CCTV

At 1999, we were assigned to build CCTV together with fire alarm system, as requested by our customer. We invited many vendor to bid this project and again we were surprised their quotation was much higher than our budget. We, then, decided to make it ourselves and, thank God, we can make it.

We have to monitor 25 locations. 16 locations have to be recorded. The other 9 locations are used just for monitoring purpose. Unlike common CCTV that monitoring is centralized in security guard’s room, in our system, monitoring all 25 locations can be done anywhere.

The concept is also simple. Signal from CCTV 1 is modulated (converted) into TV signal at frequency 1. CCTV 2 is also modulated into TV signal at frequency 2 until all 25 units CCTV. Theoretically, we can monitor up to 32 units CCTV on two groups, each 16 units. Among TV signal must not interfered each other, like commercial TV. Signal from each group are summarize by using RF combiner. Signal from RF Combiner 1 is fed into RF Combiner 2. Now on, output from RF Combiner 2, will consist of 32 TV frequencies. This frequency is amplified by using wide band RF Amplifier before distributing to TV. To see each CCTV is very simple, just to select TV signal, i.e. CCTV 1 on channel 1, CCTV 2 on channel 2, etc.

Fire Alarm System

Few years ago, we have been assigned to build integrated fire alarm system and CCTV. We have 3 manufacturing buildings and 1 office. Fire alarm of these 4 buildings must be integrated and monitored from security room. The system consists of many smoke detectors. To integrate each smoke detector, we use cable. The longest distance between fire detectors and control room is more than 1 km. We invited many companies to bid. We were surprised their quotations were very expensive. We, then, thought why didn’t we build the system ourselves? We already had the concept and we were sure that we could make it.

The concept is simple. Master (Smoke Detector Central Monitor) ask data start from slave 1, slave 2 until slave n.. Slave’s data is smoke detector condition: in danger (smoke) or not. All smoke detectors data, on central monitor, will be displayed. Monitor can be a simple monitor (just small lamp and 3 digits number), computer system or even through internet. Monitoring period of each slave is very fast (only few seconds) so its look like all smoke detectors condition’s be displayed instantaneously. If there is a fire, the nearest alarm (of the fire) and central monitor’s alarm will be ring. Security guard will immediately know fire and its location.

The advantage of this system is we only need one wire (backbone) to connect master and all slaves. The maximum backbone length is 1.5 km, and we already make it. Theoretically, we can have 225 units slave and 20 units alarm. Each slave monitor 4 sets smoke detector or total 900 units smoke detector in the system. We can use smoke detector that have data connection (preferred) or just simple or stand alone smoke detector. From above picture, based on arrow direction, master and slave communication are two ways while alarm and smoke detector are only one way communication.

We use RS-485 technology to ensure 1.5 km backbone length communication work well. If you are interested in master-slave system in electronics view, please visit….. RS-485 technology also can be studied further in ….

Injection Molding

We have more than 30 units injection machine, ranging from 60 tons until 350 tons clamping force. These machines are used to make plastic cabinet for our product. Just to inform, our factory serve total solution for consumer electronic manufacturing, from plastic cabinet, PCB assembly until ready to export product.

We do not inject our own product. We inject customer product. They give injection mold and plastic resin. We make it into plastic cabinet. Manufacturing cost per hour depend on machine clamping force tonnage and number of mold cavities. We group our machines into 4 groups:
• Group 1 : 350 tons
• Group 2 : 200, 220 and 250 tons
• Group 2A : 170 tons
• Group 4 : 60 and 80 tons

Group 1 is the most expensive manufacturing cost, while group 4 is the cheapest price. Group 1 needs highest electric power consumption. Manufacturing cost already consider manpower cost, electrical consumption, maintenance cost and expected profit, etc.

Above picture show some plastic cabinet we make. Please observe the biggest plastic cabinet. This part is made from injection machine group 1. Let’s say, this machine is only able to perform 70 shoots in one hour. Because of its dimension, mold only consist of 1 cavity so, in one hour, this machine is only able to produce 70 pieces. If manufacturing cost per hour is USD 7, manufacturing cost for one piece become USD 7 / 70 or USD 0.1. Lets say, for another smaller plastic cabinet which also use group 1. Because of plastic part dimension, mold consist of 2 cavities so in one hour the machine can make 140 pieces. Manufacturing cost for each piece become USD 7 / 140 or USD 0.05.

There are two main units on injection mold machine :
- injection unit, in simple concept, consist of
o hopper (arrow 1)
is used to minimize plastic resin humidity
o barrel (arrow 2)
is a screw tunnel and to melt plastic resin by heating process
o screw (arrow 2)
to deliver melting plastic into mould
- clamping unit
to push moving platen of mould in high force
- mold (arrow 3)
is the most important part of injection mold system, and is use to form melting plastic material into plastic cabinet

Our factory has two type clamping system : hydraulic clamping system and Toggle system

Mold. Standard mold consist of two plates :
- Cavity side
is connected to nozzle of injection unit to deliver melted plastic material (from screw) into sprue of cavity side
- Core side
is connected to clamping system so it is called moving plate. Inside this side, there are some ejector that is use to release plastic part from machine. Operator can take out plastic part manually or using robot arm in automatic system.

Above picture show 2 cavities mold. Picture A is core side and picture B is cavity side. Arrow 1A and 1B are used to form cabinet top while 2A and 2B are used to make cabinet bottom. This kind of mold is called pairing mold.

..analisa mold

Part come from injection machine consist of part itself (arrow 1 below picture) and sprue and gating (arrow 2). Part’s weight will be based on part itself. Sprue and gating will be recycled to make new part. The number of recycling process is purely depend on expected quality. The high class plastic cabinet will be made from virgin plastic resin, while very cheap plastic cabinet may come from 100% recycled material.

Another factor to consider to weight plastic cabinet is barrel cleansing process. Every time injection mold use new material, especially new color, barrel has to be cleaned by plastic resin until expected color / material can be achieved.

Surface Mount Technology

Since beginning of 1980s, more and more electronic parts use chip part, not through hole part anymore. Mounting this component on PCB can not be done by manual solder. We need Surface Mount Technology (SMT) machines.

There are two methods to mount chip component on PCB, by using solder paste or glue.

Solder paste is a solder in gel form. Solder paste will melt and solder the component during heating process in reflow oven. Glue is special glue to hold chip component. This glue will cure and firmly hold component after heating process in curing oven.

Machine for solder paste is called solder paste printer because solder paste is printed on PCB using stencil technology (in very old printing process). The arrow in below picture is glue (in tube) that will be used to glue chip component

There are two different Chip Mounting machine in our factory: rotary and modular. We used both on same production line. Both machines can be operated simultaneously or independently, depend on requirement. Our rotary technology machine has slower speed.

There are two different Chip Mounting machine in our factory: rotary and modular. We used both on same production line. Both machines can be operated simultaneously or independently, depend on requirement. Our rotary technology machine has slower speed.

In rotary technology, chip component picker is not moving, only rotate. PCB is moving. In modular technology, chip component picker is moving. PCB is stand still. Below picture is rotary and modular technology SMT. Each chip component picker is pointed by arrow.

We have two kinds of oven 5 temperature zones and 7 temperature zone. Both can be only be used for curing oven and reflow oven. Even though, to get better output 7 zone is preferred to be used as reflow oven. Temperature profile for curing oven is:

It is called reflow oven because of following reason

In 3^rd zone, there is short and peak temperature, something like solder reflow in solder pot. This zone is called reflow zone. The last zone is cooling zone, usually performed by fan. Above chart is extracted from solder paste data sheet. The actual temperature profile is:

The 5^th zone is highest temperature. Reflow zone is expected happen in this zone.  6^th zone is cooling zone, done by fan.

Statistical Process Control in Electronic Manufacturing

To control the quality of product, we implement SPC (Statistic Process Control) to ensure manufacturing process is performed in controlled procedure. Even though, there will be no perfect mass product even if our quality control is very stringent. We have to balance between price and manufacturing cost since quality is meeting customer expectation. The more stringent quality control, the more cost required

We use three tools to control manufacturing process :
- p-Chart
- u-Chart
- Pareto Analysis

p-Chart :

Is use to monitor the proportion of nonconforming units in a sample : conform or non-conform, yes or no, etc. Nonconformity is defects or occurrences found in product set. It can be described as any characteristic that is present but should not be, or any characteristic that is not present but should be. I will use our p-Chart for discussion purpose.

We use FW (fiscal week) for our production schedule. Week 5.05 is 5th week and day 5 (Friday). In 2009, FW5.05 is Friday, 30 January 2009. At FW5.05, we made 3988 sets remote control (our main product). At that day, we got 91 sets reject (Non Conformance – NC) or the proportion = 2.29%. We plot this proportion percentage on chart. At FW8.04 we made 5994 sets with 183 sets reject or 3.05%. We also plot this number into chart.

From above table / chart, we calculate UCL (Upper Control Limit) and LCL (Lower CL). These two lines are used to determine whether a manufacturing process is under control or not. If the chart is under control then it can be used to predict the future performance of the process. If the chart is not in control, the pattern it reveals can help determine the source of variation to be eliminated to bring the process back into control. Ideally UCL and LCL are taken from 1 month observation, but it can be made faster (i.e. 2 weeks). The longer the observation, the better UCL/LCL can be got.

Based on observation started from FW5.05 until FW15.01, we determine UCL= 3.16 (red dash) and LCL.= 1.87 (black dash). These control parameter are used to control next month process. In average, reject deviation from FW15.02 – FW19.04 is considered normal, only at 15.02 and 16.01 reject sets quantity are good.

If we can observe another observation period (i.e. another 30 days observation), we may get different UCL and LCL.

u Chart :

To control the number of non conformity per unit, or we say defect per unit (DPU), we use u-Chart. In our manufacturing process, the populated PCB (Printed Circuit Board) will be dipped into solder pot. After this process, there will be many defects (nonconformities), i.e. short soldered, not soldered, etc. Each defect will be counted. Let’s say there are 10 pcs PCB. There is 5 defects / nonconformities in PCB no. 1 and  3 defect in PCB no. 2 but no defect found on the rest PCB (8 pcs). We say that in 10 pcs PCB, there is 8 defects, or defect per unit = 0.8. Beside DPU, we also record defect classification and number of occurrences and then analyze the defects pattern. By knowing defect pattern, we are able to determine if the process is stable and predictable, as well as to monitor the effects of process improvement.

Please visit http://syque.com/quality_tools/toolbook/Control/do_u_calc.htm to learn how to calculate UCL and LCL. By using this formulas, we get UCL = 1.61 and LCL = -0.06

Pareto Analysis :
Another tool can be used to control manufacturing process is pareto analysis or 80 : 20 analysis. Theoretically, if we can solve top 20% reject, its mean we can solve 80% problem. In practice, 80 : 20 does not mean 80% and 20%, but if we can capture the most two or three problems, we can solve most of the problem

Beside reject percentage, we also have to record reject cause. Based on our reject cause of above table / chart, we can group into 6 reject categories. Please see below picture

You can see there are 3 most problems, no. 1, 2 and 4. For the first time we have to concentrate to solve most 2 – 3 rejects. After these reject can be solved, then we go to next reject (maybe number 5 and 3)

Incoming Material Check in Electronic Manufacturer

Single Sampling Plan MIL-STD-105D. Our material can be grouped into 3 groups : - Plastic resin, ink and paint for plastic injection process - Packaging Material - Electrical Parts We do to method for incoming materials check. - Skip lot material. Material that is grouped into this category do not need to be checked. The decision to group into skip lot is determined by QA Manager, based on Product Engineering Manager’s opinion. - Random Check We randomly check incoming material according to MIL-STD-105D Single Sampling Plan Level II, with AQL (Acceptance Quality Level): critical= 0, major= 1.0, minor= 2.5. AQL is determined by customer. Critical is related with safety. Critical= 0 mean all incoming materials must not have even single piece material defect in safety related matter. Major is related with functional and minor is related with cosmetic aspect. To determine sample size, please use Sample Size Code Letter, as follow :

Lets say our incoming material quantity is 3000 pieces. Because we use single plan level II, according to above table, sampling size code is K. According to below table, sampling size for K is 125 pieces.

Because AQL for major defect is 1.0, its mean that if we found maximum 3 pieces has major defect, this lot still can be accepted. But, if we found 4 pieces or more has major defect, this lot have to be rejected.

Quality Assurance Concept

In tough competition like these days, quality assurance is the main concern – beside price – in manufacturing business. Maintaining relationship with existing customer is the goal of quality, and it will be a best selling point for marketing team to find new customer. We must deliver more than expected products to maintain the relationship. Even though, do not make it over. Both sides must get benefit from the relation. Customer is a partner, not a king.

Our main current product is universal remote control, beside surge suppressor and wireless phone jack. In our top order period, we made more than 1.2M sets a month. Since our average manufacturing capability is around 5000 sets per production line per day, we have to run 12 ~ 13 lines to catch up the target. To maintain the quality of such quantity is not an easy process, but we do. We never had product returned sets since the beginning of factory operation (about 1992).

From beginning of operation we already implemented quality assurance process to ensure that our products always meet customer expectation, and if possible try to exceed. MIL-STD-105D is used for quality assurance process. Since 1996 we implemented. ISO9001:1994. This standard enhance in controlling product quality.

There are 3 stages quality check :
- Incoming Material Check :
After unloading raw material from container and before recorded as “ready to be used” material
- Inline Quality Check
Quality inspection in production line
- Outgoing Quality Check
Before shipping the products to customer.

We provide total solution for consumer electronic manufacturer. We provide plastic injection mould, surface part mounting and production line assembly. We are unique in raw material cycle. Raw material is supplied by customer and finished product is send to same customer. Business mapping for raw material process follows:

……picture

Inline Quality Check is performed only for new product or if necessary

Quality Leadership Process – Fundamental Concept

• We must make Quality the number one priority in our business

• Top Management must totally commit to the process

• We must exceed our customer expectation for every product and service we provide • Quality is everyone’s responsibility

• We must build trust among ourselves, with our customer and with our suppliers

• We must change from problem reaction to problem prevention by doing every job right the first time

• We must create empowered organization that allows each of us the opportunity and freedom to constantly improve our work environment

• Training, resources and support must be provided to get the job done

• This is an on going process, not “just another program”

BUILDING TRUST THROUGH QUALITY

Test Equipment Calibration and Maintenance Procedure

Revision History
1. Purpose
Provide procedure to administrate, maintain and calibrate test equipment.

2. Scope
Identify test equipment necessity for calibration

3. Reference
Describe ISO Clause to be used

4. Definition
• Meaning of calibration
• Test Equipment Categorization (A, B, B1 and C)

5. Authority and Responsibility
Describe who shall administrate, maintain and calibrate test equipment

6. Procedure
• Describe how test equipment category A, B, B1 and C shall be administrated, maintained and calibrated, including Limited Calibration
• Test Equipment readiness status
• Test Equipment handling and storage
• Test Equipment Distribution and record

7. Appendix
8. Distribution List

Document Control

Revision History

1. Purpose of Document

2. Scope Area
What documents shall be controlled by ISO regulation

3. Reference
ISO clause which been used for this documents

4. Definitions :
Explain some definitions used in ISO documents
• Internal and External Documents
• Document Levels (level 1, 2 and 3)
• Controlled and Uncontrolled Copy
• Obsolete Documents
• Control Label

5. Authority and Responsibility
Mention who shall responsible for document control

6. Document Distribution Procedure
• Document Acceptance
• Distribution
• Revision procedure for document level 1, 2 and 3
• Document Storage and Disposal
• Recipients List

7. Appendix
8. Distribution List