The interposer substrate has become the key technology for achieving even higher functionality in semiconductor products such as SiP (system in package) devices.
Until now, Sony has procured interposer substrates from third party suppliers.
However, to extract the best performance from Sony ICs through technology developments taking place within the Sony Group,
Sony has now taken the step of moving the production of these substrates in house with the development of the high-density multilayer build-up interposer substrate called LAMINATE.
Sony has established a LAMINATE mass production line at the Neagari Plant of Sony Chemical & Information Device Corporation, the only site of the Sony Group manufacturing substrates for Sony products, and started mass production in December 2008.
LAMINATE assembles, the combined power of Sony, a company that has accumulated extensive technology and know-how concerning chips, substrates, and mounting, and that has grasped the demands of users and end-product designers.
Starting with the IU046F (8M-pixel lens module for cellular phones) introduced in Vol. 56 of this journal, LAMINATE has been used in semiconductor packages for digital still cameras, video cameras, and game equipment, and is contributing to the creation of extremely attractive products.
• This is a structural component in semiconductor packages and SiP devices. Semiconductor chips are mounted on the substrate with wire bonding or flip chip technology.
• Performs pitch conversion so semiconductor devices can be mounted on motherboards.
• Extracts the full performance of the ICs used. (This is important for the electrical characteristics, reliability, and thermal dissipation in the end product.)
• Recently, the term LAMINATE has been used to refer to interposer substrates that have particularly fine feature sizes and large numbers of layers. Sony, in particular, refers to their high-density multilayer build-up interposer substrates (see the following page) as LAMINATE.
• Sony has already achieved a signal line width of 30 μ m and is working towards even finer line widths.
Reduced development times, inclusion of diverse chip types
Compared to SoC (System on Chip) technology, in which multiple functions are integrated on a single chip, SiP technology has the feature that it can reduce development times and costs by combining multiple chips in a single package.
One reason SiP solutions are of particular interest is that they allow semiconductor devices fabricated using different processes to be combined in a single package.
However, the levels of wiring densities and electrical characteristics required for the SiP interposer substrates have been increasing. By moving these efforts in house, Sony aims to contribute to semiconductor product differentiation by refining these technologies.
In implementing an SiP device, optimal design for LAMINATE and assembly is an important point. At Sony, IC design, board design, and package design are performed as part of a consistent process, making it possible to provide total solutions. This allows Sony to aim for product differentiation in technological level, quality, and cost.
■ Towards provision of total solutions
SiP solutions that can provide everything, from IC design to the wafer process, assembly, testing, and mounting
■ Bare chip mounting on a LAMINATE substrate (PiP structure)
IC design
(Implementing as a system)
SiP
Semiconductor mounting
(SiP implementation: wire bonding, flip chip)
Wafer process
LAMINATE
(increased densities and simulation)
Testing
High-density multilayer build-up interposer substrate
Motherboard design
The ICs are designed and fabricated in the wafer process.
A LAMINATE is created and testing (functional check) is performed.
Then the device is mounted on the motherboard.

■ Introduction of the latest leading-edge technologies and processes
Pattern plating process and LDI (laser direct imaging) method
Changes in the Circuit Fabrication Processes
Etching process
Existing process
Inner layer NC drilling
Copper plating
Etching resist
Patterns are created by etching away copper. There are limitations to how fine the features can be made and the shapes may not be stable due to material being removed in the horizontal direction.
Etching
Removal
Resist removal
Supporting finer feature sizes
Pattern plating process
Inner layer NC drilling
Primary copper plating
Plating resist
New process
The plating is grown according to the resist pattern. This makes it possible to create finer lines than could be produced with the earlier process.
Additive plating
Growth
Resist removal
Seed etching
Additionally
Direct Drawing Using LDI
Unlike earlier methods, in which the resist was exposed through a photomask, the pattern is drawn directly with a laser and the resist is sensitized and hardened. This can handle LAMINATE substrates in which high positional accuracy is required.
Photomask
While there are many types of multilayer substrates, the type that appeared before the build-up substrate and is now widely used is the through-hole substrate
(plated through-hole method). (See the figure at the right.) However, this method, in which through holes that pass through all layers are drilled, and connections between the conductor patterns on each layer are made by plating internally, has the following disadvantages.
1. Since the through holes are formed by drilling, there are limits to the degree of miniaturization.
2. Since the wiring associated with a through hole has a direct linear form, the wiring geometry is constrained and inflexible.
Given those problems, a new method, the build-up method, was developed in Japan at the start of the
1990s.
The build-up method can be said to have been born as an application of the layering technology used in semiconductor fabrication to substrates. On a core layer created with the normal plating through-hole method, insulating and conducting layers are stacked alternately to form the build-up layers.
In most cases holes are drilled with a laser (laser vias) and electrical connections are made to create the connections between the build-up layers and the core layer. Laser vias have smaller diameters than mechanically drilled holes and since the holes can be positioned at each layer, laser vias provide much greater flexibility than mechanically drilled vias.
Build-up substrates resolve the deficiencies of throughhole substrates and, due to their even higher wiring density and high-density mounting, make further miniaturization and thinner form factors possible. As a result the range of applications for this technology has grown and now they are widely used for interposer substrates in applications such as cellular phones and game equipment.
■ Types of interposer substrates
Build-up substrate Laser via
This is a built-up structure (1-2-1) formed by laminating one build-up layer on each side of a core layer consisting of a two-sided board. Additional layers can be added to create a multilayer structure to respond to needs for additional functionality.
L/S = 25/25 or larger, Laser via diameter: 70 µm
Board material: Glass fabric base epoxy board
(FR-5 equivalent)
Semi-additive (connections formed with copper foil)
Board thickness: 0.20 mm or more (4 layers)
Through-hole substrate
Through hole
(from two sided to up to 6 layers)
L/S = 75/75 or larger, Drilled through hole diameter: 150 µm
Board material: Glass fabric base epoxy board (FR-5 equivalent)
Board thickness: 0.40 mm or more
There are, however, only a very small number of companies that supply LAMINATE multilayer buildup interposer substrates. This is because of the high technical levels required for circuit formation, interlayer connection, leveling of the build-up layers, and other aspects, and thus assuring reliability is difficult.
Sony has now achieved in-house production of
LAMINATE substrates using the latest processes by applying the Sony Group's semiconductor technology and know-how while at the same time taking full advantage of the fine fabrication technology fostered at the Neagari Plant of Sony Chemical & Information
Device Corporation.
The figure above shows representative technologies in these new processes.
As opposed to existing processes for forming patterns by removing plating (etching process), the new process
(pattern plating process) in which, inversely, the plating is grown, can create even more precise patterns. Also, the LDI (Laser Direct Imaging) method, unlike the existing mask exposure method, does not require a photo mask. As a result, factors that lead to instability in the quality, such as the mask itself and variations in positioning precision, are excluded, and reliability can be radically improved. Sony has introduced the most advanced technologies from the technologies and processing methods that have been actually applied worldwide, and has further added Sony's own arrangements to these technologies. Despite being a late entry to the field, Sony has acquired, in a short period, strengths that can compete with the leading suppliers of LAMINATE substrates in all aspects, including quality, price, and delivery time.

Taking full advantage of Sony's substrate technologies, with their long tradition, to build the foundation (substrate) that will be the cornerstone of future developments in Sony's semiconductor and electronics businesses.
Neagari Plant
A unified development and mass production system, from IC design through mounting
High quality
Reducing the lead time for prototyping and mass production
Cooperative design/cooperative development
September 2007 Start of verification of processes and equipment
October 2007
May 2008
June 2008
Project kickoff (Hyakumangoku Project)
Equipment installation
Start of bringing mass production facilities on line, switchover to commercial operation
Start of manufacturing training
Start of prototyping and reliability evaluation
December 2008 Start of LAMINATE mass production
Combines all the strengths of the Sony Group,
Mass production of LAMINATE substrates using new processes was started in just about a year from the start of the project.
http://www.sonycid.jp/en/
Sony Chemical &
Information Device
Corporation
Neagari
(Ishikawa Prefecture)
Sony Corporation
Consumer Products &
Device Group
Semiconductor
Business Group
Sony Semiconductor
Kyushu Corporation
*
Hyakumangoku specifies an amount of rice production, 1,000,000 koku of rice, which is roughly 5,000,000 bushels of rice. This was the amount of rice produced during the Edo period (1603 to 1868) in the region in which Sony's Neagari Plant is now located, and this phrase is closely associated with the region.
Sony has taken on the challenge of a new area: mass production of LAMINATE substrates.
It was in July 2007 that the corporate officer in charge at Sony Corporation sounded out
Mr. Hirokazu Toyoda and his associates at the Sony Chemical & Information Device
Corporation regarding this idea. This was to be an enormous project in which Sony
Corporation, Sony Semiconductor Kyushu
Corporation, and Sony Chemical & Information
Device Corporation would work together as a unit on this concept. Initially, Kyushu was proposed as a candidate, but the Neagari Plant was seen as more promising since it already had the substrate production infrastructure.
“Won't it be possible to do this at Neagari?”
When asked by the corporate officer in charge,
Toyoda paused briefly. He did not think that just moving production in house would be all that meaningful. If they were to take on these challenges at all, he wanted to adopt new technologies and new processes and aim for a level of monozukuri more typical of Sony.
When he offered his honest opinion on the required equipment and budget, he was told
“We'll give you whatever authority you need.
Just do whatever you think necessary.”
The corporate officer in charge came to a decision quickly. And Toyoda also committed himself. They decided to push forward aiming to start mass production as soon as possible. No matter how difficult the problems that had to be resolved would be.
The Neagari Plant was the main site for the production of motherboards for Sony products, and it clearly had the basic facilities and infrastructure, such as chemical supply and wastewater processing, that would be required.
However, the required standards for aspects such as substrate surface cleanliness were orders of magnitude higher for production of
LAMINATE substrates. This meant that the project had to start with a thoroughgoing review of the production environment and production line.
Next, the members of the team proceeded with preparations for project startup under Toyoda's direction. Most of the members of the team already had experience working with multilayer build-up substrates. So what would the problems be? Where would we trip up? The issues were already understood at the start. In October 2007 we started the project, with a name based on the
Kaga region, the “Hyakumangoku Project.”
“Although there is occasionally a tendency for technological development to be selfserving,” said Toyoda, “in this project that was a collaboration between three companies, there was no concern about that. For example, the project members from Sony Semiconductor
Kyushu Corporation, which was in charge of Sony semiconductor assembly, had accumulated a rich store of knowledge from their experience as users of LAMINATE substrates, including what sorts of circuit forms and electrical characteristics were desirable and what could cause problems. Since we had such sharp eyes in the team, our targets were clear and we were able to take measures to resolve problems in advance.”
Since we firmly grasped the desires of the set designers who will be using the chips, mounting, and substrates, we are able to take advantage of that in our daily efforts. This environment, which is rare for a substrate manufacturer, became a huge advantage.
We were unstinting in our investments in manufacturing line equipment and raw materials. This increased our yields and allows us to supply high-precision, high-quality
LAMINATE substrates at low cost.
Based on this basic strategy, we procured the most advanced equipment from domestic and overseas suppliers, starting with the LDI mentioned previously. We also developed new automated visual inspection and other equipment in house.
Sony Semiconductor Kyushu Corporation transmitted to us their know-how, fostered in semiconductor manufacturing, concerning clean work environments, which is a critical factor for maintaining high yields. In addition to newly installing a class 1000 clean room, which became the top clean room class in substrate manufacturing, we strove for automation to reduce personnel involvement to the absolute minimum. Even in processes that would, in principle, use existing equipment, we implemented a wide range of energy saving and other environmental efforts in various areas.
These included adjusting the flow of the air currents by modifying duct layouts.
Additionally, even in the operations area, we adopted thoroughgoing quality control measures, such as instituting the rule that only members who had passed exams after completing training programs may enter the line clean room. We make no exceptions to these rules. Even corporate officers, from the president down, may not enter the actual line unless they have passed the exam.

Copper plating process
Clean work environment in which care is taken even over the flow of air currents
We built a new class 1000 clean room. Additionally, we adopted, in a variety of places, know-how fostered in Sony's semiconductor manufacturing. These efforts included modifying the placement of return ducts to prevent air current stagnation and to prevent dust being carried into the clean room by having the air currents flow in the opposite direction from personnel movement.
Copper plating process
Adding our own know-how to equipment purchased from external suppliers
For example, although the laser via drilling equipment is purchased from external suppliers, we have adjusted the hole drilling parameters, such as the output waveforms, ourselves.
LDI process
Inspection process
Taking full advantage of the latest equipment for inspection
All types of inspection results, including data from Sony developed automatic visual inspection units, is stored on a server and batch processed. Also, defect data is managed based on addresses drawn on each board by LDI. This eliminates human errors during marking.
NC drilling process
Copper plating process
“Originally,” said Toyoda, “the schedule written on the project's management chart was entered in month units. That was soon changed to day units, and when equipment installation began, that was changed again, this time to hour units. That is, we'd specify, starting from the day and hour a unit of equipment was delivered, at what time connection of the equipment would be complete.”
The start of mass production was imminent. We wanted to move up that point as much as possible.
Even the members of the team who had visited the overseas equipment manufacturers felt both that their actions had results, and a sense of urgency.
Equipment adjustment would be completed in a week or two and then we would perform startup testing.
The results were good. Then orders were issued from
Japan. You're done: don't bother tweaking it any more.
Disassemble it and bring it to Neagari immediately!
Since all the members of the team worked efficiently and quickly, for example pressing forward with thorough adjustment of the equipment on site, the project moved into its last spurt at a rapid pitch.
In December 2008, only slightly more than a year after project kickoff, we started mass production of LAMINATE substrates. As an effect of the new processes adopted, we had already achieved a signal line width of 30 μ m in the product specifications.
Future developments in LAMINATE substrates will include the development of cavity substrates, substrates with built-in components, and other technologies to achieve even smaller, even thinner, even more highly functional, and even lower cost substrates. We think that this will allow us to provide solutions that support new product development.
Cavity substrates are already in the prototype stage.
We are now engaged in activities to introduce our
LAMINATE technology to users both inside and outside the company. Keep your eye on Sony for future developments in the LAMINATE technology, an area that takes advantage of Sony's total abilities.
Hirokazu Toyoda
Senior General Manager
LAMINATE Division
Sony Chemical & Information Device Corporation
(also serving as) Hybrid System Solution Division
Semiconductor Business Group
Consumer Products & Device Group
Sony Corporation
At first, we saw being a late entry as a LAMINATE supplier to be a handicap. But it is because we were a late entry that we could adopt the most leading edge manufacturing equipment and take the utmost a d va n t a g e o f t h a t e q u i p m e n t through our own adjustments. What we thought was a handicap is actually a strength.
Also, another strength is that our interposer substrate circuit design group could aim for optimal designs while taking IC and wafer connection into account. As developments in SiP technologies advance, this know-how is becoming even more important.
Hirofumi Makino
General Manager
LAMINATE Division
Sony Chemical & Information Device Corporation
(also serving as) Hybrid System Solution Division
Semiconductor Business Group
Consumer Products & Device Group
Sony Corporation
I n t h e p a s t , i n t e r p o s e r technology was controlled b y t h e f i r s t s u p p l i e r s , a n d eve n i f we we r e t o w o r k t o d eve l o p a n ew technology, we could not get adequate support from them. We must refine our technologies internally to
Sony for the sake of further developments and product differentiation. Because we shared this common idea, we joined together with the Sony Semiconductor Business Group and Sony
Semiconductor Kyushu Corporation, and created this system to work towards creating an in-house LAMINATE capability.
Yasuhiko Naito
Senior Manager
Business Planning Department
Hybrid System Solution Division
Semiconductor Business Group
Consumer Products & Device Group
Sony Corporation
I f we c o m p e t e w i t h t h e f i r s t s u p p l i e r s o n l y o n c o s t , w e cannot hope for future advances.
W e m u s t s t r i v e t o c r e a t e unique device structures under collaborations within the Sony
Group. This will lead to market differentiation technologies, and allow us to contribute to our semiconductor customers' successes.
Hideki Matsui Baseball Museum
This memorial to the major league baseball player Hideki Matsui is near Sony's Neagari
Plant.
Sony's LAMINATE technology will also go forth into the world from Neagari.