Electronics manufacturing in China — what to expect? (part two)
first part we considered mainly the potential organizational difficulties encountered in the production of pilot and industrial batches of electronics in China. Now let's talk more about the technical and technological problems.
So, we need to go through four stages:
1. To make the PCB.
2. To purchase components (so-called BOM — bill of materials).
3. To mount components on the circuit Board (soldering).
4. To check the efficiency and quality of products.
What you need to pay attention to each stage?
Here usually we are waiting for a relative minimum of surprises. The developer (namely a developer! and it is possible when converting from a file, for example .pcb to get a few unpleasant surprises) preparing a gerbera (files in Gerber format), factory makes a multilayer printed circuit Board, all happy. Occasionally there are surprises (for example, once ran into a mirror your cost), but the manufacturer without talking fixes all of their schools, it is the norm for Chinese factories.
At the time of fabrication of the party of the multilayer (four and more layers, the double layer all make for less than a week) plat usually takes from 10 days to three weeks. Oddly enough, the experience, the timing is inversely proportional to the size of the factory. Ie large make faster, smaller is slower.
Sometimes boards have specific requirements, the specific value of the wave resistance, the thickness of the conductors, or is there a blind microvias by laser. Then you need to clarify whether this factory to do? Now here is one of the projects factory, we must provide a test report of the boards on the impedance of the particular tracks. Not all of it will go, so that when the specific requirements of the search executor may be delayed.
The most problematic part. In fact, if the Chinese do you charge "turnkey", i.e. by a complex that at this stage he will get you the most money for their work (sometimes up to 50-100% of the cost of the parts), and it's not just. To purchase several hundred items — the work itself is quite difficult, but here are two special factors intervene: the availability and quality of components.
Not all (even relatively common) components can be "in the flow" from suppliers. And if this is some kind of rarity you got. For development or prototyping of our (Russian) engineers select the components that you can buy at Home, and they don't really bother with the price and mass, and much more — the quality and reputation of the manufacturer. It turns out that the memory of the prototypes used Toshiba processors — TI, and connectors — Samtec. In our experience, most problems arise, ironically, it is with connectors. In one project for the production of 1000 units needed to purchase the 6000 is quite specific connectors. And it was Oh so easy! No, of course there is always the option to "order at the factory and wait for two months", but for some reason few people are satisfied with it. So you have to buy the parts from various suppliers, to look at the markets etc. are Often still at the stage of negotiation Boma we offer something to change — sometimes the counterparts, and are cheaper and much more affordable. If you are doing all the production "turn-key" Chinese problem with the availability of components is somewhat complicated by the fact that factories usually work with a limited number of "trusted" suppliers. Around the market to you, they will not seek, and I want to inform you about the delay and will quietly wait for the right parts will have permanent partners.
As for quality components, then it is necessary to be extremely attentive. A lot of fakes, remarked chips, and just married. In most cases, problems arise when purchasing a retail party (from units to several tens of the same title), but just recently, for example, faced with a case when the sealed reel (5000 PCs) 47 UF capacitors on the real capacity was 37 UF. This was the case with the completely unworkable party (2500 PCs) chip microcontrollers. Came to the factory representatives of the supplier, poudivlyalis you brought another coil — same thing! He apologized, returned the money. The chips had to be purchased elsewhere. And if all of them (2500 PCs!) already smontirovat?!
At once I will tell — in any case, do not subscribe to the "solder wave"! Yes, now it is a rarity, but you never know. Let better hands solder — and even cheaper.
If you're ever in Shenzhen for some Assembly factory of electronics, you definitely will boast of their "production" — a long room with tables in several rows, at which sat hundreds of former peasants with a soldering iron.
It is "our" factory, where we did the Board for Virt2Real.
Horror. Any hand soldering is a risk, and significant. Equally possible as underheating and overheating. Due to the fact that everyone is trying to meet the requirements of RoHS, is almost always solder high temperature lead-free solders. I.e. temperature soldering iron 400 degrees. Power sufficient to awkward movement to kill some delicate detail such as quartz (Oh how the Chinese love to solder the quartz! just some kind of mania).
On the left you can see a pretty good drop lead-free (!) solder, which metal body (!!) quartz (!!!) was prisobachit to the Board. Half of quartz in circulation went in the trash. It's not that we did so when something for us did... Until we moved to self-service.
Well, the highest quality (but most expensive in this case) method is, of course, surface mount machines. Here marriage is not seen.
Each customer we ask you to provide the methods and requirements for testing products. We are very committed to marriage as much as possible (the Chinese are all undone, if that, but to carry the products across the border back and forth-no fun). Completely avoid marriage rarely works, but if the customer ordered 100% (and not selective) and given the normal methods (and not "apply voltage and verify the led is lit"), the vast majority of cases, marriage — less than one percent, and they are all connected with defective components. Agree, out of 1000 memory chips a couple may be married...
Service "independent audit" of production in China is very well developed. So do not neglect this opportunity, in order to avoid unpleasant surprises on our side of the border.
Today shipped another batch of boards in the Chinese factory-the collector of our partner. 3000 sets, 9000 boards. Marriage — 12 units (replaced already). In total this is the fourth delivery on this factory, i.e. 36000 boards we have produced for this project. Life abounds.
Article based on information from habrahabr.ru
So, we need to go through four stages:
1. To make the PCB.
2. To purchase components (so-called BOM — bill of materials).
3. To mount components on the circuit Board (soldering).
4. To check the efficiency and quality of products.
What you need to pay attention to each stage?
1. PCB fabrication
Here usually we are waiting for a relative minimum of surprises. The developer (namely a developer! and it is possible when converting from a file, for example .pcb to get a few unpleasant surprises) preparing a gerbera (files in Gerber format), factory makes a multilayer printed circuit Board, all happy. Occasionally there are surprises (for example, once ran into a mirror your cost), but the manufacturer without talking fixes all of their schools, it is the norm for Chinese factories.
At the time of fabrication of the party of the multilayer (four and more layers, the double layer all make for less than a week) plat usually takes from 10 days to three weeks. Oddly enough, the experience, the timing is inversely proportional to the size of the factory. Ie large make faster, smaller is slower.
Sometimes boards have specific requirements, the specific value of the wave resistance, the thickness of the conductors, or is there a blind microvias by laser. Then you need to clarify whether this factory to do? Now here is one of the projects factory, we must provide a test report of the boards on the impedance of the particular tracks. Not all of it will go, so that when the specific requirements of the search executor may be delayed.
2. Purchase BOM
The most problematic part. In fact, if the Chinese do you charge "turnkey", i.e. by a complex that at this stage he will get you the most money for their work (sometimes up to 50-100% of the cost of the parts), and it's not just. To purchase several hundred items — the work itself is quite difficult, but here are two special factors intervene: the availability and quality of components.
Not all (even relatively common) components can be "in the flow" from suppliers. And if this is some kind of rarity you got. For development or prototyping of our (Russian) engineers select the components that you can buy at Home, and they don't really bother with the price and mass, and much more — the quality and reputation of the manufacturer. It turns out that the memory of the prototypes used Toshiba processors — TI, and connectors — Samtec. In our experience, most problems arise, ironically, it is with connectors. In one project for the production of 1000 units needed to purchase the 6000 is quite specific connectors. And it was Oh so easy! No, of course there is always the option to "order at the factory and wait for two months", but for some reason few people are satisfied with it. So you have to buy the parts from various suppliers, to look at the markets etc. are Often still at the stage of negotiation Boma we offer something to change — sometimes the counterparts, and are cheaper and much more affordable. If you are doing all the production "turn-key" Chinese problem with the availability of components is somewhat complicated by the fact that factories usually work with a limited number of "trusted" suppliers. Around the market to you, they will not seek, and I want to inform you about the delay and will quietly wait for the right parts will have permanent partners.
As for quality components, then it is necessary to be extremely attentive. A lot of fakes, remarked chips, and just married. In most cases, problems arise when purchasing a retail party (from units to several tens of the same title), but just recently, for example, faced with a case when the sealed reel (5000 PCs) 47 UF capacitors on the real capacity was 37 UF. This was the case with the completely unworkable party (2500 PCs) chip microcontrollers. Came to the factory representatives of the supplier, poudivlyalis you brought another coil — same thing! He apologized, returned the money. The chips had to be purchased elsewhere. And if all of them (2500 PCs!) already smontirovat?!
3. Installation
At once I will tell — in any case, do not subscribe to the "solder wave"! Yes, now it is a rarity, but you never know. Let better hands solder — and even cheaper.
If you're ever in Shenzhen for some Assembly factory of electronics, you definitely will boast of their "production" — a long room with tables in several rows, at which sat hundreds of former peasants with a soldering iron.
It is "our" factory, where we did the Board for Virt2Real.
Horror. Any hand soldering is a risk, and significant. Equally possible as underheating and overheating. Due to the fact that everyone is trying to meet the requirements of RoHS, is almost always solder high temperature lead-free solders. I.e. temperature soldering iron 400 degrees. Power sufficient to awkward movement to kill some delicate detail such as quartz (Oh how the Chinese love to solder the quartz! just some kind of mania).
On the left you can see a pretty good drop lead-free (!) solder, which metal body (!!) quartz (!!!) was prisobachit to the Board. Half of quartz in circulation went in the trash. It's not that we did so when something for us did... Until we moved to self-service.
Well, the highest quality (but most expensive in this case) method is, of course, surface mount machines. Here marriage is not seen.
4. Quality control
Each customer we ask you to provide the methods and requirements for testing products. We are very committed to marriage as much as possible (the Chinese are all undone, if that, but to carry the products across the border back and forth-no fun). Completely avoid marriage rarely works, but if the customer ordered 100% (and not selective) and given the normal methods (and not "apply voltage and verify the led is lit"), the vast majority of cases, marriage — less than one percent, and they are all connected with defective components. Agree, out of 1000 memory chips a couple may be married...
Service "independent audit" of production in China is very well developed. So do not neglect this opportunity, in order to avoid unpleasant surprises on our side of the border.
Today shipped another batch of boards in the Chinese factory-the collector of our partner. 3000 sets, 9000 boards. Marriage — 12 units (replaced already). In total this is the fourth delivery on this factory, i.e. 36000 boards we have produced for this project. Life abounds.
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