WO2003076694A2 - Procedes et appareils d'analyse de solutions d'electrodeposition de brasure - Google Patents

Procedes et appareils d'analyse de solutions d'electrodeposition de brasure Download PDF

Info

Publication number
WO2003076694A2
WO2003076694A2 PCT/US2003/005568 US0305568W WO03076694A2 WO 2003076694 A2 WO2003076694 A2 WO 2003076694A2 US 0305568 W US0305568 W US 0305568W WO 03076694 A2 WO03076694 A2 WO 03076694A2
Authority
WO
WIPO (PCT)
Prior art keywords
solder plating
plating solution
solution
sample solder
sample
Prior art date
Application number
PCT/US2003/005568
Other languages
English (en)
Other versions
WO2003076694A3 (fr
Inventor
Peter M. Robertson
Mackenzie E. King
Monica K. Hilgarth
Cory Schomburg
Yurij Tolmachev
Uwe Schoenrogge
Original Assignee
Advanced Technology Materials, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US10/315,629 external-priority patent/US6913686B2/en
Application filed by Advanced Technology Materials, Inc. filed Critical Advanced Technology Materials, Inc.
Priority to AU2003219869A priority Critical patent/AU2003219869A1/en
Publication of WO2003076694A2 publication Critical patent/WO2003076694A2/fr
Publication of WO2003076694A3 publication Critical patent/WO2003076694A3/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D21/00—Processes for servicing or operating cells for electrolytic coating
    • C25D21/12—Process control or regulation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N31/00—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods
    • G01N31/16—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods using titration
    • G01N31/162—Determining the equivalent point by means of a discontinuity
    • G01N31/164—Determining the equivalent point by means of a discontinuity by electrical or electrochemical means

Definitions

  • the present invention relates to methods and apparatuses for analyzing the solder plating solutions, and more specifically to methods and apparatuses for determining concentration of various components in both eutectic solder plating solutions and high lead solder plating solutions.
  • solder In the production of electrical printed circuit board, it is common to electroplate the electrically conductive regions of the board with a tin-lead coating, commonly referred to as solder. Such a tin-lead coating facilitates the subsequent connection of electrical components, such as resistors, transistors, integrated circuits, and the like, to the printed wiring board. Moreover, the increasing use of integrated circuits has necessitated use of multilayer printed wiring boards having solder plated through-holes for electrically connecting circuitry on the various layers of the board.
  • High-lead solder is also used to connect controlled collapsible chip contact (“C4 chip”) to its substrate, for relieving thermal stress and providing a reliable contact between the chip and the substrate.
  • C4 chips were intended for use in modules with low expansion substrates that minimize thermally generated stresses. These modules were often hermetically sealed to protect bare chips from the environment.
  • Eutectic solder solutions or high lead solder solutions commonly used for electrochemical deposition (ECD) of solder must be monitored in situ to insure optimal efficiency Specifically, changes in the concentrations of inorganic components (such as acid, lead, and tin) and organic additives (such as polymeric non-ionic surfactant, b ⁇ ghtener, and antioxidant) in such solder solutions must be determined during the solder plating process for accurate and precise process control
  • the present invention in one aspect relates to a method for determining concentration of an acid contained in a sample solder plating solution, comprising the steps of:
  • step (d) determining acid concentration in the sample plating solution, based on the electropotential response(s) measured in step (c) and the correlation determined in step (b).
  • the present invention in another aspect relates to a method for determining concentration of an acid contained in a sample solder plating solution, comprising the steps of:
  • the present invention in a further aspect relates to a method for determining tin concentration in a sample solder plating solution comprising tin and lead ions, by titrating the sample solder plating solution with a titration solution that comprises a material selected from the group consisting of iodine and iodide, and by measuring reduction-oxidation potential responses of such sample solder plating solution, during the titration.
  • titanium ions refers only to the two-valence Sn(II) ions, not the four-valence Sn(IV) ions, unless otherwise specified.
  • the present invention in a still further aspect relates to a method for determining lead concentration in a sample solder plating solution that comprises tin and lead ions, comprising the steps of:
  • the present invention in still another aspect relates to a method for determining lead concentration in a sample solder plating solution, comprising the steps of: (a) measuring electropotential responses of one or more calibration solutions of known lead concentrations;
  • step (d) determining lead concentration in the sample plating solution, based on the electropotential response(s) measured in step (c) and the correlation determined in step (b).
  • the present invention further relates to a method for determining lead concentration in a sample solder plating solution, comprising the steps of:
  • step (c) concurrently to step (b), monitoring the pH value of the sample solder plating solution after addition of each volume of the primary titration solution, and whenever a pH drop is observed in the sample solder plating solution, a sufficient volume of a secondary titration solution is added into the sample solution, so as to adjust the pH value of the sample solution back to the base value before addition of next volume of the primary titration solution; (d) terminating the titration process at an end point, where further addition of the primary titration solution no long causes pH drop in the sample solder plating solution,
  • a still further aspect of the present invention relates to a potentiostatic method for determining concentration of polymeric non-ionic surfactant in a sample solder plating solution, by measuring
  • a yet another aspect of the present invention relates to a potentiomet ⁇ c titration method for determining concentration of polymeric non-ionic surfactant in a sample solder plating solution, comprising the steps of (a) titrating the sample solder plating solution by adding a titration solution thereinto, so as to form an insoluble reaction product with the lead-polymeric non-ionic surfactant complex in said sample solution;
  • step (b) detecting a titration end point for the sample titration process in step (a), and recording the amount of titration solution used for reaching such titration end point;
  • step (f) determining the polymeric non-ionic surfactant concentration in the sample solder plating solution, based on the volume of the titration solution recorded in step (b) and the empirical titration factor calculated in step (e).
  • a still further aspect of the present invention relates to a method for determining concentration of brightener in a sample solder plating solution, by obtaining a UV-Vis abso ⁇ tion spectrum for the sample solder plating solution, determining the absorbance of the sample solder plating solution at a wavelength in a range of from about 393 nm to about 413 nm, and calculating the brightener concentration in the sample solder plating solution, based on the absorbance at such wavelength.
  • a still further aspect of the present invention relates to a method for determining concentration of antioxidant in a sample solder plating solution, comprising the steps of:
  • a still further aspect of the present invention relates to a method for determining concentration of antioxidant in a sample solder plating solution, comprising the steps of forming a derivative of the antioxidant that is detectable by UV-Vis spectroscopy, and conducting UV- Vis abso ⁇ tion analysis at a wavelength that maximizes UV absorbance of such derivative of the antioxidant, so as to determine the antioxidant concentration in the sample solder plating solution.
  • a still further aspect of the present invention relates to a method for determining concentration of antioxidant in a sample solder plating solution, comprising the steps of directly conducting UV-Vis abso ⁇ tion analysis of the solder plating solution at a wavelength that maximizes UV absorbance of the antioxidant, and determining the antioxidant concentration in the sample solder plating solution based on the UV-Vis abso ⁇ tion analysis result.
  • a still further aspect of the present invention relates to an optical cell for conducting spectrometric analysis of one or more test solutions, comprising:
  • one or more fluid inlets connected to the first fluid compartment for introducing one or more test solutions thereinto;
  • a fluid outlet connected to the second fluid compartment for discharging the one or more test solutions
  • a fluid mixing device in the first and/or second fluid compartment for mixing the one or more test solutions
  • an irradiation light source for irradiating light into the second fluid compartment
  • a light detector coupled with the irradiation light source for detecting light transmitted or emitted by the one or more test solutions in the second fluid compartment;
  • a computational device connected with the light detector, for collecting absorbance spectrum of such one or more test solutions and conducting spectrometric analysis based thereon.
  • a still further aspect of the present invention relates to a method for determining concentration of a component in a sample solder plating solution, based on Raman specfroscopic analysis.
  • Figure 1 is a graph that shows the electropotential responses of a solution before and after addition of a sample methanesulfonic acid solution, according to six measurements thereof, as well as the electropotential response of a solution before and after addition of a calibration methanesulfonic acid solution.
  • Figure 2 is a titration curve for the methanesulfonic acid (MSA), measured during an titration process using 0.1M KOH as titrant, and plotting the pH or recovery percentage of the MSA as a function of the volume of the KOH titrant added.
  • MSA methanesulfonic acid
  • Figure 3 is a graph that plots the electropotential of a sample solder plating solution as a function of the volume of iodine titrant added into such sample solution, according to the iodine titration method for tin analysis.
  • Figures 4A and 4B show dual platinum electrodes for measuring oxidation-reduction potential of the sample solder plating solution, according to one embodiment of the present application.
  • Figure 5 is a titration curve for iodine titration of tin ions, using dual platinum polarized electrodes.
  • Figure 6 is an iodine titration curve of tin, in which HCI is used to remove lead ions from the sample solution before the titration process, in comparison to an iodine titration curve where EDTA is used for stabilizing the lead ions.
  • Figure 7 is another iodine titration curve of tin, in which KCI is used to remove lead ions from the sample solution before the titration process.
  • Figure 8 shows the results of a series of 24 iodine titrations for tin analysis, conducted with the pre-titration removal of lead ions.
  • Figure 9 shows a linear curve connecting four iodine titration results for tin analysis, with pre-titration removal of lead ions.
  • Figure 10 shows the pH values of the sample solder plating solution during the parallel titration for lead and/or total metal analysis, in relation to the EDTA and the secondary titration solution containing OH " added thereinto.
  • Figure 11 shows multiple titration curves constructed for a sample solder plating solution according to the parallel titration method for lead and/or total metal analysis, plotting the pH value of the sample solder plating solution as a function of the volume of the EDTA addition.
  • Figure 12 shows multiple titration curves that plot the volume of NaOH (i.e., the secondary titration solution) added as a function of the EDTA added, during the parallel titration process of Figure 11.
  • Figure 13 shows UV-Vis abso ⁇ tion spectra obtained for various test solutions, including (1) a solution containing methanesulfonic acid (MSA) and the brightener; (2) a solution containing MSA, the brightener, and tin ions; (3) a solution containing MSA, the brightener, tin ions, and lead ions; (4) a solution containing MSA, the brightener, tin ions, lead ions, and the antioxidant; and (5) a solution containing MSA, the brightener, tin ions, lead ions, the antioxidant, and the polymeric non-ionic surfactant.
  • Figure 14 shows three separate calibration curves constructed for the b ⁇ ghtener analysis according to the UV-Vis spectrometric method, using fresh standard brightener solutions
  • Figure 15 shows a linear calibration curve, which plots increased b ⁇ ghtener concentration caused by each standard addition of brightener, as a linear function of absorbance measured for a nominal solder plating solution after each standard addition of b ⁇ ghtener therein
  • Figure 16 shows the initial measurement result obtained using fresh standard brightener solutions, in comparison with measurement results subsequently obtained using the same b ⁇ ghtener standard solutions, but after such standard solutions have sit for a certain period of time up to three days, according to the UV-Vis spectrometric method for brightener analysis
  • Figure 17 shows va ⁇ ous UV-Vis abso ⁇ tion calibration curves that were constructed by using standard brightener solutions of the same concentration but of different ages
  • Figure 18 is a graph plotting the oxidation-reduction potential of a sample solder plating solution as a function of the pH value of such sample solution, for antioxidant analysis
  • Figure 19 shows three oxidation-reduction potential response curves, each of which plots the oxidation-reduction potential of a calibration solder plating solution of known antioxidant concentration, as a function of the pH value of such calibration solution, for antioxidant analysis
  • Figure 20 shows va ⁇ ous UV-Vis abso ⁇ tion calibration curves measured for antioxidant-fer ⁇ c complex, using either free antioxidant solutions or antioxidant extracted from a sample solder plating solution
  • Figure 21 shows the UV-Vis abso ⁇ tion spectrum of the antioxidant-molybdenum complex, formed by adding neat antioxidant into a complexing solution containing molybdenum dichlo ⁇ de dioxide, ammonium acetate, and EDTA
  • Figure 22 shows the absorbance response measured for the M0O 2 CI 2 /NH 4 C 2 H 3 O 2 /EDTA complexing solution, as a function of the volume of neat antioxidant added into such complexing solution, for antioxidant analysis.
  • Figure 23 shows a calibration curve, constructed to quantitate the relationship between the antioxidant concentration and the absorbance measured.
  • Figure 24 plots the UV light transmission rate of an optical filter that has never been used as a function of the wavelength of the UV light transmitted by such filter, in comparison with the transmission rate and transmission wavelength of an optical filter that has been used for 3 months.
  • Figures 25 and 26 show a photometer board specifically designed for the UV-Vis spectroscopic measurements at short wavelength of about 276nm.
  • Figures 27-31 show the signals detected during various steps of the UV-light detecting process, including the firing of the UV flash lamp, the charging of a capacitor by a photodiode, the converting or translating of the stored charge into a digital signal, and the outputting of the digital signal to a personal computer.
  • Figure 32 shows a raw signal outputted by a UN enhanced silicon hybrid photodiode.
  • Figures 33 and 33A-33C show various views of an optical cell according to one embodiment of the present invention.
  • Figure 34 shows a schematic view of the optical cell of Figures 33-33C.
  • the present invention proposes various methods and apparatuses for automated analysis of the inorganic components (including acid, tin, and lead) and organic components (including polymeric non-ionic surfactant, brightener, and antioxidants) concentration in a sample solder plating solution (i.e., eutectic or high lead solder plating solution), as described in detail in the following sections.
  • a sample solder plating solution i.e., eutectic or high lead solder plating solution
  • Acid-base titration methods have been conventionally used for determining the total acid (i.e., methanesulfonic acid) concentration in solder plating solutions, by titrating the sample solder plating solution with a base titrant, so as to reach a titration endpoint where all the methanesulfonic acid (MSA) has been neutralized by the base titrant.
  • the endpoint is usually indicted by a change of color exhibited by the phenolphthalein pH indicator contained by the sample solution.
  • Phenolphthalein shows color change when the pH is near or above 8.0.
  • the dissolved metal components such as Sn 2+ and Pb 2+
  • titrants for example, hydroxides, carbonates, and amines
  • buffers or electrolytes used.
  • Such precipitation of the metal components causes errors in the conventional acid-base titration methods, because when the Sn(OH) 2 and Pb(OH) 2 precipitates form, more titrant is required in order to reach the endpoint, resulting in an MSA concentration reading that is higher than the actual MSA concentration.
  • Tin (Sn 2+ ) is particularly sensitive to formation of hydroxide, which already starts at low pH values (i.e., pH>l), whereas lead solutions can be titrated as far as pH 7 before any hydroxide precipitation starts.
  • the present invention proposes the following new methods for total acid concentration determination:
  • the direct potentiometry techniques proposed by the present invention involves direct measurement of the electropotential of the sample solder plating solution, and determination of total acid concentration in such sample solder plating solution, based on the electropotential measurement.
  • the present invention determines the total acid concentration in a sample solder plating solution, by the following steps:
  • step (d) determining acid concentration in said sample plating solution, based on the electropotential response(s) measured in step (c) and the correlation determined in step (b).
  • the sample solder plating solution is preferably diluted before any measurement is conducted.
  • the pu ⁇ ose of diluting the sample solder plating solution is to bring the pH value of such solution in a range of from about 1 to 3, preferably near 2 (7mM).
  • the sample solution may be diluted by adding the sample solution (for example 1 or 2 ml) into deionized water (for example, 50 or 100 ml), or deionized water that contains 15 to 25% KN0 3 by volume.
  • the KN0 3 is used herein as an ionic strength buffer, for minimizing interference from tin and lead during acid concentration determination.
  • One specific embodiment of the direct potentiometry proposed by the present invention uses the following steps for determining the acid concentration in a sample solder plating solution: i
  • a slope k was first determined, by measuring the electropotential responses of two successive standard additions of an acid concentrate (with known acid concentration therein) into deionized water (preferably deionized water containing 20% potassium nitrate by volume), according to the following equation:
  • Eache is the electropotential response measured after introduction of the second standard addition of the acid concentrate into the deionized water
  • E is the electropotential response measured after introduction of the first standard addition of the acid concentrate into the deionized water.
  • Slope k so determined is indicative of the correlation between acid concentration and electropotential response in a solution.
  • the electropotential of the sample solder plating solution can then be measured, using a glass electrode. It is preferred that the sample solder plating solution is diluted before the electropotential measurement.
  • the sample solution can be diluted 1/50, using deionized water (preferably deionized water containing 20% KN0 3 by volume).
  • a standard addition of acid concentrate is added into the diluted sample plating solution, and the electropotential of the sample solder plating solution with the standard addition is measured.
  • the amount of standard addition is controlled in such manner that the estimated acid concentration in the diluted sample solution is approximately doubled due to such standard addition.
  • C a is the concentration of acid in the sample solder plating solution
  • V A is the volume of the standard addition of acid concentrate added into the sample solder plating solution
  • c A is the concentration of acid in the standard addition
  • V s is the volume of the diluted sample soldering plating solution
  • E t and E 2 are the potential responses of the diluted sample plating solution measured before and after and the standard addition, respectively.
  • the above-described method for determining total acid concentration in solder plating solutions is generally characterized by a relative standard deviation of less than ⁇ 5%, and more specifically less than ⁇ 1.5%.
  • potentiomefric method uses the following steps for determining the acid concentration in a sample solder plating solution:
  • a predetermined electrical current is passed between two Pt electrodes that are submerged in a base solution, wherein the base solution contains all the components of the sample solder plating solution to be measured, except the methanesulfonic acid.
  • the electropotential between such two Pt electrodes is measured.
  • the electropotential between the two Pt electrodes is monitored for a sufficient period of time (for example 20 to about 40 seconds, more preferably about 30 seconds), so that the two Pt electrodes reach an equilibrium state with more reliable electropotential reading.
  • a certain amount of the sample solder plating solution to be measured is then added into the base solution.
  • the predetermined electrical current is again passed between the two Pt electrodes, and the electropotential of the base/sample solution is measured.
  • Such increase in electropotential is proportional to the acid concentration in the sample solution and can be used to determine the acid concentration in the sample solution.
  • calibration solutions containing the methanesulfonic acid at known, distinctive concentrations can be prepared, and the electropotential increases caused by addition of such calibration solutions are measured, so as to construct a calibration curve showing the electropotential increases as a function of the acid concentrations in solder plating solutions.
  • Figure 1 shows multiple electropotential response curves, six of which were measured for a sample solder plating solution, and one was measured for a calibration solution, according to the method described hereinabove.
  • the incomplete titration technique used by the present invention for determining the total acid concentration in a sample solder plating solution involves arbitrary selection of a titration endpoint having a pH value in a range of from about 3.5 to about 4.5, more preferably in a range of from about 3.8 to about 4.4, and most preferably a pH value of about 4.
  • the incomplete titration technique of the present invention comprises the following steps:
  • the base titrant that can be used for practicing the incomplete titration method as described hereinabove includes, but is not limited to, NaOH, KOH, and ethanolamine.
  • the incomplete titration method of the present invention distinguishes over conventional acid-based titration methods, by selecting a titration endpoint, at which most of the methanesulfonic acid in the sample solder plating solution has reacted with the strong base titrant and therefore recovered, but the lead ions in such sample solder plating solution have not started precipitate yet.
  • the incomplete titration method of the present invention terminates the titration process at such a selected endpoint defined by a pH value in a range of from about 3.5 to about 4.5, so as to maximize the recovery of the methanesulfonic acid, while concurrently minimizing precipitation of the lead ions in the sample solder plating solution during the titration.
  • the selected titration endpoint according to the present invention is preferably characterized by a pH value of sample solder plating solution in the range of from about 3.8 to about 4.4, and more preferably about 4.
  • Figure 2 shows a titration curve for the methanesulfonic acid, measured during an incomplete titration process of the present invention, as described hereinabove. It is evident that the more KOH titrant is added into the sample solder plating solution, the greater the recovery of the methanesulfonic acid. At pH 4, the methanesulfonic acid recovery rate is about 99%. [0088] Total acid analysis was conducted using the incomplete titration method described hereinabove. Three standard solutions containing methanesulfonic acid at various known concentrations were tested, and the test results are as follows:
  • the present invention determines the tin concentration in a sample solder plating solution that comprises both tin and lead ions, by an oxidation-reduction potential (ORP) tifration process, which comprises the steps of titrating such sample solution with a titrant solution, and monitoring the ORP response of the sample solder plating solution during the titration.
  • ORP oxidation-reduction potential
  • tifration solutions can be used, for generating an ORP response that is indicative of the tin concentration in the sample solution.
  • titration solution comprises either iodine or iodide.
  • I. IODINE TITRATION USING STABILIZING SOLUTION [0091]
  • One specific embodiment of the present invention relates to determination of tin concentration in a sample solder plating solution using iodine titration techniques, which comprises the following steps:
  • step (d) calculating the tin concentration in the sample solder plating solution, based on the tifration end point determined in step (c).
  • the sample solder plating solution is first diluted in deionized water before the stabilizing solution is added.
  • the stabilizing solution used by the present invention may comprise ethylenediaminetetraacetate (EDTA) which complexes with the lead ions in the solder plating solution, so as to keep the lead ions from precipitating with iodine during the subsequent iodine titration.
  • EDTA ethylenediaminetetraacetate
  • the stabilizing solution preferably comprises both EDTA and ammonia acetate, wherein ammonia acetate functions to adjust the pH value of the sample solder plating solution to above 4, so that the lead ions therein will effectively complex with EDTA.
  • the tin ions in the diluted sample solder plating solution are titrated with a titration solution comprising iodine.
  • the tin ions in the solder plating solution undergo the following oxidation-reduction reaction with the iodine in the titration solution: I 2 + Sn l 2I ⁇ + Sn
  • the oxidation-reduction potential (ORP) of the sample solder plating solution can be readily monitored, by using a ORP electrode during the iodine titration process, for the piupose of determining an end point of the titration, where all the +2 tin ions in the solder plating solution haven oxidized to the +4 valence.
  • the iodine solution may also comprise a small amount of potassium iodide (KI), for pu ⁇ ose of preserving the iodine therein.
  • KI potassium iodide
  • the lead ions in the sample solder plating solution are stabilized by using EDTA or EDT A/acetate buffer, which complexes with the lead ions in the solder plating solution, so as to keep the lead ions from precipitating with iodine during the subsequent iodine titration.
  • the present invention employs dual polarized platinum electrodes for detecting the titration endpoint during such iodine titration process.
  • the use of the dual platinum electrodes in the present invention solves the electrode passivation problem commonly seen in systems using other types of electrodes, by facilitating automatic in-line cleaning of the analytical cell and the electrodes via an electrolysis process in a conducting electrolyte.
  • dual platinum electrodes as those show in Figures 4A and 4B of the present application can be used, which include a first electrode that can be connected to a potential measurement device and functions as the oxidation-reduction potential (ORP) electrode, and a second, auxiliary elecfrode used solely for electrolytic gas generation.
  • ORP oxidation-reduction potential
  • the first elecfrode is connected to the potential measurement device for ORP measurements of the sample solder plating solutions, as shown in Figure 4A.
  • the first elecfrode is disconnected from the potential measurement device, and connected to a current source (with an operating voltage of about 5-12 VAC), together with the second, auxiliary electrode, as shown in Figure 4B.
  • Both the first and the second electrodes are then immersed in a conducting electrolyte solution. Electrical current passes through the first and second electrodes and the electrolyte solution, generating gases (shown as air bubbles in Figure 4B) and providing a vigorous surface process which peals away any deposit on the electrode surface that may passivate the electrode response to the electropotential changes.
  • gases shown as air bubbles in Figure 4B
  • Figure 5 shows a tifration curve measured for iodine titration of tin ions using the dual platinum electrodes as described hereinabove.
  • the ORP response shows a readily determinable titration endpoint.
  • Another specific embodiment of the present invention relates to iodine titration techniques with pre-titration removal of lead ions from the sample solder plating solution, which comprises the following steps
  • step (d) calculating the tin concentration in the sample solder plating solution, based on the titration end point determined in step (c)
  • the sample solder plating solution is first diluted in deionized water before the lead-precipitating agent is added
  • the lead-precipitating agent used by the present invention may comprise any chemical compound that reacts with the lead ions in the sample solder plating solution to form an insoluble precipitate, provided that such chemical compound does not cause precipitation of the tm ions and has little or no effect on the tin titration result
  • such lead-precipitating agent is selected from the group consisting of HCI, NaCl, KCI, and mixtures thereof More preferably, such lead-precipitating agent compnses hydrochloric (HCI) acid in a solution at a concentration of from about 20% to about 45% by weight, and most preferably at a concentration of from about 35% to about 40% by weight
  • Such lead-precipitating agent may also comprises potassium or sodium chloride (KCI or NaCl) in a solution at a concentration of from about IM to about 3M, and more preferably at a concentration of about 2M
  • Figure 6 shows an iodine titration curve of tin using HCI to remove
  • Figure 7 shows another iodine titration curve of tin, using KCI to remove lead ions from the sample solution before the titration process.
  • Figure 8 shows the results of a series of 24 tin iodine titrations, which were conducted with the pre-titration removal of lead ions, as described hereinabove. The overall standard deviation was about 5%. No cleaning of the ORP electrode was conducted during these titration runs. However, after 14 runs, the titration results started to gradually deviate from the original titration results, which indicates that the ORP needs to be cleaned after about 14 titrations. After about 22 titration runs, the ORP electrode was cleaned with a paper tissue, while the titration result immediately returned to the level of the original titration results.
  • Figure 9 shows the linearity of four iodine tifration results with pre-titration removal of lead ions as described hereinabove, using the ramp function. Good linearity was shown between the volume of sample solder plating solution added and the volume of iodine titrant used.
  • Lead concentration determination can be conducted indirectly, by first determining the total metal concentration in a sample solder plating solution, and then determining tin concentration in such sample solution, using methods described hereinabove, so that lead concentration can be determined by subtracting the tin concentration from the total metal concentration.
  • the total metal concentration can be determined by a titration method.
  • an excess amount of complexing agent (such as EDTA) is added into a preferably diluted sample solder plating solution, in which such complexing agent forms complexes with the metal ions (i.e., both tin and lead ions).
  • a diluted sample solder plating solution in which such complexing agent forms complexes with the metal ions (i.e., both tin and lead ions).
  • an EDTA/ammonia acetate solution is used as the complexing agent, so that the EDTA forms complexes with the tin and lead ions, and the ammonia acetate adjusts the pH value of the solution to above 4.
  • a titration solution which preferably comprises copper sulfate.
  • the CuS0 4 titration can be monitored using a sensor, such as an ion selective electrode (ISE), a photometric sensor, or a thermometric sensor, etc., for determining the titration end point wherein all the excess EDTA is consumed by copper sulfate.
  • the amount of copper sulfate used in the titration is then subtracted from the total amount of EDTA added, to yield the amount of EDTA that has actually complexed with tin and lead ions in the sample solder plating solution, for determining the total metal concentration in the sample solder plating solution.
  • concentration of tin ions in the sample solder plating solution can be separately and independently determined using the various methods described hereinabove for "TIN ANALYSIS.”
  • the concentration of lead can then be determined, by subtracting the tin concentration from the total metal concentration.
  • the lead concentration can also be directly determined, using a direct potentiometry method similar to that described for acid concentration determination, which comprises the steps of:
  • step (b) determining lead concentration in the sample solder plating solution, based on the electropotential response(s) measured in step (c) and the correlation determined in step (b).
  • the sample solder plating solution is preferably diluted before any measurement is conducted.
  • the sample solution may be diluted by adding the sample solution into deionized water or a concentrated electrolytic solution, so as to maintain the pH value of the sample solder solution above 3, where there is a much more stable potential response from the electrode.
  • One embodiment of the present invention uses the following steps for determining the lead concentration in a sample solder plating solution based on the direct potentiometry method described hereinabove:
  • a slope k was first determined, by measuring the electropotential responses of two successive standard additions of a lead concentrate (with known lead concentration therein) into deionized water using a lead ion selective electrode, according to the following equation:
  • E.. - E. k log 2 [0124]
  • E is the electropotential response measured after introduction of the second standard addition of the lead concentrate into the deionized water
  • E is the electropotential response measured after introduction of the first standard addition of the lead concentrate into the deionized water
  • the electropotential of the sample solder plating solution can then be measured, using a lead ion selective electrode It is preferred that the sample solder plating solution is diluted before the electropotential measurement
  • the sample solution can be diluted 1/100, using deionized water
  • a standard addition of lead concentrate is added into the diluted sample plating solution, and the electropotential of the sample solder plating solution with the standard addition is measured by the lead ion selective electrode
  • the amount of standard addition is controlled in such manner that the estimated lead concentration in the diluted sample solution is approximately doubled due to such standard addition
  • C / is the concenfration of lead ions in the sample solder plating solution
  • V A is the volume of the standard addition of lead concentrate added into the sample solder plating solution
  • c A is the concentration of lead in the standard addition
  • V s is the volume of the diluted sample soldering plating solution
  • E t and E 2 are the potential responses of the diluted sample plating solution measured before and after and the standard addition of the lead concentrate, respectively.
  • One way to reduce the error rate of the above-described lead concentration determination is to reduce the effect of the difference in activity coefficients between the sample solder plating solution and the standard addition, by diluting the sample solder plating solution in a concentrated solution of electrolyte. The dilution of sample solder plating solution is even more necessary when analyzing the eutectic sample solder plating solution, in which the concentration of tin is higher than that of lead.
  • the present invention proposes a parallel tifration method for directly determining the lead concentration in a sample solder plating solution, which uses a primary titration solution comprising EDTA and a secondary titration solution comprising a strong base, preferably a metal hydroxide (such as NaOH or KOH).
  • a primary titration solution comprising EDTA
  • a secondary titration solution comprising a strong base, preferably a metal hydroxide (such as NaOH or KOH).
  • EDTA ethylenediaminetetraacetic acid
  • EDTA ethylenediaminetetraacetic acid
  • the present invention employs a primary titration solution comprising EDTA for complexing with the metal ions in the sample solder plating solution, and a glass pH probe for monitoring the pH changes of the sample solution caused by EDTA addition.
  • the present invention employs a secondary titration solution that comprises a strong base, such as NaOH or KOH, to neutralize the released protons after every EDTA addition, so as to compensate for the pH changes caused by the released protons and to ensure that the pH value of the sample plating solution is the same before every EDTA addition.
  • a strong base such as NaOH or KOH
  • the glass pH probe accurately measures and records the pH drop caused by every EDTA addition, while each pH drop so measured and recorded has the same "starting point" and therefore can be compared with each other.
  • the parallel titration method of the present invention starts with the step of conditioning a sample solder plating solution, by adjusting the pH value of such sample solder plating solution to a base value that is within a range of from about 4 to about 4.5.
  • the tin ions in the sample solder plating solution is already in the form of insoluble tin hydroxide (Sn(OH) 2 ), so that the sample solution appears slightly milky.
  • the pH value of the sample solder plating solution can be adjusted by using a base solution comprising hydroxide ions (OH ), such as NaOH or KOH.
  • the sample solution can first be subjected to a total acid concentration analysis using the incomplete titration method described hereinabove, during which the pH value of the sample solder plating solution is titrated to about 4, so that the sample solder plating solution can be used directly for lead concentration analysis according to the parallel titration method described hereinafter, without any sample conditioning or pH value adjusting step.
  • the lead ions are not in hydroxide form, unlike the tin ions, so the protons released by the EDTA during the lead-EDTA complexing are not neutralized, which cause an immediate pH drop in the sample solder plating solution that can be detected and recorded by the pH probe immersed therein.
  • the chemical reaction in this step is as follows:
  • a secondary titration solution comprising hydroxide ions is added into the sample solder plating solution after each EDTA addition, for neutralizing the protons released by the EDTA and for titrating the sample plating solution back to the above-mentioned base pH value.
  • Such secondary titration solution may comprise one or more strong base compounds such as NaOH and/or KOH.
  • the pH value of the sample plating solution is the same (i.e., equal to the base value) before next EDTA addition during the lead-EDTA complexing, so that the pH drop caused by each EDTA addition can be easily quantified and compared with each other.
  • Another advantage of this titration of released protons is that the incremental additions of EDTA and titration of the so released protons ensures that the pH of the solution never decreases to low values that might cause precipitation of the EDTA complex (EDTA and complexes become less soluble as the pH decreases).
  • Figure 10 illustrates the pH values of the sample solder plating solution during the parallel titration described hereinabove, in relation to the EDTA and the secondary titration solution containing OH ' added thereinto.
  • the pH value of the sample solder plating solution remains the same at the base value, regardless of the continuous addition of EDTA.
  • each EDTA addition causes a pH drop in the sample solder plating solution, due to the protons released by the EDTA.
  • Secondary titration solution comprising OH " is then added to the sample solder plating solution after each EDTA solution, so as to neutralize the released protons and adjust the pH value of the sample solution back to the base value.
  • further EDTA additions no longer cause pH drop in the sample solder plating solution, indicating that the end point of the lead-EDTA complexing is reached, and that no additional secondary titration solution is needed. [0144] Therefore, by recording the total amount of OH ' added, one can directly and independently determine the lead concentration in the sample solder plating solution, without any correction.
  • Figure 11 shows multiple titration curves constructed for a sample solder plating solution according to the parallel titration method described hereinabove, plotting the pH value of the sample solder plating solution as a function of the volume of the EDTA addition, starting from the point where the first pH drop in the sample solution is detected. As shown in Figure
  • each addition of EDTA causes a pH drop in the sample solder plating solution, while after the lead-EDTA complexing, EDTA addition no longer results in pH drop, as indicated by the flat "tails" of the titration curves.
  • Figure 12 shows multiple titration curves that plot the volume of NaOH (i.e., the secondary titration solution) added as a function of the EDTA added.
  • the NaOH is added into the sample solder plating solution after each EDTA addition, for neutralizing the released protons and for adjusting the pH value of the sample solution back to the base value.
  • the ratio of NaOH: EDTA is approximately 2: 1 during the lead-EDTA complexing, as shown by Figure
  • the total volume of NaOH used during the parallel titration process can be used for direct calculation of the lead concentration in the sample solder plating solution, because NaOH is only used during the lead-EDTA complexing, and the amount of NaOH consumed is stoichiometric with respect to the lead concentration in the sample solution.
  • the present invention in one embodiment employs potentiostatic methods for determining the concentration of polymeric non-ionic surfactant in solder plating solutions.
  • Cyclic voltammograms scan (CVS) at a scan rate of 100 mV/s were collected in eutectic solder plating solutions that contain polymeric non-ionic surfactant at concentrations varying from 0 to 26 mL/, at an electrode rotation speed of 1200 ⁇ m L
  • a diffusion-limited current plateau was observed when the electrode potential applied was between -0 5 and -0 6 V versus Ag/AgCl reference electrode Such diffusion-limited cu ⁇ ent plateau was stable and reproducible, only slightly dependent on the electrode potential Such diffusion-limited current plateau is likely caused by a potential-independent diffusion process, while metal cations penetrate through the adsorbed surface layer on the electrode
  • the inventors of the present invention have discovered that the time required for the transition from the diffusion-limited current plateau to the unlimited increase of the plating current depends on both the electrode potential applied on the electrodes and the organic polymeric non-ionic surfactant concentration in the sample solder plating solution When the electrode potential applied is held constant, such transition time correlates with the polyme ⁇ c non-ionic surfactant concentration in the sample solder plating solution, and it therefore can be used for polymeric non-ionic surfactant analysis
  • the inventors have discovered that the analytical signals (such as the plating current or the stripping charge), as measured du ⁇ ng the occurrence of the unlimited plating current increase, are strongly dependent on the concentration of polymeric non-ionic surfactant in the solder plating solution In fact, when the polymeric non-ionic surfactant was titrated into an inorganic matrix of solder plating solution, sigmoidal dependency similar to that of conventional titration curves was observed [0153] Therefore, by monitoring the analytical signals during the occurrence of the unlimited increase in plating current, one can readily determine the concenfration of polymeric non-ionic surfactant in the solder plating solution.
  • the anodic limit of the potential region is preferably more negative than +0.1 V versus saturated calomel elecfrode (SCE) vs Ag/AgCl.
  • Plating potential in a range of from about -0.60 to -0.70 V versus Ag/AgCl is generally adequate for measuring sample solder plating solutions with a polymeric non-ionic surfactant concentration of 0.5 to 2 mL/L.
  • Stripping charges rather than plating currents are preferably used herein as the analytical signal, since use of stripping charges results in reduction of noise, as well as reduction of interference caused by hydrogen evolution and oxygen reduction. More preferably, normalized stripping charge is used.
  • Each plating cycle is preferably conducted with a plating time of about 15 seconds, or a plating time of about 2-5 seconds.
  • the stripping potential is preferably about -0.15 V versus Ag/AgCl. In order to avoid large anodic cu ⁇ ents (100mA), an even smaller stripping potential of about -0.25 V or -0.3 V vs. Ag/AgCl can be used.
  • the optimal parameters were found to be: cathodic limit -650--.25 mV, scan rate 50-100 mV/s, and end point at 0.700 of the value in the eutectic VMS solution, with the sample being titrated into the eutectic VMS solution.
  • the optimal parameters were found to be: plating potential -625 ⁇ 25 mV, plating time 2-5 seconds, stripping potential - 300 or -150 mV, and end point at 0.600 of the value in the eutectic VMS solution.
  • the measurement temperature is preferably in a range of from about 30-45°C. Optimization tests for the present invention were conducted at 36.6°C, but better-defined inflection points can be obtained at higher temperatures, such as 40-45°C. When the temperature rises to about 50°C, the titration curves showed poorly defined transitions, and therefore it is desirable to control the measurement temperature at below 50°C.
  • the present invention in another embodiment employs a potentiometric titration method for determining the concentration of polymeric non-ionic surfactant in solder plating solutions.
  • the polymeric non-ionic surfactant used in solder plating solutions is generally a polyether or a polyalkalene glycol.
  • Such non-ionic surfactant is capable of forming a weak complex with a large metal ion, such as barium, and therefore becomes cationic. Since the solder plating solutions contain a large amount of lead ions, which can form the cationic complex with the polymeric non-ionic surfactant therein, no additional metal ions need to be introduced in the present invention.
  • potentiometric titration can be directly carried out in the present invention, by adding a sodium tetraphenylborate titrant solution into the sample solder plating solution, to form an insoluble reaction product with the lead/polymeric non-ionic surfactant complex in such sample solution.
  • the end point of such potentiometric titration can be readily detected by a surfactant electrode.
  • surfactant electrodes suitable for the practice of the present invention can be obtained from Orion Research Inc., Boston, MA.
  • the potentiomefric titration method provides a quick and simple analytical process for the polymeric non-ionic surfactant analysis and generates reproducible and reliable measurement results.
  • the present invention in one embodiment employs UV-Vis spectrometry for determining concentration of the brightener in the solder plating solutions.
  • the first step for UV-Vis spectrometric analysis is to determine a suitable wavelength for the incident UV light, at which the abso ⁇ tion effectuated by the brightener is maximized.
  • the UV-Vis abso ⁇ tion spectra of various test solutions were obtained, which include (1) a solution containing methanesulfonic acid (MSA) and the brightener; (2) a solution containing MSA, the brightener, and tin ions; (3) a solution containing MSA, the brightener, tin ions, and lead ions; (4) a solution containing MSA, the brightener, tin ions, lead ions, and the antioxidant; and (5) a solution containing MSA, the brightener, tin ions, lead ions, the antioxidant, and the polymeric non-ionic surfactant.
  • MSA methanesulfonic acid
  • Figure 13 shows the UV-Vis abso ⁇ tion spectra obtained for the above-mentioned test solutions.
  • the solution containing only MSA and the brightener shows a single abso ⁇ tion peak at a wavelength of approximately 345 nm, while the solution containing tin ions in addition to MSA and the brightener shows a single abso ⁇ tion peak at a different wavelength of approximately 403 nm. Therefore, addition of tin ions causes the abso ⁇ tion peak to shift by approximately 60 nm, which may be contributed to formation of a tin/brightener complex. The addition of lead ions has little effect upon the position of the abso ⁇ tion peak.
  • the solution containing MSA, the brightener, tin and lead ions, and the antioxidant shows two abso ⁇ tion peaks, one at a wavelength of approximately 276 nm, and the other at a wavelength of approximately 403 nm
  • the solution containing MSA, the brightener, tin and lead ion, the antioxidant, and the polymeric non-ionic surfactant shows two abso ⁇ tion peaks at 276 nm wavelength and 403 nm wavelength, respectively
  • the second abso ⁇ tion peak at 403 nm wavelength is contributed to the tin/b ⁇ ghtener complex, while the first abso ⁇ tion peak at 276 nm wavelength is contributed to both the polymeric non-ionic surfactant and the antioxidant
  • the wavelength of approximately 403 ⁇ 10 nm, preferably 403 nm ⁇ 5 nm, and more preferably 410 nm, is chosen for conducting the UV-Vis spectrometric analysis of the brightener concentration in solder plating solution
  • the incident UV light is provided by an UV light source, preferably a super-bright white LED
  • a filter is a ⁇ anged between the UV light source and an analytical chamber that contains the sample solder plating solution to be analyzed, and such filter permits only UV light having wavelength within the suitable range (I e , approximately 403 ⁇ 10 nm, preferably 403 nm ⁇ 5 nm, and more preferably 410 nm) to pass therethrough
  • a UV detector is provided on the other side of the analytical chamber, opposite to the UV light source and the filter, for measuring the amount of UV light that passes through the analytical chamber, and determining the amount of UV light absorbed by the sample solder plating solution in such analytical chamber
  • the absorbance A varies with the concentration c of a specific species in a solution, and a linear relationship between the absorbance A and the concentration c, as follows
  • A ⁇ x b x c [0172] wherein e is the molar absorbtivity of the species, and b is the path length of the sample (i.e., the path length of the cuvette in which the sample is contained).
  • the dilution ratio is preferably within 10-100 for a nominal eutectic solder plating solution (having a brightener concentration of 5 mL/L) or a high lead solder plating solution.
  • standard additions of the brightener of known concentration is successively added into a standard eutectic solder solution that contains only inorganic components, without any polymeric non-ionic surfactant or antioxidant therein.
  • the absorbance at approximately 410 nm is then measured for each standard addition, so as to produce a linear calibration curve, by plotting brightener concentrations as a function of the absorbance measured.
  • the absorbance of the sample eutectic solder plating solution which contains all the components including the organic additives (approximately 100 mL/L polymeric non-ionic surfactant, 5 mL/L brightener, and 10 mL/L antioxidant), can then be measured at similar wavelength, i.e., approximately 410 nm.
  • the concentration of the brightener in the sample eutectic solder plating solution can be readily determined.
  • Figure 14 shows three separate calibration curves constructed for the brightener analysis, which demonstrate good reproducibility of the UV-Vis spectromefric method described hereinabove. The linearity of these calibration curves is excellent, showing very little drift.
  • an extrapolation method is used for conducting the UV-Vis spectrometric analysis and for determining the concentration of the brightener.
  • such extrapolation method comprises the following steps:
  • the absorbance of the sample eutectic solder plating solution which contains all the components including the organic additives (i.e., the polymeric non-ionic surfactant, brightener, and antioxidant), is measured at a wavelength of about 410 nm and recorded as A 0 .
  • the organic additives i.e., the polymeric non-ionic surfactant, brightener, and antioxidant
  • Standard additions of brightener of known concentration are then successively added to the sample solder plating solution.
  • the absorbance of such sample solution after each standard addition of brightener is measured and successively recorded as A A 2 , A 3 , ....
  • the brightener concentration of such sample solution after each standard addition are also calculated and successively recorded as C,, C 2 , C ⁇ , ... , as shown in Figure 15.
  • a linear calibration curve can then be constructed, which plots the brightener concentrations Cj, C 2 , C 3 ... as a linear function of the absorbance A A 2 , A 3 ..., as shown in Figure 15.
  • Figure 16 shows the initial measurement result obtained using fresh standard brightener solutions, in comparison with measurement results subsequently obtained using the same standard solutions, but after such standard solutions have sit for a certain period of time up to three days. It is evident that subsequent measurement results slowly drifted away from the initial results when time passed.
  • Figure 17 shows various abso ⁇ tion calibration curves that were constructed by using standard brightener solutions of the same concentration but of different ages. Specifically, a calibration curve, which was constructed by using a fresh standard brightener solution from Advanced Technology Materials, Inc.
  • AMI American Type Culture Collection
  • Danbury fresh std is compared to (1) a calibration curve constructed by using a shaken 5-day-old standard brightener solution provided by ATMI and identified as “Danbury 5 day old std-shake,” and (2) a calibration curve constructed by using an unshaken (i.e., settled) 5-day-old standard brightener solution provided by ATMI and identified as “Danbury 5 day old std-settled.”
  • the absorbance of the "Danbury 5 day old std-settled” calibration curve is about 25% less than that of the "Danbury fresh std” calibration curve, while the absorbance of the "Danbury 5 day old std-shake" calibration curve is about 20% more than that of the "Danbury fresh std” curve.
  • a calibration cure as constructed by using a fresh standard brightener solution from AMD Saxony Manufacturing GmbH ("AMD") at Dresden, Saxony and identified as “Dresden fresh std,” is compared to a calibration curve constructed by using a shaken 13-day-old standard brightener solution provided by AMD and identified as “Dresden 13 day std-shake.”
  • the absorbance of the "Dresden 13 day std-shake" calibration curve is about 20% more than that of the "Dresden fresh std" calibration curve.
  • a filtering mechanism is preferably used for filtering out the particulates formed in the brightener solutions.
  • the antioxidant used in solder plating solution is a catechol species, which serves as an antioxidant in eutectic solder plating solutions, in order to prevent oxidation of Sn +2 to Sn +4 .
  • the present invention proposes two methods for measuring the antioxidant concentration in solder plating solutions, which include an oxidation-reduction potential method and a UV-Vis spectrometry, as discussed hereinafter.
  • the antioxidant i.e., catechol
  • oxidation-reduction reaction usually undergoes oxidation-reduction reaction in the solution, according to the following equation:
  • one embodiment of the present invention uses an oxidation-reduction potential electrode to monitor the oxidation-reduction potential response of the sample solder plating solution during acid titration.
  • an acid titration solution e.g., methanesulfonic acid
  • the solder plating solution i.e., said acid does not form irreversible products with any component of the solder plating solution
  • was added into to the diluted sample plating solution so as to change the acidity of the sample solder plating solution, by raising the pH value of said sample solder plating solution to a predetermined level.
  • the oxidation-reduction potential of the sample solder plating solution during such acid titration process was measured by the ORP electrode and used to construct an oxidation- reduction potential response curve, by plotting the oxidation-reduction potential as a function of the pH value of the sample solder plating solution.
  • the slope k of the oxidation-reduction potential response curve was determined for the sample solder plating solution, based on the measurements described hereinabove. [0197] Such slope k was then compared with slopes of oxidation-reduction potential response curves constructed for several calibration solder plating solutions of known antioxidant concentration, for the pu ⁇ ose of determining the antioxidant concentration in the sample solder plating solution.
  • Figure 18 shows a graph that plots the reduction-oxidation potential response measured for a sample solder plating solution, as a linear function of the pH value of such sample solution.
  • Figure 19 shows a graph that contains three calibration curves showing the oxidation-reduction potential responses measured for three calibration solutions of known antioxidant concenfration.
  • the present invention in another embodiment employs UV-Vis spectroscopy techniques for determining antioxidant concentration in solder plating solutions.
  • the UV-Vis spectroscopy can be conducted either by detecting formation of an antioxidant-derivative, or by direct detection of the antioxidant molecule in the solder plating solution.
  • One specific embodiment of the present invention involves using ferric chloride to form a blue complex with the antioxidant, which has a maximum absorbance around 750 nm and is detectable by UV-Vis spectrometry.
  • Such antioxidant-ferric complex decomposes in approximately 5-20 minutes in water, but it is stable in methanol solution. Addition of pyridine to the methanol solution decreases the transient period of color development, increases the maximal extinction coefficient by about 3-5 times, and blue-shift the abso ⁇ tion maximum to 600 nm.
  • a FeCl 3 /Pyridine/Methanol solution is employed by the present invention for complexing with the antioxidant in the solder plating solution.
  • 0-450 ⁇ m standard antioxidants can be added into a methanol solution comprising 12.5 mM pyridine and 7.5 mM ferric chloride. Experimental results show that such standard antioxidants produced a linear calibration curve with stable absorbance reading within two minutes after the mixing of the antioxidants with the FeCl 3 /Pyridine/Methanol solution.
  • the UV-Vis absorbance reading is conducted using antioxidant as extracted from the aqueous solder plating solution, so as to eliminate the deleterious impact of the solution matrix. More preferably, ethylacetate is used for extracting the antioxidant from the solder plating solution.
  • Figure 20 shows two calibration curves marked by squares, which were obtained by adding a freshly made 0.1 M aqueous solution of antioxidant to a 25g (35ml) FeCl 3 /Pyridine/Methanol solution that contained 12.5 mM pyridine and 7.5 mM FeCl 3 in methanol.
  • the calibration curve marked by the solid squares was measured at a wavelength of about 585 nm
  • the calibration curve marked by the open squares was measured at a wavelength of about 715 nm. Both curves show linear abso ⁇ tion responses.
  • Figure 20 also shows two calibration curves marked by circles (either open or solid), which were obtained by extracting the antioxidant from a fresh eutectic samples prepared with neat antioxidant solution, by using ethylacetate. Specifically, 10 ml of each sample were extracted with 2 ml of ethylacetate, and 0.1 ml of the extract was injected into 25g (35ml) FeCl 3 /Pyridine/Methanol solution that contained 12.5 mM pyridine and 7.5 mM FeC in methanol. The calibration curve marked by solid circles was measured at a wavelength of about 585 nm, and the calibration curve marked by open circles was measured at a wavelength of about 715 nm.
  • Figure 20 further contains two calibration curves marked by triangles, which were obtained by using ethylacetate to extract the antioxidant from a Solderon® SC antioxidant concentration commercialized by Shipley Ronal at Marlborough, MA. The abscissas of the data points were calculated under the assumption that the Solderon® SC antioxidant concentrate has a catechol concentration of about IM.
  • the UV-Vis specfroscopic analysis of a nominal eutectic sample as described hereinabove can be performed in an automated analyzer, while extraction and analysis of the antioxidant can be carried out in a photometric cell of such automated analyzer.
  • the sample solder plating solution is used for a UV-Vis specfroscopic analysis in such automated analyzer, and the total volume of the sample solder plating solution plus the ethylacetate solution is about 15 ml.
  • approximately 0.3 ml of the antioxidant extract is injected into the photometric cell for automatic UV-Vis spectroscopic analysis.
  • the photometric cell is preferably filled with about 16 ml of the FeCl 3 /Pyridine/Methanol solution for measuring the reference light intensity of the solution (i.e., the reference measurement).
  • An alternative embodiment of the present invention involves use of molybdate ions to form a yellow-orange colored antioxidant-molybdenum complex with the antioxidant, which can be readily measured via UV-Vis spectroscopy
  • the wavelength at which the antioxidant-molybdenum complex shows maximum absorbance was first determined using a complexing solution containing molybdenum dichlo ⁇ de dioxide, ammonium acetate, and EDTA Neat antioxidant was added into such complexing solution, and the UV-Vis spectrum of the solution was measured, as shown in Figure 21
  • the antioxidant-molybdenum complex shows maximum absorbance at a wavelength in a range of from about 280nm to about 320nm, and approximately 300nm
  • Figure 22 shows the absorbance response measured for the M0O2CI 2 /NH4C2H3O2/EDTA solution, as a function of the volume of neat antioxidant added into such solution
  • the absorbance response of the solution shows a linear relationship with the antioxidant concentration in the solution (1 e , volume of the antioxidant added into such solution), m compliance with Beer's law
  • a complexing solution comprising 0005M molybdenum dichlo ⁇ de dioxide, 1 5M ammonium acetate, and 0 IM EDTA can be used for forming the antioxidant-molybdenum complex, and the measurement results using such complexing solution demonstrated good reproducibility
  • UV-Vis spectroscopic analysis of antioxidant concenfration in a high lead solder plating solution which comprises Sn, Pb, MSA, and antioxidant at a concentration of about 10 ml/L
  • a high lead solder plating solution which comprises Sn, Pb, MSA, and antioxidant at a concentration of about 10 ml/L
  • 15 ml of the Mo ⁇ 2 Cl 2 /NH 4 C 2 H 3 ⁇ 2 /EDTA solution as described hereinabove
  • 1 5 ml of the sample high lead solder plating solution A calibration curve as shown in Figure 23 was constructed to quantitate the relationship between the antioxidant concentration and the absorbance measured, using 0 5 ml antioxidant diluted in water with an additional 0 25 ml of neat ethanolamine added therein
  • the present method for determining the antioxidant concentration in a sample solder plating solution overcomes the background interference from tin, lead, and brightener in such sample solution, and allows accurate determination of antioxidant concenfration
  • UV-Vis spectromefric techniques at 276 ⁇ 20 nm may also be used for determining the concentration of antioxidant in a sample solder plating solution UV-Vis spectrometric detection at such a short wavelength requires that the UV optics, the photometer board, and the UV detection devices be specifically designed for generating, transmitting, and sensing such short-wavelength UV light
  • a small, inexpensive, long lived UV light source for generating UV lights having wavelength of a broad spectrum, preferably from about 200nm to about 2500nm, and more preferably from 160nm to about 5000nm
  • such UV light source has a low power consumption, l e , it requires power of not more than 5 watts, more preferably not more than 2 watts, and it draws a peak current of not more than 2 amp, more preferably not more than 1 amp, which can be easily supplied by an onboard transformer
  • It is also preferred that such UV light source has a high emission intensity of at least 30 mJ/pulse, more preferably at least 40 mJ/pulse, and a high emission frequency of at least 25 Hz, more preferably at least 50 Hz
  • the size of such UV light source is preferably small, l e , having a cross-sectional area of not more than 2 dm 2 , more preferably, not more than 1 dm 2 , and most preferably not
  • optical filters that selectively transmit UV light of a wavelength in the vicinity of 276 nm (I e , 276 ⁇ 20 nm), and block UV light of other wavelength are employed for providing a single beam of UV light having 276 ⁇ 20 nm wavelength
  • One group of optical filters particularly suitable for practicing the present invention are the narrow band interference filters manufactured by MK Photonics, Inc at Albuquerque, NM
  • Such narrow band interference filters from MK Photonics selectively transmit UV light having wavelength centered at 276 nm, with a full-width half-maximum (FWHM) of ⁇ 6nm and a minimum peak transmission of 20%.
  • FWHM full-width half-maximum
  • Figure 24 shows a graph that plots the transmission rate of a filter that has never been used as a function of the wavelength of UV light transmitted by such filter, in comparison with the transmission rate and transmission wavelength of a filter that has been used for 3 months, indicating that the degradation of the optical filters leads to significant changes in the wavelength of the UV light transmitted by such filter and the transmission rate. Therefore, a periodic maintenance of at least once a month with respect to the optical filter is preferred.
  • the transmission of the filtered UV light to the sample solution to be analyzed and then to the detection device must be conducted using optical materials that are transparent to UV light, especially to UV light with wavelength of about 276nm.
  • Fiber optics is particularly prefe ⁇ ed in the present invention, which can be inco ⁇ orated into special adapters for adapting the UV light source to the optical cell.
  • Low-hydroxl fibers are more preferred, and three different sizes of the fibers can be used to attenuate or increase light intensity, including 400 micron, 600 micron, and 1000 micron.
  • SMA 905 multimode connector suitable for single fiber connections is most preferred for forming such adapters.
  • optically clear fluorinated ethylenepropylene (FEP) tape having a thickness of about 0.011 inch with adhesive backing can be used on the UV optics, which will provide longevity for the expensive UV optics and reduce the periodic maintenance frequency of such UV optics.
  • FEP fluorinated ethylenepropylene
  • Figures 25 and 26 show new photometer board specifically designed for the UV-Vis spectroscopic measurements at short wavelength of about 276nm, which allows dispersive measurement of the UV light emitted by pulsed or continuous UV light sources.
  • photometer board is hereby used for measuring the UV-Vis abso ⁇ tion spectrum of the antioxidant, which has a maximum abso ⁇ tion wavelength at 276nm.
  • photometer board can also be used to measure other the UV-Vis abso ⁇ tion spectrum of other chemical species of different maximum abso ⁇ tion wavelength in the solder plating solution, by changing the optical filters used on the UV optics.
  • photometer board can also be used for UV-Vis specfroscopic analysis of the brightener, using an optical filter for selectively transmit UV light having wavelength centered at about 403 nm (which is the maximum abso ⁇ tion wavelength for the tin/brightener complex). Therefore, the photometer board of the present invention can be arranged and configured to measure UV-Vis abso ⁇ tion spectrum of multiple components in a sample solder plating solution, by simple changing the optical filters used.
  • Such new photometer board houses the equivalents of two full spectrometers with reference features in addition to a temperature-sensing component. Further features of such photometer board include:
  • the 24 volt input is regulated down to an isolated 12V (Ml) and 5V (M2) on the board.
  • Peak capture diodes (D2 & D3) on the signal inputs can capture microsecond transient signals.
  • optical fibers allowing flexibility in the light sources used.
  • the photometer board is a printed circuit board that contains specific electronics thereon. In addition to its analog - to - digital (ADC) and digital - to - analog (DAC) capabilities, it contains a PIC microprocessor that controls the sensor operations.
  • the PIC is programmed by a PC, on which the source code for the sensor software is stored and compiled. Because the PIC is an EEPROM, it can be programmed by a personal computer (PC), shut off, and retain the stored information. Besides controlling all aspects of sensor operation, the PIC can be programmed directly from the PC and communicates serially via RS-232 protocol with a PC.
  • the PC preferably provides a user interface for the photometer board. Furthermore, an interface program stored in the PC allows the user to save data from the sensors, set alarm and operational values in the sensor, and create a real-time, continuously updating graph of the sensor data.
  • the peak-detect-capture technique used with operational amplifier allows measurement of a fast signal, through the following steps •
  • the Xenon flash lamp fires UV light, causing the hybrid photodiode to respond with a photo-generated current subsequently magnified by the on-board operational amplifier into a voltage pulse
  • the voltage pulse travels down to the photometer board where it enters the operational amplifier non-inverting terminal on line A7 on connector PI •
  • the operational amplifier inverting terminal matches the non-inverting terminal and creates a pulse in the feed back circuit comprising a resistor R5 and two diodes D2 and D3
  • the gain in the feed back circuit is 100K/30K while the diode allows charge to pass in one direction only to charge up the 0 1 microfarad capacitor at TP5, while preventing the capacitor from being discharged
  • the second diode compensates for the voltage drop over the first diode (0 7V), so that signals of less than the diode's 0 7V turn on voltage can be measured
  • Figure 27 shows the pulse generated by the photodiode (for example, a SiC photodiode) in response to the flash of UV light generated by the flashlamp Such pulse is converted into charge stored on a capacitor, which can be read by a A/D device
  • the left-hand picture depicts a pulse from the photodiode after it has been magnified by the operational amplifier as viewed from an oscilloscope trace at Test Point 1 (TPl) on Figure 25
  • the right-hand picture depicts three repeated pulses from the photodiode, each pulse leading to stored charge on the capacitor as measured at Test Point 5 (TP5) on Figure 25
  • TP5 Test Point 5
  • FIG. 28 shows the start of the signal process, where a 3 6V transistor-transistor logic (TTL) signal from the PIC microcontroller causes the flash lamp to fire a UV light pulse, and the end of the signal process, where a smaller 2 5V photodiode detector response is captured 40 microseconds later on the capacitor and read by the A/D chip back into the PIC microcontroller
  • TTL transistor-transistor logic
  • Figure 29 shows the conversion or translation of the analogue signal, which is the stored charged on the capacitor caused by the photodiode response, into a digital format by a A/D device
  • the conversion or translation starts when a TTL signal (I e , the square wave on Figure 29) occurs, which is approximately 11 microseconds after the peak stored voltage has been reached in the capacitor
  • the first 40 microsecond pulse followed by a 20 microsecond dip is actually the digital data input m the form of a 3 bit word that configures the Linear Technology 1298 A/D chip to enable the start of the conversion.
  • Such conversion or translation image is captured by an oscilloscope.
  • Figure 30 shows the whole process including the initial signaling, the signal detection, the conversion from analog to digital format, and the outputting of the digital data to the PIC microcontroller, all taking place within 540 microseconds, which is much shorter than the time intervals between signals, as determined by the repetition rate of the flash lamp (usually about 10 Hz). Specifically, the latter three steps (i.e., the signal detection, the conversion, and the data outputting) occur within the time period when the voltage charge is stored on the capacitor.
  • Figure 31 shows a typical pulse series measured at the capacitor as the output of the operational amplifier UIA.
  • the process illustrated in Figure 28 occurs, which includes the charging of the capacitor upon detection of the flash UV light by the photodiode, the reading of the stored charge, the conversion of the charge data into a digital format, the transmission of such digital data into the PIC microcontroller, and the discharging of the capacitor after the data has been read.
  • the pulse frequency is approximately 800 milliseconds or 12.5 Hz.
  • the present invention employs a hybrid photodiode or a photodiode equipped with an integrated operational amplifier, so as to minimize signal interference.
  • a hybrid photodiode such as a UV enhanced silicon photodiode in a standard T05 package, allows for an extremely robust signal prior to any amplification and generates stable pulse peak heights of smaller variance.
  • Figure 32 shows a raw signal from the UV enhanced silicon photodiode as described hereinabove, in a sample cell containing air only and measured by an oscilloscope
  • the magnitude of the raw signal is greater than 1 7 volts, without any amplification, and the FWHM is approximately 120 microseconds
  • This signal is significantly better than that measured by the conventional SiC photodiode, which could not be measured without at least one stage of amplification by the photometer board
  • the strong signal seen above indicates that the signal-to- noise ratio will no longer be an issue.
  • the present application in another aspect relates to an optical cell for conducting spectrometric analysis of a target component, such as the brightener or the antioxidant, contained by a sample solder plating solution
  • Such optical cell may comprises
  • one or more fluid inlets connected to the first fluid compartment for introducing one or more test solutions thereinto;
  • a fluid outlet connected to the second fluid compartment for discharging one or more test solutions
  • a fluid mixing device in the first and or second fluid compartment for mixing the one or more test solutions; an irradiation light source for irradiating light into the second fluid compartment;
  • a light detector coupled with the irradiation light source for detecting light transmitted or emitted by the one or more test solutions in said second fluid compartment;
  • a computational device connected with the light detector, for collecting absorbance spectrum of the one or more test solutions and conducting spectrometric analysis based thereon.
  • Figure 33 shows an exterior view of an optical cell according to one embodiment of the present invention, having two light source housings, two detecting housings, a stirring motor assembly, and eight fluidic ports for introducing test solutions.
  • Figure 33 A shows the top half of the optical cell, comprising a cap and a mixing shaft for mixing the test solutions.
  • Figures 33B and 33C shows the cross-sectional views of the bottom half of the optical cell, comprising a large fluid compartment and small fluid compartment connected thereto.
  • the small fluid compartment has a volume of about 1/5 to about 1/2 of that of the large fluid compartment.
  • the light source and the light detector are arranged and constructed to provide one or more light paths through such small fluid compartment for spectrometric analysis.
  • the fluidic ports are connected to the large fluid compartment for introducing one or more test solutions thereinto, and the mixing shaft extends through the whole large fluid compartment into the small fluid compartment and terminates above where the light paths are.
  • the large fluid compartment provides a sufficiently large space for fluid introduction and mixing, without obstructing the light paths or otherwise interfering with the spectrometric analysis in the small fluid compartment.
  • Such double-compartment configuration for the optical cell requires a minimum amount of sample solder plating solution to be used for analysis pu ⁇ ose, as determined by the volume of the small fluid compartment, instead of that of the large fluid compartment.
  • the present invention provides an opaque polymeric cover for covering both the large and the small fluid compartments.
  • Such opaque polymeric cover is preferably a black polyvinyl chloride cover.
  • the optical cell of the present invention preferably comprises a corrosion-resistant liner on the interior surface of each of the large and the small fluid compartments.
  • Such corrosion-resistant liner is more preferably a tetrafluoroethylene liner, and most preferably a Teflon® liner.
  • Figure 34 shows a perspective view of the optical cell of the present invention, wherein a light source directs light through the small fluid compartment into a light detector, for conducting spectrometric analysis.
  • a computation device (not shown here) can further be provided, which connects to the light detector for collecting absorbance spectrum of said one or more test solutions and conducting spectrometric analysis based thereon.
  • Said computation device may comprise personal computers, work stations, microprocessors, on-line analyzer, or any other suitable computation devices.
  • Raman spectroscopy is a non-destructive, quantitative, and qualitative tool used for the identification and analysis of both inorganic and organic species. It has been widely considered a complementary analysis method to infrared spectroscopy. A significant advantage that Raman spectroscopy possesses over infrared spectroscopy is the ability to collect useful molecular information under aqueous conditions using sample cells made of glass or quartz.
  • Instrumentation for Raman spectroscopy comprises three major components: a high- intensity irradiation source, a sample illumination system, and a specteophotometer.
  • Irradiation sources that have been used for Raman spectroscopy range from HeNe lasers to Nd: YAG lasers.
  • the choice of laser used for the analysis is largely determined by the method of analysis and molecular species.
  • Sample illumination can be achieved using a number of techniques. With the advancement of fiber optic technology, great variability in cell design can be achieved.
  • the Raman spectroscopy system can be inco ⁇ orated into an analyzing cell that is designed for analyzing solder plating solutions, which allows continuous flow of sample solder plating solutions therethrough and offers real-time, in situ analysis of the sample solution.
  • the analyzing cell also comprises inlet and outlet valves, so that such cell can be isolated from the sample flow during calibration or cleaning process.
  • Raman spectrophotometer detects the amount of radiation energy scattered by a specific component of the solder plating solution, and because the intensity of such scattered radiation energy is linearly proportional to the concentration of the specific component, Raman spectroscopy can be used to accurately and precisely determine the concentrations of various components, including inorganic or organic components, in solder plating solutions.
  • Raman spectroscopy provides efficient concentration determination method for solder plating solutions, or other type of metal plating solutions. Moreover, the recent availability of spectral database make it possible to perform spectral searches using obtained spectral data, therefore, spectra of multiple components in a sample solution can be separated, and impurities or by-products in such sample solution can be readily determined. [0252] Although the invention has been variously disclosed herein with reference to illustrative embodiments and features, it will be appreciated that the embodiments and features described hereinabove are not intended to limit the scope of the invention, and that other variations, modifications and other embodiments will suggest themselves to those of ordinary skill in the art. The invention therefore is to be broadly construed, consistent with the claims hereafter set forth.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Automation & Control Theory (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Investigating And Analyzing Materials By Characteristic Methods (AREA)

Abstract

L'invention concerne des procédés et un appareil permettant de déterminer des concentrations de divers composants organiques et non organiques dans des solutions d'électrodéposition de brasure, qui comprennent des procédés de titrage ou de titrage en parallèle, des procédés de potentiométrie directe, des procédés d'étalonnage, ainsi qu'une analyse d'absorption d'UV-Vis.
PCT/US2003/005568 2002-03-08 2003-02-24 Procedes et appareils d'analyse de solutions d'electrodeposition de brasure WO2003076694A2 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2003219869A AU2003219869A1 (en) 2002-03-08 2003-02-24 Methods and apparatuses for analyzing solder plating solutions

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US36274102P 2002-03-08 2002-03-08
US60/362,741 2002-03-08
US10/315,629 US6913686B2 (en) 2002-12-10 2002-12-10 Methods for analyzing solder plating solutions
US10/315,629 2002-12-10

Publications (2)

Publication Number Publication Date
WO2003076694A2 true WO2003076694A2 (fr) 2003-09-18
WO2003076694A3 WO2003076694A3 (fr) 2004-09-30

Family

ID=27807710

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2003/005568 WO2003076694A2 (fr) 2002-03-08 2003-02-24 Procedes et appareils d'analyse de solutions d'electrodeposition de brasure

Country Status (3)

Country Link
AU (1) AU2003219869A1 (fr)
TW (1) TW200306418A (fr)
WO (1) WO2003076694A2 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2909179A1 (fr) * 2006-11-29 2008-05-30 Commissariat Energie Atomique Procede de mesure du pouvoir complexant global d'une solution comprenant plusieurs especes chimiques complexantes
CN101923055A (zh) * 2010-07-04 2010-12-22 肖才斌 便携式多功能比色仪
CN102323316A (zh) * 2011-08-16 2012-01-18 浙江大学 一种高温高压pH电极的标定装置及标定方法
CN111766277A (zh) * 2020-06-09 2020-10-13 安徽大学 一种区分金属离子Fe3+及Cu2+的方法
CN112098393A (zh) * 2020-09-14 2020-12-18 中国工程物理研究院机械制造工艺研究所 抗氢钢管hr-1直读光谱多元素测定方法
CN114486972A (zh) * 2022-02-16 2022-05-13 云南惠铜新材料科技有限公司 一种铜箔电镀液快速测定方法
CN116183534A (zh) * 2022-11-30 2023-05-30 盐城吉瓦新材料科技有限公司 一种电镀液光亮剂的检测方法
CN116337805A (zh) * 2023-05-22 2023-06-27 成都博瑞科传科技有限公司 基于阵列光谱和离子选择法的水中总磷检测方法及传感器

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4696721A (en) * 1985-12-27 1987-09-29 Kabushiki Kaisha Toshiba Electroforming method and electroforming apparatus
US4812210A (en) * 1987-10-16 1989-03-14 The United States Department Of Energy Measuring surfactant concentration in plating solutions
US5286358A (en) * 1991-08-01 1994-02-15 The Foxboro Company Method of analyzing the complexing power of a pickling liquor
US5324400A (en) * 1992-12-04 1994-06-28 Hughes Aircraft Company Electrode preconditioning method for a plating bath monitoring process
GB2327126A (en) * 1997-07-10 1999-01-13 Atotech Deutschland Gmbh Monitoring surfactant/polyelectrolyte concentration in electroplating bath by zeta potential measurement

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5655842A (en) * 1979-10-12 1981-05-16 Japan Spectroscopic Co Monitoring device for concentrating of mixed acid by laser raman spectroscopy
JPS5885140A (ja) * 1981-11-16 1983-05-21 Nec Corp めつき液中の光沢剤濃度の測定方法
JPH06255610A (ja) * 1993-02-26 1994-09-13 Tokyo Autom Mach Works Ltd 結束機並びにベール梱包装置及び結束方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4696721A (en) * 1985-12-27 1987-09-29 Kabushiki Kaisha Toshiba Electroforming method and electroforming apparatus
US4812210A (en) * 1987-10-16 1989-03-14 The United States Department Of Energy Measuring surfactant concentration in plating solutions
US5286358A (en) * 1991-08-01 1994-02-15 The Foxboro Company Method of analyzing the complexing power of a pickling liquor
US5324400A (en) * 1992-12-04 1994-06-28 Hughes Aircraft Company Electrode preconditioning method for a plating bath monitoring process
GB2327126A (en) * 1997-07-10 1999-01-13 Atotech Deutschland Gmbh Monitoring surfactant/polyelectrolyte concentration in electroplating bath by zeta potential measurement

Non-Patent Citations (11)

* Cited by examiner, † Cited by third party
Title
DATABASE CAPLUS [Online] ADAMOVA N.A. ET AL: 'Determination of some surfactants by alternating current polarography', XP002976656 Retrieved from STN Database accession no. 1986:226718 & IZVESTIYA AKADEMII NAUK MOLDAVSKOI SSR, BIOLOGICHESKIE I KHIMICHESKIE NAUKI vol. 1, 1986, pages 73 - 76 *
DATABASE CAPLUS [Online] MILLER R.L.: 'LC methods development employing spectroscopy: analysis of electroplating solutions', XP002976658 Retrieved from STN Database accession no. 1981:508107 & CHROMATOGRAPHY NEWSLETTER vol. 9, no. 1, 1981, pages 10 - 12 *
DATABASE CAPLUS [Online] TSINGARELLI R.D. ET AL: 'Solid-phase electrodes selective to lead and cadmium ions', XP002976655 Retrieved from STN Database accession no. 1986:417263 & ZHURNAL ANALITICHESKOI KHIMII vol. 41, no. 3, 1986, pages 449 - 452 *
DATABASE CAPLUS [Online] WEISHENG Y.: 'Solder mask protective technology in production of multilayer printed circuit boards', XP002976657 Retrieved from STN Database accession no. 2003:45687 & CAILIAO BAOHU vol. 35, no. 3, 2002, pages 49 - 50 *
HALMEKOSKI J.: 'Quantitative spectrophotometric determination of catechol, hydroquinone and resorcinol in aqueous solutions' J. SUOMEN KEMISTILEHTI vol. 32, 1959, pages 274 - 276, XP002976700 *
HORKANS J.: 'Polagraphic methods of monitoring addition agent in the electroplatig of Sn-Pb solders' IBM J. RES. DEVELOP vol. 42, no. 5, September 1998, pages 621 - 628, XP002976683 *
KONISHI ET AL: 'Control of lead-tin fluoroborate plating bath and analysis of the deposit' KINZOKU HYOMEN GIJUTSU vol. 17, no. 9, 1966, pages 343 - 350, XP002976671 *
KONISHI ET AL: 'Lead-tin alloy bath control' METAL FINISHING September 1996, pages 66 - 74 *
SCHOLZ E.: 'Analysis of fluoroborate baths and other fluoroborate solutions' GALVANOTECHNIK vol. 66, no. 10, 1975, pages 811 - 819, XP002976664 *
SHIPULO ET AL: 'Potentiometric titration in analysis of electroplating baths' ZAVODSKAYA LABORATORIYA vol. 57, no. 10, 1991, pages 15 - 17, XP002976684 *
SKOOG D.A.: 'Principles of Instrumental Analysis, 3rd edition', 1985 pages 627 - 633, XP002981923 *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2909179A1 (fr) * 2006-11-29 2008-05-30 Commissariat Energie Atomique Procede de mesure du pouvoir complexant global d'une solution comprenant plusieurs especes chimiques complexantes
CN101923055A (zh) * 2010-07-04 2010-12-22 肖才斌 便携式多功能比色仪
CN102323316A (zh) * 2011-08-16 2012-01-18 浙江大学 一种高温高压pH电极的标定装置及标定方法
CN111766277A (zh) * 2020-06-09 2020-10-13 安徽大学 一种区分金属离子Fe3+及Cu2+的方法
CN112098393A (zh) * 2020-09-14 2020-12-18 中国工程物理研究院机械制造工艺研究所 抗氢钢管hr-1直读光谱多元素测定方法
CN114486972A (zh) * 2022-02-16 2022-05-13 云南惠铜新材料科技有限公司 一种铜箔电镀液快速测定方法
CN116183534A (zh) * 2022-11-30 2023-05-30 盐城吉瓦新材料科技有限公司 一种电镀液光亮剂的检测方法
CN116183534B (zh) * 2022-11-30 2024-05-03 盐城吉瓦新材料科技有限公司 一种电镀液光亮剂的检测方法
CN116337805A (zh) * 2023-05-22 2023-06-27 成都博瑞科传科技有限公司 基于阵列光谱和离子选择法的水中总磷检测方法及传感器
CN116337805B (zh) * 2023-05-22 2023-07-21 成都博瑞科传科技有限公司 基于阵列光谱和离子选择法的水中总磷检测方法及传感器

Also Published As

Publication number Publication date
AU2003219869A8 (en) 2003-09-22
WO2003076694A3 (fr) 2004-09-30
TW200306418A (en) 2003-11-16
AU2003219869A1 (en) 2003-09-22

Similar Documents

Publication Publication Date Title
US6913686B2 (en) Methods for analyzing solder plating solutions
CN107085117B (zh) 测量装置和测量方法
US4049382A (en) Total residual chlorine
US20040046121A1 (en) Method and system for analyte determination in metal plating baths
US20030030800A1 (en) Method and system for the determination of arsenic in aqueous media
CA2025766A1 (fr) Methode et appareil de determination de concentrations de substances chimiques pour le traitement des semiconducteurs
WO2003076694A2 (fr) Procedes et appareils d'analyse de solutions d'electrodeposition de brasure
Freeman et al. A fiber-optic absorption cell for remote determination of copper in industrial electroplating baths
US20150070702A1 (en) Changed optical path measuring device for component concentration of water and measuring method thereof
Choi et al. Development of sulphide-selective optode membranes based on fluorescence quenching
US20030049858A1 (en) Method and system for analyte determination in metal plating baths
US10920336B2 (en) Analysis of silver ion and complexing agent in tin-silver electrodeposition solution
EP2982967A1 (fr) Procédé et système de surveillance en temps réel et in-situ d'une solution au cours d'un procédé à base d'une solution
EP0501480B1 (fr) L'analyse des solutions de placage en étain, plomb ou alliage d'étain-plomb
US20090103084A1 (en) OXYGEN SENSOR FOR USE IN HARSH, ESPECIALLY HIGH, pH ENVIRONMENTS
JP2019113357A (ja) 分析方法および分析装置
US11340205B2 (en) Systems and methods for determining concentrations of materials in solutions
US20230122644A1 (en) Sensor for measuring a ph value of a measuring liquid
CN117074487B (zh) 光电性能检测分析设备和方法
Shalyt et al. Comprehensive Characterization of All Inorganic and Organic Components in Neutral Tin Plating Bath for Electronics Applications
JP2003004726A (ja) メッキ液の硫酸濃度測定方法
Shalyt et al. Control of electroless nickel baths
WO2003008919A1 (fr) Procede et systeme de determination d'analytes dans des bains de galvanoplastie
Periolatto et al. Routine Monitoring of Trace Arsenic in Water by Lab-on-a-chip Technology: a Preliminary Study
JP4029815B2 (ja) めっき装置、めっき液評価装置、めっき液の運用方法及びめっき液の評価方法

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GE GH HU IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SK SL TJ TM TR TT UA UG UZ VN YU ZW

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PT SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
NENP Non-entry into the national phase in:

Ref country code: JP

WWW Wipo information: withdrawn in national office

Country of ref document: JP