Be in when semiconductor industry pretentious make Cheng technology newly breakthrough, rub Er law lasts applicable when, right for the person that enclose a technology, suffering just is wanting to begin, because use the chip that makes Cheng implementation newly to be run impossibly with naked crystal pattern, the chip that must corresponding, collocation makes Cheng newly is enclosed, making Cheng technology however is advanced more, shrink close, enclose a technology to be about to bear to make the pressure that Cheng place brings along with all the others and challenge much newlier more, because answer,want new pressure and new challenge, also write with respect to imply enclose a technology to want to have new course of action, new trial, ability is overcome or slow new pressure. Enclose also can saying is the crust that shows chip of installation semiconductor integrated circuit is used, it is held the position of not only place, chip of fixed, sealed, protection and the action that enhance heat conduction performance, and the contact on the chip of bridge ─ ─ that still communicates chip interior world and exterior circuit goes to those who enclose crust to guide with lead join online, these lead pass through printed circuit again board the lead that go up and other spare parts establish link. Accordingly, to product of a lot of integrated circuit, enclosing a technology is very crucial one annulus. For the product that gives priority to with chip so to memory, enclose a technology to make sure chip and outside are kept apart not only, the impurity in preventing air is right of chip circuit corrode and cause function to drop; And the stand or fall that encloses a technology still is mattered to directly with chip connective printed circuit board (PCB) design and make, produce profound effect to the expression of chip oneself function and play thereby. Above all, more more transistor, circuit can be accommodated inside same area, more circuit are general also imply is written there is more connecting outside needing to follow chip, this expresses to be enclosed identically inside need has more number that accept a base, and the requirement that the number that accept a base raises is a pressure namely. Inchoate DIP encloses chip enclosing technical sort is varied really, such as DIP, PQFP, TSOP, TSSOP, PGA, BGA, QFP, TQFP, QSOP, SOIC, SOJ, PLCC, WAFERS... a series of names, look very multifarious, actually, should make clear only the course that chip encloses development is not fathomless also. Of chip enclose a technology to already experienced the changes via several generation, generation of technical layer class is more advanced than generation, incorporate chip the area is compared with what enclose an area more and more adjacent, applicable frequency is taller and taller, heat-resisting performance is better and better, and lead counts grow in quantity, guide line span is reduced, weight is reduced, dependability promotion, use more convenient etc, it is the change that sees so that see. 20 centuries when 70 time, the symmetrical still foot that chip encloses popularity enclose, abbreviation DIP(Dual Ln-line Package) . DIP is enclosed at that time to have comfortable the character that secures at soldering on the feed hole of PCB, have than TO model enclose be opposite easily PCB wiring and operation are relatively convenient wait for a few characteristics, the framework form that its enclose is very much also, include multilayer DIP of pottery and porcelain, DIP of monolayer pottery and porcelain, DIP of lead frame type is waited a moment. But measure a chip to enclose a technology advanced main index is chip the area is compared with what enclose an area, this ratio is more adjacent 1 better. More plastic than using wire of 40 I / O like biserial inserts type to enclose continuously (the chip of PDIP) is exemple, its chip area / enclose area = (3 X3) / (15. 24 X 50) =1 ︰ 86, from 1 differ very far. See not hard, this kind encloses dimension far many bigger than chip, the specification encloses efficiency very low, occupy went area of a lot of effective installation. QFP (Quad Flat Pack) enclose, QFP encloses law and LCC to enclose a law identical, it is to be in those who enclose body to be configured quadrilateral accept a base, but the design that accepts a base is more exquisite, compact, make the number that accept a base OK increase continuously, QFP is highest and OK the administrative levels to 208-pin, 216-pin, the time that is as long as several years can enclose the chip that will receive a foot high to count demand because of answering with QFP only in the past. Although QFP still can increase the number that accept a base continuously, but must make the original width that accept a base more cut, be in so finite quadrilateral the edge grows ability to place more to accept a base, like that this makes difficulty promote not only, after chip solder reinforce is used it is more difficult also to measure (sweep in JTAG border take aim before the technology has not put forward) , cost is higher also, do not gain ground accordingly. Went to what 80 time appear to enclose a technology to be a delegate with TSOP, it is used generally very quickly for industry place, still hold the mainstream position that writes memory to enclose so far. TSOP is the abbreviate of English Thin Small Outline Package, meaning namely miniaturization is enclosed. A typical feature that TSOP memory encloses a technology is in those who enclose chip namely all round make wire, like the integrated circuit of SDRAM memory two side have lead, the integrated circuit all sides of SGRAM memory has lead. TSOP suits to use SMT technology to install wiring on PCB. When TSOP encloses over all dimension, when electric current changes substantially, cause output voltage to disturb reduce, suit high frequency applying, the operation is more convenient, reliability is higher also. The 90 time improvement along with the progress that writes synthetic skill, equipment mixes 20 centuries to make the use of Cheng newly, LSI, VLSI, ULSI appears in succession, chip synthesis spends ceaseless promotion, number of lead of I / O increases quickly, power also increases subsequently, the requirement that encloses to integrated circuit is more strict also. ▲ people is right the first impression of integrated circuit, IC, chip, it is associate with popularizes the DIP of be current to enclose about most namely, strip, perforation solders used metal accepts a base, make whole enclosed exterior associates easily together with centipede, DIP is enclosed small to 4-pin, 6-pin, come greatly 40-pin, 68-pin. Use lesser and lesser already now like that. Latter-day ball type is enclosed- - is BGABGA enclosed why can you contain more number that accept a base? The answer depends on: Change the regulation of the configuration that accept a base, design again, past DIP uses enclosed or so side only, QFP is to use 4 side, the such numerary that accept a base increases to suffer be restricted to grow in the edge, want to increase an edge to grow to must raise the long wide area that encloses body, make enclose cost to increase then. Opposite, BGA is applied whole the bottom area that encloses body comes arrangement, setting accepts a base, the placement that accepts a base from " 4 side " change " whole underside " , such nature can let receive crural amount to soar. To satisfy the need of development, be in original on the foundation that encloses mode, added form of new ball of mode ─ ─ to enclose again (Ball Grid Array, BGA, also call stannic ball array is enclosed or stannic foot encloses body) . BGA encloses a technology to although,lead of such I / O of ︰ of a few characteristics are counted grow in quantity, but lead span is not small, promoted consequently assemble fine rate; Although its power increases, but the electric heat performance that BGA can improve it; Chroma and weight relatively previously enclose a technology to decrease somewhat, signal transmission delay is little, use frequency promotes greatly, reliability is high. Nevertheless BGA is enclosed still exist take up the question with substrate bigger area. Beauty of ▲ United States is smooth (Micron) the RLDRAM of the company (RL is Reduced Latency, the meaning with cut defer) memory, odd a capacity 576Mbits, collect a 144-pin BGA to enclose, what BGA encloses is see receive a foot to be in the graph " stannic ball " shape. Gradually the CSP of beginning to show ability or talent begins to push in BGA technology exhibit while, additionally one kind of CSP that comes from BGA development encloses a technology to showing instinctive quality of its fresh troops gradually. CSP, full name is Chip Scale Package, namely chip enclosed meaning, also have person Chip Size Package, identical abbreviate letter (S) have however different write completely. The chip that serves as new generation encloses a technology, on the foundation of BGA, TSOP, the function of CSP had again jump in great quantities litre. CSP is enclosed can let chip area and the 1/3 that enclose an area to be common BGA about, be equivalent to the 1/6 of area of TSOP memory chip merely. Fall in identical bulk so, integrated circuit can load more chip, increase unit size thereby. That is to say, enclose photograph comparing with BGA, it is OK that the CSP below coequal space is enclosed will store the capacity promotes 3 times. Nevertheless, also somebody is defined directly with the area, as long as exterior the 150 ％ that enclose an area to be less than area of interior naked brilliant, can be CSP. CSP is enclosed not only volume is minor, at the same time thinner also, its metal substrate arrives of radiator come loose the most effectively hot way is only 0. 2mm, promoted chip the reliability after be run for long greatly, circuit impedance is reduced significantly, chip speed also gets subsequently substantially promotion. In addition, the pressure on environmental protection, chip (or enclose) course of study person had felt pressure in recent years, because this put forward to be enclosed without plumbic type (Lead Free) , some chip products that emphasize entire company already pursued the policy that do not have lead, the product that has a plenty of 9x ％ above already was collected do not have lead all right, additionally also ego issues commitment, in 200x devoid lead shipment can be stridden after year. Order sb to do sth within a certain time of these environmental protection law also want what test has to enclose euqally technology and make Cheng. CNC Milling