Many configured consumer chemical products add the three- dimensional configuration, which introduces yet another opportunity for technical invention, often referred to as product technology. For example, when designing halogen light bulbs to provide longer life and softer colors, the high operating temperatures often require a secondary casing, to protect against burns, in addition to the normal primary casing (for example, a quartz bulb). As discussed in Section 17.2, this introduces a new product technology, which is represented in the product-technology layer of the innovation map, to be introduced next.
For this discussion, to provide a brief introduction to innovation maps for configured consumer products, an inno- vation map is presented that traces back to the initial inven- tion associated with light bulbs. Note that a more detailed history is presented in Section 16.2.
Beginning in the early 1800s, Humphrey Davy created light by passing electrical current through a platinum fila- ment, with the heat-generated radiating light in the visible range. Then, about 80 years later, low-wattage light bulbs Material Technology Process/ Manufacturing Technology Customer- Value Proposition Technical Differentiation
Barium Boron Silicate Glass
Isopipe Glass Fusion Process
Mg,Ca,Sr,Ba Boron Silicate Glass Products Corning-7059 (1987) Corning-1737 (1994) Eagle™ 2000 (2000) Eagle™ XG (mid-2000) Mg,Ca Boron Silicate Glass As, Sb, Ba-free Boron Silicate Glass
Environmentally Friendly Low CTE
Durability Transparentat 350 nm Alkali Free
High Viscosity Glass Fusion Process
As, Sb, Ba Free Lower CTE
Manufacturing
Higher Strain
Point Higher Modulus Scalability
Figure 1.5 Innovation map for
thin glass substrates in liquid- crystal displays (LCDs)
were manufactured using carbon filaments, with the disad- vantage that their combustion products turned the bulbs dark black. This was overcome in 1903, when William Coolidge invented an improved method of making tungsten filaments, which outlasted all other types of filaments, enabling Cool- idge to manufacture light bulbs at practical costs.
Shortly thereafter, in 1906, the General Electric Company patented a method of making tungsten filaments for use in incandescent light bulbs. Tungsten filaments offer a high melting temperature and low vapor pressures, which translate to a lower evaporation rate of tungsten vapor and reduced blackening. Subsequently, another GE researcher, Irving Langmuir, suppressed the tungsten evaporation by filling the light bulb with an inert gas that wouldn’t burn the filament. However, the inert gas circulated in the bulb, carrying away too much heat, which, in turn, significantly reduced the brightness of the bulb. To reduce heat losses, Langmuir invented the tight-coil filament, the basis for modern incandescent light bulbs.
The innovation map in Figure 1.6 begins with the dark grey elements to the left that show the progression of materials and process/technology inventions, together with the customer-value proposition (that is, the customer needs), through the early 1900s. These are discussed in detail in Section 16.2. At this point, it is sufficient to recognize that these proceed in parallel, with the customer initially seeking light bulbs lasting for 750 hr, versatile in shape, having various light qualities, and at low cost. These needs were eventually met by a progression of inventions involving the use of tungsten, inert gases, and the Coolidge process for the manufacture of ductile tungsten rods.
Consider the dark grey entries to the left in Figure 1.6. Of the six layers in that figure, the fourth shows the technical differentiations enabled by the materials and process/ manufacturing technologies, in this case low-cost manufac-
turing, a high tungsten melting point, and a low tungsten evaporation rate. In the third layer are the new product tech- nologies enabled by the technical differentiations (that is, tightly coiled filaments, gas-filled bulbs, and high-wattage bulbs). These, in turn, lead to the principal product in the second layer, the incandescent light bulb, which in the early 1900s satisfied the four customer needs in the first layer. Conveniently, the innovation map shows all of these linkages very clearly.
The next linkages, in dotted boxes in the innovation map, trace the development of the halogen light bulb, which is discussed in detail in Sections 16.2 and 17.2. By the 1980s, the customer needs had been extended to include longer-life bulbs, on the order of 2,000 hr, with improved light quality, including warm, cool, and daylight qualities. To fulfill these, the discovery of Frederick Mosby that halogen gases react with tungsten at high temperature (3,100 K) in chemical equili- brium, permitting tungsten vapor to redeposit on the tungsten filament, added a key materials technology. This, coupled with a quartz primary casing to contain the hot gases, provided the technical differentiations, that is, the high-temperature reaction and equilibrium deposition that led to a new product technology (a secondary casing, to prevent burns). This, in turn, led to the small halogen light bulb products that satisfied the five customer needs (four in the dark grey boxes, one in a dotted box).
Throughout the second half of the 20th century, a com- peting technology, fluorescent light, was developed. This involves a gas-discharge lamp that uses electricity flowing between electrodes at both ends of a fluorescent tube, which excites mercury vapor and produces shortwave light of ultraviolet photons. These photons collide with the phosphor coating on the inside of the fluorescent tube, creating light in the visible region. A magnetic ballast is required to turn on the fluorescent lamp.
To illustrate these advances, the innovation map in Figure 1.6 is extended with entries having a cross-hatched background.
Material Technology Product Technology Process/ Manufacturing Technology Customer- Value Proposition Technical Differentiation Gas-filled Bulb Long-life Light Bulb 750 hr Low-cost Manufacturing Tungsten Light Quality: Warm, cool, daylight Versatility of
Shape Low Cost
Coolidge Process for Ductile Tungsten Rod
Inert Gases Tight-Coiled Filaments High Melting Point Low Evaporation Rate High-wattage Bulb Halogen Gases Equilibrium Deposition Quartz Primary Casing Secondary Casing High Temp. Reaction Products Incandescent Light Bulb Halogen Light Bulb Fluorescent Tube Compact Fluorescent Lamp (CFL) Gas-Filled
Tube ElectronicBallast
Magnetic Ballast Phosphor Coating Mercury Phosphor Select Frequency Range Gas-Filled Coil Energy Efficient 2000 hr Light Bulb Phosphor Energy Efficient Long-life Light Bulb > 20,000 hr
Heat Sink & Dome Lenses Encapsulation White LED Lighting Phosphor Encapsulation Color Mixer Red LED Chip Green LED Chip Blue LED Mono- Chromatic Light Cold Lighting Metal Organic Chemical Vapor Deposition
Ga,P,As, Al, In Ga, N Long-life Light Bulb > 8,000 hr Fit in Standard Light Fixtures
Figure 1.6 Innovation map for light bulbs
Here, the customer needs were longer-life bulbs, exceeding 8,000 hr, especially for display and industrial lighting, as well as increased energy efficiency. The new materials technologies involved mercury, in small nontoxic quantities, and phosphors, which, coupled with phosphor coatings, were deposited using a new process/manufacturing technology, to give a select fre- quency range, the desired technical differentiation. Initially, new product technologies—that is, a magnetic ballast and gas- filled tubes—provided the fluorescent tube product, which satisfied the two additional customer needs.
However, more recently, in the 1990s, when the consumer needs expanded to include compact bulbs that would fit into standard light fixtures, a new electronic ballast was invented, as a new product technology. This eliminated the slow starting and flickering of fluorescent tubes, and permitted the introduction of the compact fluorescent lamp (CFL).
Even more recently, in the early 2000s, an emerging technology for home lighting is LED-based lighting, a solid-state technology (with no moving or loose parts) formed using Group III-V semiconductor materials. As a current passes through the p-n junctions created in these materials, light is emitted. Depending on the selection of the materials (GaP, GaAs, AlGaAs, AlInGaP), various mono- chromatic lights (red and yellow) are produced. The intro- duction of GaN offered the ability to produce blue and green LEDs. For home lighting, white LEDs are produced by incorporating phosphors into the encapsulating materials (epoxies) and using light management lenses.
LED technologies are introduced into the innovation map in Figure 1.6 using elements in light grey, toward the right boundary. Here, the consumer needs are expanded to even longer-life bulbs exceeding 20,000 hr, also at high-energy efficiencies. The new materials technologies include com- pounds of Ga, P, As, Al, In, and N. The manufacturing process for the LED wafer—that is, metal-organic, chemical-vapor deposition (MOCVD)—is a key new process/manufacturing technology. These new technologies provide monochromatic light and cold lighting, the two technical differentiations. As mentioned earlier, phosphors can be incorporated in the encapsulating materials to produce white LEDs suitable for home lighting. Together with: (1) LED encapsulation using epoxy resin, which is critical to protect the fragile LED chip, light design forms, and color transformation; (2) dome lenses to direct the light; and (3) color mixers, these product technologies lead to the white LED lighting product.
The major advantage of LED lighting, compared to tungsten filaments, is the durability of the light source (LED chip), which gives lifetimes in excess of 20,000 hr. Furthermore, the energy efficiency of LED light depends on heat management through the encapsulating materials.
As discussed above, the evolution of the innovation map is helpful to view after a series of new products has been introduced over time. For a product design team, it is important to be fully aware of the history before positioning new technologies, customer needs, and the potential products that link them together.