201116960 六、發明說明： 【發明所屬之技術領域】 本發明是有關於一種對氣體（gas)或液體等的流體的 ml 1進行控制的質量流量控制器（mass fl〇w c〇ntr〇uer )。 【先前技術】 例如，當將用於製造半導體的各種氣體等供給至半導 體製造裝置時，在這些氣體等的供給流路中分別設置質量 流量控制器，借此來對氣體流量分別進行調節。而且，先 前在各質量流量控制器上分別串聯附帶著壓力調節器 (pressure regulator)，使各質量流量控制器的流路内壓力 不會發生極端的變動，從而使流量控制變得容易。 所述質量流量控制器的流量控制方式基本上是比例積 分微分（Proportional Integral Derivative，PID)控制，例 如，如專利文獻1所示，已知在過渡性響應狀態與穩定狀 態下，對PID係數進行切換而進行反饋控制（feedback control) ° 具體而言’專利文獻1所示的技術是使用將流量設定 值代入至規定的函數中所得的值，來作為與比例運算中之 偏差相乘的增益值（gain value)，例如代入的流量設定值 越小’則計算出的穩定狀態下所使用的所述規定的函數的 值就越小。即，專利文獻1所示的先前的質量流量控制器 僅是使穩定狀態下的比例係數、積分係數以及微分係數（以 下也稱作PID係數）僅與流量設定值成比例地變更。 然而，本申請案發明人獲得了如下的實驗結果：在穩 201116960 定狀態下，當一次側壓力（valve inlet pressure )上升時與 下降時，ΡΠ)係數的最佳值不同；即便一次侧壓力的經時 性變化量相同’如果變化前的一次側壓力不同，那麼PID 係數仍不同；而且，流量設定值與PID係數最佳值並無線 性關係。於是明白了在穩定狀態下，如果僅使PID係數與 流量設定值成比例’那麼壓力鈍感（pressurehisensitive， PI)性能的提尚存在極限。 專利文獻：日本專利特開2007-34550號公報 【發明内容】 因此，本發明是為了一舉解決所述問題點而研製成 的’其主要的預期課題在於使質量流量控制器的P〗性能進 一步提高。 即，本發明的質量流量控制器的特徵在於包括：流量 感測器（sensor)部，對在流路内流動的流體的流量進行 測定，並輸出表示該流量的測定值的流量測定信號；流旦 控制閥’設置在所述流量感測器部的上游侧或下游側；^ 算部’對由所述流量測定信號表示的流量測定值與目標值 即流量設定值的偏差實施PID運算，以計算出輸出至流量 控制闊的反饋控制值；以及開度控制信號輸出部，基 述反饋控制值而產生開度控制信號，並輸出至流^控制 閥；所述計鼻部基於一次侧壓力、該一次側壓力的經時性 變化量以及所述流量設定值中的至少兩個，來對穩定狀賤 下的用於PID運算中的比例係數、積分係數以及微分係& 進行變更。 4 201116960 上如上所述的質量流量控制器，由於基於-次側壓 =人側壓力的經時性變化量以及所述流量設定值中 的至夕兩個，來對穩定狀態下的用於PID運算中的比例係 數^分雜以及微分舰進行變更，因此，與先前的借 由抓置°又疋絲使比例舰、積分係數錢微分係數成比 例地變更的方法她，可獲得更合__魏、積分係 數=及微分係數，結果，不易受到—次_力的壓力變動 的影響，可進行穩定的流量控制。 變更 特別是在穩定狀態下，當一次側壓力上升時與下降 時’比例係數、積分係數以及微分係㈣最佳值有所不同， 因此丄較理想的是，所料算部根據—次側壓力的經時 里的正負來對比例係數、積分係數以及微分係數進行 為了使比例係數、積分係數以及微分係數成為最 值，不易受到一次側壓力的壓力變動的影響，並進行 的流量控制，較理想的是，所料算部根據—次 經時性變化量的正負，對比例係數、積分係數以八的 數進行變更，接著，使用將流量設定值代入至規定的$係 中而獲得的值來進行規定運算，借此來對經變更的比=數 數、積分係數以及微分係數進行變更，然後，使用將 側壓力代入至規定的函數中而獲得的值來進行規定運〜人 變更 借此來對經變更的比例係數、積分係數以及微分係數戽，201116960 VI. Description of the Invention: [Technical Field] The present invention relates to a mass flow controller (mass fl〇w c〇ntr〇uer) for controlling ml 1 of a gas such as a gas or a liquid. [Prior Art] For example, when various gases or the like for manufacturing a semiconductor are supplied to the semiconductor manufacturing apparatus, a mass flow controller is provided in each of the supply flow paths of the gas or the like, thereby adjusting the gas flow rates. Further, a pressure regulator is attached in series to each mass flow controller in advance so that the pressure in the flow path of each mass flow controller does not change extremely, and the flow rate control is facilitated. The flow control mode of the mass flow controller is basically Proportional Integral Derivative (PID) control. For example, as shown in Patent Document 1, it is known to perform PID coefficients in a transient response state and a steady state. The feedback control is performed by switching. Specifically, the technique shown in Patent Document 1 uses a value obtained by substituting a flow rate set value into a predetermined function as a gain value multiplied by the deviation in the proportional calculation. (gain value), for example, the smaller the flow rate set value is substituted, the smaller the value of the predetermined function used in the calculated steady state is. That is, the previous mass flow controller shown in Patent Document 1 changes only the proportional coefficient, the integral coefficient, and the differential coefficient (hereinafter also referred to as PID coefficient) in the steady state in proportion to the flow rate setting value. However, the inventors of the present application obtained the following experimental results: in the stable state of 201116960, the optimum value of the ΡΠ) coefficient is different when the valve inlet pressure rises and falls; even if the primary side pressure is The amount of change over time is the same 'If the primary side pressure before the change is different, then the PID coefficient is still different; moreover, the flow set value has no linear relationship with the optimal value of the PID coefficient. Thus, it is understood that in the steady state, if only the PID coefficient is proportional to the flow rate set value, there is a limit to the pressure sensitivity (PI) performance. Patent Document: Japanese Patent Laid-Open No. 2007-34550 SUMMARY OF THE INVENTION Therefore, the present invention has been developed in order to solve the above problems in one place. The main expected problem is to further improve the performance of the mass flow controller. . That is, the mass flow controller of the present invention includes a flow sensor unit that measures a flow rate of a fluid flowing through the flow path, and outputs a flow rate measurement signal indicating a measured value of the flow rate; The control valve 'is disposed on the upstream side or the downstream side of the flow sensor portion; the calculation unit performs a PID calculation on the deviation between the flow rate measurement value indicated by the flow rate measurement signal and the target value, that is, the flow rate setting value, Calculating a feedback control value outputted to the flow control width; and an opening degree control signal output portion, generating an opening degree control signal based on the feedback control value, and outputting to the flow control valve; the metering portion is based on the primary side pressure, The proportional change amount of the primary side pressure and the flow rate set value are used to change the proportional coefficient, the integral coefficient, and the differential system & for use in the PID calculation in the stable state. 4 201116960 The mass flow controller as described above is used for the PID in the steady state due to the time-dependent change amount based on the secondary side pressure = the human side pressure and the two of the flow rate setting values. The proportional coefficient in the calculation is mixed and the differential ship is changed. Therefore, it is possible to obtain a more __ method by changing the proportional ship and the integral coefficient of the differential coefficient by the previous method. Wei, integral coefficient = and differential coefficient, as a result, it is not susceptible to the pressure fluctuation of the secondary force, and stable flow control can be performed. In particular, in the steady state, when the primary side pressure rises and the descending time, the 'proportional coefficient, the integral coefficient, and the differential system (four) optimum value are different. Therefore, it is preferable that the calculated part is based on the secondary side pressure. In order to make the proportional coefficient, the integral coefficient, and the differential coefficient the highest value, the proportional coefficient, the integral coefficient, and the differential coefficient are not easily affected by the pressure fluctuation of the primary side pressure, and the flow rate control is ideal. The calculation unit changes the proportional coefficient and the integral coefficient by eight in accordance with the positive and negative changes of the time-dependent change amount, and then uses the value obtained by substituting the flow rate setting value into the predetermined $ system. By performing a predetermined calculation, the changed ratio=number, integral coefficient, and differential coefficient are changed, and then the value obtained by substituting the side pressure into a predetermined function is used to perform the predetermined change. For the changed scale factor, integral coefficient, and differential coefficient,
^ "J，L 【發明的效果】 5 201116960 根據以所述方式構成的本發明，可使質量流量控制器 的pi性能提高。 ° 為讓本發明之上述和其他目的、特徵和優點能更明顯 易懂，下文特舉較佳實施例，並配合所附圖式，作詳細說 明如下° 【實施方式】 以下，參照附圖來對本發明的質量流量計1〇〇的一實 施方式進行說明。另外，圖丨是本實施方式㈣量流量控 制器的整體不意圖’圖2是使用質量流量控制器的流量控 制系統（system)的構成例，圖3是控制部的功能方塊圖， 圖4是表示PID係數變更順序的流程圖（fl〇wchart)，圖$ 是表示用於變更PID係數的函數的示意圖。 <裝置構成> 如圖1的示意圖所示，本實施方式的質量流量控制著 100包括：内部流路i;流量感測器部2，對在所述内部访 路1内流_趣F的録進行測定；流量㈣闊3，^ 置在所述流量感測器部2的例如下游側；壓力感測器部4 : 設置在所錢錢量控侧 =制部5;且例如圖2所示，該質量流量控制器刚是 用在乳體供給“巾，減體供給祕在半導體製輕 (Pr〇CeSS)令，將氣體供給至腔室（chamber)。 以开 對各料進行說明，在内部祕1的上游端開口 .，導入口（port) P卜在該内部流路1的下游端開口 以形成導出㈣，例如，導人σρι經 6 201116960 氣叙（b⑽b)等的流體供給源B相連接，導出口 κ 外部配管而與用以製造半導體的腔室（未圖示 = =出如圖2所示’從-個流體供二 刀支出夕個配官’在各崎上分別設置質量流量 Γ未力調節器PR僅設置在流體供給源β的出二 管上設置質量流量控制器100用的壓力調 即器。另外，符號FV是氣壓閥。 …雖然、未對流量感測！!部2的詳細内容進行圖示 ，置感測器部2例如包括設置在流路1上的-對熱感測°器 (thermal Sensor )’通過該熱感測器來將流體f 二 檢測為電信號，且通過内部電子電路來將該電: 等，接著輸出具有與檢測流量相對應的值的流量測定信號。 雖然同樣未對流量控制閥3的詳細内容進行圖示，但 該流量控侧3例如可通過包含㈣元件（他。咖她 element)的致動器（actuat〇r)來使閥開度發生變化，且通 過接收來自外㈣電信號利度控繼號來對所述致動器 進打驅動，㈣開度難為與關度㈣錢的值相對應 的閥開度，從而對流射的流量進行控制。 " 、雖然未對壓力感測器部4的詳細内容進行圖示，該壓 力感別…p 4例如包括膜片（di_ragm )(不錄鋼膜片 (stainless diaphragm )或矽膜片（smc〇n diaphmgm )等） 及對該膜片的位移進行測量的壓敏元件（卿咖 也mem) ’通過該壓敏元件來將膜片的位移檢測為電信 號’通過内部電子電路來將該電信號放大等，接著輸出具 201116960 有與檢測流量相對應的值的壓力測定信號。 控制部5是由具有中央處理器（central Processing Unit ’ CPU)、記憶體（memory)、類比/數位轉換器、數位 /類比轉換器等的數位（digital)或類比（anai〇g)電子電 路所構成，該控制部5可為專用的控制部，也可在一部分 或全部中使用個人電腦（personal computer)等的通用電 腦。另外，該控制部5可不使用cpu而是僅利用類比電路 來發揮所述各部分的功能，也可由通過有線或無線來彼此 連接的多個设備所構成，而無需在物理性上成為一體。 另外，將規定的程式（program)存儲在所述記憶體 中，根據該程式來使CPU或該CPU的周邊設備協同運轉， 借此，如圖3所示，所述控制部5至少發揮作為信號接收 部6、計算部7、開度控制信號輸出部8以及流量輸出部9 的功能。 信號接收部6接收從流量感測器部2發送而來的流量 測定信號、從其他電腦等輸入的流量設定信號等、以及從 壓力感測器部4發送而來的壓力測定信號，並將這些信號 的值存儲至例如記憶體内的規定區域。 a十舁部7包括：偏差計算部71，取得由所述流量測定 k號表示的流量測定值，並且對該流量測定值與目標值即 所述流量設定信號所表示的流量設定值的偏差進行計算； 以及控制值计算部72，對所述偏差實施ρφ運算而計算出 施加至流量控制閥3的反饋控制值。 開度控制信號輸出部8產生具有基於所述反饋控制值 8 201116960 並將該開度㈣Ht號輸A至流量控 的值的開度控制信號， 制閥3。 瞀出=值1測定值實施規定的運算而計 可在外部被利用的方式而將具有該 流量表示2作為值的流量絲信號（舰 號）予以輸出。 而J· ’在該實施方式中，控制值計算部72基於一次 側壓力（供給壓）、該-次侧壓力的經時性變化量以及所述 流量設巧’對流量穩定流動的狀態（穩定狀態）下的用 於PID運算中的比例係數（Ρ)、積分係數（〗）以及微分係 數（D )(即穩疋狀態的pid控制過程中所使用的pip係 數）進行變更。此處，所謂穩定狀態是指除了變化期間（例 如兩秒左右）以外的期間的狀態，流量設定值幾乎不發生 變化’所述變化期間是從使流量設定值在單位時間内變化 規定量或規定量以上的時間點算起的規定期間。另外，按 照相對于滿量刻度（full scale)的百分比值計，所謂規定 罝是指〇〜10%左右，優選0.3%〜5%。另外，所謂規定期 間是指數秒左右’具體而言為〇秒〜10秒左右，優選0.3 秒〜5秒。 更詳細而言，控制值計算部72根據一次側壓力（質 量流量控制器的上游側的壓力）的經時性變化量的正負， 對比例係數、積分係數以及微分係數（以下也稱作PID係 數）進行變更’接著，使用將流量設定值代入至規定的函 數而獲得的值來進行運算，借此來對經變更的PID係數進 201116960 行變更’然後’使用將一次侧壓力代入至規定的函數中而 獲得的值來進行運算，借此來對經變更的PID係數進行變 更。而且’控制值計算部72根據一次側壓力的經時性變化 量的正負’即’根據dp/dt>〇的情況與dp/dtSO的情況， 來使流量設定值所固有的函數改變及使一次侧壓力所固有 的函數改變。 以下’參照圖4來對控制值計算部72的具體的變更 方法進行說明。 首先’控制值計算部72取得由壓力感測器部4而獲 得的一次側壓力的壓力測定信號，對一次側壓力及該一次 側壓力的經時性變化量進行計算。 接著’控制值計算部72對一次側壓力的經時性變化 量的正負進行判斷（步驟（step) Sl)。當判斷出一次側壓 力的經時性變化量為正（dp/dt>〇)時，即，當一次侧壓 力上升時’控制值計算部72通過以下的數學式，並基於流 量設定值來對PID係數進行變更（步驟幻）。 P' = PxFu(set) ( 1 ) I' = IxFu(set) (2) D' = DxFu(set) (3) 此處，Fu ()是流量設定值所固有的函數即設定係數 轟數1!!\表示流量設定值。如圖5 (a)所示，本實施方 式的係數函數Fu是0_50%的比例常數與50%〜100% 的比有所不同的折線函數。折線形狀並不限於此， 町適虽叹定該折線形狀。另外，可將該設定係數函數Fu 201116960 S史為曲線函數’但存在運算處理量增大且難以對PID係數 進行調整的問題。 接著’控制值計算部72通過以下的數學式，並基於 一次側壓力來對通過所述（1)〜（3)而獲得的PTD，係數 進行變更（步驟S3)。 P,、P，xGu(P) (4) r==I’xGu(p) (5) D，-D'xGu(p) (6) 此處’ Gu ()是一次側壓力所固有的函數即壓力係數 函數’ P表示一次侧壓力值。如圖5 (a)所示，本實施方 式的壓力係數函數是對與所輸入的一次側壓力成比例的值 所計算出的比例函數。另外，也可將該壓力係數函數Gu 設為折線函數或曲線函數。在將該壓力係數函數Gu設為 曲線函數的情況下，存在運算處理量增大且難以對PID係 數進行調整的問題。 根據以上内容，當一次側壓力的經時性變化量為正 時，控制值計算部72基於流量設定值及一次側壓力來將 P、I、D變更為P”、I”、D”，並使用該PID係數（比例係 數P"、積分係數Γ以及微分係數D”）來對偏差實施ΡΠ) 運算，以計算出反饋控制值（步驟S4)。 另一方面’控制值計算部72在判斷出一次侧壓力的 變化量為負的情形下，即，當一次侧壓力下降時，通過以 下的數學式’並基於流量設定值來對PID.係數進行變更（步 驟 S5)。 11 201116960 P' = PxFd(set) (7) r = IxFd(set) (8) D' —DxFd(set) (9) 此處，Fd」二是^量設定值所固有的函數即設定係數 函數’ set表不流置设疋值。如圖.5 (b、 — y 數函數Fd是與所述設定係數函數F ::線疋: 拐點_ing P〇int)及比例常數有所^折=數可將 該設定係數函數Fd設為曲線函數 大且難以對係數進行調整的問題:存在運异處理里增 其二欠，控制值計算部72通過以下的，並基於 一次侧壓力來對通過所述（7)〜（ 、 進行變更（步驟S6) 0 PM = P'xGd(p) (10) I” = rxGd(p) (11) D" = D'xGd(p) (12) (9)而獲得的PTD，係數 此處，Gd 〇是一次側壓力所固有的函數㈣力係數 ϋΛ 次侧壓力值。如圖5 (b)所示，該壓力係 數函數Gd是與所述壓力係數函數叫目同的比例函數, 比例常數與所述壓力係數函數Fd的比例常數不同。另外， 吟可將該壓力係數函數Gd設為折線函數或曲線函數。在 將該[力ir、數函數〇d設為曲線函數的情況下，存在運算 處理量增大且難崎PID係數進行調整的問題。 根據以上内谷，當—次側歷力的經時性變化量為負 時’控制輯算部基於流量設定值及壓力來將 12 201116960 P、I、D變更為P”、I"、D”，並使用該PID係數（比例係 數P”、積分係數Γ以及微分係數D”）來對偏差實施pID 運算，以計算出反饋控制值（步驟S4)。 <本實施方式的效果> 根據以所述方式構成的本實施方式的質量流量控制 器100，由於基於一次側壓力、該一次側壓力的經時性變 化量以及所述流量設定值，來對穩定狀態下的用於pID運 算中的比例係數、積分係數以及微分係數進行變更，因此， 與先前的藉由流量設定值來使比例係數、積分係數以及微 分係數成比例地變更的方法相比’可獲得更合適的比例係 數、積分係數以及微分係數，結果，不易受到一次側厚力 的壓力變動的影響，可進行穩定的流量控制。 <其他變形實施方式> 另外’本發明並不限於所述實施方式。在以下 中，對與所述實施方式相對應的構件附上相同的符號5明 例如，在所述實施方式中，基於一次側壓力、^ 侧壓力的經時性變化量以及所述流量設定值的全部x:次 PID係數進行變更，但也可使用所述三個中的兩^固“如2 次側壓力與該一次側壓力的經時性變化量的組合、戈 侧壓力與流量設定值等的組合來進行變更。 2 一次 而且，在所述實施方式中，PID係數的變更順序θ「 據一次側壓力的經時性變化量來進行變更」—「根 设定值來進行變更」—「根據一次侧壓力來進行變更1'量 順序，但並不限於此順序，也可為其他組合。 」的 13 201116960 另外’也可將控制閥設置在流量感測器部的上游侧， 流量感測器部並不限於所述熱感測器，也可為差壓式感測 器（differential pressure sensor )等的其他流量測定方式的 感測器。 此外’可將所述實施方式或變形實施方式的一部分或 全部加以適當組合，當然本發明並不限於所述實施方式， 可在不脫離本發明的主旨的範圍内進行各種變形。 雖然本發明已以較佳實施例揭露如上，然其並非用以 限定本發明’任何熟習此技藝者，在不脫離本發明之精神 和範圍内，當可作些許之更動與潤飾，因此本發明之保護 範圍當視後附之申請專利範圍所界定者為準。 【圖式簡單說明】 圖1是本發明的一實施方式的質量流量控制器的整體 示意圖。 圖2是使用該實施方式的質量流量控制器的流量控制 系統的構成例^ 圖3是該實施方式中的控制部的功能方塊圖。 圖4是表示該實施方式中的j>ID係數變更順序的流程 圖。 圖5之（a)、圖5之（b)是表示用於變更piD係數 的函數的示意圖。 【主要元件符號說明】 1 流路 2 流量感測器部 201116960 3 流量控制閥 4 壓力感測器部 5 控制部 6 信號接收部 7 計算部 8 開度控制信號輸出部 9 流量輸出部 71 偏差計鼻部 72 控制值計算部 100 質量流量控制器 B 流體供給源 F 流體 FV 氣壓閥 PI 導入口 P2 導出口 PR 壓力調節器 SI ' S2 ' S3、S4、S5、S6 步驟 15^ "J, L [Effects of the Invention] 5 201116960 According to the present invention constructed as described above, the pi performance of the mass flow controller can be improved. The above and other objects, features, and advantages of the present invention will become more apparent from the aspects of the appended claims appended claims An embodiment of the mass flow meter 1 of the present invention will be described. In addition, FIG. 3 is a configuration example of a flow rate control system using a mass flow controller, and FIG. 3 is a functional block diagram of a control unit, and FIG. A flowchart (fl〇wchart) indicating the order in which the PID coefficients are changed, and a graph $ is a schematic diagram showing a function for changing the PID coefficients. <Device Configuration> As shown in the schematic diagram of Fig. 1, the mass flow control 100 of the present embodiment includes an internal flow path i, and a flow rate sensor unit 2 for in-stream flow in the internal access 1 The measurement is performed; the flow rate (four) is 3, which is disposed on the downstream side of the flow sensor portion 2, for example, the pressure sensor portion 4 is disposed at the money control side = the portion 5; and, for example, FIG. As shown, the mass flow controller has just been used in the supply of the milk, and the supply of the gas to the chamber is provided by the semiconductor-made light (Pr〇CeSS). Opening at the upstream end of the internal secret 1 , the inlet port P is opened at the downstream end of the internal flow path 1 to form a lead (4), for example, a fluid supply such as a guide σρι via 6 201116960 (b(10)b) The source B is connected, and the outlet κ is externally connected to the chamber for manufacturing the semiconductor (not shown == as shown in Fig. 2, 'from one fluid for two knives, one for the official') Setting the mass flow rate, the force regulator PR is only disposed on the outlet tube of the fluid supply source β, and the mass flow controller 100 is disposed. In addition, the symbol FV is a pneumatic valve. ... Although the details of the flow sensing!! 2 are not illustrated, the sensor portion 2 includes, for example, a pair disposed on the flow path 1. A thermal sensor 'detects the fluid f 2 as an electrical signal through the thermal sensor, and the electric current is passed through an internal electronic circuit: etc., and then the flow having the value corresponding to the detected flow rate is outputted The signal is measured. Although the details of the flow control valve 3 are also not illustrated, the flow control side 3 can be opened, for example, by an actuator (actuat〇r) containing the (four) element (other). The degree changes, and the actuator is driven by receiving the external control signal from the external (four) electrical signal, and (4) the opening degree is difficult to be the valve opening corresponding to the value of the degree (4) money, so that the flow is The flow rate is controlled. " , although the details of the pressure sensor unit 4 are not illustrated, the pressure sense...p 4 includes, for example, a diaphragm (di_ragm) (stainless diaphragm or diaphragm) Tablet (smc〇n diaphmgm), etc.) and the membrane The pressure sensitive element (measured by the pressure sensitive element to detect the displacement of the diaphragm as an electrical signal) is amplified by an internal electronic circuit, and then the output is detected by the 201116960. The pressure measurement signal of the corresponding value. The control unit 5 is a digital device having a central processing unit 'CPU, a memory, an analog/digital converter, a digital/analog converter, or the like. The analog circuit (anai〇g) is an electronic circuit. The control unit 5 may be a dedicated control unit, or a general-purpose computer such as a personal computer may be used in part or all of the control unit. Further, the control unit 5 can perform the functions of the respective parts by using only the analog circuit without using the cpu, or can be constituted by a plurality of devices connected to each other by wire or wireless, without being physically integrated. Further, a predetermined program is stored in the memory, and the CPU or the peripheral device of the CPU is operated in cooperation according to the program, whereby the control unit 5 functions as at least a signal as shown in FIG. The functions of the receiving unit 6, the calculating unit 7, the opening degree control signal output unit 8, and the flow rate output unit 9. The signal receiving unit 6 receives a flow rate measurement signal transmitted from the flow rate sensor unit 2, a flow rate setting signal input from another computer or the like, and a pressure measurement signal transmitted from the pressure sensor unit 4, and these The value of the signal is stored, for example, in a predetermined area in the memory. The tenth portion 7 includes a deviation calculating unit 71 that acquires a flow rate measurement value indicated by the flow rate measurement k number, and performs a deviation between the flow rate measurement value and a target value, that is, a flow rate setting value indicated by the flow rate setting signal. The calculation value calculation unit 72 calculates a feedback control value applied to the flow rate control valve 3 by performing a ρφ calculation on the deviation. The opening degree control signal output portion 8 generates an opening degree control signal having a value based on the feedback control value 8 201116960 and inputting the opening degree (4) Ht number to the flow rate control, and the valve 3 is formed. The measurement value of the value = 1 is output, and a flow rate signal (ship number) having the flow rate indication 2 as a value can be outputted by external calculation. In the embodiment, the control value calculation unit 72 is based on the primary side pressure (supply pressure), the temporal change amount of the secondary side pressure, and the flow rate setting state of the steady flow of the flow rate (stable In the state), the scale factor (Ρ) used in the PID calculation, the integral coefficient (〗), and the differential coefficient (D) (that is, the pip coefficient used in the pid control process of the steady state) are changed. Here, the steady state means a state in which the flow rate set value hardly changes except for a period other than the change period (for example, about two seconds). The change period is a change from the flow rate set value to a predetermined amount per unit time or a predetermined amount. The specified period from the time point above the amount. Further, the photographic value is about 10%, preferably 0.3% to 5%, based on the percentage value of the full scale. Further, the predetermined period is about the exponential seconds "> specifically, the leap second to about 10 seconds, preferably 0.3 seconds to 5 seconds. More specifically, the control value calculation unit 72 compares the positive and negative of the temporal change amount of the primary side pressure (the pressure on the upstream side of the mass flow controller), the proportional coefficient, the integral coefficient, and the differential coefficient (hereinafter also referred to as PID coefficient). "Change" Next, the calculation is performed by substituting the value obtained by substituting the flow rate setting value into a predetermined function, and the changed PID coefficient is changed to 201116960, and then the primary side pressure is substituted into the prescribed function. The value obtained in the middle is calculated to change the changed PID coefficient. Further, the 'control value calculation unit 72 changes the function inherent to the flow rate setting value according to the case of dp/dt> 与 and the case of dp/dtSO based on the positive or negative of the amount of change in the temporal change of the primary side pressure. The function inherent to the side pressure changes. Hereinafter, a specific method of changing the control value calculation unit 72 will be described with reference to Fig. 4 . First, the control value calculation unit 72 acquires the pressure measurement signal of the primary side pressure obtained by the pressure sensor unit 4, and calculates the temporal change amount of the primary side pressure and the primary side pressure. Next, the control value calculation unit 72 determines the positive or negative of the temporal change amount of the primary side pressure (step S1). When it is judged that the temporal change amount of the primary side pressure is positive (dp/dt> 〇), that is, when the primary side pressure rises, the control value calculation unit 72 passes the following mathematical expression and based on the flow rate setting value. The PID coefficient is changed (step magic). P' = PxFu(set) ( 1 ) I' = IxFu(set) (2) D' = DxFu(set) (3) Here, Fu () is a function inherent to the flow set value, that is, the set coefficient is 1 !!\ indicates the flow setting value. As shown in Fig. 5 (a), the coefficient function Fu of the present embodiment is a polygonal line function in which the proportional constant of 0_50% differs from the ratio of 50% to 100%. The shape of the fold line is not limited to this, and Machi is sighed by the shape of the fold line. Further, the set coefficient function Fu 201116960 S history can be a curve function ', but there is a problem that the amount of arithmetic processing is increased and it is difficult to adjust the PID coefficient. Then, the control value calculation unit 72 changes the coefficient of the PTD obtained by the above (1) to (3) based on the primary side pressure by the following mathematical expression (step S3). P,, P, xGu(P) (4) r==I'xGu(p) (5) D,-D'xGu(p) (6) where ' Gu () is a function inherent to the primary side pressure That is, the pressure coefficient function 'P represents the primary side pressure value. As shown in Fig. 5 (a), the pressure coefficient function of the present embodiment is a proportional function calculated for a value proportional to the input primary side pressure. Alternatively, the pressure coefficient function Gu may be set as a line function or a curve function. When the pressure coefficient function Gu is set as a curve function, there is a problem that the amount of arithmetic processing increases and it is difficult to adjust the PID coefficient. According to the above, when the amount of change in the time of the primary side pressure is positive, the control value calculation unit 72 changes P, I, and D to P", I", and D" based on the flow rate set value and the primary side pressure, and The PID coefficient (proportional coefficient P", integral coefficient Γ, and differential coefficient D) is used to perform a calculation on the deviation to calculate a feedback control value (step S4). On the other hand, when the control value calculation unit 72 determines that the amount of change in the primary side pressure is negative, that is, when the primary side pressure drops, the following equation is used to calculate the PID coefficient based on the flow rate set value. Change (step S5). 11 201116960 P' = PxFd(set) (7) r = IxFd(set) (8) D' - DxFd(set) (9) Here, Fd" is the function inherent to the set value, that is, the set coefficient function. The 'set table does not set the value of the stream. As shown in Fig. 5 (b, - y number function Fd is the same as the set coefficient function F :: line 疋: inflection point _ing P〇int) and the proportional constant has a fold = number can set the set coefficient function Fd to The problem that the curve function is large and it is difficult to adjust the coefficient: in the case of the difference in the transfer processing, the control value calculation unit 72 passes the following, and based on the primary side pressure, the change is performed by the (7) to (, Step S6) 0 PM = P'xGd(p) (10) I" = rxGd(p) (11) D" = D'xGd(p) (12) (9) Obtained PTD, coefficient here, Gd 〇 is a function inherent to the primary side pressure (4) force coefficient ϋΛ secondary side pressure value. As shown in Fig. 5 (b), the pressure coefficient function Gd is the same proportional function as the pressure coefficient function, proportional constant and The proportionality constant of the pressure coefficient function Fd is different. In addition, the pressure coefficient function Gd can be set as a polygonal line function or a curve function. In the case where the [force ir, the number function 〇d is a curve function, there is an operation. The problem that the amount of processing increases and the difficulty of the PID coefficient is adjusted. According to the above inner valley, the temporal change of the time of the secondary side is When the 'control calculation unit changes 12 201116960 P, I, D to P", I ", D" based on the flow set value and pressure, and uses the PID coefficient (proportional coefficient P), integral coefficient Γ, and differential coefficient D The PID calculation is performed on the deviation to calculate the feedback control value (step S4). <Effects of the present embodiment> According to the mass flow controller 100 of the present embodiment configured as described above, the primary side is based on The pressure, the amount of change in the time of the primary side pressure, and the flow rate set value are used to change the proportional coefficient, the integral coefficient, and the differential coefficient used in the pID calculation in the steady state, and thus, with the previous flow rate The set value is such that the proportional coefficient, the integral coefficient, and the differential coefficient are proportionally changed. The more suitable proportional coefficient, integral coefficient, and differential coefficient can be obtained, and as a result, it is less susceptible to the pressure fluctuation of the primary side thick force. Stable flow control is performed. <Other variant embodiment> Further, the present invention is not limited to the embodiment. In the following, The components corresponding to the embodiment are given the same reference numerals. For example, in the embodiment, based on the primary side pressure, the temporal change amount of the side pressure, and all the x: secondary PID coefficients of the flow rate set value. Although it is changed, it is also possible to use the combination of the two side pressures, the combination of the secondary side pressure and the time-dependent change amount of the primary side pressure, and the combination of the side pressure and the flow rate set value. In the above-described embodiment, the PID coefficient change order θ is changed based on the amount of change in the time of the primary side pressure—the “root setting value is changed”—“change according to the primary side pressure” 1' quantity order, but not limited to this order, but also other combinations. 13 201116960 In addition, the control valve can also be disposed on the upstream side of the flow sensor portion, and the flow sensor portion is not limited to the thermal sensor, and can also be a differential pressure sensor. Sensors for other flow measurement methods such as ). In addition, some or all of the above-described embodiments and modified embodiments may be combined as appropriate, and the present invention is not limited to the embodiments, and various modifications can be made without departing from the spirit and scope of the invention. While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic overall view of a mass flow controller according to an embodiment of the present invention. Fig. 2 is a block diagram showing a configuration of a flow rate control system using the mass flow controller of the embodiment. Fig. 3 is a functional block diagram of a control unit in the embodiment. Fig. 4 is a flow chart showing a procedure for changing the j> ID coefficient in the embodiment. Fig. 5 (a) and Fig. 5 (b) are schematic diagrams showing functions for changing piD coefficients. [Description of main component symbols] 1 Flow path 2 Flow sensor unit 201116960 3 Flow control valve 4 Pressure sensor unit 5 Control unit 6 Signal receiving unit 7 Calculation unit 8 Openness control signal output unit 9 Flow rate output unit 71 Nose 72 Control value calculation unit 100 Mass flow controller B Fluid supply source F Fluid FV Air valve PI Guide inlet P2 Outlet PR Pressure regulator SI ' S2 ' S3, S4, S5, S6 Step 15