The scope of this teardown is 'electronics only' and does not include the cost of the metal enclosures and 'actuator' portion of the assembly. Placeholders are in the bill of materials for all mechanical components.
Mitsubishi Actuator Control Unit WNZ-179-01 Main Image
Overview / Features
This device is a custom turbo (assumed) actuator control module from Mitsubishi. Little is known about the module itself and consists primarily of a Microcontroller (Renesas - M37630M4T-xxxFP - Microcontroller - 8-Bit, CAN, 16252 Bytes ROM, 512 Bytes RAM, 35 I/O's, 8-Bit x 8-Ch A/D) an EEPROM, and the balance of the BOM are all low-level discrete transistors, diodes, capacitors, etc., none of which stand out as particularly costly or noteworthy.
For the purposes of this teardown analysis, we have assumed a lifetime production volume (over an approximate 4 year product lifetime) of 500,000 units produced.
As a reminder, teardown volume production assumptions are primarily used for our cost analysis in terms of amortized NRE and tooling costs, especially for custom components specific to the model being analyzed (mechanical components especially). Unless assumed volumes are different by an order of magnitude, minor changes in volume (say 1 million vs. 2) rarely have a large net effect on our final analysis because of this.
For the most part, we are assuming that standard ‘commodity’ pricing for low level (passive and some common discrete semiconductors) rarely applies in the automotive space, because of QS manufacturing qualification requirements, extended temperature range components, longer than average MTBFs and/or increased duty cycles, etc. that all of these factors can significantly increase pricing for such components.
The major material cost drivers on the Main PCB are:
Renesas - M37630M4T-xxxFP - Microcontroller - 8-Bit, CAN, 16252 Bytes ROM, 512 Bytes RAM, 35 I/O's, 8-Bit x 8-Ch A/D - Qty(1)
NEC - 2SK3377-Z - MOSFET - N-Channel, 60V, 20A - Qty(6)
Enclosure, Controller, Bottom - Injection Molded Polybutylene terephthalate, w/ 2 Metal Inserts - Qty(1)
Main PCB 4-Layer – FR4 - Qty(1)
Enclosure, Controller, Top - Injection Molded Polybutylene terephthalate - Qty(1)
Vishay - SM5S36A - Transient Voltage Suppressor - Qty(1)
Chemi-Con - EMVH500ARA101MKE0S - Electrolytic - SMD, 125C, 50V, 100uF, Low ESR - Qty(2)
Total w/Manufacturing ~$12.48**
* - General comment on ASICs - Because of the non-commodity nature of the core ASICs, without being ‘in the room’ at negotiations here, the actual price ‘paid’ for these core parts are anyone’s guess. We have modeled the silicon costs and using assumed package and test costs derived a chip ‘cost’.
** - This represents a bare-bones manufacturing costs which represents auto-insertion direct line costs only, direct hand labor, and basic testing (with setup costs amortized here) costs. Advanced testing costs (burn-in, etc.), not considered.
IC Price Evaluator – Core Silicon Cost Modeling Notes
The only cost modeling performed in this analysis was on the core Microcontroller. For cost purposes we have made process geometry assumption of 0.25 micron and applied silicon cost models (see ASIC tab in the spreadsheet analysis) which accounts for the cost of the die, packaging, test and then a final margin figure to estimate costs.
Automotive IC’s are typically not so much manufactured in the most cutting-edge technologies (such as 0.13, 90 and 65nm), but are more often, like RF IC’s fabbed in more conventional mid-stream or older technologies, (0.25um and higher). The process geometry is an assumption.
Above average margins have been applied, however it is possible that our standard silicon price model may not sufficiently account for the rigors of automotive applications testing and packaging, as well as the indirect cost of component, system, and facilities qualifications, etc.
What Is Not Included in our Cost Analysis
The total materials and manufacturing costs reported in this analysis reflect ONLY the direct materials cost (from component vendors and assorted EMS providers), AND manufacturing and test. Not included in this analysis are costs above and beyond the material manufacture of the core device itself – cost of intellectual property, royalties and licensing fees (those not already included into the per component price), software, software loading and test, shipping, logistics marketing and other channel costs including not only EMS provider and the OEM’s margin, but that of other resellers. Our cost analysis is meant to focus on those costs incurred in the manufacture of the core device and exceptionally in some circumstances the packaging and literature as well.
Country of Origin / Volume Assumptions
The unit is assumed to have been assembled in the Japan, per the label stating Mitsubishi Japan on the device. This is inconclusive, however, and may be made by subsidiaries elsewhere in the world.
Country of origin assumptions relate directly to the associated cost of manufacturing, where calculated by iSuppli. In the cases of ‘finished’ sub-assemblies (none really apply in this case), we do not calculate internal manufacturing costs, but rather assess the market price of the finished product in which case country of origin assumptions may or may not have a direct effect on pricing.
The issue of labor rates was revisited in Q2 2006 as we began to apply some research by one the major worldwide EMS suppliers and are now applying some of their research on total loaded costs by country and region to arrive at these new rates which are pronouncedly higher on the low end in China. Remember that labor rates are applied directly only to hand inserted components and systems in our bill of materials, and although regional assumptions do, these new rates do not have a direct effect on our modeled calculations of placement costs for automated SMD assembly lines.
Design for Manufacturing / Device Complexity
We typically look at the overall component count to help make comparisons of relative complexity between devices, and in this case, however in this case, we have little else to compare to. This Mitsubishi actuator control module nonetheless consists of 235 total components on the PCB which would qualify as simple.
Mechanically speaking, however, though we have created a complete mechanical component BOM, these items were not cost estimated and considered beyond the scope of this analysis.
Component counts have a direct bearing on the overall manufacturing cycle times and costs, and also can increase or decrease overall yields and re-work. Our calculations of manufacturing costs factor counts and more qualitative complexities in the design. Note that manual labor rates have a much smaller effect on auto-insertion assembly lines (for the Main PCB, for example), where manufacturing costs are much more capital equipment intensive and driven primarily by these investment costs.
The Main PCB in this design completely orbits around a central microcontroller of unknown origin, and the rest of the design consists of low-level discrete components. Below are listed the ‘major’ components in descending order of cost impact to the BOM.
Microcontroller (Renesas - M37630M4T-xxxFP - Microcontroller - 8-Bit)
NEC - 2SK3377-Z - MOSFET - N-Channel, 60V, 20A
Vishay - SM5S36A - Transient Voltage Suppressor
Chemi-Con - EMVH500ARA101MKE0S - Electrolytic - SMD, 125C, 50V, 100uF, Low ESR
NXP Semiconductors - TJA1050 – High-speed CAN transceiver
ST Microelectronics - L4949E - Regulator - LDO 5V w/ Power-On Reset and Input Voltage Sense