LG sells an OSAT a 1.5-micron maskless imager, betting packaging capacity is the bottleneck

LG Electronics' Production Technology Institute has signed a contract this week with an outsourced semiconductor assembly and test firm to supply a maskless laser direct imaging tool for patterning metal interconnects in chip packaging, with the vendor claiming potentially higher yields than currently available tools, according to ETNews as relayed by Tom's Hardware ^[1]. The interesting part is what the tool gives up: laser direct imaging cannot match modern DUV, EUV or e-beam resolution, and trades that for much higher throughput and large-area processing ^[2], which is a wager that the binding constraint in advanced packaging is capacity rather than linewidth, at a moment when TSMC's CoWoS remains constrained ^[3].

The hardware, per various media reports cited by Tom's Hardware, uses a 405-nm laser-diode source and handles substrates up to 600 x 600 mm ^[4]. That is 0.36 square metres of substrate per plate ^[5]. The highest-resolution version of the system prints 1.5-micron line-and-space patterns, good for wiring pitches of roughly 3 microns ^[6].

Where that number lands is the whole story. TSMC's CoWoS-R and CoWoS-L use RDL interposers with a minimum 4-micron pitch, or 2-micron line width and spacing ^[7], so 1.5 microns leaves about half a micron of headroom against that layer ^[8]. It does not go further. Both CoWoS-S and CoWoS-L/EMIB-like schemes require considerably higher resolution than current-generation LDI, which makes the RDL interposer the most advanced structure these machines can pattern ^[9]. LG is selling into the substrate and redistribution-layer tier, not into the interposer tier that defines the packaging roadmap.

It is also not walking into an empty room. The direct-imaging market is led by KLA, Screen Holdings, Limata and ORC, with roughly a dozen participants from Germany, France, Switzerland, Japan and China ^[10], and competing products already ship in 1-micron, 3-micron and 5-micron variants ^[11]. LG's 1.5-micron figure targets the higher end without being the finest thing on the market, and the plan is to price competitively ^[12].

The more durable technical argument is not resolution at all. Because the pattern is generated digitally by a pattern generator and projection optics rather than transferred through a photomask, the system can create and calibrate patterns in real time ^[13]. That matters because packaging substrate geometry varies and organic substrates expand, contract or warp during processing ^[14]. At 1.5-micron wiring, a shift from the nominal layout can produce a solder bridge or a faulty contact, which is yield loss ^[15]. Mask-based flows cannot chase a warped panel; a digital one can.

Context on the seller: unlike Samsung and SK Group, LG Group does not produce chips, though its divisions supply materials and components to the industry ^[16]. The system is positioned for advanced packaging on organic and later glass substrates, plus displays, MEMS, and high-density or prototype PCBs ^[17].

What to watch. The buyer is not identified in the report ^[18], so the volume and the application tier are unknown. Watch whether the stated glass-substrate path arrives with the resolution intact, since glass removes the warpage problem that justifies digital correction in the first place ^[14][17]. And watch pricing: against incumbents with 1-micron tools already in the field ^[11], competitive pricing ^[12] is the only lever LG has named.