Introduction: Industrial-level Quality PCB Through Hole Plating

Picture of Industrial-level Quality PCB Through Hole Plating

WARNING for US Readers: For some meaningless reasons the hypophosphorous acid and its salts (including calcium hypophosphite) is included into DEA List I of chemicals, so its distributions is controlled and availability is limited. I'm really sorry, that this method is unavailable for US readers.

Described method does not use expensive,  hazardous or hard to obtain chemicals, provides good adhesion of plated copper and has very good productivity, because all holes are processed at once. Sounds like miracle? But it is not.

Basically the method is very simple to use: just put board into activator solution, then into oven for about a half of hour, then wash it and put into galvanic bath to perform electroplating of the copper layer of necessary thickness. That't it. Of course the key is the activator solution. You need to prepare it once and then you can process several boards with it. While not in use solution can be stored for a long time without degradation of its properties.

Note, that description below does not include the electroplating step. There are several guides, recipes and detailed descriptions of the process, so I see no need to repeat them again. Especially taking into account, that most convenient one heavily depends on various conditions, availability of chemicals/materials and other things.

Lets begin with a little bit of history. This method uses ability of the some copper compounds to decompose under high temperature with the release of nano-particles of metallic copper. This allows to form a conductive layer on the processed surface and then deposit solid copper layer using regular electroplating. It was developed several years ago at the former USSR as a replacement for expensive palladium based method. After death of the USSR development of this method continued and at the beginning of the 90x group of the chemists leaded by Oleg Lomovsky obtained patent for the industrial version of the PCB through hole plating method (page is in Russian). This method was almost unknown to wide hobbyist audience until about year ago, when at VRTP.RU forum user JIN  published his article (page is in Russian) about through hole plating. The article described early version of the method, which has some issues which prevented its use in industry, but most of these issues are irrelevant for home use. What is more important, the article described recipe of base activator solution suitable for repeating in home environment. In fact method described below heavily based on the same recipe. Since then method started quickly gaining popularity in Russian-speaking hobbyist communities.

As mentioned above, to use this method, we need an activator solution. Next step describes preparation of the activator solution in details.

Step 1: Preparing Activator Solution

Picture of Preparing Activator Solution

Although all ingredients are not hazardous in general, they still present danger to your skin.
Also, it is suggested to perform final steps of the solution preparation at the open air or with very good ventilation (keeping window open might be not enough). See below why.

To prepare an activator solution we will need following things:
1. Distilled water
2. Copper sulfate 
3. Calcium hypophosphite (Ca(H2PO2)2)
4. Ammonium hydroxide (25%)
5. Liquid soap

All ingredients are required in small quantities (see below) and most of them are widely available. The only less accessible component is calcium hypophosphite, but in fact it is not rare nor expensive, just can't be purchased in nearest drugstore or Home Depot. Probably simplest way to obtain it is just buy online as an analytic reagent. Minimal quantities usually about 1kg, this will be enough to open your own small PCB shop :)

The activator solution is prepared as follows.
1. Take 140ml of water and dissolve 30g of copper sulfate in it. Stir until all copper sulfate is dissolved. At this point solution will get light blue color.
2. Pour into solution 22g of calcium hypophosphite and carefully stir it for 3-4 minutes. Once you pour calcium hypophosphite into solution, there will appear sediment which change solution color to white-blue. The sediment consists mostly of gypsum (calcium phosphate). Note that there is quite high amounts of sediment, so use at least 0.5 liter cans for preparing solution.
3. Filter the solution through funnel with filter paper placed into it. Again, use large funnel. Also, at the end speed of the filtering might be quite slow, so be patient. The solution should have light blue (perhaps a little dull) color.
4. Pour through the sediment another 100ml of water.
5. Remove funnel and add 40ml of 25% ammonium hydroxide. WARNING! This reagent stink! So, while you'll be doing this, try to keep nose as far from the solution as possible. Once ammonium hydroxide is dissolved in the solution, it stinks much less, so activation solution is usable indoor, although it still stink so the container with the solution should not be left open for long time. The solution quickly thicken for some time and you'll see white flakes, but they quite quickly disappear and solution obtains deep blue color. You may speedup this process by stirring the solution.
6. Add about 5-6ml of liquid soap and stir for few seconds.
7. Add about 8-10g of calcium hypophosphite. Part of it will dissolve, but part of it will remain as a sediment in the solution. Stir solution for few seconds to speedup process.
Solution is ready. It is quite stable and can be stored for a long time without loosing its properties. Use tightly closed container and store it in dry place, away from direct sunlight and out of reach of children and pets. Since solution contains copper compounds, it might be toxic if you'll drink it, so it is not recommended to do so :)
Solution requires maintenance, especially if used intensively. Maintenance is quite simple - just check from time to time if there is still calcium hypophosphite sediment at the bottom of the container where solution is stored and if necessary add few grams of calcium hypophosphite.

Once you prepared the solution you're ready for the next step.

Images provided below show activator solution at different stages of preparation.

Step 2: Preparing Copper Laminate

Picture of Preparing Copper Laminate

Preparation of the laminate is very important step, it actually defines quality of holes after plating, so take special attention to this step.

1. Cut laminate to size slightly larger than board size. One edge usually is used for the fixing board during electroplating, so at one side make larger margin. 
2. Drill the board. All drills must be of exact necessary size, there will be no chance to drill hole of larger diameter without destroying copper in hole once hole is plated. Use tungsten carbide drill bits to get clean holes suitable for the plating.
3. Carefully inspect all holes against the light source and make sure there are no copper chips left in the holes.
4. Carefully sand copper surface with the flint paper of largest available number (i.e. with the smallest size of abrasive particles) and make sure that there are no copper borders around holes, especially at the opposite side.
5. Carefully wash the board using dishwashing detergent with soft abrasive, for example Cif or something like that. 
6. Finally carefully rinse the board in water.
7. Inspect holes again and make sure they are clean.

The board is ready for the next step.

Image shows prepared board right before activation.

Step 3: Activating the Board Surface

Picture of Activating the Board Surface

This process is quite simple:

WARNING! DO NOT TOUCH BOARD DURING THIS STEP, EVEN IN GLOVES! This may cause problems with the plating.

1. Open the container with the activator and slowly put horizontally oriented board into the solution for 2-3 seconds (do not touch the bottom of the container!) and then lift it slightly above the surface of the liquid to let the activator flow down. You'll see that liquid at the board changes its color around the holes. This does mean that activator freely flows through the holes and wets them properly. Check if color is changed around all holes and if not, slowly put board back into solution and immediately lift above the surface. Usually this step need not to be repeated more than twice. If this is not so, then you have problem with the holes, so rinse the board in large amount of water, fix the problem and repeat entire step again. It is not recommended to keep board in the activator more than few seconds because this may result to problems at the further steps.
2. Once holes are wet, put board off the solution, rotate it vertically and let excessive activator flow down back to container.
3. Once most of the excessive activator flew down, close the container and distribute remaining activator as uniformly as possible by rotating board.

Once activator is distributed, board is ready for the next step.

Image shows activated board. Notice that all holes hold the activator. There is no need to remove it specially, but also no need to do anything if some hole lacks the activator film inside.

Step 4: Thermal Treating

Picture of Thermal Treating

To perform this operation you'll need some kind of electric oven. The monitoring and controlling of temperature is necessary.

1. Put board into the oven and start heating. When temperature reaches 125 degrees (Celsius) hold it at this level for at least 10 minutes (12-15 minutes highly recommended). 
2. Resume heating until it reaches 175 degrees and hold it at this level for at least 5 minutes (7-8 minutes highly recommended).
3. Stop heating and open oven but keep board inside until it's temperature crosses point 100 degrees.

At this point board has thin copper layer at most surfaces (including holes) covered with thick layer of remaining products of pyrolysis of the activator. All we need to do is just gently remove these products from the board as the next step. 

Images shown below show the board after first and after second stage of thermal treating.

Step 5: Cleaning Up the Board

Picture of Cleaning Up the Board

This step is quite simple: just gently rinse the board in the water using soft sponge and some liquid soap. WARNING: Do not use washing liquids with soft abrasives at this step! The copper layer is very thin and can be damaged. Unlikely that you'll be able to remove it completely (adhesion is quite good), but you may break electrical connection between deposited layer inside holes and laminated copper. During electroplating lack of connection results to lack of copper deposition. So, be careful at this step.

Once board is cleaned up it is ready for the electroplating.

Image shows the board seen at previous steps after about 5 minutes (out of required ~60) of electroplating (i.e. it's almost the very beginning of the process). All holes are already plated with smooth shiny copper layer. 


AliG89 (author)2017-03-03

Hello, calcium hypophosphite is not available in Turkey. What can I use alternative chemistry. thank you

Dokali (author)AliG892017-04-14


you can got calcium hypophosphite from reaction of sodium hypophpsphite and calcium chloride.

Sunil Jeurkar made it! (author)2017-01-24

Anyone wondering what happens to the solution when kept for 1 year or so.

When kept for long crystals form at the bottom of the container and liquid changes color from Cobalt Dark to Dark Greenish-Blue .

It can be regenerated by adding Ammonia & Calcium Hypohosphite have tested the solution and working fine. But crystals seems to be impossible to dissolve in water . Will update this message if its possible to dissolve those crystals.

This was not the actual color ( as in pic ), I have added ammonia to the container to reclaim any remaining stuff.

Muhammad NourE (author)2016-09-28


Very nice

I have some questions regarding the chemicals used in the method, first of all can you in simple words :D explain the need of every component

For copper sulfate it is easy and obvious but for the other 2 components, I have no idea!

Also is there any alternatives for the Calcium hypophosphite ?

I am not expert in chemistry nor even beginner, my knowledge is extremely primitive and I barely know that heating accelerate reactions, nothing more :lol


SachinS84 (author)2016-08-17


Appreciate this great article !!

having read the article and all the comments , i have manged to plate my vias and holes. I am to apply the dry film photo resist film over the copper clad now and would later expose and develop it. My problem is :-

How would i protect the PTH from etching away

mientos4 (author)SachinS842016-09-14

If you're using dry film, there is no problem - it can be used for tenting holes. But you must take care with lamination - too high temperature or pressure will damage the dry film around holes (I turn the laminator on for ~20-30s, then wait 20s and then insert the pcb, the temperature of rolls is something like 60C). Recommended temperature is 100C, but it depends of the pressure which cannot be adjusted in my case, and 100C damage my dry film.

messina.david.7 (author)2016-08-02

Hello, I realized the solution,
I ask myself the following questions.

What is the chemical composition of the solution?
What is the reaction to 125 ° C?
What is the reaction to 175 ° C?
is there a safety sheet?

Chemical composition of the solution, at the best of my (limited) knowledge is the ammonia complex of copper hypophosphite. Both reactions (at 125 and at 175 degrees) are thermolysis of this complex with the release of copper nanoparticles. During first phase most of the copper is released while second phase is reflow during which copper nanoparticles are joined together. I believe that operational window for both reactions +- 10-15 degrees. Note that I'm not a chemist and here I just repeating what (and how) I did get from papers and from discussions with chemists. So, take this information with care.

ericmitc (author)2016-03-01

If still interested: there is a way using Sodium Hypophosphite. to make an activator-solution like this one.

After some testing and reading through the literatur our Lib, I figured out an easy way that works with stuff that can be freely bought. In germany, like in many other countries its hard to get calcium hyp. when you dont want to order from china for actually at least 100€ (for 1 kg - gets less when order big quantities) with shipping-costs.

Well this is no receipe because Im still trying to normalize the procedure with best working parameters, but its at least one possible way to go.

You need:

sodium hypophosphite,

Ammonium Hydroxide


and HCL acid,

At first we need to get Hypophosphorous acid (the stuff your government won't like because its used to make crystal meth) from the sodium-hypophosphite and the HCL-acid.

Therefore you heat the sodium-hyp. to about 80C and put you HCL to it.

As a result you'll get Hypophosphorous acid and salt.

Cool down the solution to just over 0C for less soluability of salt and filter out the salt. Now you got a good acid with the clou that it can react with copper-salts to copper-hypophosphite, the main part of the reaction that syevtushenko described!

But there will be the problem that the Hyp.Acid directly wants to reduce a solution of copper-salts to copper in front of your eyes. That is why you need to make the sulfate-solution not with water but with the ammonium-hydroxid-solution. It builds complexes that cant be reduced this way. So put some of the Copper Sulfate (doesnt matter with hydrated or not) with the ammonium hydroxid together till all the CuSo4 got dissolved. Try to make a nearly saturated solution.

Then you put a little hypophosphorous acid to it and stirr.

When you go on as described by syevtushenko with putting your clean pcb into it and heating up the stuff, the ammonium hydroxid fastly evaporates and you'll get your nano-copper on the surface.

Of course you should use some soap, ethanol or tensides to make a solution that flews easily through the holes like described.

If there is still a need for informations, feel free to ask. I hope that someone is helped by these informations that took much time for me to get

Kind regards,

Eric Pidun

LeeW65 (author)ericmitc2016-06-08

Hi Eric.

Thanks for the above. I'm keen to follow your instructions and wondering if you could share what quantities of the chemicals you are uesing?

sean01 (author)2016-05-14

Hi ericmitc

Do I understand that I
can replace the Calcium Hypophosphite with Sodium Hypophosphite and do
the rest as per the recipe and it will work? What do you mean with 4/3
of amount of Copper Sulfate of you Sodium Hyp? I don't understand?

really hope this would work I can not get hold of the Calcium
Hypophosphite at all here in South Africa? I am also struggeling to get
hold of Ammonium Hydroxide normal Ammonia I can get that they use in
cleaning products.

Kind Regards

ericmitc (author)2016-03-18

For still interested people trying to do this with Sodium hypophosphite : it works fine! You need to take about 4/3 of the amount of CuSO4 of you Sodium Hyp. :)


sean01 (author)ericmitc2016-05-14

Hi ericmitc

Do I understand that I can replace the Calcium Hypophosphite with Sodium Hypophosphite and do the rest as per the recipe and it will work? What do you mean with 4/3 of amount of Copper Sulfate of you Sodium Hyp? I don't understand?

I really hope this would work I can not get hold of the Calcium Hypophosphite at all here in South Africa? I am also struggeling to get hold of Ammonium Hydroxide normal Ammonia I can get that they use in cleaning products.

Kind Regards

ericmitc (author)2016-03-01

But by the way I am actually not sure that it will not work with sodium hypophosphite substite the calcium hyp. You will definately have to change the amounts but after what I read it should be possible anyhow

VedranS (author)2015-11-23

I was looking at this link:

which bot402 posted

It had very detailed information and now it is removed.

If anyone saved any data from that link, please send it to me.

mientos4 (author)VedranS2015-11-25

I'm also interested in this tutorial. Have you found it?

VedranS (author)mientos42015-11-26

I found these videos:

This is one of the methods from that link which uses palladium chloride, there were at least two other methods, one uses silver nitrate and other one uses gold chloride.

I vaguely remember that silver nitrate method needs ammonium hydroxide and some other chemicals.

There was also electroless tin method:

600ml deionized water

citric acid unknown amount


thiourea unknown amount

As i remember you put two tin electrodes in citric acid and apply current for some time to get tin salt and then mix ingredients. When you put copper inside a layer of tin should appear on surface couple of atoms thick because when copper is tinned reaction stops. I found some articles and patents on internet. I have to go through all off them when I find some time for it.If I find something I will inform you.

mientos4 (author)VedranS2015-11-26

Thank you for this videos and informations.

I've bought all the reagents required for this metalisation method, that's why it's important for me to know the procedure. I know all the ingredients, but not the quantities and the order. Maybe it will help:

deionized water

500ml deionized water
5min, 35C

Silver nitrate 0,15g
500ml deionized water
5min, 35C

Electroless copper plating:
Copper sulfate pentahydrate (CuSO4 * 5H2O)
EDTA disodium (C10H14N2Na2O8 * 2H2O)
Potassium ferrocyanide (K4[Fe(CN)6] * 3H2O) - optional
100ml+400ml? deionized water
1h, 35C?

All ingredients that I've bought:
Sodium hydroxide (NaOH)
Silver nitrate (AgNO3)
Tin chloride anhydrate (SnCl2)
Copper sulfate pentahydrate (CuSO4 * 5H2O)
EDTA disodium (C10H14N2Na2O8 * 2H2O)
Borax (Na2B4O7 * 10H2O)
Paraformaldehyde (Formaldehyde substitute)
Potassium ferrocyanide (K4[Fe(CN)6] * 3H2O) - optional

VedranS (author)mientos42015-11-26

I've found this pdf:

It's a bit different method. You can find some similarities.

mientos4 (author)VedranS2016-01-03

Thank you very much for this links. I did this metallization according to the pdf. The results are great! Vias have resistance of 20mR after 50min of electroless plating. Later I did experiments with NaOH instead of sulfuric acid for degreasing solution and borax instead of ammonia in activation solution. These methods also worked and with borax the container has been plated too :D. Solutions can be used several times. Here's the recipe (I didn't try electroplating):

1. Degreasing
Immerse in H2SO4 (38%) at 95C for 30min

1a. Degreasing
Immerse in
DI water --- 400ml
NaOH --- 20g
at 45C for 5min

rinse with water

2. Sensitization
DI water --- 200ml
HCl --- 2ml
SnCl2*2H2O --- 1.4g

temp. 35C for 5min
rinse with water

3. Activation
DI water --- 180ml
NH4OH --- 20ml
(NH4)2SO4 --- 10g
AgNO3 --- 0.75g

3a. Activation
DI water --- 200ml
Borax --- 4g
AgNO3 --- 0.45g

temp. 35C for 3-5min
rinse with DI water

4. Electroless copper plating
DI water --- 200ml
CuSO4*5H2O --- 0.75g
EDTA --- 1.89g
KOH --- 2.58g
Triethanolamine --- 0.2ml
K4[Fe(CN)6]3H2O--- 0.1g
Paraformaldehyde--- 0.58g

It is important that the components were added into the DI
water in the order listed and given sufficient time to dissolve before
the next component was added.
pH 12.5
temp. 55C for >20min

5. Electroplating
DI water --- 1l
CuSO4*5H2O --- 200g
H2SO4 --- 60g <<< volume ?
PEG --- 0.5g
CuCl --- 0.14g

Current density 250mA/cm^2
temp. room for 50-60min
nicamarvin (author)VedranS2015-11-24

it has been removed, While I don't do PCB I do Spray On Copper, I will be doing a instructable on how to do copper mirror with chemicals found on your kitchen and off the drug store, very cheap very beautiful copper mirrors, which could also work on PCB because its basically an Auto Catalytic Copper plating solution.

Spydamonky (author)2013-05-05

Very cool, now here is my question.
What is the best method of etching now that plating has happened? Do you fill the plated holes with etch resist and then photo or toner the traces?

syevtushenko (author)Spydamonky2013-05-05

There are at least two widely used methods - electroplating of tin as etching resist and tenting. First one is quite complex but more repeatable in mass production. Second one is much simpler but has slightly lower yield. I'm using second method. Basically this is regular dry film photoresist based method. I.e. dry film photoresist is laminated, exposed and developed (both sides are processed together). Then board is etched as usual. Two things are important here: for photomoask should be used only (respectively) top and bottom copper layers (as they are present in PCB design). There should be no drills merged to these layers (this is quite common practice for DIY PCB, when etched holes in copper used as guide for drilling). If photomasks are prepared properly then exposed and developed photoresist forms tents at both sides of each plated hole protecting it from being etched. Second important thing is that photoresist must support tenting. All modern dry film photoresists I'm aware of support tenting. Details about these should be present in datasheet for photoresist.

Spydamonky (author)syevtushenko2013-05-07

So If I were you predrill all my vias and pads and then etch my traces, what is the best method for resisting the plated holes while preserving the integrity of the corners. What I mean is how do you stop what happened to "alirezakhz" below while etching?

syevtushenko (author)Spydamonky2013-05-07

Please, take a look at following description of the tenting process

ThomasE41 (author)syevtushenko2016-02-07

This is neat; you've researched existing literature of plating methods, and wrote up everything so clearly along with your own innovations.

About protecting the plated holes during etching step: Is there any reason why the following method is not feasible? I ask because for certain practical reasons, I typically use presensitized boards (which come with photoresist pre-attached, meaning I cannot laminate the film to the board after drilling like you suggested for tenting the holes)

0) start with presensitized board (i.e., photoresist-attached copper board)

1) drill holes on board (cutting through photoresist at the hole positions)

2) put board through activator/pre-plating step; this naturally coats only holes and not rest of board (since rest of board is protected with photoresist)

3) put board through developer/etchant step

4) put board through plating step, which plates only the holes, because activator/pre-plating in step #2 only coated the holes

I feel like this should work, although #3 might be a problem -- the developer or the etchant might wash away the activator?

If so, do you have any other suggestion for the presensitized-board situation like mine, if I want to protect the plated holes during etching?

sodor (author)2016-01-05

What is the function of Calcium hypophosphite on the chemical reaction?

syevtushenko (author)sodor2016-01-09

Reaction between copper sulfate and calcium hypophosphite results to creation of copper hypophosphite which is main component of the activator solution. The copper hypophosphite ability to decompose under high temperature with the release of nano-particles of metallic copper is the base of whole method.

JoiceW (author)2015-11-04

We are manufacturer of Sodium hypophosphite monohydrate in China. Anyone interested can contact us. Thank you!

mgdaubo (author)2015-08-21

Hi, what is the smallest hole diameter on your board? and why in the step 3, "it is not recommended to keep board in the activator more than few
seconds because this may result to problems at the further steps"? what is the problem?

Because in my board there are quite small holes (0.2mm diameter), so I would like to put and lift the board into activator some more times to ensure the activator flow though the smallest hole. What is the problem if we keep it in activator so long?

Thank you very much for very helpful sharing :)

syevtushenko (author)mgdaubo2015-08-23

Smallest hole diameter at my boards is 0.3mm.
About note on step 3: if to keep board in the solution for too long the surface of copper is get oxidized. Maximal allowed time in the solution can be found by experimenting.

mgdaubo (author)syevtushenko2015-08-26

Thank you Syevtushenko, so I hope it works fine for 0.2mm hole diameter. I will do experiment and see how.

Thank you very much.

skoupinis (author)2014-10-05


Is there a good electroless copper plating recipe after the activation process ?

Also knows anyone a guide with the industry method with palladium ?

bot402 (author)skoupinis2015-08-05

madisoz (author)2013-07-30

First - I forgot to thank you for this project. Thank you!

As many people here I also do have difficulties of getting Ca(PO2H2)2 So the following is where I´ve got so far
Got all needed ingredients on July 29th.
Reactives used Methanol 99.7%
Sodium Hypophosphite monohydride
Calcium Chloride anhydrate
July 29th

Drying of Sodium Hypophosphite monohydride started in 3 glass jars with inner diameter 70mm filled with 60g of substance in each jar kitchen oven set to switch off at 120 Celsius (switches on at 105 Celsius). Measured with K-type sensor placed under one of the jars.
at the bottom of the jars the substance has turned semiliquid (like sugar with very little of water). Periodical stirring is needed to give water better way to evaporate
Sodium Hypophosphite loss of weigth is about 16% (theoretical loss would be 20%. Next day test showed that additional baking for 5hrs more resulted in loss of weigth 17% total - only 1% more gained)
- dissolved 60g of dried Sodium Hypophosphite in 750ml of methanol
- dissolved 37g of CaCl2 in 250ml of methanol (some little inbalance in favor of CaCl2 is intentional)
all this takes some time. Periodical stirring helps. Dissolving of CaCl2 in methanol produces some heat - nothing dangerous - just enough to feel the warmth increase by hand when holding the jar. Both solutions look clear
Both solutions poured together into larger jar and stirred. Reaction is quite instantaneous. The product looks exactly like milk. After 10 minutes solution shows some clearing at the top layer. Solution stirred thoroughly some times and left overnight to settle.

July 30th
Methanol in jar is clear with thick layer of sediment on bottom. Filtering of the reaction product started
As filtering result I got some amount of white powder mixture with methanol and about 800ml clear looking methanol. This methanol contains probably some 14g of NaCl and possible unreacted residues of the reaction) (This might not be important but it shows that saved methanol can be reused at least once. In the saved 800ml of methanol next solutions were made. 50g of Sodium Hypophosphite in 600ml and 32g of CaCl2 in 200ml. The solutions do not look quite clear and not all substance is dissolved. However later it seems that reaction when solutions were mixed - everything looks good. A lot of sediment and methanol gets clear after a while)
10.00 - 13.00
the product and filter has been let to dry in plastic container.
13.00 started to dry the product in oven at 40 - 60 Celsius. This isn´t necessary, I just wanted to check that everything went as expected.
Drying ended

Source ingredients total 97g.
Theoretical product should be 58g of Ca(PO2H2)2 and 39g of NaCl
NaCl dissolved in 1000ml methanol - theoretical max 14g
Theoretical outcome after filtering should be 83g. Ca(PO2H2)2 58g and NaCl 25g
Real product is 77g of fine grained white powder after filtering and 5hrs drying.
Looks realistic. So the real product should hopefully be something like 54g of Ca(PO2H2)2 and 23g of NaCl
Now I do have to get rid of NaCl or most of it at least. This is for tomorrow. Also started testing the reaction in glycerol. Doesn´t look very promising due to viscosity. Maybe mixture of methanol with glycerol as solvent would be a good idea but I have run out of pure methanol.

Jahusi (author)madisoz2014-04-07

What is about dissolving CuCl2 and Ca(PO2H2)2 in pure ethanole? Both ingredients are easily available and high solubile in ethanole. They should "react" to NaCl which is not solubile in EtOH and Cu(PO2H2) in solution....
Do you think that could work?

madisoz (author)Jahusi2014-04-08

If you have Ca(PO2H2)2 available then you should stick to process initially described in this instructable.

Jahusi (author)madisoz2014-04-08

Sorry, what I meant is mixing CuCl2 + 2 Na(PO2H2)-->Cu(PO2H2)2 + 2 NaCl. Otherwise it would not make sense.. :)

That could be a way to use this instructable without Ca(PO2H2)2.

kralikba (author)Jahusi2015-06-24

Did you try this? Did it work in the end?

psykhon (author)madisoz2014-02-18

Im also very interested to see how this turns out

madisoz (author)psykhon2014-04-08

Sorry for late answer.

Actually I got best results using glycerol. Takes a lot of time to react and filtering is real PITA. For speeding up the filtering some methanol can be used. The resulting product has to be washed with alcohol to get rid of glycerol.

Still no 100% plating, 90-95% at the best.

There is an interesting method of producing Copper Hypophosphite

I discovered. It is based on the fact that sodium sulfate is nearly insoluble in water below 0 Celsius.

So I made a solution of 27g Sodium Hypophosphite and 30g Copper Sulfate in 100ml water. Then cooled the solution down to about -6 Celsius.

Now with the solution cooled when you stir it with plastic spoon you can see that a lot of long thin crystals are formed in the solution. These are typical sodium sulfate crystals. Now you have just filter it fast. The result is solution of Copper Hypophosphite. Funnel and filter have to be precooled also.

The results were about as good as when using glycerol.

zizo1991 (author)madisoz2014-04-17


Thank you so much for your efforts :)

I did the last thing u did (cooling down method) and it worked, but the amount of copper hypophosphite was tooooo little, how many mL did you obtain from this method? using the amounts you have mentioned?

kirkguille (author)madisoz2014-02-17

Did it work? I'm very interested in this proccess! Thanks.

minimalmonk (author)2015-05-14

could i use cloudy ammonia instead of hydroxide and soap?

syevtushenko (author)minimalmonk2015-05-14

Perhaps you can use cloudy ammonia instead of hydroxide, but then amounts should be recalculated. Soap will be still necessary because it's not included into reaction. Instead it serves two other purposes - increases wetting capability of the solution and works as kind of grease during thermal treating.

EelcoScheers (author)2014-11-19

Well hi there.

The problem in the Netherlands is can't get the calcium hypophosphite :-(

but can i use sodium hypophosphite instead of the calcium hyphophosphite?

greetz Eelco

sortegas (author)2014-08-26

Hi!, i'll try to do this but i have a doubt: it's obviously that's impossible to use ferric chloride for attack the pcb. if i haven't a cnc machine how can i do for attack it? any ideas?

thanks alot for this guide :-)

m1mahesh (author)2014-07-11

Hi syevtushenko,

almost after year i am giving try on this, yesterday i took some test on this method but not work.

i strictly followed below processor but did not find any luck

1) Drill PCB with 20000 RPM drill bit

2) Countersink with little larg bit top and botto layer,

3) Cleaned Board with fine Grade Sandpaper , Liquid Soap and water

4) Dipped board into solution for 1 sec removed again dipped for 2 seconds. i can clearly see solution is flowing through holes

5) Theremal Treated pcb for 125-127 15 Minutes, then 172-176 C for 8 minutes. then down to 28C ( here i get conductiovity between two layes around 78K)

6) washed PCB with plain water . after 5 minute i check conductivity and it gone upto 3-5M Ohms.

7) Put it into galvanic solution for hour with 1 AMP constant current. i get nice bright plating on top and bottom layer. but not holes

what i obsered is after second wash(thermal treating) conductivity is no more there and coating is washed away.

i use distilled water to make solution and followed steps strictly. i give 6 attempts with different time and curren settings but nothing is helping.

may be you can put little light on this.

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