How to Reball a BGA: 5 Stages from Deciding Whether to Reball, Removing Old Balls, Placing New Balls and Reflow, to Cleaning, Inspection and Records

BGA reballing means replacing or restoring the solder balls on the underside of a ball grid array (BGA) package. It is a form of rework, not a universal fix. Whether you can reball depends first on where the part came from, whether it can go through reflow again, whether the pads are damaged, and whether the customer agrees. While doing it, old solder must be cleaned off completely, flux applied fully, ball size and alloy must be right, and reflow should be as close as possible to production conditions. Afterward, the part must be cleaned, inspected and recorded. One journal paper replaced lead-free balls with tin-lead balls: reballed assemblies failed earlier in thermal cycling than assemblies that had not been reballed, and there was no difference between three reballing methods. When a part is inexpensive and available, or of unknown origin, replacing it with a new one is often simpler than reballing.

• Ask “why reball?” first: defective balls on a new part, reusing an old part, and changing alloy each have different requirements; if the part’s origin is unknown or the customer does not agree, use a new part (Stage 1).
• Clean off old solder, apply enough flux, and get ball size and alloy right: the common line causes of missing balls, offset and mixed ball sizes all fall in this part of the process (Stages 2 and 3).
• Keep reflow close to production, and count the cycles: every reflow uses up part of the life of the component and the board; bake moisture-sensitive parts before reflow (Stage 4).
• Clean, inspect and record: looking clean does not mean meeting cleanliness requirements; write the pass criteria before you start (Stage 5).

This article starts when a BGA needs to be reballed and ends when it has been inspected and recorded. It covers small-volume reballing in factories and repair shops, not a packaging house’s production line. For how to inspect BGA joints (X-ray, dye-and-pry, cross-section), see “How to Inspect BGA Solder Joints: X-ray, Dye-and-Pry or Cross-Section, in 5 Stages.” For exposure time and baking after a part is opened, see “Storage and Baking Conditions for Moisture-Sensitive Devices: How to Handle 4 States After Opening.” Mounting the BGA back onto the board (stencil printing, alignment, rework station setup), rework of parts other than BGAs, and solder joint failure analysis are outside its scope. Each stage covers how to do it, what public sources say, and how JIAHON can help; sources, exceptions and terms are in the notes at the end.

Figure 1. BGA reballing in five stages. (1) Decide whether to reball — why reball and where the part came from; whether it can be reflowed again; whether the customer agrees. (2) Remove old balls and prepare the pads — mask the package and wick point by point; do not drag, to avoid scratching the solder mask; confirm the pads under a microscope. JIAHON can help: desoldering wick, soldering tips and sponges, high-temperature tape, magnifiers. (3) Apply flux and place new balls — correct ball size and alloy; flux fully applied and checked; carrier, stencil or manual ball placement. JIAHON can help: ESD tweezers, finger cots. (4) Reflow — profile close to production; record how many reflows the part has had; bake moisture-sensitive parts before reflow. JIAHON can help: nitrogen smart programmable ovens, dry cabinets. (5) Clean, inspect, record — measure ionic residue after cleaning; check ball positions, ball size and bridging; write down what was done and who decided. JIAHON can help: cleaning agents, ultrasonic cleaners, ionic contamination testers, labels.

Stage 1: Decide whether to reball at all

Reballing takes manual labor, a reflow and an inspection, and it is not worthwhile for every part. Ask four things first: why reball, where the part came from, whether it can go through reflow again, and whether the customer agrees.

Figure 2. Whether to reball: three questions (illustration). A BGA has a ball problem → Are its origin and history clear, and are the package and pads intact? → Does the component maker say it can be reflowed again? → Does the customer agree to reballing? If the answer to any of them is “no,” use a new part or do not reball: for parts with an unknown history, a new part is safer; for inexpensive, available parts, a new part is often simpler; if the cause of failure has not been found, find it first, then decide. If all three are “yes,” evaluate reballing: write down why you are reballing, and write the pass criteria first.

How to do it:

• Write down “why reball” first: defective balls on a new part, reusing an old part, and alloy conversion each have different requirements and different inspection items.
• Ask the customer first: whether reballing is allowed, how many times a part may be reworked, what equipment to reflow with, and whether a new part is required or an old one may be used. A common line practice is to write these down as conditions before starting.
• Check the part’s history: where it came from, how it was removed, and how many reflows it has already had. If the history is unknown, use a new part.
• Ask the component maker for the reflow limits in its data sheet (number of cycles and temperature); if you cannot get them, treat it as uncertain.
• Bake moisture-sensitive parts before reflow and record the exposure time; see “Storage and Baking Conditions for Moisture-Sensitive Devices.” For why moist parts crack in reflow, see “What Is the Popcorn Effect: Why Moist ICs and Boards Crack in Reflow.”
• Write down the pass criteria (ball size, ball position, missing balls and bridging, coplanarity) before you start.

What public sources say:

• A university reliability research group (2010 journal paper) replaced the balls on lead-free BGAs with tin-lead balls using three reballing methods, and thermally cycled them (−55 to 125 °C; the abstract prints “55C to 125C”) together with lead-free and mixed-alloy assemblies. For the same part, reballed assemblies had similar life whichever method was used, but all were shorter-lived than mixed-alloy and lead-free assemblies; failures were all in the bulk solder on the component side. These are lead-free-to-tin-lead conditions and cannot be taken directly as a conclusion for your parts.
• The reballing procedure example page published by IPC (marked Date: 10/11; IPC notes it is for reference): first confirm the part can withstand multiple reflows; multiple reflows may damage the part and the board; handle moisture-sensitive parts per J-STD-033 and bake if needed.
• IEC TS 62647-4:2018 is a technical specification (the page gives a stability date of 2028) setting requirements for BGA reballing in aerospace, defense and high-reliability products, aimed at reballing suppliers. The flow in the pre-publication slides (URL dated November 2016): confirm the reballing supplier is on the approved list, incoming inspection, determine and label the solder composition, preheat and control temperature during ball removal, confirm the part withstands lead-free reflow temperatures, and qualify new part numbers.

Stage 2: Remove the old balls and prepare the pads

If old solder is not cleaned off, or pads are scratched or lifted, every later step suffers. There are three ways to remove balls, and public sources do not agree on them.

How to do it:

• A common line practice: first blow loose dust off the package surface; place the part on polyimide high-temperature tape, cover the package body surface with tape, and confirm nothing is exposed.
• Use an ESD (electrostatic discharge) brush to apply flux over the whole ball area, then desolder.
• Use wick and iron point by point without dragging; dragging scratches the solder mask. The iron set temperature depends on the solder (tin-lead and lead-free differ) and should be written into the work instruction; before starting, wait for the tip to reach the set temperature.
• If there is dirt on the pads, remove it carefully without damaging the pads or solder mask.
• Confirm under a stereo microscope that the old solder is fully removed, the pads are not scratched or lifted, and the solder mask is intact.
• Check package coplanarity (whether all pads or ball tops lie in the same plane) before reballing.
• After ball removal, send the part for cleaning to remove the flux; see Stage 5 for cleaning.
• Wear finger cots (and cotton gloves if needed) and a grounded wrist strap to avoid contamination and static.

What public sources say:

• The rework equipment maker’s article: remove flux residue with an approved solvent and clean the pad area thoroughly; almost any standard aqueous cleaning method will do.
• The IPC example page: clean and inspect both before and after reballing, with cleaning agents and wipes listed among the materials; it does not describe a ball removal method and refers to other procedures in the standard.

How JIAHON can help:

• Removing old solder: desoldering wick (the page lists three series — lead-free, no-clean and rosin; 1.5 mm width for fine leads, 2.0 to 2.8 mm for general pads, 2.8 to 3.7 mm for large pads; the page says to choose a width close to the pad width, since too wide a wick covers neighboring joints).
• Soldering tips: soldering tips (the page lists two series by soldering station model, with many tip shapes), and another tip line (the page says it must match that brand’s station; when asking for a quote, give the station model and tip shape; tin the tip after use for protection).
• Tip cleaning: soldering iron sponges (the page says to expand with water before use and keep slightly damp; replace when dry or carbonized).
• Masking the package surface: gold finger masking tape (the page lists 260 °C heat resistance, 0.07 mm thickness, and no residue after removal).
• Contamination and static: finger cots (the page lists latex and nitrile butadiene rubber (NBR); the blue NBR type is marked antistatic) and antistatic wrist straps (the page says corded types are reliable when well grounded).
• Magnified inspection: a 40x handheld magnifier, high-resolution 7-inch digital microscope, and the digital microscope series (see each product page for specifications).
• For pricing and availability, please contact us.

Stage 3: Apply flux and place the new balls

All three methods can reball; the main differences are volume and equipment. One journal paper found no difference in life between the three methods.

Figure 3. Three reballing methods (illustration). Carrier — apply flux to the pads, place the part on the carrier, reflow; for full reballing in small quantities; the carrier stays on through reflow and is removed after cooling. Stencil and fixture — fix the part in the fixture, cover with the stencil, pour in balls and shake to fill, pour off excess balls and remove the stencil; for larger quantities of the same part number; keep enough balls in the fixture, clean the fixture thoroughly when changing ball size, and remove the stencil before reflow. Preformed balls and manual placement — place balls one at a time with a pick pen or tweezers, located by edge alignment or a fixture; for replacing a few missing balls; eutectic balls need flux plus controlled reflow. One journal paper found no difference in life between the three methods; the choice depends mainly on volume and equipment.

How to do it:

• First check that ball size, alloy and count match the BGA as it was. When changing ball size or alloy, clean fixtures and stencils first and do not mix them; a common view on the line is that mixed ball sizes are one cause of large and small balls.
• Apply flux over the whole ball area, then confirm under a microscope that every pad is covered; flux applied too close to the pad edge makes balls more likely to shift.
• Label both flux and balls with control labels: part number, ball size and alloy, opening or loading time, and next replacement time; material changes should be signed off. Cover unused balls and return them to a low-humidity environment.
• Choose stencils or fixtures by pad pitch and ball size; keep enough balls in the fixture, or the squeegee will hit the balls.
• Manual ball placement: pour the balls you need onto a lid, pick one with a pick pen and place it on the pad missing a ball; work with the part on a cleanroom wipe.
• After placement, check ball positions and missing balls under a microscope before reflow.
• Wear finger cots and a grounded wrist strap while working.

What public sources say:

• The 2010 journal paper above: no difference in life between the three reballing methods.
• The rework equipment maker’s article: flux can be dispensed or printed; brushing is commonly used.
• The PCB contract manufacturer’s blog: confirm ball size and alloy, match the stencil or fixture to the pad pitch, and check ball coverage, alignment and missing balls.

How JIAHON can help:

• Picking and placing: ESD tweezers (the page lists a conductive plastic round-tip type for handling round or spherical components and solder balls; there is also a gold-label ESD version).
• Brushes for applying flux: ESD brushes (the page lists nylon bristles for dust removal, 23 models in all).
• Contamination and static: finger cots and antistatic wrist straps (see Stage 2); for magnified inspection, see Stage 2.
• Printing or dispensing methods need solder paste: solder paste and solder wire (the page lists SAC305-T4 solder paste and solder wire in various specifications, with prices that move with the market).
• For pricing and availability, please contact us.

Stage 4: Reflow, and record how many reflows the part has had

Reflow sets the shape of the balls, and it also uses up part of the component’s life.

How to do it:

• Before reflow, check that the oven program matches the requirements for that lot’s part number; if not, change the program, let the oven stabilize, re-measure the profile once and record it. This is a common way lines manage it.
• Keep rework parts separated by lot number; do not handle two lots on the same bench at the same time.
• The customer may require that reflow after reballing be done in a reflow oven, not with a hot-air gun or hot plate; if so, follow that requirement.
• Limit the waiting time from reballing to reflow, and from reflow to cleaning, to what the work instruction allows; while waiting, keep parts in a humidity-controlled box or dry cabinet.
• Mark the reballing method (manual or fixture) on the record, and record the number of reflows.
• After reflow, let the part cool before handling it.

What public sources say:

• None of the articles above gives a common temperature and time; this article does not either (see the notes).
• An example of a BGA rework method: one presentation specified that each module may be reworked once, a new part must always be used, soldering must be done in a reflow oven, and other heating methods are prohibited. The flow was: remove with a hot-air gun, clean residual solder with an iron and wick (iron no higher than 280 °C), apply flux, place the new part with a rework machine, reflow with the production profile, and X-ray inspect. The presentation noted there was no rework experience with this product and the method had been simulated on another product; it did not explain why hot air was allowed for removal but not for soldering, gave no success-rate data, and did not describe the effect of removal on neighboring parts and the board. The lesson: if the customer specifies the number of reworks and the heating method, follow it and record it.

How JIAHON can help:

• Drying before reflow: smart programmable ovens (the page says nitrogen is used during baking to drive out moisture and oxygen, ramp profiles can be programmed, and sizes can be customized; temperature ranges RT–100 °C, 150 °C, 200 °C and 300 °C).
• Holding while waiting: ultra-low-humidity electronic dry cabinets (the page lists two humidity grades; hold times and baking conditions follow the component maker’s data sheet).
• Checking for moisture: blue six-dot humidity indicator cards (the page says blue means dry and pink means moist, and the color change is reversible).
• For pricing and availability, please contact us.

Stage 5: Clean, inspect and record

Placing the balls is not the end: the flux must be cleaned off, the balls inspected, and what was done recorded, so that the part’s history can be explained later.

How to do it:

• Clean with approved solvents, and do not clean equipment and tools with unapproved solvents; afterward, rinse off solvent residue with deionized water. Both are common line practices.
• Sample and measure ionic residue, recording values before and after cleaning; looking clean does not count.
• The pass criteria were written in Stage 1; inspect against them now. If a part still fails after rework, scrap it; to rework it again, get the customer’s agreement first.
• When inspection finds a defect, trace back as in the figure below: a common line practice maps missing balls, offset and mixed ball sizes each to a few common causes.
• After washing and baking, place the part in a low-humidity environment and restart the exposure time count; see “Storage and Baking Conditions for Moisture-Sensitive Devices.”
• Give rework parts a separate sub-lot number and a routing card, and put defective parts in a clearly marked container so they do not mix with normal stock. This is a common line practice, so you can tell at a glance which parts have been reworked.
• Records should include at least: part number and source, why it was reballed, ball removal method, reballing method, ball size and alloy, flux, number of reflows and profile, cleaning method and cleanliness, inspection results, and who decided.

Figure 4. When inspection finds a defect, where to trace back first. Missing balls — common causes: dirty pads or foreign matter, poor gold plating, oxidized balls → check Stages 2 and 3. Ball offset — common causes: flux applied off-position, offset during placement → check Stage 3. Mixed ball sizes — common causes: flux applied too close to the pad edge, too few balls in the fixture so the squeegee hits the balls, fixture not cleaned when changing ball size so different sizes got mixed → check Stage 3. These are common causes on the line, not all causes. Once the cause is found, write it into the record.

What public sources say:

• For whether flux residue needs cleaning and how to judge white residue, see “Does Flux Residue Need Cleaning? Judging White Residue and a 3-Step Decision”; this article does not repeat it.
• In one cleaning Q&A, an equipment vendor representative suggested material analysis in addition to ionic testing, and functional testing after mounting.

How JIAHON can help:

• Cleaning agents: stencil cleaners and flux removers (the page says the JH series is designed for no-clean and rosin flux removal, with three models differing in formulation; please give the cleaning target and process conditions when asking for a quote, and a Material Safety Data Sheet (MSDS) is available; for ultrasonic cleaning it lists “confirm the board wash withstands ultrasonic vibration without foaming”; 5 gallons per drum). There is also a page on test reports and SDS highlights for stencil cleaner JH64.
• Solvents: industrial alcohol series (the page lists isopropyl alcohol (IPA) at 99% or higher, for cleaning electronic components and removing flux; flammable, keep away from flames and static).
• Ultrasonic cleaning: ultrasonic cleaner (the page lists a 10 L tank, power adjustable from 10% to 100%, heating with constant temperature, and a stainless steel tank; “for precision parts, power can be turned down to lower the risk of damage”). For whether parts tolerate ultrasonics, see the notes.
• Sending whole boards for cleaning: offline PCBA cleaner (the page lists a 610 × 600 mm cleaning area, water or chemical cleaning modes, and a programmable number of rinses).
• Rinse water: ultrapure / deionized water systems (two models: the page for JH-DI-200 lists output of 200 L/h or more and outlet resistivity of 2–10 MΩ·cm (depending on feed water); for JH-DI-1000, please ask for specifications).
• Cleanliness: ionic contamination tester (the page lists extraction with a 3:1 mix of isopropyl alcohol and deionized water, measuring conductivity and ion concentration at 40 ± 1 °C, static and dynamic modes, ±3% accuracy, and boards from 100 × 100 mm to 350 × 600 mm).
• Storage and holding: ultra-low-humidity electronic dry cabinets (see Stage 4).
• Marking “reballed” and lot numbers: custom adhesive labels (the page lists custom sizes, materials and printing).
• For pricing and availability, please contact us.

Related reading

To cover the related process steps, continue with these articles:

• “How to Inspect BGA Solder Joints: X-ray, Dye-and-Pry or Cross-Section, in 5 Stages”
• “Storage and Baking Conditions for Moisture-Sensitive Devices: How to Handle 4 States After Opening”
• “What Is the Popcorn Effect: Why Moist ICs and Boards Crack in Reflow”
• “Does Flux Residue Need Cleaning? Judging White Residue and a 3-Step Decision”

Notes: sources and exceptions

These notes are for readers who want to check the sources; you can follow the steps above without them. Where your customer’s specifications or the component maker’s written specifications differ from this article, they take precedence.

Sources for each practice

Standards and references

Refer to the current version published by each issuing body for the standards cited here.

• IPC-7711/7721D, Rework, Modification and Repair of Electronic Assemblies (the ANSI store page shows the 2024 edition, stating it revises the 2020 revision C with Amendment 1; the store description does not mention BGAs or reballing; cited for its purpose: rework and repair procedures; for the reballing procedure, this article read IPC’s public example page (marked Date: 10/11), not the revision D text; the standard must be purchased from the issuer). Issuer: IPC
• IEC TS 62647-4:2018, Process management for avionics — Aerospace and defence electronic systems containing lead-free solder — Part 4: Ball grid array (BGA) re-balling (technical specification, edition 1, April 10, 2018; the IEC page gives a stability date of 2028; cited for its purpose: requirements for BGA reballing in high-reliability products; this article cites the scope on the standard page and the pre-publication slides; the standard must be purchased from the issuer). Issuer: International Electrotechnical Commission (IEC)
• J-STD-033D, Handling, Packing, Shipping, and Use of Moisture/Reflow Sensitive Surface-Mount Devices (the JEDEC page title says revision D, April 2018, while the URL says revision C; this article follows the title; cited for its purpose: handling and baking of moisture-sensitive parts before reflow; the standard must be purchased from the issuer). Issuers: IPC and JEDEC Solid State Technology Association, jointly

This describes the general case; individual situations may differ.

Exceptions and limitations

• Nature of the sources: the statements here come from standards’ tables of contents and description pages, IPC’s public example page, a journal paper abstract, articles by an equipment maker and a PCB contract manufacturer, a consulting firm’s column and an expert Q&A; the standards themselves must be purchased from their issuers.
• Sources with a perspective: the rework equipment maker sells rework equipment, the PCB contract manufacturer offers BGA assembly and rework evaluation, and the cleaning Q&A answerers are from equipment and cleaning-agent vendors. They are used just to show “what the industry says,” not as criteria.
• Standard versions: IPC-7711/7721 is shown as the 2024 revision D on the ANSI store page, whose description does not mention BGA; the reballing procedure read here is IPC’s public example page (marked Date: 10/11) and may differ from revision D. IEC TS 62647-4 is edition 1 of April 2018; the page does not say whether it is current, just that its stability date is 2028; the pre-publication slides (URL dated November 2016) may differ from the final version. The JEDEC page title for J-STD-033 says revision D (April 2018) while the URL says revision C; this article follows the title; for baking conditions, see the standard text.
• Where sources differ: IPC and the equipment maker’s article list desoldering braid for ball removal, while the IEC slides (pre-publication) say the standard discourages it. This article lists both; decide according to the component maker, the customer and the standard you follow. For high-reliability use and lead-free-to-tin-lead conversion, follow IEC TS 62647-4 and the customer’s requirements.
• Conditions of the paper: lead-free BGA balls replaced with tin-lead balls, thermal cycling from −55 to 125 °C, specific parts; it cannot be applied directly to same-alloy reballing or other parts, and just the abstract page was read.
• Rework count: public sources do not define a maximum; the PCB contract manufacturer’s blog says there is no universal limit, and that it depends on the board, the part, the materials, the process history, the product class and the customer’s requirements. This article gives no number.
• Temperature and time: this article gives no figures for iron or reflow temperatures and times; follow the solder, the component maker’s data sheet and the customer’s requirements.
• Ultrasonics: reader responses to the consulting firm’s column warn that ultrasonics may damage wire bonds, die attach and MEMS parts (while the column’s author believes the claim of wire bond damage has been overturned by extensive research and that you should test with your own parts). The product page for JIAHON’s ultrasonic cleaner says “for precision parts, power can be turned down to lower the risk of damage,” and the flux remover product page says to confirm the board wash withstands ultrasonic vibration without foaming. Whether a part tolerates ultrasonics is for the component maker and your own validation to decide.
• ESD brushes: the product page lists dust removal as the use; applying flux with them is a line practice, not a use stated on the product page.
• This article’s synthesis and recommendations: the following are this article’s arrangement from the sources, not what the sources say: splitting reballing into five stages (decide, remove old balls, place new balls, reflow, clean, inspect and record); writing “why reball” first; writing the pass criteria first; checking under a microscope before reflow; choosing a method mainly by volume and equipment (the paper says just that the methods did not differ in life); limiting waiting time and holding parts in a controlled box; marking “reballed” and assigning a sub-lot number; scrapping parts that still fail after rework and getting customer agreement before reworking again; and the fields a record should include.
• Line practice: line practices vary by plant; follow your own process validation.
• Scope: this article does not cover the details of mounting the BGA back onto the board (stencil printing, alignment, rework station setup), rework of parts other than BGAs, production reballing at packaging houses, solder joint failure analysis, or warranty and after-sales responsibility for reworked parts.
• Equipment and products: specifications are as stated on each product page. This article lists just items stated on JIAHON’s product pages; for anything else, please ask. For pricing and availability, please contact us.

This article summarizes the general case. It is not a restatement of any standard, not an endorsement of any vendor, equipment maker or service provider, and not a promise about your product or process. Follow your customer’s specifications, the component maker’s written specifications, local regulations and your own validation; individual situations may differ.

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