Technical Guide(1295KB)

SURFACE MOUNT RESISTORS
TECHNICAL GUIDE
Ver.3
Device Solutions Business Division
Automotive & Industrial Systems Company
Panasonic Corporation
TECHNICAL GUIDE Ver.3
Contents
1.
First:
···················2 page
2.
Construction of Surface Mount Resistors:
···················3 page
3.
Manufacturing Method of Thick-film Chip Resistors:
···················4 page
4.
System of Surface Mount Resistors:
···················5 page
5.
Kinds of Surface Mount Resistors:
···················6 page
6.
Reliability:
···················7 page
7.
Failure Mechanism:
···················8 page
8.
Application Notes:
···················9 to 10 page
9. Technique
9.1.
Circuit Design:
···················11 to 17 page
9.2.
Design of Printed Substrate:
···················18 to 19 page
9.3.
Used Environment:
···················20 to 22 page
9.4.
Mounted Method:
···················22 to 25page
10.
Technical Trend in the Future:
···················26 to 27 page
1
TECHNICAL GUIDE Ver.3
1. First
Fixed resistors are principal electronic components composed electronic circuit. They
are developed with demands of various electronic circuits and used. This technical
guide is summarized the application technique about surface mount resistors used for
electric machine and tools, especially, which need high density mount in these fixed
resistors,
For selection of various surface mount resistors, confirm with the characteristic of that
circuit, in general, following step is proper.
(1) Single chip resistor or Composite chip resistor
(2) Single chip resistor: Thick-film chip resistor or Thin-film chip resistor
(3) Composite chip resistor: Chip resistor array (common terminal circuit) or
Chip resistor network (isolated circuit)
(4) Select the shape of surface mount resistors in accordance with using voltage
(power).
In our company, there are numerous kinds of surface mount resistors in order to
respond customer’s various needs. However, we are happy if you could understand the
contents of this technical guide, and talk over technical contents with us before use, so
that you can use it more stability.
Moreover, it is separately introduced as for other fixed resistors, components of noise
countermeasure and so on.
This technical guide might change.
2
TECHNICAL GUIDE Ver.3
2. Construction of Surface Mount Resistors
The construction figures of representative surface mount resistors are shown below
(Fig 1 to Fig 6). It is different a little by the application of surface mount resistors.
Foundation substrate: alumina substrate, Termination: thick-film conductive element,
Resistance: thick-film resistor or thin-film resistor.
Protective coating
Inner termination
Protective coating
Inner termination
(thick film)
High purity
High purity ceramic substrate
alumina substrate
Middle termination (Ni plating)
Middle termination
Thin film (NiCr)
Outer termination
Thick-film resistive element
Outer termination
(sn plating)
Fig.1. Thick-film chip resistor
Fig.2. Thin-film chip resistor
Protective coating
Protective coating
Thick-film resistive element
Thick-film
resistive element
High purity
Thick-film conductive element
alumina substrate
High purity
Thick-film
alumina substrate
conductive elemet
Fig.3. Chip resistor array (concave-type)
Fig.4. Chip resistor array (convex-type)
Protective coating
Thick-film
Protective
coating
樹脂保護コート
resistive element
(Resin)
Thick-film
Termination
resistive element
(Thick-film Au)
Inner
内部端面電極
termination
Middle termination (Ni plating)
Thick-film conductive element
中間電極(Niメッキ)
High purity
alumina substrate
Outer termination (Sn plating)
High purity alumina substrate
Fig.5. Chip resistor network (concave-type)
Fig.6. Chip resistor network (convex-type)
3
TECHNICAL GUIDE Ver.3
3. Manufacturing Method of Thick-film Chip Resistors
Manufacturing method of thick film chip resistors of surface mount resistors (the most
representative) is shown Fig.7.
Alumina substrate
Electrode paste
∇
Termination (upper)
∇
Termination (back)
Breaking slot
Electrode formation
Resistance paste
∇
Resistance
Resistance printing
Pre-coat glass
Calcined
Glass paste
∇
Pre-coat glass printing
Calcined
Trimming slot
Revise resistance value
Protective resin
Protective coating
∇
paste
Protective resin printing
Substrate subjected to first breaking
Hardness
First breaking
Electrode (resin)
∇
paste
Termination
Electrode spread
Hardness
Substrate subjected to
Secondary breaking
Plating material
∇
secondary breaking
Plating film
Electrode plating
Packaging material
∇
Pckaging (taping. bulk)
Shipment
Fig.7. Manufacturing process chart of thick-film chip resistor
4
TECHNICAL GUIDE Ver.3
4. System of Surface Mount Resistors
The range of resistance value and resistance temperature characteristic (TCR) of thick-film
chip
resistor (by kind) are shown in Fig.8.
600
600
400
400
±100ppm type
一般級
general
300
300
±100ppmタ イ プ
±50ppm type
±50ppmタ イ プ
200
200
抵 抗温度 特性(ppm/ ℃)
(ppm / degree)
Resistance temperature characteristic
500
500
100
100
0
0
-100
-100
-200
-200
-300
-300
-400
-400
-500
-500
-600
-600
1.0
1.0
10
100
10
1k
100
10k
100k
1K
10K
抵抗値(Ω)
1M
100K
10M
1M
10M
Resistance value (ohm)
Fig.8. System figure of thick-film chip resistor
ERA6Y(2012)
ERA6Y
(2012)
ERA3Y(1608)
抵 抗 温 度 特 性(ppm/ ℃)
ERA3Y (1608)
(ppm / degree)
Resistance temperature characteristic
The range of resistance value and TCR of thin-film chip resistor (by kind) are shown in Fig.9.
200
200
100
100
0
0
-100
-100
-200
1.0
1.0
-200
10
100
10
1k
100
10k
1K
100k
10K
1M
100K
抵抗値(Ω)
1M
10M
10M
Resistance value (ohm)
Fig.9. System figure of thin-film chip resistor
The range of resistance value and TCR of thin-film chip resistor (by kind) are shown in Fig.10.
Fig.10. System figure of thin-film chip resistor (low resistance value)
ERJ12R, 14R, 1WR
400
ERJL
□□
ERJL□□
ERJ6R,
ERJ6R,8R
400
300
(ppm / degree)
300
200
200
抵 抗 温 度 特 性(ppm/ ℃)
Resistance temperature characteristic
ERJ12R,14R,1WR
ERJM1
ERJM1
100
100
00
-100
-100
-200
-200
-300
-300
-400
-400
1m
1m
10m
10m
100m
100m
1.0
1.0
抵抗 値 (Ω )
Resistance value (ohm)
5
10
10
100
100
8R
TECHNICAL GUIDE Ver.3
5. Kinds of Surface Mount Resistors
±5% (J-level)
General
±2% (G-level)
±1% (F-level)
High-precision
Thick-film Chip
±0.5% (D-level)
Resistor
Anti-serge
Anti-sulfuration
High-function
Single Chip
Trimmable
Fuse resistor
Resistor
Low resistance
value
±0.5% (D-level)
High-precision
±0.1% (B-level)
Thin-film Chip
Resistor
Surface Mount
Thermal sensitive
High-function
Resistor
Concave
termination
Chip Resistor
Array
chip
2-element
4-element
2-element
Convex
termination
Composite Chip
4-element
8-element
Resistor
Concave
Resistor
termination
Network
8-element
8-element
Convex
termination
Fig.11. Kinds of surface mount resistors
6
15-element
TECHNICAL GUIDE Ver.3
6. Reliability
Field failure rate of surface mount resistors (thick-film chip resistors) is shown in the table-1.
(Set : television)
Table-1: Field failure rate
∗
Failure rate (fit)
Products
(Shape)
Quantity of
used parts
(n)
Used time
(n x T)
ERJ2G
(1005)
1.21x1010
(From 1990)
5.86×1013
(From 1990)
ERJ3G
(1608)
5.64×1010
(From 1986)
ERJ6G
(2012)
Failure
(r)
Point
estimation
(λ 0)
Reliability level 60%
0
0.0
0.0000156
4.41×1014
(From 1986)
0
0.0
0.0000020
1.20×1011
(From 1986)
1.38×1015
(From 1986)
0
0.0
0.0000006
ERJ8G
(3216)
5.06×1010
(From 1986)
8.38×1014
(From 1986)
0
0.0
0.0000011
ERJ14
(3225)
1.11×109
(From 1987)
7.66×1012
( From 1987)
0
0.0
0.0001200
ERJ12
(4532)
1.01×109
(From 1987)
7.25×1012
(From 1987)
0
0.0
0.0001268
ERJ1W
(6432)
1.53×108
(From 1990)
8.87×1011
(From 1990)
0
0.0
0.0010360
(λ 60)
Used time (T) = Use 6 hours / a day × 365 days
<Calculating method of failure rate>
Reliability level = 60%
Reliability guaranteed coefficient of market fraction defective = X2 {2 (r + 1), α }
(When it is “0”)
2
=0.92
Market fraction defective λ 60 = X2 {2 (r + 1), α} × 109
2 (n X T)
=
0.92
X109 (f i t)
n×T
7
TECHNICAL GUIDE Ver.3
7. Failure Mechanism
Failure mechanism of thick-film chip resistor and chip resistor array is shown in Fig.12,
Failure mechanism of thin-film chip resistor is shown in Fig.13. As destruction mode, it
could be resistance value open or large changing of resistance value, it could not be
short circuit mode of resistors,
Failure mode
Failure mechanism
Manufacturing factor
Application factor
Quantity of solder
Unbalance
Thin electrode-film
Electrode crack
Solder stress
Ununiform
Resin for mold
Unsuitable pattern design
Stress of P-board
Unsuitable of
Solder breaking
Thin-middle-Ni
Oven
Ununiform
Electrode
corrosion
Solder
degradation
Resistor chipping
soldering condition
Sulfur atmosphere
Temperature
Over-load
rising
Glass chipping
Large of division stress
Crack
Large of mount zipper
Shape defective
Voltage
power
Inner loss of resistor
breakdown
Large of pulse-load
Large change of
Resistance value
Voltage
Large of static electricity
degradation
Lot of pulse-times
Transition of
electrode material
Temperature
Over-load
rising
Fig.12. Failure mechanism
(Chip fixed resistors, Chip resistor array, Chip resistor network)
8
TECHNICAL GUIDE Ver.3
Failure mode
Failure mechanism
Electrode crack
Solder stress
Manufacturing factor
Thin electrode-film
Ununiform
Application factor
Quantity of solder
Unbalance
Resin for mold
Unsuitable patterm
design
Stress of P-board
Using atmosphere
(humidity,gas)
Electrode corrosion
Open
Pollution
Electrolytic
corrosion
High temperature
load
Over-load
Load concentration
Defect of resistance
film
Oxide of resistancefilm heat
Permeation of
pollutant
High ambiont
temperature
Over-load
(include pulse-
Soldering
degradation
Temperature
rising
Crack of
resistor-film
Protective-film
chipping
Current breakdown
of resistor film
Over-load
Large of division
stress
Inner-loss of
resistor
Large of pulse-load
Large static
electricity
Fig.13. Failure mechanism of thin-film chip resistors
8. Application Note
8.1. Precautions in handling resistors
Our products are intended for use in general standard applications for general electronic
equipment (AV products, household electric appliances, office equipment, information
and communication equipment, etc.); hence, they do not take the use under the
following special environments into consideration. Accordingly, the use in the following
special environments, and such environments, and such environmental conditions may
affect the performance of the products; prior to use, verify the performance, reliability,
etc.
(1).
Use in liquids such as water, oil, chemical, and organic solvent.
(2).
Use under direct sunlight and in outdoor and dusty atmospheres.
(3).
Use in places full of corrosive gasses such as sea breeze, Cl2, H2O, NH3, SO2, and
NOX.
(4).
Use in environment with large static electricity and strong electromagnetic waves.
9
TECHNICAL GUIDE Ver.3
(5).
Where the product is close to a heating component, and where an inflammable such
as a polyvinyl chloride wire is arranged close to the product.
(6).
Where the resistor ids sealed and coated with resin, etc.
(7).
Where water or a water-soluble detergent is used in cleaning free soldering and in
flux cleaning after soldering (Pay particular attention to water-soluble flux.)
8.2.Requests
(1).
This technical guide is summarized technical contents of surface mount resistors
(produced and sold by our company) so that customer can use it properly.
(2).
In traffic transportation equipment (trains, cars, traffic signal equipment, etc.),
medical equipment, aerospace equipment, electric heating appliances, combustion
and gas equipment, rotating equipment, disaster and crime preventive equipment,
etc. in cases where it is forecast that the failure of this product gives serious damage
to the human life and others, use fail-safe design and ensure safety by studying the
following items to.
∗
Ensure safety as the system by setting protective circuits and protective equipment.
∗
Ensure safety as the system by setting such rebundant circuits as do not cause
danger by a single failure.
(3).
When it is happened that a doubt about safety of this product, let us know quickly
and you must examine technically.
(4).
If transient load (heavy load in a short time) like pulse is expected to be applied,
carry out evaluation and confirmation test with the resistors actually mounted on your
own board. Moreover, if it is used under the specific condition, talk over it
beforehand.
(5).
High-active flux as halogen-type (chlorine, bromine, etc) is not recommended as the
residue may affect performance or reliability of resistors. Confirm it before use.
(6).
When soldering with soldering iron, never touch the body of the chip resistor with a
tip of the soldering iron. When using a soldering iron with a tip at high temperature,
solder for a time as short as possible.(up to 350 degree, less than 3 seconds)
(7).
Avoid physical shock to the resistor and nipping of the resistor with hard tool (pliers
or tweezers) as it may damage protective coating or body of resistor and may affect
resistor’s performance.
(8).
Avoid immersion of chip resistor in solvent for a long time. Use solvent after the
effect of immersion is confirmed.
8.3. Storage method
If the product is stored in the following environments and conditions, the performance
and solderability maybe badly affected. Avoid the storage in the following environment.
(1).
Storage in places full of corrosive gasses such as sea breeze, Cl2, H2S, NH3, SO2,
and NO2.
(2).
Storage in places exposed to direct sunlight.
10
TECHNICAL GUIDE Ver.3
(3).
Storage in places outside the temperature range of 5deg to 35deg and humidity
range of 45% to 85%RH.
(4).
Storage over a year after our delivery (This item also applies to the case where the
storage method specified in item (1) to (3) has been followed.
9. Technique
9.1. Circuit design
If using surface mount resistors, pay attention the following performance. (Primarily for
film-chip resistors.)
9.1.1. Resistor noise
In general, resistor noise is calculated from the following formula.
Resistor noise = thermal fuse + 1 / f noise
It is thermal noise that depends on shake of speed distribution by clash of carrier and
grid. It is 1 / f-noise that factor, which controlled electric current, shakes in some cause
and, as the result, it arises from density of carrier and modulation of electric current. It is
thought to be in proportion to a reciprocal of frequency.
Regarding thick-film chip resistor, it is formed resistance value by connect resistance.
Therefore, 1 / f-noise shall be primarily noise, and it is calculated from the following
formula.
Noise Index (dB) = A –10 Log (w l t)
A: Resistive material, value by manufacturing condition
w • l • t: W-dimensions, L-dimensions, t-dimensions
Noise level average of chip resistor by shape is shown in Fig.14.
TECH 3 1 5C)
電流
雑 音characteristic
特 性 (QUAN
Current
noise
(QUANTECH315C)
ノ イ ズINDEX ( d B )
Noise INDEX (dB)
+2 0
+20
G
22G
3G, 6G
3G,6G
8G
18G
4
1 2 , 1W
+10
+1 0
0 0
Thick-film chip resistors
2G: 1005
3G: 1608
14
6G: 2012
12,1W
-10
-10
8G: 3216
Thick-film resistor
厚膜抵抗器
-20
-20
14: 3225
12: 4532
Thin-film
resistor
薄膜抵抗
器
-30
-30
-40
-40
-50
-50
1W: 6432
Y
33Y
6Y
Thin-film chip resistors
6Y
10 Ω
10
100 Ω
100
1k Ω
1K
1 0k Ω
10K
1 0 0k Ω
100K
1MΩ
1M
(ohm)
Fig.14. Noise level average of chip resistor
11
TECHNICAL GUIDE Ver.3
From Fig.14, a noise level tends to become large, so that form becomes small.
Therefore, in the circuit that attaches importance to the noise-characteristic, chip
resistor of large shape or thin-film chip resistor is recommended.
9.1.1. Over-load characteristic of chip resistor
There are the following 3 cases in the over-load phenomenon of chip resistors.
(1).
∗
Over-load life characteristic: Applied over rated power for a long time.
∗
Static electric (ESD) characteristic: Applied high-voltage momentarily.
∗
Pulse characteristic: Applied several times of voltage for a short time.
Over-load life characteristic
Resistance value changing model of over-load life characteristic of thick-filfm chip
resistor is shown in Fig.15.
∆ R (%)
△R(%)
Fig.15. Resistance value changing model of over-load life characteristic of thick-film chip resistor
時間(t)
Time (t)
As shown in Fig.15, if impressed in the state of over-load for a long time, decreasing
part of insulation resistance in the resistor occur, and resistance value continues
decreasing. However, if it is still continued applying, electric current starts to concentrate
in that part, decreasing of insulation resistance accelerates and resistors destroy by
joule heat, resistance value start to rise, finally, come to be disconnection.
Regarding our thick-film chip resistor, as shown in table-2, the electric power guarantee
that carried out the one rank rise of the conventional rated electric power.
Table-2 Power-up assurance of thick-film chip resistors
Shape
Size
Rated power
ERJ3G
1608
1/16W→1/10W
ERJ6G
2012
1/10W→1/8W
ERJ8G
3216
1/8W→1/4W
However, since the temperature of soldering part may serves high temperature by
generation of heat by load depending on ambient temperature when there is no
12
TECHNICAL GUIDE Ver.3
resistance value chance if electric power is impressed in the state of over-load foe a
long time, sufficient reliability check is required.
0.4W
40 degree
0.4W
70 degree
Fig.16. Reliability deterioration of soldering part in long time over-load
(2).
Static electricity characteristic
In thick-film chip resistors, correlation with length of L-size and W-size of resistor and
changing rate of resistance value when ESD voltage is impressed is shown in Fig.17.
Change of L-length
(W ? 0.22 mm)
Change of W-width
Serge voltage 1-applied
Serge voltage 10-applied
Resistance change rate
Resistance change rate
Serge voltage 10-applied
Fig.17. Correlation with L-size, W-size of thick-film chip resistor and ESD characteristic
From Fig.17, ESD characteristic is greatly influenced by termination interval. Therefore,
resistance value by ESD characteristic tends to become large following on becoming
small. Moreover, it is influenced by conductive mechanism of resistive material,
resistance value trends to be influenced with the range from 100 ohms to 100k ohms,
and the ESD characteristic is hard to be influenced by ESD in the domain where
resistance value is lower than that range or a high domain.
13
TECHNICAL GUIDE Ver.3
As reference, ESD characteristic of ERJ3G-type (1608-size) is shown in Fig.18.
ESD characteristic
ERJ3G-type (1608)
Impressing frequency: once
Impressing voltage (kv)
Fig.18. ESD characteristic (ERJ3G-ype)
14
TECHNICAL GUIDE Ver.3
(3).
Pulse characteristic
Regarding the pulse characteristic of thick-film chip resistors, examination for the
contents shown below is required.
Pulse limit power (PP), Pulse limit voltage (VP) and Pulse limit current (IP) shall be
calculate by the following formula.
PP (VP, IP)
τ
T
PP
=
VP
=
IP
=
: Pulse continuous time
(s)
: Pulse period
(s)
: Rated power
(W)
: Rated voltage
(V)
: Rated current
(A)
: Normal resistance value (Ω)
VPmax : Max. pulse limit voltage (V)
* T > 1 (s) → T = 1 (s)
* T / τ > 100 → T / τ = 100
* PP (VP, IP) < P (VR, IR)
→ P (VR, IR) stands for PP (VP, IP)
* The voltage which can be added is less than
VPmax.
* Judgement : Resistance change +/-5%
(After 1000 hours)
τ
T
P
VR
IR
R
<Note>
KּPּT/τ
KּPּRּT/τ
KּPּ1/RּT/τ
#Constant K and VPmax shall be shown in the below table.
Rated Power
(W)
ERJ2G
ERJ3G
ERJ6G
ERJ8G
ERJ14Y
ERJ12Y/12ZY
ERJ1WY/1TY
0.1
0.1
0.125
0.25
0.5
0.75
1.0
~ 10Ω
0.11
0.18
0.36
0.22
0.22
0.20
0.45
10Ω ~
0.11
0.18
0.36
0.22
0.22
0.20
0.45
15
K
100Ω ~
0.11
0.18
0.24
0.15
0.15
0.20
0.30
1kΩ ~
--0.15
0.20
0.12
0.12
0.16
0.25
10kΩ ~
--0.12
0.16
0.10
0.10
0.13
0.20
VPmax
100
100
200
400
400
400
500
TECHNICAL GUIDE Ver.3
Approximation method
Pulse wave shall be approximated to rectangle wave form
as below.
* The discharge waveform of a capacitor.
VP
VP
0.4 x VP
τ
τ/2
* Sine curve
VP
VP
τ
τ/2
* Triangular wave
VP
VP
τ
τ/3
* Special wave
VP
VP
0.4 x VP
τ
16
τ/2
TECHNICAL GUIDE Ver.3
Test method: The limit value when impressing the shortwave of the following condition is grasped.
Impressing time: 1m sec, 10m sec, 100m sec, 1 sec ; →10 ohm
Period: 10 sec; →100 ohm
Impressing frequency: 1000 times (criteria, changing rate of resistance value within 5%); →1k ohm
I Impressing power (w)
Number of sample: n = 5; →10k ohm
Impressing time (sec)
Fig.19. Pulse limited data of ERJ3G (1608)-type
Test method: The limit value when impressing the shortwave of following condition is grasped.
Impressing time: 1m sec, 10m sec, 100m sec, 1 sec; 10 ohm
Period: 10 sec; 100 ohm
Impressing frequency: 1000 times (criteria, changing rate of resistance value within 5%); 1k ohm
I Impressing voltage (w)
Number of samples: n = 5; 10k ohm
Impressing time (sec)
Fig.20. Pulse limited data of ERJ6G (2012)
Fig.19 and 20 is reference data to the last, and please fully perform a reliability check
with your system in the use of the circuit that pulse-load is impressed.
17
TECHNICAL GUIDE Ver.3
9.2. Design of Printed Substrate
When using surface mount resistor, caring about the following point and please perform
printed substrate.
9.2.1. Recommended land pattern
9.2.1.1 Chip resistors
Recommended land pattern of chip resistor by each shape is shown in Fig.21.
C
c
a
a
b
b
Products
ERJXG
ERJ1G
ERJ2G
ERJ3G
ERJ6G
ERJ8G
ERJ14
ERJ12
ERJ12Z
ERJ1T
ERJL1W
a
0.15 to 0.20
0.3 to 0.4
0.5 to 0.6
0.7 to 0.9
1.0 to 1.4
2.0 to 2.4
2.0 to 2.4
3.3 to 3.7
3.6 to 4.0
5.0 to 5.4
3.6 to 4.0
Dimensions (mm)
b
c
0.5 to 0.7
0.20 to 0.25
0.8 to 0.9
0.25 to 0.35
1.4 to 1.6
0.4 to 0.6
2.0 to 2.2
0.8 to 1.0
3.2 to 3.8
0.9 to 1.4
4.4 to 5.0
1.2 to 0.8
4.4 to 5.0
1.8 to 2.8
5.7 to 6.5
2.3 to 3.5
6.2 to 7.0
1.8 to 2.8
7.6 to 8.6
2.3 to 3.5
7.6 to 8.6
2.3 to 3.5
Fig.21. Recommended of chip resistor
9.2.1.2. Chip resistor array
Recommended land pattern of chip resistor array by each shape is shown in Fig.22.
f
a
b
c
P
18
TECHNICAL GUIDE Ver.3
Products
Dimensions (mm)
c
0.3
14V
a
0.3
b
0.3
P
0.5
f
0.8 to 0.9
18V
0.2 to 0.3
0.15 to 0.20
0.15 to 0.20
0.4
0.8 to 0.9
24V
28V
0.500
0.4
0.35 to 0.40
0.525
0.3
0.25
0.65
0.5
1.4 to 1.5
1.4
N8V
0.45 to 0.50
0.35 to 0.38
0.25
0.5
1.4 to 2.0
V4V,V8V
34V,38V
S8V
2HV
0.7 to 0.9
0.7 to 0.9
1.0 to 1.2
1.0
0.4 to 0.45
0.4 to 0.5
0.5 to 0.75
0.425
0.4 to 0.45
0.4 to 0.5
0.5 to 0.75
0.25
0.8
0.8
1.27
0.5
2.0 to 2.4
2.2 to 2.6
3.2 to 3.8
2.00
ig.22. Recommended land pattern of chip resistor array
9.2.1.3. Chip resistor network
Recommended land pattern of chip resistor network by each shape is shown in Fig.23.
2.5
2.5
0.5
0.5
1.27
1.27
EXB
E/D-type
P
P
B
B
D1
D1
A
A
D2
D2
4.5
4.5
EXB A-type
C1
C1
C2
C2
Products
EXBE
EXBD
A
0.4
0.3
B
0.5
0.4
C1
3.1
2.65
C2
5.1
4.15
D1
1.5
0.9
D2
3.5
2.6
Fig.23. Recommended land pattern of chip resistor network
19
P
0.8
0.635
TECHNICAL GUIDE Ver.3
9.2.2. Components arrangement
Since the stress to the curvature or bending at the time of breaking printed substrate
may cause fault when arranging surface mount resistor near printed substrate breaking
point, consideration is required for the method of arrangement of surface mount resistor.
Arrangement method when arranged surface mount resistor near the breaking part of
substrate is shown in Fig.24.
X×
O
○
AA
B
B
CC
DD
Fig.24. The caution when attaching to the place is easy to bend
The probability that surface mount resistor will break by stress when substrate break is
followed below.
A > C > B (near infinite) D
Therefore, arrange to the break line of printed substrate as in parallel as possible, or
keep away from break line as much as possible.
9.3. Used environment
Please consider enough and use under the following environment for it especially, to the
environment in the case of using surface mount resistor.
9.3.1. Anti-gas characteristic of chip resistor (sulfurated atmosphere)
In the case of thick-film chip resistor that is used the material of Ag-system as inner
termination, sulfulated gas invades from the space between a protective-film and plating
in atmosphere , such as sufulated gas (it is possible to occur by heat-stress while
mounting), and there is rarely case that inner termination of Ag-system cause
disconnection, from a reaction as shown in the following chemical formula progressing.
Ag → Ag+ + eS + 2e- → S22Ag+ + S2- → Ag2S
The reaction velocity in this case is influenced by sulfurated gas density, temperature
and humidity greatly.
As especially the factor of sulfulated atmosphere, there are cases, rubber that is used
sulufur as vulcanization,and sulfur-chlorination or sulfur oil is used in heat and
20
TECHNICAL GUIDE Ver.3
high-humidity atmosphere.
appearance and cross-sectional picture when inner termination of Ag-system is
influenced by sulfuration are shown in Fig.25.
Appearance picture of sulfuration
Sectional picture
Fig.25. Sulfurated effect for chip resistor
9.3.2. Resin mold of chip resistor
In using resin mold of the resistor, the protective-film of resistor may exfoliate, the crack
in a solder joint point may occur by the stress at the time of mold resin hardening or
resistance value change and disconnection may be generated under the influence of
the ingredient contained to the resin (to be mold), please fully perform reluability
evaluation.
The example which the crack is generated in the solder joint part by stress at the time of
resin mold are shown in Fig.26.
21
TECHNICAL GUIDE Ver.3
Crack
Fig.26. Disconnection by resin mold of chip resistors
9.4. Mounting quality
Please use surface mount resistor in consideration of the following contents to the
method of mounting in a printed substrate, and the washing method after mounting.
9.4.1. Soldering method
Since the manhattan phenomenon at the time of exfoliation of upper surface termination
or mounting may occur when it mounts two or more parts in a common land pattern, be
careful for separating land pattern by solder resist and the amount of solder beyond
necessity not to adhere.
Bad example
Good example
Without solder resist
With solder resist
Fig.27. The mounting method in common land
22
TECHNICAL GUIDE Ver.3
Moreover, in mounting surface mount resistor in narrow pitch, in order to suppress
generating of a solder ball, it recommends the solder cream that is used the solder of
the shape of a delicate solder ball.
In mounting of the chip resistor in narrow pitch, and mounting of chip resistor array and
chip resistor network etc., with flow soldering, since the solder bridge between
termination may be generated, use of reflow soldering is recommended. In addition,
regarding repair of surface mount resistor, pay attention for shock for termination part by
soldering iron and temperature and time of soldering iron.
Moreover, when putting a resistor with tweezers etc., the consideration to not giving a
shock to protective coating and shock to soldered termination is required.
9.4.1. The limit of resistance to soldering heat
The limit of resistance to soldering heat of surface mount resistor is shown in Fig.28.
Temperature (degree)
5 sec
Peak temperature
Rising temperature 1
Pre-heating
Gradual cooling
Rising temperature 2
Main heating
Rising temperature 1: normal to preheating, 30 to 50 sec
Pre-heating: 140 to 160 deg, 60 to 120 sec
Rising temperature 2: pre-heating to 200 deg, 20 to 40 sec
Gradual cooling: 200 to 100 deg, 1 to 4 deg / sec
Peak temperature (degree)
Time (minute)
Time of above 200 degree (sec)
(Main heating parts)
Fig.28. The limit of resistance to soldering heat of surface mount resistor
Please setup of the soldering profile by the within the limita of Fig.28.
23
TECHNICAL GUIDE Ver.3
9.4.1. Washing method
Although the fron detergent has been conventionally used for washing of a mounting
base widely, it is difficult for an ozone layer depletion problem to use. Therefore,
although the cases changed in this opportunity by reexamination of flux material or a
reliability evaluation into no washing have increased in number in general market, the
case changed into a fron-alternative detergent in part is also seen.
Principal fron-alternative detergent and characteristic are shown in table-3.
Table-3 Principal fron alternative detergent and characteristic
Fron (CFC-113)
A → Excellence
Water
Solvent
Harmful
HCFC
Flashing
Silicon
Reference
A
A
B
A
B
B
A
B
A
B
A
A
B
B
A
A
A
A
B
A
A
A
B
B
B
B
B
B
B
A
C
A
(to B)
A
A
A
A
Detergent: IPA
Ethanol
Detergent: M
Detergent: N
O
Detergent: P, Q
B
A
B
A
A
B
B
A
A
B
B
A
A
B
A
B
A
B
A
A
B
B
A
B
A
A
A
A
A
A
B
C
B
B
A
B
C
C
New of flux
Alchohol
washing
residue
Alkali
natural
Hydrocarbon
oil
Hydrocarbon
(oil)
Anti-semiwater
Parts damage
Semiwater
Part (space)
Surfactant
Anti-ion residue
Water (pure water)
Water-soluble
detergent
Safety
(water-soluble for flux)
Detergent: A, B, C,
D, E
Detergent: F
Detergent: G
Detergent: H, I
Detergent: J, K, L
Primary detergent
(and maker)
Ion residue
Classification
Reliability
Ozone destruction
washing power
A
A
(to B)
A
B
B
B
A
A
(to B)
A
A
B
B
C → Problem
B → Some problem
Evaluation method of anti-washing and its condition are shown in table-4, anti-washing
characteristic of principal fixed resistor and fron-alternative detergent is shown in
table-5.
From table-5, regarding the washing nature of chip fixed resistor, it is comparatively
good. However, table-4 is reference data to the last, and performs fully reliability check
with your system in actual use.
24
A
A
A
A
A
A
TECHNICAL GUIDE Ver.3
Table-4. Evaluation method of anti-washing and its condition
Washing (substrate attachment state)
Pure water
IPA
Detergent; A
B
E
Detergent; J
Detergent; G
Detergent; M
Reliability test
Ultrasonic washing→Drying
(normal (temperature) 5 min)→(110 deg, 30 min)
Ultrasonic washing→Drying
(normal, 5 min)→(110 deg, 30 min)
Ultrasonic washing (60 deg, 5 min) → Rinse (normal, running
water; 2 min, pure water; 1 min) → Drying (110 deg, 30 min)
Life test in humidity (1000 hours, etc)
The catalog test conditions for every
parts are centers. In part, others are
also carried out)
Ultrasonic washing (60 deg, 5 min)→ Rinse (IPA 1min)→
Drying (110 deg, 30 min)
Ultrasonic washing (normal), 5 min) → Rinse (normal, running
water; 2 min, pure-water; 1 min) → Drying (110 deg, 30 min)
Ultrasonic washing (FRW-17: 40deg, 5 min)→ Rinse (FRW-1;
normal, 2 min)→ Drying (FRV-1; 100 deg, 2 min)
Note1) Although ultrasonic wave are the following conditions, some parts are immersed.
Techno care; 15v / l, 28KHz,
Others; 6v / l, 28 to 45 to 100KHz swing
Note2) Heat-resistance low parts are dried at 80 deg, for 30min.
Note3) Using flux is RA-grade, water-soluble is non-halogen type
Note4) It is carrying out without putting flux into a detergent at all.
Table-5. Anti-washing of principal fixed resistor and fron-alternative detergent
A
E
J
G
Product name
M
a
a
a
a
b
d
b
d
b
f
a
f
a
f
a
f
a
a
d
d
f
f
f
f
a
a
a
a
f
f
f
f
c
c
c
c
c
c
c
c
a
a
a
a
a
a
a
a
f
b
c
b
b
b
b
c
a
a
a
a
a
a
a
a
f
a
f
a
f
d
f
d
f
f
f
f
f
f
f
f
a
a
d
d
f
f
f
f
(Fixed resistor
division)
Metal (oxide) fuse
resistor
Thermal sensitive
resistor
Wirewound
resistor (ERW)∗
Metal film resistor
(ERX)
Network resistor
(SIP-type)
Network resistor
(SMD-type)
EMI filters
Chip EMI filters
Chip bead core
Capacitor network
Dew condensation
sensor
Chip feed through
capacitor array
MR elements
IPA
B
Pure water
IPA
(Fixed resistor
division)
Solid resistor
Carbon film
resistor
Carbon fuse
resistor
Wirewound
resistor (ERF)
Metal (oxide)
resistor
Thick-film
chip resistor
3-teriminal
capacitor
(with lead)
Chip 3-terminal
capacitor
Thermal cut-off
Precision metal
film resistor
Metal film resistor
(ERO)
Pure water
Product name
B
e
e
e
e
e
e
e
e
a
a
d
d
f
f
f
f
c
c
f
f
f
f
f
f
c
c
c
c
c
c
c
c
f
a
a
a
a
a
a
a
c
a
c
c
c
c
c
c
f
f
f
f
f
b
b
b
b
f
c
c
b
c
f
b
b
b
b
f
b
b
b
b
f
b
b
b
b
f
b
c
b
b
f
c
b
b
c
f
a
a
a
a
a
a
a
a
f
f
f
f
f
f
f
f
A
E
J
G
M
(∗ → without condition of ultrasonic wave)
a: performance, marking→OK
b: performance→OK, marking→attention
c: performance, marking→attention (The limit of washing condition and complete of rinse condition)
d: unusable
e: No assurance of washing from the former
10.
Technical
trend in the Future
f: individual correspondence
25
TECHNICAL GUIDE Ver.3
As trend of surface mount resistor, those with four and its flow are greatly indicated to
be, (1) the formation of small-light weight of components,
As trend of surface mount resistors, those with four and its flow in Fig.29 are greatly
indicated to be (1) formation of small-light weight of components, (2) composition of
components, (3) high-precision and advanced features, (4) the earth environment
protection and saving resources.
Small size
2012 type
1608 type
1005 type
0603 type
1005 Fillet-less
Composite(narrow pitch)
Array
3216:4 res.
5022:4 res.
p:0.8
p:1.27
concave
concave
05025 type
0603 Fillet-less
1616:2 res.
p:0.8
concave
3216:4 res.
p:0.8
convex
3816:8 res.
p:0.5
convex
1010:2 res.
p:0.65
convex
1616:4 res.
p:0.8
convex
2010:4 res.
p:0.5
convex
0806:2 res.
p:0.5
convex
1806:4 res.
p:0.5
convex
0606:2 res.
p:0.4
convex
Network
6432:4 element
p:1.27 concave
4021:8 element
p:0.8 concave
3216:8 element
p:0.65 concave
3816:15 element
p:0.5 convex
Tol.:+-2%
TCR:+-200ppm/K
Tol.:+-1%
TCR:+-100ppm/K
Tol.:+-0.5%
TCR:+-50ppm/K
Tol.:+-0.5%
TCR:+-25ppm/K
Tol.:+-0.1%
TCR:+-25ppm/K
High precision
Thick-film type
3216 type
chip resistor
Tol.:+-5%
TCR:+-200ppm/K
Thin-film type
High function
Low resistance value
10 ohm
1 ohm
Series
Trimable
Anti-sulfuroted
chip
chip resistor
Composite
R/C chip network
0.1 ohm
0.05 ohm
0.02 ohm
Tol.:+-0.05%
TCR:+-25ppm/K
Pelative accuracy
array
0.001 ohm
chip fuse resistor
C network
Earth environment protection/Saving resouires
Taping
Bulk
Narrow pitch
P:4mm
P:2mm
Reduction of tape-width
W:8mm
Reduction of environment load matter
Plating of
Spread of resin
electrode
P:1mm
W:5mm
Pb-free of
resistive
Fig.12. Trend of surface mount components
Although it becomes 0603 chip as present minimum form parts about the trend of
miniaturization of parts, from the last of 93, this product began to appear in the market,
and time is in a situation still required for establishment of mounting technology.
Therefore, it is surmised that considerable time is required for the appearance of the
further small parts. Then, the high-density mounting method is also improved fillet-less
chip of 1005 chip that can make good use of mounting technique of conventional chip in
a narrow chip. Furthermore, there is composition of components as method of
high-density mounting. A parts interval can be lost by composition and mounting area
can be made smaller the single article mounting. Naturally, also in this composition,
narrow pitch is progressing (1.27 → 0.8 → 0.5 mm), from now on, a narrow pitch is
accelerated to further 0.4 or 0.3 mm, and it will be surmised that the center of further
high-density is borne.
26
TECHNICAL GUIDE Ver.3
As a high- precise trend, although correspondence is possible to resistance tolerance: ±
0.5%, TCR: ±50 ppm / degree, with the thick-film technology, the present level
presumes the limit and the high-precision product beyond this becomes a thin-film
resistor, for example, resistance tolerance: ±0.1%, TCR: ±25 ppm / degree.
Moreover, chip with various functions is produced commercially in the present. For
example, there are resistor for functional trimming of alternation of half-fixed resistor,
chip fuse resistor with fuse function, low resistance chip with low resistance, anti-serge
chip strong against serge voltage, and anti- sulfurated chip strong against sulfuration
atmosphere. From now on, it is thought that series of those products will progress.
Finally, the earth environment protection and saving-resources are explained. a market
is considered. that the measure is advanced focusing on reduction of an environmental
load substance, and waste now. About reduction of environmental load substance, the
conditional examination for lead-free solder use is specially tackled. To this trend, our
company is conjecturing resin of protective –film, resin of external termination and
focusing on reduction of Pb and Pb-composed among environmental substances, such
as Pb-free plating of external termination. This demand will become strong further, from
now on. Moreover, as part of waste reduction, re-use of taping reel, narrow pitch of
paper carrier-taping pitch, and packaging form also think that the change to a bulk
cassette from taping etc. are accelerated.
27
TECHNICAL GUIDE Ver.3
References
(1) “ Soldering Mount Guide Line” Panasonic Electronic Devices Co., Ltd.
Soldering no-amendment WG
(2) “ SMD Reliability Guide Line” Panasonic Electronic Devices Co., Ltd.
(3) “ Fixed Resistor Technical Guide” Panasonic Electronic Devices Co., Ltd.
Resistor Division
(4) “ Reliability Data Book of Surface Mount Components”
Panasonic Electronic Devices Co., Ltd.
Surface Mount Resistors
TECHNICAL GUIDE
Published Date; First Edition
November, 1, 1999
Publication; Circuit Components Business Unit
Industrial Devices Company
Panasonic Corporation
*2012 Apr.
Renamed to Panasonic Corporation
Unapproved reproduction is forbidden
28