For the current week, the overall ratings of 18 Semiconductor stocks are worse, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Advanced Semiconductor Engineering (NYSE:ASX) is on the decline this week, earning a D (“sell”) after receiving a C (“hold”) last week. Advanced Semiconductor Engineering is an independent provider of semiconductor packaging and testing services. In Portfolio Grader’s specific subcategories of Earnings Growth and Sales Growth, ASX also gets F’s. To get an in-depth look at ASX, get Portfolio Grader’s complete analysis of ASX stock.

Aixtron (NASDAQ:AIXG) earns an F (“strong sell”) this week, moving down from last week’s grade of D (“sell”). Aixtron provides deposition equipment, such as that used in lighting, fiber optic communication systems, and mobile telephone applications, to the semiconductor industry. The stock gets F’s in Earnings Momentum, Earnings Revisions, and Equity. Cash Flow and Margin Growth also get F’s. For a full analysis of AIXG stock, visit Portfolio Grader.

Semtech Corp. (NASDAQ:SMTC) earns a D this week, moving down from last week’s grade of C. Semtech is involved in the design, production and marketing of products that are sold primarily into applications within the high-end consumer, industrial, and computing and communications markets. The stock also gets an F in Margin Growth. The stock’s trailing PE Ratio is 47.60. For more information, get Portfolio Grader’s complete analysis of SMTC stock.

This is a rough week for Freescale Semiconductor (NYSE:FSL). The company’s rating falls to F from the previous week’s D. Freescale Semiconductor provides embedded processing semiconductors and related solutions. The stock gets F’s in Earnings Revisions and Sales Growth. To get an in-depth look at FSL, get Portfolio Grader’s complete analysis of FSL stock.

United Microelectronics (NYSE:UMC) is having a tough week. The company’s rating falls from a D to an F. United Microelectronics is a semiconductor wafer foundry that provides wafer fabrication services and technologies. The stock gets F’s in Earnings Revisions and Cash Flow. For a full analysis of UMC stock, visit Portfolio Grader.

Siliconware Precision Industries (NASDAQ:SPIL) experiences a ratings drop this week, going from last week’s C to a D. Siliconware Precision Industries provides semiconductor packaging and testing services. For more information, get Portfolio Grader’s complete analysis of SPIL stock.

Slipping from a D to an F rating, ON Semiconductor (NASDAQ:ONNN) takes a hit this week. ON Semiconductor supplies analog, standard logic, and discrete semiconductors for data and power management. The stock gets F’s in Earnings Revisions, Earnings Surprise, and Sales Growth. The stock has a trailing PE Ratio of 387.50. For a full analysis of ONNN stock, visit Portfolio Grader.

The rating of MaxLinea (NYSE:MXL) declines this week from C to a D. MaxLinear provides integrated, radio-frequency analog and mixed-signal semiconductor solutions for broadband communications applications. The stock also gets an F in Equity. To get an in-depth look at MXL, get Portfolio Grader’s complete analysis of MXL stock.

The rating of Photronics (NASDAQ:PLAB) slips from a D to an F. Photronics manufactures photomasks, which are high precision quartz plates that contain microscopic images of electronic circuits. The stock gets F’s in Earnings Revisions and Sales Growth. As of Jan. 23, 2013, 10.8% of outstanding Photronics shares were held short. For more information, get Portfolio Grader’s complete analysis of PLAB stock.

Skyworks Solution (NASDAQ:SWKS) earns a D this week, falling from last week’s grade of C. Skyworks Solutions is an innovator of analog and mixed-signal semiconductors. For a full analysis of SWKS stock, visit Portfolio Grader.

This week, Silicon Laboratorie (NASDAQ:SLAB) drops from C to a D rating. Silicon Laboratories designs and develops proprietary, analog-intensive and mixed-signal integrated circuits that can be used in a range of applications. The stock currently has a trailing PE Ratio of 31.90. For more information, get Portfolio Grader’s complete analysis of SLAB stock.

This week, Teradyne’s (NYSE:TER) rating worsens to a D from the company’s C rating a week ago. Teradyne is a designer, manufacturer and global supplier of automatic systems and solutions used to test complex electronics. As of Jan. 23, 2013, 10.2% of outstanding Teradyne shares were held short. To get an in-depth look at TER, get Portfolio Grader’s complete analysis of TER stock.

Maxim Integrated Products (NASDAQ:MXIM) gets weaker ratings this week as last week’s C drops to a D. Maxim Integrated Products designs, develops, manufactures, and markets a broad range of linear and mixed-signal integrated circuits. For a full analysis of MXIM stock, visit Portfolio Grader.

Micrel Inc.’s (NASDAQ:MCRL) rating weakens this week, dropping to an F versus last week’s D. Micrel designs, develops, manufactures and markets a range of high-performance analog power integrated circuits, mixed-signal and other products designed to address a range of end markets including cellular handsets, portable computing, enterprise and home networking, wide area and metropolitan area networks, digital televisions and industrial equipment. The stock gets F’s in Earnings Revisions and Earnings Surprise. The trailing PE Ratio for the stock is 28.40. For more information, get Portfolio Grader’s complete analysis of MCRL stock.

This week, Cohu Inc.’s (NASDAQ:COHU) rating worsens to an F from the company’s D rating a week ago. Cohu develops, manufactures, markets, sells, and services test handling and burn-in related equipment and thermal sub-systems for the global semiconductor industry. The stock gets F’s in Earnings Growth, Earnings Revisions, Margin Growth, and Sales Growth. To get an in-depth look at COHU, get Portfolio Grader’s complete analysis of COHU stock.

The rating of Microchip Technology (NASDAQ:MCHP) slips from a D to an F. Microchip Technology makes specialized semiconductor products used in a variety of embedded control applications. The stock also rates an F in Earnings Growth. The stock has a trailing PE Ratio of 31.90. For more information, get Portfolio Grader’s complete analysis of MCHP stock.

This week, Power Integrations (NASDAQ:POWI) drops from C to a D rating. Power Integrations designs, develops, and markets analog integrated circuits for use in alternating current to direct current power conversion. The stock gets F’s in Earnings Growth, Earnings Momentum, and Margin Growth. For a full analysis of POWI stock, visit Portfolio Grader.

Atmel (NASDAQ:ATML) is having a tough week. The company’s rating falls from a D to an F. Atmel is engaged in the design, development, manufacture, and sale of semiconductor integrated circuit products. In Earnings Growth, Earnings Momentum, Margin Growth, and Sales Growth the stock gets F’s. The trailing PE Ratio for the stock is 37.30. To get an in-depth look at ATML, get Portfolio Grader’s complete analysis of ATML stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.