Your Premier Prototype PCB Assembly Supplier
Venture is more than just a leading PCB Fabrication manufacturer, but also a one-stop shop for all your printed circuit board Assembly requirements, we provide PCB design & layout, PCB prototype, and Assembly services and turnkey services all under one roof.
Venture PCB Assembly division has a workshop with 1800 square meters and 150 employees include 4 SMT lines and one prototype assembly team.
We handle all types of PCB assembly projects with any quantity especially small batch assembly, low volume PCB assembly and prototype PCB assembly, from basic through-hole PCB assembly technology to standard surface mount assembly, mixed assembly, kit assembly to ultra-fine pitch BGA assembly.
Our PCB types for prototype PCB assembly include: rigid PCB, Metal Core PCB, flex PCB and rigid-flex PCB..etc.
If you are looking for a high-quality Prototype PCB assembly manufacturer and partner? You’ve come to the right place — Prototype PCB Assembly is our specialty.
We provide high-quality prototype PCB assembly services to engineers and companies all around the world, from component sourcing, PCB manufacturing, prototype PCB assembly to testing all under one roof, using our highly flexible assembly process with a reasonable price.
We at Venture handle prototype PCB assembly quantities from 1 to 25 boards, our engineering team is able to work closely with you at your design stage to optimize the array design and also run DFM review before you start prototype PCB assembly process with us, we will review Engineering questions( EQ ) and component issues with you before the prototype PCB assembly job is started, this way can help you save your time and cost. Our prototype PCB assembly station is set up to meet the flexible mixing of automated and manual part loading stations, and we can also handle the fine pitch and BGAs assembly for your prototype PCB assembly jobs.
Your Leading Prototype PCB Assembly Supplier in China
We can work with BGA of 0.25mm pitch with X-ray testing, Passive Components minimum 01005 (0602) package, Fine Pitch Components minimum 0.38mm pitch.
Our Test types include visual inspection, X-ray inspection, AOI testing, In-Circuit test and functional test (customer provide functional test instructions). For prototype PCB assembly services, our fastest delivery time goes from 8 hours to 48 hours when components are ready.
- You can provide all the electronic components by ordering on Digikey ( or Mouser,Arrow..etc) and ship to us, our PCB manufacturing can start as soon as your parts procurement is processed, and we will ship you the assemble boards; (20% our customers’ choice)
- You can also provide partial components ( for example: certain components hard-to-buy or we are not able to get in a short time or important ICs) and we purchase the reminder components and run the prototype pcb assembly for your boards. (20% of our customers’ choice)
- We can also provide you turn-key prototype PCB assembly services, by we make the bare printed circuit boards and purchase all the components, and run the assembly. (60% of our customers’ choice)
Our purchasing team will deal with as many distributors as is needed to fulfill the procurement task in the best possible way! We will optimize the choice of packaging (cut tape, tube, bulk, etc.) vs quantity in smaller BOMs to lower total cost for your prototype PCB assembly project. To get a prototype PCB assembly quote, pls send the following files to firstname.lastname@example.org
- Your BOM
- Your Gerber files
- Your required prototype PCB assembly quantities
No matter you are an electrical engineer, a product designer, a system integrator or a maker looking for flex PCB assembly, Venture will be your perfect China PCB prototype assembly house in China.
Through our 2 hours rapid response services from our 24/7 sales and tech support team, and excellent after-sales service, we will be your best prototype PCB manufacturing and assembly partner in China.
At Venture we can help you reduce vendor count, production delays, and improve overall circuit quality with prototype PCB assembly, pls feel free to contact us anytime for your prototype PCB assembly projects.
Prototype PCB Assembly: The Ultimate Guide
PCB prototype assembly offers the perfect opportunity to manufacture quality PCBs.
Prototype assembly enables you to identify errors before actual manufacturing which cuts manufacturing costs.
That is why you need to learn more about prototyping assembly of PCBs.
It is for this reason that this guide takes a look into every aspect of PCB prototype assembly in a basic manner.
At the end of the guide, you are better equipped and ready to start your PCB prototype assembly before actual production begins.
Have a look.
Prototype PCB Assembly
What is Prototype PBC Assembly?
When we talk of prototype PCB assembly, we mean the process of assembling the initial sample of a PCB. This happens first before the mass production of the PCBs.
This process is crucial as it assists in determining the designs and specifications of the PCBs.
It is also through this process that you get to identify any flaws on the prototype PCB and rectify them before mass production.
Prototype PCB assembly involves fabricating a PCB. Then, testing it to see if it can function in a given application.
It also entails rectifying any flaws in the system and coming up with a PCB prototype to be used in mass production.
In simple terms, that’s what prototype PCB assembly involves. However, you need to know more which is what we are going to discuss in the following chapters.
Prototype PCB Assembly Basics
Before we proceed, it will be good if we start by identifying the basic points about prototype PCB assembly.
The knowledge will help in further discussing in details the Prototype PCB.
Benefits of the Prototype PCB Assembly
Several advantages come with a prototype PCB assembly. These advantages go a long way in facilitating the manufacturing of your PCBs.
Among these advantages include:
1.Early flaw detection
Prototype PCB allows you to detect any flaw in the development stages of a product.
This enables you to rectify the defects thus saving you the resources if the product had gone into full production with the flaws.
Making these changes later in the production stages may require more technicalities which can be costly.
2.Individual testing of the components
A prototype enables you to individually test the elements of a system before setting it up. This is crucial for complex projects that have several PCB based parts.
By validating each component individually helps in identifying areas where there are issues that you have to solve. Thus, the project can function correctly.
3.Reduced overall costs
The use of prototype PCB in your projects helps in reducing the total cost of your project.
Prototyping enables you to identify errors available in the project and rectify them before actual production takes place.
Once you have rectified possible flaws, you can go ahead and manufacture your PCB in large scale thus saving you cost.
The purpose of prototyping PCB is to test if the project will work effectively. Testing involves identifying errors available and rectifying them.
Thus, the final PCB thus after prototyping will be quality PCBs which meet international standards.
5.Reduced turnaround time
Prototype PCB assembly reduces the turnaround time for the actual production of your PCBs. While using prototype PCBs, you can highlight the flaws which you correct before actual production.
Hence, the final prototype is defect free which implies that your manufacturer will produce your PCBs quickly.
Limitations of Prototype PCB Assembly
there are various limitations that you will experience when it comes to prototype PCB assembly. Such limitations include;
Printed circuit board prototyping
Prototype PCB assembly will cost you when it comes to the cost of the materials and the labor for fabricating the prototype.
Such cost, may have an impact on the final project especially if you did not have a budget for it.
Remember, after prototyping, you will need to start from scratch again to fabricate your PCB. This will involve purchasing other materials which push the cost upwards.
You will have to fabricate a prototype, test it and identify the errors it has which helps in the production of your PCB.
All this consumes time which may affect the actual production schedule.
You, therefore, need to factor in this time to keep up with the schedule especially if it is an urgent order.
Prototype PCB Assembly Technical Specifications
Before you begin your prototype PCB assembly, you will have to meet precise specifications. These specifications will ensure your prototype PCB works effectively.
So, what are these specifications?
PCB design and layout
Among the information, you need to check here include the copper weight both on the inner and outer layer of your prototype.
Also, you need to check on the tolerance of the copper thickness.
Generally, the copper weight on the inner layer can be between 0.5 and 1.0 ounce. That of the outer layer can be between 1.0 and 2.0 ounce.
Tolerance of the copper thickness can be between 0 to 20 micrometers.
·Plating and finishing of the prototype
There are different finishes that your prototype PCB can have. Each one comes with its share of advantages and disadvantages.
However, the common types of finishes include; HASL, immersion tin, immersion copper and OSP. There is also, ENIG and Gold finishes.
We will discuss these types of finishes later on in this guide.
When selecting a solder mask for your prototype PCB, you need to ensure that it the right one for prototype use.
The solder masks offer protection against short-circuiting of the solder bridges.
Here, you are at liberty to select your preferred color.
·Prototype PCB minimum spacing
This is an essential aspect of your prototype PCB. Minimum spacing refers to the distance between each trace in the prototype PCB.
It can also be the measurement of the width of the traces on the PCB.
However, minimum spacing depends on such factors like the size of the board and the copper weight and thickness.
·Vias type and hole size
The hole size is crucial in determining the size and the type of vias that you will use. There are three types of vias available for use.
They are through-hole vias, blind vias and buried vias. You need to ensure that the holes are of standard sizes at each point of the PCB prototype.
·PCB prototype dimension
To minimize your overall cost of production, you need to ensure that you have utilized each available space.
Also, your PCB needs to have a regular shape since irregular shapes lead to wastage of space.
·Number of layers
You prototype PCB can have some layers depending on the final application. For instance, a prototype PCB can have between 1-8 layers.
That is to say; you can have a prototype PCB with a minimum of one layer and a maximum of eight layers.
·Prototype quality grade
To ensure the safety of the user, you need to work with a prototype quality grade that meets the ISO standards. The quality of most prototypes is usually the standard IPC 1.
There are variations in the quality depending on the application that you can select.
However, these variations need to meet the standards set by the relevant authorities and the ISO standards.
·Type of material
The kind of material you select matters a lot. The material should be able to hold the pressure that the prototype will experience.
·Quantity of prototypes
Your application can have as many prototypes as possible depending on your final product.
For instance, for complex projects, you can have multiple prototype PCBs each functioning separately but as a unit.
However, for simple products, you can have a minimum of one prototype.
·Prototype PCB thickness
The thickness of your prototype depends on the complexity of your project. Complex projects will require a thicker board to tolerate such factors as high temperature.
It is important to note however that thickness of between 0.4 and 2.0mm affect the tolerance of the prototype.
How to Get Quotes for Prototype PCB Assembly
The success of your prototype PCB assembly narrows down to the cost the design of your prototype PCB determines the cost of assembling it.
For you to know the cost, you have to submit the design to your manufacturer who will then hand you a quote.
If you want to get a favorable quote, check on these factors.
Rigid PCB design
·Size of the prototype PCB
Your prototype PCB needs to be of standard size to work well in various applications.
By selecting a larger prototype PCB, you increase the cost, therefore, getting a higher quotation.
·Prototype PCB layers
The complexity of our PCB increases the quotation cost. For instance, most complex projects have 42 layers while standard project consists of 10 layers.
Lowering quotation involves lowering the number of layers of your project.
Even though the number of layers has an impact on the overall thickness of your board, actual thickness is the measure of copper in ounces.
The thicker the board, the higher the quotation due to the copper in use.
Most projects utilize copper of between 1 to 2 ounces.
1)Why are prototype PCB assembly quotes important?
The following are the reasons as to why quotes are essential when it comes to prototype PCB assembly.
A quote is an essential aspect of your prototype PCB assembly since it will dictate the amount you are to spend on the project.
By obtaining a quote, you can determine the cost that you will spend in your prototypes and the actual PCBs.
Quotes are important in determining the quantity of prototype PCBs that you are going to assemble.
If the cost is high, you need to reduce the number of your prototypes.
One of the factors that affect your quote is the design of your prototype PCB. A complex prototype will have a higher quote than a simple prototype.
Complexity can be in terms of the layers or even the size of the prototype. Where possible, try to minimize the complexity of your project to obtain a favorable quote.
2)Fundamental aspects of prototype PCB assembly quotation
When it comes to getting quotes, there are very vital elements that you need to pay attention to. Some of these elements will dictate the cost of your quote.
This section takes a look at the main aspects of your prototype PCB assembly that you need to pay attention during quotation.
BOM list refers to the Bill of Materials. Basically, it relates to the list of all the parts that you require to manufacture a given prototype PCB.
Your prototype PCB design software is the one responsible for generating the BOM list.
The CAD system needs to have part information to produce the BOM list to achieve this.
Normally, CAD system store the part information in the CAD library section.
The elements available inside the BOM list includes the following:
Every part of the PCB needs a unique identification that acts as a comment in the BOM. In general. The company number designate usually serve as a comment.
However, this is not a must. An example of a comment can be “28-0467-02”.
This is a definition of the part. If the comment is 28-0467-02”, then the description is “CAP 10uF 20% 6.3V”.
Every part on the PCB has its unique reference designator. For instance, in a 10uF capacitor, the designator can be C27.
Footprint refers to the physical CAD footprint that a part uses. For example, C27 can use a CAD footprint CAP-1206.
The value of the comment element is on one that organizes the BOM. You can include the other core elements that associate with it.
Depending on the requirements of your prototype PCBs, you can include additional information on the elements. Such information consists of the tolerance and its values and any information that defines the part.
The only disadvantage that you will have here is you may end up having a long BOM list.
Using BOM list on your prototype PCB assembly has several advantages. Such as:
- Format changing of the COM. BOM list allows you to change the outlook of your BOM by altering the organization of the elements. For instance, you can group the BOM using comment information with the use of footprint information being the alternative.
- The inclusion of unfitting components. BOM gives you the option of including elements that you may consider unfit.
- Different BOM variant generation. You are at liberty to generate different BOMs for use in your prototype PCB assembly.
b) Gerber files
Gerber files refer to an open image file format that comes in a 2D binary vector. This is the standard file that manufacturers use in the fabrication of prototype PCBs ad the actual PCBs.
Generating garber files
Manufacturers use it to describe the prototype PCB images including the solder masks legend and the copper layers.
There are three Gerber formats available for the fabrication of your prototype PCBs, that is standard Gerber who is the oldest type of Gerber
Remember, there is also Extended Gerber also known as RS-274X and the Gerber X2 which is the latest type of Gerber.
For use to use a Gerber file, you need a Gerber file viewer which is basically a software that allows you to view the Gerber file.
While selecting a Gerber file viewer, you need to consider the following features:
- Updated support file format. A quality Gerber file viewer needs to be able to support popular latest file types. Such includes HPGL/HPGL-2 and Excellon.
- Support precision viewing. A good Gerber file viewer needs to have features such as precision measurement and zooming ability. This allows you to check through the components to rectify any visible error.
- Broad printer compatibility. A good Gerber file should be compatible with various printers. It should also allow for different printing options.
Gerber file viewers that are in common use include online Gerber viewer, EasyEDA Gerber viewer and Numerical Innovation Gerber viewer.
While using a Gerber file, you will notice most of them associates with file extensions. There are different types of file extensions such as, .GBR, .ToP, .GBX and.BOT.
Four elements are critical to a Gerber file, especially in an ASCII.
They are configuration parameters, Aperture definition, XY coordinate locations in flash and draw commands and Flash and draw command codes.
There are two considerations that you need to consider when designing and transferring a Gerber file to a prototype PCB. That is the legacy ad Design for Manufacture (DFM) issues.
You will experience several advantages and disadvantages while using Gerber file for your prototype PCB assembly. Among the benefits include:
- Gerber file is the most comfortable file format to use in the fabrication of your prototype PCBs.
- It is one of the popular file formats when it comes to manufacturing of prototype PCBs and actual PCBs.
- You can quickly view a Gerber file using a free viewing software.
Its disadvantages include:
You will need to have multiple files which depend on the format
Also, you have to examine all the files before fabrication.
Prototype PCB Assembly Capabilities
Prototype PCB assembly capabilities are available in different forms. Each of these forms has its advantages and disadvantages that you need to analyze before selecting one.
Prototype PCB Assembly
To assist you in selecting the perfect form for your prototype PCB assembly, lets’ look at each of these forms.
·Through Hole Prototype PCB Assembly
A through- hole prototype PCB refers to a PCB which has a metallic lead or wire mounted to the PCB by placing them through-plated holes. After setting the wire or metallic lead, soldering takes place.
Here, the quality of the solder joints plays a crucial purpose since they are the actual connection point between the board and the component.
Preparing the through-hole prototype PCB involves several steps.
First is the preparation of the pad and the holes where soldering will take place. Remember to place lead through the hole in a way that it bends above the soldering area which will reduce the heat and solder needs.
Next, the step involves applying heat evenly to the pad, hole, and the lead. The purpose here is to aid the solder to adhere to both surfaces.
The third step is the solder contacting the iron end causing the solder to turn into liquid hence flowing through the hole. Once the solder flows, it forms a mound on both sides of the board.
Now, since the lead soldering took place on the topside, you need to check the bottom side if it has enough solder.
Adequate solder clearance non the inner side of the hole allows the solder to flow evenly through the board.
There are two ways that through-hole prototype assembly can happen. That is an automated through-hole assembly and manual through-hole assembly.
PCB Through hole assembly
The automated through-hole prototype assembly utilizes machines throughout the entire production period. On the other hand, manual through hole assembly employs humans throughout the production process.
Through- hole assembly prototype assembly has two main mounting components. That is the Axial and radial leads.
The axial lead component involves placing the leads on both ends of the elements. On the other hand, radial lead components involve putting the leads on one end of the component.
There are several advantages that you have by using through-hole in your prototype PCB assembly.
- Reliability – You can rely on the connections of through-hole prototype assembly due to it having a strong connection between the PCB and the board.
- Easy to use – Since you can easily replace the components in a through-hole assembly, it facilitates the ease through which you can test the prototype.
- High heat adaptability – The solders in a through hole assembly allows for a strong bond between the components and the board. This allows the prototype to have a high heat tolerance which means you can test in high heat applications
However, there are some disadvantages that you will experience when using through-hole for your prototype PCB assembly.
- Space – When you compare to surface mounting. Through-hole requires a lot of space for proper soldering of the components. This can be a challenge especially if the size of application or your PCB is small.
- Through- hole packaging consumes a lot of time – In most cases, you will have to place all the components manually on the board before soldering. This consumes a lot of time which can have an impact on the overall production schedule.
- Cost – The overall price of prototype PCB assembly, in this case, is higher. This is as a result of the drilling of the holes and the subsequent soldering.
- Speed – The operation speed of the prototype PCBs assembled under such will have a lower speed. This is due to the feeding all the leads through the board which allows for one-sided use.
·Surface Mount Prototype PCB Assembly
Surface mount prototype PCB assembly is a mounting that does not involve drilling of holes on the board.
Instead, the components have surface mount packages (SMD) that consist of leads around or below them.
The leads are the ones that make a connection with the pads present on the PCB. What happens is that you will place a stencil solder paste on the empty pads.
Then a pick and place machine place the components onto the pads that have the solder paste. After setting the elements on the pad, you will set them on a reflow oven for soldering to take place on the PCB.
You will find different SMD packages in the market depending on the shape and the material. However, there are three categories of packages.
They include; Rectangular passive components category which includes standard and capacitors and resistors.
You also have Small Outline Transistor (SOT) and Small Outline Diode (SOD) which are for diodes and transistors.
Surface mount PCB assembly
Lastly, you have the category that is for Integrated Circuits (ICs) such as transceivers and microcontroller.
Surface mount prototype has its shares of advantages and disadvantages. Its main benefits include:
- Increased board density – The fact that the SMD components are smaller in size implies that you can increase the overall density of the board. This is in contrast with the through-hole prototype PCB assembly.
- Utilization of space – Surface mounting allows for maximum utilization of space. This is possible since you can place the SMD components on both sides of the board.
- Cost – Perhaps the best advantage you have with surface mounting prototype PCB assembly is when it comes to the cost. Remember, you don’t have to worry yourself about the drilling of holes.
- This, in the long run, cuts the overall production cost of your prototype PCBs.
- Time-saving – The use of a Pick and Place machine reduces the production time for your prototype PCBs. Also, the effect of this is that you have a guarantee of timely delivery of your prototype PCBs.
of this is that you have a guarantee of timely delivery of your prototype PCBs.
Among the limitations of surface mounting when it comes to prototype PCB assembly include:
Power applications. There is a limitation to the amount of power that you can apply to these prototype PCBs. This is due to the SMD not being adaptable to high power- applications.
If you are considering prototype PCB assembly for small circuits, then surface mounting is not the ideal option for you. This is due to incompatibility.
·Mixed Prototype PCB Assembly
Mixed prototype PCB assembly refers to a kind of technology that combines both Surface mounting and through-hole mounting.
It entails using technology to collaborate the surface mount and through-hole since they will be on the same board.
Coming up with a unique arrangement sequence for the board is mandatory since it will dictate the areas to drill holes and which not to.
Mixed prototype PCB assembly
Mixed prototype PCB assembly comes in different forms.
·Single side mixed prototype PCB assembly
In this form, the assembly process involves the following procedure. First is the solder paste printing, then SMD parts placement after which you allow reflow soldering.
Then you do through hole component placement, and lastly, you do wave soldering.
In place of wave soldering, you can apply hand soldering if you have small through-hole quantities.
·One side SMT and one side Through-hole technology
In this form, the assembling procedure involves the following.
First is the surface mount adhesive followed by SMD parts placement then solidification.
After that, you are flipping the board follows then through-hole component placement after which you do wave soldering.
However, this is not an ideal form to use since the adhesive burdens the overall cost of the prototype PCB. It may have issues on soldering.
·Double side mixed prototype PCB assembly
There are two options when it comes to this form. That is, prototype PCB with adhesive and prototype PCB without adhesive.
Adhesive increases the cost of the prototype PCB assembly. The procedure under this form if it has adhesive involves the following steps.
First is solder paste printing then SMD parts placement followed by reflow soldering.
After that, you flip the board, apply SMT adhesive followed by SMD parts placement then solidification.
After solidification, you flip the board, then through-hole component placement takes place followed by wave soldering.
In case it does not have the adhesive, the process will involve the following steps. Solder paste printing followed by SMD parts placement then reflows soldering then flipping of the PCB.
After flipping, solder paste printing takes place then SMD parts placement followed by reflow soldering.
Reflow soldering takes place after that followed by through-hole component placement and lastly wave soldering.
Remember, you can use hand soldering depending on the quantity of soldering.
·BGA Prototype PCB Assembly
Ball Grid Array (BGA) prototype PCB assembly is a kind of surface-mount packaging. High density and a relatively lower packaging cost characterize BGA packaging.
Unlike surface mounting, BGA utilizes underside connection which offers ample space for connection. The spacious area increases the density of the PCB leading to higher electric performance.
By using BGA, you will experience the following advantages.
- Maximum utilization of space – BGA allows for maximum utilization of the available board space. This is because you will be using smaller footprints and fewer components’ participation.
- Increase in electrical and thermal performance – The small size of BGA allows for easy dissipation of heat mounting silicon water at the top provides for the transmission of heat down to the ball grids.
- Also, the fact that there are no pins in BGA means that the board cannot bend or break. This makes it stable allowing for higher electrical performance.
- Fewer damage leads – BGA leads consists of solid solder balls which cannot be damaged easily during the assembling process.
- Lower cost – Generally, if you compare BGA with other types of packaging, you will notice it is relatively cheaper.
- Starting with fewer materials during manufacturing to higher electrical performance, BGA is a more affordable option for your prototype PCB assembly.
BGA PCB Assembly
While testing under this packaging method, it is ideal to use X-ray inspection. X-ray inspection allows you to inspect the hidden features of the board.
·Turnkey Prototype PCB Assembly
This is a relatively new method of packaging your prototype PCB that is different from the other ways.
Here, technology and onshore manufacturing do your prototype PCB assembly for you.
In fact, turnkey PCB assembly is becoming more popular.
Turnkey PCB assembly
What happens is that you have a cloud-based software and onshore manufacturing who handle your orders.
The manufacturer will handle every aspect of your prototype assembly from procuring the materials to testing of the prototypes.
They are also responsible for the manufacturing of the final FCBs. All you have to do is to provide the prototype design and manufacturing starts.
There are several advantages that you get by choosing turnkey for assembling your prototype PCBs. They include:
- Prototyping – Turnkey facilitates the manufacturing of your prototype PCBs. You can have your prototypes relatively fast and at a cheaper cost.
- This is particularly important if you have an urgent order.
- Single point of contact – Since you are dealing with one manufacturer for the fabrication of your prototypes, you can easily reach out for changes. An effective turnkey provider implies that you will be able to get the right prototypes.
- Instant quotes – The best thing about using turnkey for assembling your prototypes is that you get instant quotes.
- Once you submit your design, you will get an instant quote.
- This is important especially if you are working on a budget since it will help you either to change the design or source for capital.
Prototype PCB Assembly Surface Finish Types
You can describe the surface finish as a coat that you apply around the outside layer of the prototype PCB.
The coating dissolves on the solder mask forming a connection between the primary electrical connection and the prototype PCB.
PCB surface finishes
Different types of surface finishes are available for your prototype PCB assembly.
Before selecting a surface finish for your prototype PCB, you need to consider several factors such as:
- Chemical resistance
- Finish availability
- The shelf life of the finish
- Contact with other finishes
- Wear resistance
- Wire bonding
Surface finish has an influence influences your prototype PCB in several ways.
For instance, how it works, the field failure rate, the process yield, the amount of rework and the scarp rate.
Also, the kind of surface finish you select will influence the overall cost of the prototype PCB.
With that in mind, here is a look at the types of surface finishes in detail.
·Hot Air leveling (HASL)
This is the most common surface finish that you can find. There are two types of HASL available for your prototype PCB, that is, spray tin with lead and spray tin with lead- free.
Its advantages include long storage time, cheaper, ideal for lead-free soldering. On the other hand, its limitations include not suitable for binding due to roughness on the surface.
The copper is also prone to dissolving the board subjected to high temperature.
Immersion tin is a kind of surface finish that is prone to copper and tin. Its application involves positing metallic finish as a result of a chemical displacement reaction.
You apply this reaction directly over the base of the metal of the PCB which is often copper. The tin will protect the copper against oxidation.
Also, the advantage here includes the provision of a flat surface and the surface finish allowing for reworkability. It is also ideal for fit pin insertion.
Its limitations include it easily causes handling damage, difficulty in measuring the thickness and it is not ideal for multiple assembly processes. You will also find it had to electoral test the prototype with this kind of surface finish.
·Organic Solderability Preservative (OSP)
OSP is a water-based surface finish that is organic which is common in copper pads.
It works by applying a thin protective layer over the copper that is exposed using the conveyorized process.
The layer bonds with the copper to form an organometallic layer which offers protection to the copper. The OSP has several advantages compared to other types of surface finishes.
They include; its ability to provide a flat surface, it is cost-effective, it a straightforward process and also it allows for re-workability.
However, it has its limitations such as it not being ideal for thickness measuring, it has a short life, and it is not suitable for plated through holes. OSP is sensitive to handling.
·Electroless Nickel Immersion Gold (ENIG)
ENIG is a widely used surface finish for prototype PCBs. It constitutes a double layer of a metallic coat having nickel as a barrier to both the copper and the surface of the PCB.
A layer of gold offers protection to the nickel during storage. On the other hand, the nickel protects the base of the metal board.
Its advantages include the ability to offer a flat surface, it having a longer shelf life and it is ideal for plated through holes.
However, its limitations include it being expensive, it not allowing for reworkability and it is costly.
Immersion silver is a fast and straightforward surface finish that you can have of your prototype PCB.
Again, immersion silver allows you to apply directly to the base of the PCB metal using a chemical replacement method.
This makes the copper and the silver to diffuse each other. Its advantages include; it is a simple process; it offers a flat surface as well as it being a cheap process.
Among its disadvantages include; it requires high storage conditions due to ease of pollution, and it is hard to test the prototype electrically.
Also, it is prone to electromigration phenomena.
Quality Test in Prototype PCB Assembly
The most important aspect after manufacturing your prototype PCB is to test it. This can be a challenge especially if you don’t have the know-how.
However, you don’t have since I am going to take you through the testing process of your prototype PCB.
PCB Quality Testing
Before we start, here are some of the advantages that quality testing your prototype PCB assembly offers;
- Quality testing stimulates the environment in which the prototype operates in.
- In some cases, quality testing eliminates other tests that your prototype PCB needs to undergo.
- It checks on the functionality of your prototype PCB. In the long run; this reduces the operating time of your prototype PCB.
- Through quality testing, you can identify flaws and rectify them in readiness for the actual manufacturing.
With that in mind, there are several quality tests that your prototype PCB can undergo. Each of this test aims at determining a specific aspect of the quality of the prototype PCB.
Generally, there are three areas that your quality test can focus on.
- Fabrication – The main focus here is to ensure adherence to the specification for the design in terms of the drill hole size.
- Computer alignment – Here, the tests are carried out to compare the prototype with your BOM for accuracy – Also, you can have tests for components tolerance and solderability.
- Assembly – The tests here determine if all the components of your prototype PCB are in the right place. This ensures that the prototype PCB functions accordingly.
So, what are the tests that your prototype PCB cab undergo?
We can broadly categorize these tests into four groups. That is assembly test, in-circuit test, bare-board test, and functional test.
Assembly test refers to an analysis carried on prototype PCBs to check on their circuit functionality once you complete the assembly process.
The tests can either be Manual Visual Inspection (MVI) or carried out using Automated Test Equipment (ATE).
Various equipment that falls under ATE such as Automated Optical Inspection (AOI) and Automated X-ray Inspection (AXI).
The AOI test is usually carried out to examine the quality of the solders and verify the trace and pad connections.
2.In- Circuit Test (ICT)
ICT is a test on the prototype PCB that checks for availability of short circuits.
It also confirms the capacitance and resistance of the board and any component value that determines the proper assembly of the board.
You can perform an ICT using a bed of nail tester. This is a test tool that comprises many pins which are at every end of the instrument.
Bare-board test is carried out on a free board to ascertain that the definition of the circuit connection is proper on the circuit board.
For you to carry out this test, you will need a multimeter table, a netlist printout, and a highlighter pen.
The purpose of the multimeter table is to help you in carrying out a continuity test.
A functional test is usually the last test that you perform on the prototype PCB.
This test aims to confirm the presence of all components, if they are correctly assembled and if they are functioning accordingly.
Numerous tests fall under this. Each of the tests has a specific purpose as we can see below.
- Peel test – This is a test that analyzes the amount of strength of your prototype PCB that is needed to peel the laminate from the board.
- Solder pot test – The purpose of this test is to analyze the solderability of the Plated Through Hole (PTHS).
- Solder float test – This test aims to analyze the degree of thermal stress which a prototype PCB hole can tolerate.
- X-ray inspection – The purpose of this is to have a look at the internal elements of the prototype PCB. This includes checking the layers as well as the vias.
- X-ray inspection allows you to verify the authenticity of the prototype PCB as well as its type.
- Time Domain Reflectometry (TDR) – The test determines the impedance characteristics of your prototype PCB. You can also use this test t determine the matching of the differential traces which allows good signal integrity.
- The resistivity of Solvent Extract (ROSE) Testing – The purpose of this test is to ensure that your PCB lacks a significant amount of surface debris as a result of the manufacturing process.
Apart from these tests, there are other types of tests for your prototype PCBs depending on their models.
If you have a rigid prototype PCB, then you need to subject your prototype to QA test.
On the other hand, if you have flex prototype PCB, then bend test a mandatory test for your PCB.
How to Choose Prototype PCB Assembly Service Provide
Selecting a prototype PCB assembly service provider can be hectic. In as much as there are plenty of service providers. You need to provide who can offer the services you need.
So, how do you go about a prototype PCB assembly service provider?
It is quite simple.
Here are a few tips that can come in handy when you are selecting a prototype PCB assembly service provider.
Quality is the first tip that you need to consider when selecting a prototype PCB assembly service provider. The prototype PCB needs to be of high quality for it to function effectively.
Prototype PCB assembly should be:
- Free from errors. Remember, even a small drill hole different from the original design can be a disaster.
- PCB board should be free from defects, which may cause it to malfunction properly.
You should check the seriousness of the provider towards the client. You can also interrogate their customer care to check on their knowledge concerning your prototype services.
You can also check on the provider’s website on their quality standards. A reliable service provider will have information concerning the quality of their services on their sites.
Also, you should evaluate the customer reviews.
Good reviews are an indicator that the service provider offers quality prototypes.
·Minimum Order Quantity (MOQ)
Minimum Order Quantity refers to the minimum number of a prototype you can order.
You need to remember that prototype PCBs are subject to various modifications before the actual production of the PCBs. For this reason, you need a manufacturer who offers the bare MOQ for your prototype PCB assembly.
You can negotiate with different manufacturers to be able to reach a reasonable MOQ for your prototype PCBs.
This will be vital in reducing the overall cost of prototype PCBs as well as actual PCB production.
A significant tip to consider when selecting a prototype PCB assembly service provider. Different service providers offer varying cost for the prototype PCB assembly.
It is upon you to determine which service provider will fit your budget. However, you need to note that even though the costs are different, the services they offer are also various.
You need to check on the cost as well as the services they offer on the prototype PCB assembly to decide which manufacturer to pick.
Some of these services include quality and the turnaround time for your prototype PCBs. There is a possibility that a service provider may offer different packages depending on the services you require.
It is therefore vital that before you select a service provider based on the cost, you need to interrogate the services that bill up to the cost.
One of the easiest ways of selecting your prototype PCB assembly service provider is by checking on the turnaround time. Turnaround time refers to the time it takes a provider to manufacture your prototype from the moment you place an order.
Turnkey PCB assembly
The importance of this tip is because the manufacturing process of most prototypes is under tight schedules.
As such, you don’t have to put up with providers who cannot keep up with your plan.
Most established providers do keep up with the schedules they have as long as you give all the necessary specifications on time.
The average turnaround time for most of these providers is between 2 to 7 days.
This is from the time you place your order and submit all the specifications concerning your prototype PCB. Remember, once you submit the specs, your service provider will have to approve them before actual manufacturing takes place.
In a real sense, prototypes are not the actual PCBs. They are bound to change before the final manufacturing takes place.
This might involve changing the shape, components or even the entire design. As such, you need a service provider who can help in customizing your prototype PCBs.
Check if the available service providers have this option as it will facilitate your prototype PCB assembly needs.
If you are searching for a service provider abroad, you need to check if they do international delivery. Established providers offer this service even though some will pass the charges to you.
So, when searching, you can also inquire about the cost of delivery and who bears the cost.
This will help you in finding the best provider to deal with for your prototype PCB assembly.
·Instant quote facility
As we have seen earlier, quotes are essential when it comes to prototype PCB assembly. Most established serve provider offer instant quotes on their websites.
When selecting a service provider, be on the look for such providers.
The experience of a particular service provider especially in handling the kind of prototype assembly services you need will matter.
It is always advisable that you go for a provider who has longer experience in the industry.
This is particularly important when you are dealing with sophisticated projects like communication-based technology projects.
Also, if you are dealing with multilayer prototype PCBs, an experienced service provider is the best option.
Another aspect when you are searching for a service provider for your prototype PCB assembly is to check on the services they offer.
A service provider with multiple services is best equipped to handle your prototype PCB assembly requirements.
·Safe packaging and shipping
This is a crucial element that your service provider needs to offer. Remember, prototype PCBs are delicate products thus require special packaging and shipping.
As a requirement, you need to select a service provider who meets the international packaging and shipping standards.
The importance of this s that it will minimize damages to your prototype PCBs
You are now an expert in prototype PCB assembly. Go ahead and prototype a PCB for your application.
However, remember to pay attention to the specifications and the considerations before fabrication.
Of importance is to select the right material and follow the fabrication procedure to obtain a quality prototype PCB.
A reliable manufacturer can also come in handy if you are stuck.
Remember, you can always get in touch with us for all your PCB prototyping assembly issues and we will be glad to help.