (△Cy)
Relative chromaticity (△Cx)
0.020
700mA
0.010
1000mA
0.005
0.000
-0.005
-0.010
-0.015
-0.020
0
100
25
50
75
100
Ts (℃)
Ts (℃)
[ Relative chromaticity (△Cx)
Vs. Ts @RJ 5000K ]
[ Relative chromaticity (△Cy)
Vs. Ts @RJ 5000K ]
0.362
0.38
RJ
0.360
0.37
25℃
0.358
350mA
Cy
Cy
0.36
0.35
0.356
50℃
0.354
700mA
1000mA
75℃
0.352
0.34
100℃
0.350
0.33
0.33
0.34
0.35
0.340
0.36
0.344
0.348
0.352
Cx
Cx
[ Color shift @RJ 5000K ]
[ Color shift @RJ 5000K ]
15
2.6 Optic characteristics
3000K V0 (85Ra)
5000K RJ (70Ra)
[ Optic diagram of White LED ]
Normalized CCT [K]
0.10
0.06
0.04
0.02
0.00
-90 -60 -30 0
30 60
Emission Angle (deg.)
-90 -60 -30 0
30
Emission Angle (deg.)
90
[ △u’v’ over angle ]
60
90
[ CCT over angle ]
1.2
Normalized spectrum
Delta_u'v'
0.08
7000
6000
5000
4000
3000
2000
1000
0
1.0
1
0
30
0.8
0.6
60
0.5
0.4
0.2
0
380 430 480 530 580 630 680 730 780
Wave length [nm]
[ Spectrum ]
-90
-60
0.0
-30 0.0
00.0
Emission Angle (deg.)
90
0.5
1.0
Normalized intensity
[ CCT over angle ]
Optic graphs should be used only for reference.
For accurate design, please refer to the linked optic raw-file of LH351B from webpage.
http://www.samsung.com/global/business/led/lighting/component/high-power/resource
(ASAP,FRED,LightTools,Photopia,SimuLux,Speos,TracePro,Zemax,RS8).
16
3.1 Current sweep comparison
For verification of Tool (circle-B) and for
testing LH351B, simple experiment is
done. Without 2nd optic and power supply
unit(PSU), the current sweep performance
of assembled module mounting LH351B 6 LEDs, McPCB and heat-sink are
measured and then compared with data
from Tool at 25℃ Ts condition.
LH351B
LED cost
Flux factor Electrical efficiency
100%
Step : LED → CCT → CRI → Bins → IF_current →
Input filed
CASE
A
1
2
3
4
5
6
CCT
[K]
5000
CRI
[Ra]
Optical efficiency
70
100~40
%
100~40
%
100%
100%
LED
Vf : Min.Typ.Max
Bins
Flux : J1,K1,M1,N1
LED performances @min/flux_rank
IF_driving
#
Ts Ta
[A]
of LED [℃] [℃]
0.350
0.500
0.700
1.000
[ Real module test without 2nd optic and PSU ]
6
6
6
6
25
25
25
25
25
25
25
25
VF
[V]
Flux
[㏐]
2.86
2.92
2.99
3.07
159.7
217.5
289.4
386.2
$
/100lm
TJ
[℃]
∑Flux
[㏐]
29.0
30.8
33.4
37.3
958
1305
1736
2317
Sorting IF_driving
Typ =
0.350 A
Tj_max. =
150 ℃
Sorting Temperat
M1 ure
= 85 ℃
IF_max. =
1.500 A
Estimations of system
Derating performance
Efficac
∑LES ∑cost Rth(J-a) IF_max. IF_margin
∑Power
y
Location
[W]
(A)
(A)
[㎟]
[$] (℃/W)
[Lm/W]
6.0
8.8
12.6
18.4
159.4
148.7
138.1
125.9
74
74
74
74
4.0
4.0
4.0
4.0
1.500
1.500
1.500
1.500
1.150
1.000
0.800
0.500
Safe zone
Safe zone
Safe zone
Safe zone
[ Current sweep simulation ]
Luminous flux output [lm]
2400
2000
measurement
1600
simulation
1200
958lm
800
868lm
400
0
0.2
0.4
0.6
0.8
1
1.2
Forward current [A]
Relative luminous flux ratio [%]
From the graph of measurement and simulation, two points come to be noticeable. One is
that their absolute real data does not equal with each case, another is their deviation ratio is
almost same. In case of simulation, deviation parameter is linked with initial starting value
which is same value of datasheet. Otherwise, measurement value might need some calibration
due to wrong center allocation of DUT(device under test) with integrating sphere and also
need to check calibration file of software.
Through this simple test, deviation used in Tool might be considered as a quite reliable. And in
order to get more exact measuring data, considerable calibration of measuring instrument
would be necessary when real measurement.
240%
ratio_measurement
ratio_simulation
200%
160%
120%
80%
0
0.2
0.4
0.6
0.8
1
1.2
Forward current [A]
[ Luminous flux compare
@25℃ measurement vs simulation ]
[ Relative luminous flux ratio compare
@25℃ measurement vs simulation ]
17
3.2 Temperature sweep comparison
With same DUT, temperature sweep test
is also done. At constant 700mA driving
current, output is measured at every 25℃,
40℃, 50℃ and 60℃ which is saturation
temperature. And this measured output
is compared with simulation result.
Similar comparison result comes out like
as current sweep test.
LH351B
LED cost
Flux factor Electrical efficiency
100%
Step : LED → CCT → CRI → Bins → IF_current →
Optical efficiency
Input filed
CASE
A
1
2
3
4
5
6
CCT
[K]
5000
70
100~40
%
100~40
%
LED
100%
Bins
100%
LED performances @min/flux_rank
CRI IF_driving
#
Ts Ta
[Ra]
[A]
of LED [℃] [℃]
0.700
0.700
0.700
0.700
[ Real module test without 2nd optic and PSU ]
6
6
6
6
25
40
50
60
25
25
25
25
VF
[V]
Flux
[㏐]
2.99
2.97
2.95
2.94
289.4
279.8
273.5
267.2
$
/100lm
Vf : Min.Typ.Max
Flux : J1,K1,M1,N1
Sorting IF_driving
Typ =
0.350 A
Tj_max. =
150 ℃
Sorting Temperat
M1 ure
= 85 ℃
IF_max. =
1.500 A
Estimations of system
Derating performance
Efficac
∑LES ∑cost Rth(J-a) IF_max. IF_margin
y
Location
(A)
(A)
[㎟]
[$] (℃/W)
[Lm/W]
Safe zone
12.6 138.1
74
4.0
1.500
0.800
Safe zone
12.5 134.6
74
11.2
1.500
0.800
Safe zone
12.4 132.2
74
16.1
1.500
0.800
Safe zone
12.3 129.8
74
21.0
1.500
0.800
TJ
[℃]
∑Flux ∑Power
[W]
[㏐]
33.4
48.3
58.3
68.2
1736
1679
1641
1603
[ Temperature sweep simulation ]
From this temperature sweep test, deviation parameter used in Tool might be considered as a
quite reliable. And calibration factor also necessary to match compensation between
measurement and simulation.
In case of current sweep test, 1.19 calibration factor is calculated and 1.17calibration factor of
temperature sweep test is calculated.
105%
1736lm
1600
1549lm
1400
1200
1000
measurement
simulation
800
600
0
20
40
60
80
Relative luminous flux ratio [%]
Luminous flux output [lm]
1800
Ts. Temperature of solder [℃]
100%
95%
90%
ratio_measurement
ratio_simulation
85%
80%
0
20
40
60
80
Ts. Temperature of solder [℃]
[ Luminous flux compare
@700mA measurement vs simulation ]
[ Relative luminous flux ratio compare
@700mA measurement vs simulation ]
18
3.3 Derating curve
[ Derating performance simulation ]
With same DUT, Ts becomes 60℃ in saturation
time. Tool (circle-B) could supply derating property
of system through the graph. From the graph,
system thermal resistance (22.7K/W-Rth) and max
allowable current (1.0A) could be known at that
operating condition. Therefore this operating status
is located at ‘safe zone’ with safe margin about Tj
and max current.
Maximum current [A]
[ DUT ]
CASE-C.1
CASE-C.1
1.200
1.000
0.800
0.600
0.400
0.200
0.000
0
20
40
60
80 100 120 140
Ta Ambient temperature [℃]
[ Derating curve ]
[ Derating performance simulation ]
If heat-sink thermal capacity is reduced, surely
weaker reliability of system could be expected.
Actually like as case C.2, solder temperature
increase until 120℃. At that point, Tj reaches up to
135.1℃ and allowable max current becomes low
as 0.795A. This value is within 10%, therefore
status is ‘warning zone’. If Ts more increase and Tj
start to over Tj-max(150℃) and allowable current
falls down under 0.7A, then status of location
would change to ‘out of range’.
Maximum current [A]
[ DUT ]
1.200
1.000
0.800
0.600
0.400
0.200
0.000
0
20
40
CASE-C.1
CASE-C.2
CASE-C.1
CASE-C.2
60
80 100 120 140
Ta Ambient temperature [℃]
[ Derating curve ]
19
4.1 SMT guide
Ø 3.1
120˚
1.09
1.23
Vac. Hole Ø 1
Unit : mm
Ø 3.1
Ø 4.0
Ø 4.0
[ The nozzle of pick-up & place tool ]
[ Recommended foot-print for SMT ]
Solder
Mask
O
X (missalign)
X (solderlack)
X (solderincline)
O
X (faultcathode)
X (faultcathode)
X (missplace)
O
X (solderlack)
X (solderball)
Pick
&
Place
After
reflow
[ Recommended example ]
20
X (thicksolder)
Date
2014.7.4
Revision History
-. New Version
21
Writer
Drawn
Approved
Y. J. Lee
I.H. Choi