COB LCD Module vs COG LCD Module vs COF LCD Module

     Classification of LCD Module

     LCD Module(LCM) has 4 parts: LCD screen, LED backlight, IC and PCB (maybe a plastic shell).   We can simply consider that it has two parts: LCD screen and LED backlight because we can see  from the appearance and they are the main constituents.   LCM can be divided into COB(chip on board),  COG(chip on glass) and COF(chip on film) by the position of chip. It can also be divided into segment LCD and dot matrix LCD by the content they are going to display.
COB is the abbreviation for Chip On Board, which is a most common way of processing the drive circuit board of LCM. The IC is attached directly to a specified location on the PCB with a sticky piece of plastic.  See the picture below and the IC is under the black plastic. The electrodes of the chip are connected to the corresponding pads of PCB board with aluminum wire by a soldering machine.   And they are covered by a sticky piece of plastic on the surface.
COB LCD
COB  is the most common, reliable  and cheapest technology which requires high precision equipments and a complicated processing procedure. It uses PINs to connect and fasten the LCD screen,  LED backlight and PCB all together, so it can’t  be disconnected.  It is very reliable and it can’t be damaged under normal circumstances.  But if it is damaged, unfortunately, it can’t be repaired. I think this is the main defect that COB has.  If our customers don’t have any special requirements, we would suggest that we use COB technology.
COG is the abbreviation for Chip On Glass, where IC is bound to the ITO glass directly.  Please see the picture below.  It can greatly reduce the size of the LCD module and be easy for mass production for consumer electronics products,  such as: mobile phones, PDAs and other portable products.
COG LCD

COG doesn’t need PCB. It is cheaper, isn’t it?  I am sorry to tell you that on the contrary, it is not.  COG is going to need a dedicated glass mold and a dedicated LCD FPC mold which COB doesn’t need.  Maybe it needs a dedicated light guide plate mold and a dedicated backlight FPC mold because of its special structure.  So the tooling fee of COG is the most expensive among the three of them.    If the quantity you want is only 1000 pieces, the unit price will be incredibly high because of the tooling fee. At the same time, the tooling fee can be almost  negligible if the order quantity is very large, say like 100 thousand, 1 million.
Is it safer?  Of course, it is not.  COB is the most reliable one.   The only reason I think why COG is popular is that it can save a lot of space by concentrating all the functions on a single IC. It is extremely important for the modern portable electronic products which require small volumes
COF is the abbreviation for Chip On Film, where IC is bound to a flexible film conveyor belt directly.  Please see the picture below. It can greatly reduce the size of the LCD module too.
COF LCD
The tooling fee of COF is less than COG’s, but it is more than COB’s.  It needs a dedicated FPC mold, compared to COB.  But I think it is the most unreliable one because the IC is bound to a flexible film which is moving all the time. So if you really want to save the space, I strongly suggest that you choose COG instead of COF.

Segment LCD  only  shows the fixed pattern. Take the 7 segment LCD panel for example.  See the picture below. Figure 0 has  six segments are turning  red; figure 9 has five segments which  are turning red; figure 8 has seven segments which are turning red and so on.
7 segment LCD panel
Segment LCD can’t show any graphic unless you have pre-designed it.
Take 6086LCD for example:
6086LCD light view
6086LCD size
Please see the two pictures above, there are 3 figure “8″ and 6 individual segments. Each figure “8″ has 7 segments. So there are (3*7+6)27 segments in this LCD screen.
6086LCD PIN
It is not easy to draw a blueprint for segment LCD.  But it can greatly decrease the cost.  We can use IC HT1622 which is very low class.  IC is a very important part of cost.  Let us look at 6086 LCD again.  It total has 11 PINs(4 com PINs and 7 seg PINs). See the picture above.  It can save the PINs too.
There are 3 main kinds of connection for LCD screen.  See my post:  The Connection Type Of LCD
Metal PIN connection is the most reliable one, but it is expensive.
Dot matrix LCD which is composed of an array of independent segments can show any graphics you want.
Let us look at 12864 LCD module
12864 LCD module
It is very easy to draw the blueprint for  dot matrix LCD.  But it has so many segments (128*64 = 8192), we we have to use very high class of IC.  I don’t suggest we use  dot matrix LCD screen unless it is necessary because of the cost.
Besides, IC is not the only cost that is going to increase.   I can give you an example. Hypothetically, You have a very expensive watch. So you want  everything to look good with the watch. You have to buy a very expensive suit, even a pair of diamond shoes. So if you choose dot matrix LCD, the cost of all the other parameters are going to go up.
Please see the COB dot matrix LCD modules we already have in stock. If you choose the dot matrix LCD modules we have developed, you don’t pay for the tooling and it can save you a lot of time.

NO

Model

Content

CharsXLines

Module size

W x H(mm)

View area

W x H(mm)

Dot size

W x H(mm)

Character size

 W x H(mm)

Driving

 Method

Controller

LSI or Equiv

   character LCD module              

6205LCM

BLY-0802B

8X2

58X32

38X16

0.45X0.49

2.45X3.72

1/16

S6A0069

6206LCM

BLY-1202A

12X2

55.7X32

45.5X15.5

0.45X0.6

2.65X5.55

1/16

S6A0069

6207LCM

BLY-1601A

16X1

80X36

65X14

0.61X0.71

3.21X5.96

1/16

S6A0069

6208LCM

BLY-1601B

16X1

122X33

99X13.5

0.92X1.1

4.84X9.22

1/16

S6A0069

6209LCM

BLY-1602A

16X2

80X36

64.5X15.5

0.56X0.61

2.96X5.16

1/16

S6A0069

6210LCM

BLY-1602B

16X2

122X44

99X24

0.88X1.05

4.8X7.95

1/16

S6A0069

6211LCM

BLY-1602C

16X2

80X36

64.5X15.5

0.56X0.66

2.96X5.56

1/16

S6A0069

6212LCM

BLY-1602D

16X2

84X44

64.5X15.5

0.56X0.61

2.96X5.16

1/16

S6A0069

6213LCM

BLY-1602F

16X2

85X29.5

64.2X15.8

0.56X0.61

3.5X5.6

1/16

SPLC780D

6214LCM

BLY-1604A

16X4

87X60

62X27.2

0.56X0.56

2.96X4.76

1/16

S6A0069

6215LCM

BLY-1604B

16X4

82X40

59X26

0.52X0.54

2.76X4.6

1/16

S6A0069

6216LCM

BLY-2002A

20X2

98X60

83X18.6

0.59X0.64

3.21X5.57

1/16

S6A0069

6217LCM

BLY-2002B

20X2

116X37

83X18.6

0.59X0.64

3.21X5.57

1/16

S6A0069

6218LCM

BLY-2004A

20X4

98X60

76X25.2

0.56X0.56

2.96X4.76

1/16

S6A0069

6219LCM

BLY-2004B

20X4

77X47

60.6X22.6

0.42X0.46

2.3X4.03

1/16

S6A0069

6220LCM

BLY-4002B

40X2

182X33.5

153X17

0.6X0.65

3.2X5.55

1/16

S6A0069

 

graphic LCD module

             

6221LCM

BLY-12232A

122X32

84X44

60X18.5

0.36X0.42

0.40X0.46

1/32

SBN1661G_18

6222LCM

BLY-12232C

122X32

76.4X29.1

60.7X21

0.36X0.41

0.4X0.45

1/32

SBN1661G_18

6223LCM

BLY-12232F

122X32

76.2X38

60X18.5

0.36X0.41

0.4X0.45

1/32

ST7920中文字库

6224LCM

BLY-12232A

122X32

84X44

60X18.5

0.36X0.41

0.4X0.45

1/32

ST7920中文字库

6225LCM

BLY-14432A

144X32

84X36

65X16

0.39X0.39

0.42X0.42

1/32

ST7920中文字库

6226LCM

BLY-12832A

128X32

110X65

77.6X24.6

0.53X0.53

0.57X0.57

1/32

S6B0108A

6227LCM

BLY-12832B

128X32

90X32.5

60X18

0.36X0.42

0.40X0.46

1/32

SBN1661G_18

6228 LCM

BLY-12864A

128X64

78X70

62X44

0.39X0.55

0.44X0.6

1/64

S6B0108A

6229 LCM

BLY-12864C

128X64

93X70

72X40

0.48X0.48

0.52X0.52

1/64

S6B0108A

6230 LCM

BLY-12864D

128X64

113X65

72X40

0.48X0.48

0.52X0.52

1/64

S6B0108A

6231 LCM

BLY-12864D-C

128X64

113X65

72X40

0.48X0.48

0.52X0.52

1/64

S6B0108A

6232 LCM

BLY-12864E

128X64

93X70

72X40

0.48X0.48

0.52X0.52

1/64

S6B0108A

6233 LCM

BLY-12864G

128X64

113X65

73.4X38.8

0.458X0.458

0.508X0.508

1/64

S6B0108A

6234 LCM

BLY-12864I

128X64

54X50

43.5X29

0.28X0.35

0.32X0.39

1/64

S6B0108A

6235 LCM

BLY-12864A-C-2

128X64

78X70

62X44

0.39X0.55

0.44X0.6

1/64

S6B0108A

6236 LCM

BLY-12864A-C-3

128X64

78X70

62X44

0.39X0.55

0.44X0.6

1/64

S6B0108A

6237 LCM

BLY-12864A-C-4

128X64

78X70

62X44

0.39X0.55

0.44X0.6

1/64

S6B0108A

6238 LCM

BLY-12864E

128X64

93X70

72X40

0.48X0.48

0.52X0.52

1/32

ST7920中文字库

6239 LCM

BLY-12864F

128X64

78X70

62X44

0.39X0.55

0.44X0.6

1/32

ST7920中文字库

6240 LCM

BLY-12864G

128X64

113X65

73.4X38.8

0.48X0.48

0.52X0.52

1/32

ST7920中文字库

6241 LCM

BLY-12864H

128X64

87.5X70

72X40

0.48X0.48

0.52X0.52

1/32

ST7920中文字库

6242 LCM

BLY-12864I

128X64

93X70

72X40

0.48X0.48

0.52X0.52

1/32

ST7920中文字库

6243 LCM

BLY-16032A

160X32

116X35

83X18.6

0.44X0.44

0.48X0.48

1/32

ST7920中文字库

6244 LCM

BLY-16032B

160X32

122X44

99X24

0.51X0.52

0.56X0.57

1/32

ST7920中文字库

6245 LCM

BLY-19264A

192X64

130X65

104X39

0.46X0.46

0.51X0.51

1/64

S6B0108A

6246 LCM

BLY-19264B

192X64

120X62

104X39

0.46X0.46

0.51X0.51

1/64

S6B0108A

6247 LCM

BLY-19264C

192X64

100×60

84X31

0.36X0.36

0.41X0.41

1/64

S6B0108A

6248 LCM

 BLY-19264A

192X64

120X62

100X37

0.46X0.47

0.5X0.51

1/32

ST7920中文字库

6249 LCM

 BLY-19264B

192X64

130X65

104X39

0.46X0.46

0.51X0.51

1/32

ST7920中文字库

6250 LCM

BLY-24064A

240X64

180X65

132X39

0.49X0.49

0.53X0.53

1/64

T6963C

6251 LCM

BLY-24064B

240X64

180X65

132X39

0.49X0.49

0.53X0.53

1/64

T6963C

6252 LCM

BLY-24064A

240X64

180X65

132X39

0.49X0.49

0.53X0.53

1/64

RA8803

6253 LCM

BLY-240128A

240X128

144X104

114X64

0.4X0.4

0.5X0.5

1/128

T6963C

6254 LCM

BLY-240128B

240X128

144X104

114X64

0.4X0.4

0.5X0.5

1/128

T6963C

6255 LCM

BLY-240128B-1

240X128

144X104

114X64

0.4X0.4

0.5X0.5

1/128

T6963C

6256 LCM

BLY-240128C

240X128

144X104

114X64

0.4X0.4

0.5X0.5

1/128

T6963C

6257 LCM

BLY-240128C

240X128

144X104

114X64

0.4X0.4

0.45X0.45

1/128

RA8803

6258 LCM

BLY-320240A

320X240

160X109

122X92

0.33X0.33

0.36X0.36

1/240

RA8835

6259 LCM

BLY-320240A

320X240

160X109

122X92

0.33X0.33

0.36X0.36

1/240

RA8803

6260 LCM

BLY-320240A-COG

320X240

160X108.9

119.7X91

0.345X0.345

0.36X0.36

1/240

NT7702

6261 LCM

BLY-320240A-T(touch screen)

320X240

160X109

122X92

0.33X0.33

0.36X0.36

1/240

RA8806L2N-5

6262 LCM BLY-128128A

128X128

95X86

68.9X68.9

0.46X0.46

0.49X0.49

1/128

T6963C

                 

Please see the COG dot matrix LCD modules we already have in stock.

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